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  Current Issue
 
2023 Vol.43 Issue.7,Published 2023-07-20
Air Pollution Control
Water Pollution Control
Solid Waste
Soil Pollution Control
Environmental Ecology
Environmental Impact Assessment and Management
Environmental Toxicology and Health
Carbon Emission Control
Air Pollution Control
3265 National Day effect and source analysis of atmospheric volatile organic compounds in the Pearl River Delta region
CHEN Jun, GONG Dao-cheng, LIAO Tong, ZHOU Yan, ZHANG Tao, WANG Rui-Wen, WANG Hao, CHEN Duo-hong, WANG Bo-guang
The typical urban and suburban sites in the Pearl River Delta (PRD) were selected to analyse the concentration, source and O3 formation potential of VOCs before, during and after the CNDH in 2021. The results showed that the overall O3 concentration in the PRD decreased from pre-CNDH to after-CNDH. O3 pollution was serious pre-CNDH and during CNDH, and the mean concentrations were (102.6±64.3), (80.2±47.7)µg/m3, respectively. In addition, the occurrence frequency of O3 pollution and excessive O3 concentration in urban areas were higher than those in suburban areas. The changes of TVOC and alkanes in the PRD were consistent, and alkanes could be the main components affecting the changes of TVOC. The concentrations of alkynes, highly active olefins and aromatic hydrocarbons in urban areas showed a pattern of decreasing during the holiday and increasing after the CNDH. The concentrations of alkynes increased the most after the holiday with a maximum increase of 82%. During the CNDH, the concentrations of VOCs from industrial sources such as toluene and xylene decreased significantly (about 30%), while the concentrations of VOCs from traffic sources such as n/iso-butane and n/iso-pentane increased (about 10%), showing a holiday effect of work and production shutdown plus travel peak during holidays. The source analysis based on the ratio of characteristic markers and positive matrix factorization (PMF) showed that the main contribution sources of VOCs in the PRD during holidays were vehicle emission sources (32.4%±5.3%). During non-holiday periods, in addition to vehicle emission sources (31.2%±10.8%) and solvent use sources (20.0%±7.9%), oil and gas evaporation sources (21.3%±3.8%) and combustion sources (23.9%±12.3%) should also be paid attention to in urban areas and suburban areas. The change of the largest contribution source between non-holidays and holidays reflected the different directions of population flow. The major contribution groups on holidays and non-holidays in urban areas were aromatic hydrocarbons, and those in suburban areas were olefins or aromatic hydrocarbons. The OFP ratios of olefins during holidays in urban and suburban areas were higher than those during non-holidays, while the ratios of aromatic hydrocarbons were the opposite.
2023 Vol. 43 (7): 3265-3280 [Abstract] ( 253 ) [HTML 1KB] [ PDF 2871KB] ( 1692 )
3281 Sources and environmental effects of C2~C8 non-methane hydrocarbons in the atmosphere over the East China Sea
LIU Zhen-fei, WU Ying-cui, QIAO Hao, ZHOU Li-min, ZHANG Hong-hai
The concentrations of 16 kinds of C2~C8 non-methane hydrocarbons (NMHCs) such as alkanes, alkenes and aromatic hydrocarbons in the atmosphere over the East China Sea during October 2021 were determined with the three-step low-temperature preconcentration system coupled with a gas chromatography-mass detector, which were used to explore their spatial distribution characteristics and sources and further evaluate their environmental effects. The atmospheric mixing ratios of the total NMHCs ranged from 1.15×10-9 to 18.05×10-9 with an average of (4.98±4.91)×10-9, and the average values of alkanes, alkenes and aromatic hydrocarbons were (2.11±2.02)×10-9, (1.18±1.04)×10-9 and (1.69±2.51)×10-9, respectively. The concentrations and spatial distributions of different NMHCs components were quite different. The concentrations of alkanes and aromatic hydrocarbons were higher near the shore and lower away from the shore, but the concentration differences between different stations of alkanes were smaller, while the alkenes showed relatively uniform distribution characteristics, though they were strongly affected by human activities. Source apportionments by positive matrix factorization (PMF) model showed that the ship emissions were the highest contributor for atmospheric NMHCs, which accounted for (32±30)%, and the contribution of marine emission sources was (28±23)%. Aromatic hydrocarbons were the key active components of the atmospheric NMHCs over the East China Sea, and their contributions to the generation of ozone (O3) and secondary organic aerosol (SOA) were significantly greater than those of alkanes and alkenes.
2023 Vol. 43 (7): 3281-3289 [Abstract] ( 195 ) [HTML 1KB] [ PDF 951KB] ( 1340 )
3290 Establishment and evaluation of prediction model for PM2.5 concentration extension period in Shanghai
MA Jing-hui, QU Yuan-hao, YU Zhong-qi, XU Jian-ming
In this study, two newly developed long short-term memory (LSTM) model and Light Gradient Boosting Machine (LGBM) algorithms were introduced for application in extended-range forecasting of PM2.5 in Shanghai by incorporating three members of the sub-seasonal-to-seasonal prediction project (S2S) forecasting, six prediction models were obtained. Therefore, based on six models forecast results, an accurate ~40d PM2.5 prediction fusion model over Shanghai was developed by LSTM algorithm, providing new insights for air pollution extended-range forecasting. The evaluation results indicated the fusion model exhibited not only much better accuracy but also captured the pollution process more closely compared to than any of the six single model. The correlation coefficients for the fusion model forecasts on lead times of 11~40 days ranged from 0.47 to 0.76, 23.5%~31.1% higher than other six single model. The root mean square errors (RMSE) for the fusion model forecasts on lead times of 11~40 days ranged from 19 to 25.1µg/m3, 19%~19.3% lower than other six single model. The fusion model could not only better predict the overall trend of PM2.5 concentration, but also the occurrence time of peak and valley, and its Heidke Skill Scores (HSS) was between 0.18 and 0.5, showing a good prediction skill. The fusion model could predict pollution episodes at a lead of 11~40 days, and the overall prediction accuracy was 75.5% at a lead of 11~40 days. For three pollution episodes lasting for 3 days or more, the prediction accuracy reached 100% at a lead of 11~40 days .The prediction efficiency of the fusion model was up to 40days, nearly four times that of the current pollution numerical prediction model (generally 96~240h), and the calculation speed was fast, which could save a lot of computing resources and time costs.
2023 Vol. 43 (7): 3290-3298 [Abstract] ( 247 ) [HTML 1KB] [ PDF 959KB] ( 1452 )
3299 High resolution simulation of temporal and spatial variation of PM2.5 concentration based on random forest——A case study of Central Plains Urban Agglomeration Core Area
LU Jun-mo, ZENG Sui-ping, ZENG Jian, WANG Sen, SONG Yuan-zhen
In order to explore the estimation method of near-surface PM2.5 concentration in urban scale or smaller area, two random forest models, RF (PM2.5~TOA) and RF (PM2.5~Image), were constructed by taking the PM2.5 concentration measured by the air monitoring station as the dependent variable, taking the top of atmosphere reflectance data (TOA) calculated from MODIS L1B satellite images and the eigenvalues directly extracted from the images (Image) as two groups of main independent variables, and integrating the auxiliary factors of meteorological features, topographic features and temporal and spatial features. Finally, RF (PM2.5~Image) was selected to estimate the monthly mean concentration of near-surface PM2.5 in the core area of Central Plains Urban Agglomeration under the spatial resolution of 250m in 2020. The results showed that: the coefficient of determination (R2) of the two models were 0.93, and the root mean square prediction errors ( RMSE) were 9.23, 8.28μg/m3, respectively. When the two models reached a similar degree of R2, a lower prediction deviation was found in RF (PM2.5~Image), and the importance of features with spatial resolution in it higher than 250m accounts for up to 44.2%, which can more accurately describe the change of near-surface PM2.5 concentration with a spatial resolution of 250m. The average annual concentration of PM2.5 in the core area of the Central Plains urban agglomeration in 2020 was 53.80μg/m3, and the pollution phenomenon was serious, with 0~8 pollution processes occurring in different units. On the whole, there was a spatial differentiation characteristic of increasing from southwest and northwest mountainous areas to eastern plain and a time variation pattern of high in winter, low in summer and transition in spring and autumn.
2023 Vol. 43 (7): 3299-3311 [Abstract] ( 253 ) [HTML 1KB] [ PDF 3069KB] ( 2491 )
3312 Driving role of Siberian High's in the anomalous variations of winter PM2.5 in the Twain-Hu Basin
YAO Jing-yan, BAI Yong-qing, ZHAO Tian-liang, XIONG Jie, ZHOU Yue, ZHU Yan, SUN Xiao-yun, ZHANG Ling
This study explored the correlation and physical mechanisms between the Siberian High intensity (SHI) in the East Asian winter monsoon (EAWM) and the anomalous variations of wintertime PM2.5 in the Twain-Hu Basin with the statistical correlation analysis, atmospheric circulation diagnosis and numerical simulation, for which the PM2.5 concentration data observed in the Twain-Hu (Hunan-Hubei) basin of central China in January from 2015 to 2022, combined with the China high air pollutant (CHAP) data and ERA5 meteorological reanalysis data, were used. The results show that the interannual PM2.5 variations in the Twain-Hu Basin over the period from 2015 to 2022 were negatively correlated with the SHI (r = -0.82, P<0.05) when excluding the effect of anthropogenic emissions, and the PM2.5 reanalysis of January 2000~2019 also presented a significant negative correlation with the interannual variation of SHI (r = -0.77, P<0.05), revealing that the variations in SHI of the EAWM could modulate the interannual variations in wintertime PM2.5. Siberian High in the system of EAWM was a key factor influencing the atmospheric diffusivity for interannual anomalies of PM2.5 in the Twain-Hu Basin. In strong (weak) SHI winters, the latitudinal-type circulation in the middle and upper troposphere was weak (strong), the zonal westerly components at high altitude was weakened (enhanced), the East Asian trough was deepened (weakened). Anomalous northerly (southerly) in the middle and low levels were the favorable (unfavorable) with cold air southward advances, and enhancing (weakening) the ventilation coefficients in the Twain-Hu Basin for the anomalous regional PM2.5 changes. The FLEXPART-WRF simulation also verifies that the Siberian High regulated the local PM2.5 variations by altering the atmospheric diffusivity and local accumulations in the Twain-Hu Basin.
2023 Vol. 43 (7): 3312-3321 [Abstract] ( 214 ) [HTML 1KB] [ PDF 4820KB] ( 1838 )
3322 Difference of ozone pollution under the continuous high temperature and strong sunlight weather in Tianjin
XIAO Zhi-mei, LI Peng, KONG Jun, GAO Jing-yun, XU Hong, LI Dan, CAI Zi-ying, YANG Ning
In order to understand the patterns of O3 pollution in Tianjin, based on the monitoring data of O3, concentrations and compositions of precursors, and meteorological data, differences in the key influencing factors and variation characteristics of O3 during two typical periods were analyzed by using the atmospheric chemical model and marker source tracking technology. The study period was from August 1th to 4th and September 8th to 10th in 2022, during which there were two typical processes of continuous high temperature and strong light weathers. The results showed that the impact of atmospheric diffusion condition on the precursors and ozone formation potentials (OFP) was the key factor affecting the O3 concentration in the two high-temperature processes. The 50.6% difference in ventilation coefficient, 137.5% difference in NO2 concentration and 6.4% difference in OFP led to the obvious difference of O3 concentration in two high-temperature processes, the O3 concentration was at good level from August 1th to 4th, while O3 concentration was at lightly to moderately pollution level from September 8th to 10th. Observation and chemical model showed good consistency in the analysis of O3 formation. Compared with the period of August 1th to 4th, the net production of O3 in the daytime increased by 2.04µg/(m3·h) and the net loss of O3 at night decreased by 0.88µg/(m3·h) from September 8th to 10th, which led to a significant difference in the concentration of O3 between the two processes. In addition, the low-pressure system was more likely to reduce the surface O3 concentrations than the high-pressure system after the weakening of thermal rise at night, which was the auxiliary reason for the difference of O3 concentrations during the two continuous high temperature processes. Analysis of the two processes and the characteristics of O3 pollution in the summer of 2022 showed that OFP was greatly restricted by the influence of atmospheric diffusion conditions on precursors except the influence of photochemical indicators such as temperature and ultraviolet radiation in 2022, under the high temperature and strong light weather conditions, the correlation coefficient between ventilation coefficient and O3 concentrations from July to September has reached 0.61. With the continuously promote of PM2.5 and O3 collaborative control, indicators such as low wind speed, low mixing layer and ventilation coefficient, which are used to analyze the atmospheric diffusion for PM2.5 will be more indicative in O3 prediction and control in the future.
2023 Vol. 43 (7): 3322-3330 [Abstract] ( 222 ) [HTML 1KB] [ PDF 471KB] ( 1187 )
3331 Heterogeneous oxidation of secondary organic tracers of isoprene by hydroxyl radicals
SHEN Ping, HU Qian, CAO Gang, ZHU Rong-shu
When the tracer-based method is applied to analyze the contribution of various gas precursors to secondary organic aerosols (SOA), the heterogeneous oxidation reactions between organic tracers and atmospheric oxidants (·OH, O3, NO3, etc.) will lead to uncertainty in source apportionment. In this paper, the secondary organic tracers of isoprene SOA, 2-methylerythritol (2-ME) and its analogue erythritol (AME) pure substance were studied by oxidation by ·OH under different experimental conditions in an atmospheric smog chamber. The experimental results show that the heterogeneous oxidation reaction effective rate constant of AME and ·OH is in the range of 3.64×10-11 ~ 4.15×10-11cm3/ (molecule·s) at 24.7 (±1.5) ℃.The effective lifetime of AME is about 4.46 ~ 5.09h when the average typical concentration of atmospheric ·OH is 1.5×106molecule/cm3. The effective rate constant of 2-ME ranges from 4.39×10-12 to 9.05×10-12cm3/(molecule·s), corresponding to the atmospheric lifetime of 0.85 ~ 1.76d. The ·OH oxidation reaction of isoprene organic tracer was significant, and tracer-based method would underestimate the contribution of isoprene to SOA.
2023 Vol. 43 (7): 3331-3338 [Abstract] ( 195 ) [HTML 1KB] [ PDF 646KB] ( 1729 )
3339 Characteristics and source analysis of PM2.5 and PM1 metal elements in Qingdao under marine low-sulfur regulation
TAO Wen-xin, TAN Yu-ran, ZHANG Yi-sheng, YANG Jian-li, LIU Zi-yang, LIU Dan-tong, DU Jin-hua, HU Yu-sheng, MA Zi-zhen, PENG Liang, ZHANG Hou-yong
To identify the sources of atmospheric PM2.5 and PM1, daily observations were conducted in Qingdao during the summer and autumn-winter of 2021. Measurements at coastal and urban stations were performed. Source apportionment of metal elements in PM were performed by enrichment factor method and positive matrix factorization (PMF) model. The backward trajectory of air mass and potential source contribution function (PSCF) were adopted to analyze source region. The vanadium to nickel ratio was used to indicate ship emissions. The results showed that the concentrations of V and Ni in PM2.5 and PM1 in summer were significantly lower than those reported during DECA 1.0. The concentrations of V in PM1 in autumn and winter were also lower than previous reports. Ni had more complex sources also affected by land emissions. According to PMF model results, ship emissions contributed to 11.1% and 8.4% of metal elements in PM2.5 and PM1 in summer, respectively. The V/Ni ratios in PM2.5 and PM1 of fresh marine air mass in summer were (0.71±0.24) and (1.06±0.65), respectively. The V/Ni ratio in PM1 from marine air mass in autumn-winter was (0.54±0.24), which was significantly higher than those in the mixed air mass and inland air mass. Therefore the air mass history should be considered when using V/Ni ratio to assess the impact of ship emissions. The potential source regions of V and Ni in PM2.5 and PM1 located in Lianyungang, around Rizhao and Jiaozhou Bay of Qingdao, while in autumn and winter this mainly located around the Bohai Sea.
2023 Vol. 43 (7): 3339-3349 [Abstract] ( 181 ) [HTML 1KB] [ PDF 2002KB] ( 2298 )
3350 Research on optimizing air pollutant emission inventory based on electricity consumption data
ZHOU Wei-qing, LI Peng, WU Hua-cheng, HE Xue-juan, SUN Shi-da, BO Yu, HE Ke-bin
In order to improve the spatial and temporal resolution of the air pollutant emission inventory in the industrial sector, the method of optimizing the time and spatial distribution in the industrial sector based on the electricity consumption data was proposed, and taken Tangshan city, Hebei province as an example, the basic emission inventory and the optimized emission inventory were input into the WRF-CMAQ model to verify its optimization effect. The results showed that the WRF-CMAQ model well simulated the temporal variation and spatial distribution of pollutant concentrations in Tangshan in January, April, July and October 2019. Compared with the basic emission inventory, the correlation between the annual average simulation value and the monitoring value of PM2.5 in the optimized emission inventory increased by 3.3%, with the best improvement effect on NO2. The improvement effect was the most obvious in October, with the DR2 of PM2.5, PM10 and CO exceeded 1.4. The change of PM2.5 concentration in the optimized emission inventory had more obvious regional characteristics, with high value areas of difference appeared in some areas, such as Qianxi county and Zunhua city. The optimized emission inventory improved the accuracy of spatial simulation to a certain extent, and can better reflect the changes of pollutant emissions in the industrial sector.
2023 Vol. 43 (7): 3350-3359 [Abstract] ( 293 ) [HTML 1KB] [ PDF 4679KB] ( 1629 )
3360 Experimental study on gas emission characteristics of carbon black oxidation under water condition
MENG Zhong-wei, WU Dai-geng, HUANG Jun-feng, JIANG Yan-zhi
Based on the particle oxidation process during the regeneration of Diesel Particulate Filter (DPF), the gas emission under different temperatures (495~565℃), water concentrations (0~9%), oxygen concentrations (5%~21%) and catalysts on the oxidation process of uniformly stacked carbon black particle layer were studied in a fixed bed reactor. Gas emissions were measured using a gas analyzer to obtain the emission characteristics of carbon black oxidation. The experimental results showed that increasing temperature, oxygen concentration and adding catalysts promoted the oxidation of carbon black, and CeO2 or Pt/Al2O3 catalysts reduced CO near to zero. However, the addition of water vapor decreased the emissions of CO2 and CO, as well as the oxidation efficiency. This inhibition effect was more pronounced at higher oxygen concentrations. When the water concentration increased from 0% to 9%, the gas emission and oxidation efficiency first decreased, then increased, with the strongest effect at 3%. Ultimately, the emission of CO2 increased. In addition, the CO2/CO ratio of carbon black oxidation emission decreased with an increase in temperature, with little effect by oxygen concentration. This ratio gradually increased with water concentration.
2023 Vol. 43 (7): 3360-3367 [Abstract] ( 207 ) [HTML 1KB] [ PDF 1010KB] ( 1351 )
3368 Preparation of hybrid manganese dioxide aerogel and its application in ammonia adsorption
ZHI Jian-hui, SHI Ze-peng, SUN Xiao-qian, CHEN Ting, GENG Hong
Pure manganese dioxide aerogel was synthesized by one-step reduction method and ice template method. Cellulose nanofibers (CNF) were used to hybridise and enhance the mechanical properties of pure manganese dioxide aerogel materials. Through characterization techniques, the formation mechanism and microscopic mechanism of the hybrid aerogel were explored. The adsorption effect of hybrid aerogel on NH3 was analyzed. Inside the material, CNFs acted as skeleton to disperse MnO2 nanoparticles, while MnO2 and hydroxyl groups on CNFs surface were combined by forming hydrogen bonds, which effectively improved the mechanical strength of the material. It's specific surface area was 56.50cm2/g, and it's average pore diameter was 9.32nm. The adsorption of NH3 was the combined action of physical adsorption and chemical adsorption. NH3 molecules entered the aerogel pores by van der Waals forces, and were absorbed by the adsorption sites and retained in the interior of the material. When the ambient temperature was 15℃ and the relative humidity was 50%, the adsorption effect of the hybrid aerogel on 10x10-6 NH3 for 6h was 99.7%.
2023 Vol. 43 (7): 3368-3377 [Abstract] ( 212 ) [HTML 1KB] [ PDF 1015KB] ( 1581 )
3378 Effect of preparation methods on NH3-SCO performance of SSZ-13 supported Cu catalysts
CHEN Li, FAN Xing, LI Jia, ZHANG Wei-hang, LI Jian
Cu-SSZ-13 and CuO/SSZ-13 catalysts were prepared by ion exchange and impregnation methods, respectively and tested for selective catalytic oxidation of NH3 (NH3-SCO). Cu-SSZ-13(2) catalyst, which was prepared by ion exchange for two times, performed the best in improving NH3 conversion and N2 selectivity at low temperatures (£200℃). Effects of O2 content and gas hourly space velocity (GHSV) on the oxidation of NH3 over Cu-SSZ-13(2) were investigated. Physicochemical characteristics of the catalysts and the surface reaction process were characterized by N2 adsorption-desorption, XRD, NH3-TPD and NH3-TPSR techniques. The results showed that NH3 conversion and N2 selectivity reached 98.5% and 92.2%, respectively at 200℃ over Cu-SSZ-13(2). With the increase of O2 content, NH3 conversion at low temperatures increased, but N2 selectivity decreased. With the increase of GHSV, NH3 conversion at low temperatures decreased, but N2 selectivity was hardly affected. Low N2 selectivity for NH3 oxidation at low temperatures (£200℃) over Cu-SSZ-13 and CuO/SSZ-13 was mainly due to the formation of N2O by-product. Compared with CuO/SSZ-13, Cu-SSZ-13(2) had larger values of specific surface area, pore volume and pore size, less CuO and more Lewis and Brønsted acid sites on the surface, which might explain the higher NH3 conversion and N2 selectivity obtained at low temperatures over Cu-SSZ-13(2). Apart from N2O, NO and NO2 by-products were also detected during the NH3-TPSR process over Cu-SSZ-13(2). It could be inferred that NH3-SCO over Cu-SSZ-13(2) followed the internal selective catalytic reduction (iSCR) mechanism considering the fact that NO and NO2 selectivity increased with the increase of GHSV at low temperatures.
2023 Vol. 43 (7): 3378-3386 [Abstract] ( 181 ) [HTML 1KB] [ PDF 736KB] ( 1494 )
3387 Gaseous pollutant emissions and control in the municipal waste leachate treatment facility
WANG Yu-jing, LÜ Fan, ZHANG Yi-ma, KANG Xin-yue, NIE Qing, LIN Jie, ZHANG Hua, HE Pin-jing
To control the gaseous pollution in the leachate treatment facility effectively, this work characterized the emissions of odor, greenhouse gases, and bioaerosol, and evaluated the treatment efficiencies of biotreatment and scrubber for these pollutants, as well as the environmental and health risks, taking a leachate treatment facility in a landfill as an example. The results indicated that hydrogen sulfide was the key odorant, nitrous oxide was the dominant greenhouse gas, and various pathogenic microorganisms existed in the bioaerosol in the gas emitted from the leachate treatment facility. The biotreatment effectively controlled odor in the leachate treatment facility with the hydrogen sulfide removal rate higher than 99%. But the biotreatment or the combination of biotreatment and scrubber reduced less than 25% of the total emissions of greenhouse gases (carbon dioxide equivalent), and they could be the sources of bioaerosol (pathogenic microorganisms), causing environmental and health risks. Therefore, odor, bioaerosol, and greenhouse gases should be considered comprehensively for the collaborative reduction of pollutants and carbon emissions when designing and evaluating the gaseous pollution control system in leachate treatment facilities.
2023 Vol. 43 (7): 3387-3395 [Abstract] ( 177 ) [HTML 1KB] [ PDF 1171KB] ( 1261 )
3396 Novel CoMn/SBA-15 catalyst for highly efficient low-temperature catalytic oxidation of toluene
SUI Mei-jun, LIU Zhi-gang, YANG Chen, WANG Dong, LAN Ming-xin, SUN Hong
CoMn/SBA-15 composite catalysts were prepared by hydrothermal-impregnation method, and their catalytic performance in catalytic oxidation of toluene was evaluated. Furthermore, the synergistic effect between Co, Mn active components and the support SBA-15 was also investigated by XRD, TEM, N2 adsorption-desorption, FTIR, XPS and H2-TPR. The results showed that when the mole ration of Mn: Co was 4:1, Co1Mn4/SBA-15 catalyst exhibited the best low-temperature catalytic activity, and its T50 and T90 were both 40℃ lower than those of Mn/SBA-15 and Co/SBA-15. The excellent catalytic performance was attributed to the higher content of Co3+, Mn3+, surface adsorbed oxygen and the consequently boosting redox ability. The synergistic effect between Co and Mn led to the formation of Co-O-Mn sosoloid and Si-O-Mn structure, and thus more lattice defects were produced. Moreover, the prepared catalysts presented the high CO2 selectivity, good reaction stability and carbon deposition resistance.
2023 Vol. 43 (7): 3396-3403 [Abstract] ( 251 ) [HTML 1KB] [ PDF 1202KB] ( 2027 )
3404 Evaluation of four Lagrangian particle concentration calculation methods-Box counting, Gaussian kernel, Uniform kernel and Parabolic kernel
YANG Li, WANG Cun-you, CHEN Yi-xue, ZHUANG Shu-han, LI Xin-peng, FANG Sheng
The efficiency of four concentration calculation methods for Lagrangian particle dispersion model (the Box counting, Gaussian kernel, Uniform kernel and Parabolic kernel) was investigated, by simulating the local-scale dispersion of radionuclides 137Cs released from the Fukushima Daiichi nuclear accident. The meteorological diagnostic model CALMET was used to calculate the input wind field for the Lagrangian particle dispersion model LAPMOD. The simulated 137Cs concentrations were validated with measured data at the Futaba and Naraha monitoring stations. The four methods successfully reproduce most of the measured peaks at the two stations (average FAC10 of Futaba: 0.57; average FAC10 of Naraha: 0.55) was indicated by the results. The results of the Box counting, Uniform kernel and Parabolic kernel were closer to the observed peaks and generally met the statistical acceptance criteria, but the results of the Gaussian kernel were significantly underestimated. The concentration distribution results indicated that the Box counting, Uniform kernel, and Parabolic kernel follow the same numerical trend. In addition, the plumes of the Uniform kernel and Parabolic kernel spread more widely, while the concentration results of Gaussian kernel decayed rapidly in the downwind direction.
2023 Vol. 43 (7): 3404-3415 [Abstract] ( 200 ) [HTML 1KB] [ PDF 2976KB] ( 2038 )
3416 Advances and prospective of nitrated organic compounds in the atmosphere
BAI Xu-rong, LI Hong, REN Yan-qin, LONG Fang-yun
Nitro-polycyclic aromatic hydrocarbons, nitro-phenols and organic nitrates are three forms of nitrogen-containing organic compounds which are greatly affected by human activities, highly reactive and have significant impacts on the atmosphere, climate change and human health. This paper focuses on the current state of research on the three forms of nitrogen-containing organic compounds in the atmosphere, and summarizes the latest findings on their environmental behavior, analysis methods, pollution characteristics, sources and causes, and then proposes their pollution prevention measures. The conclusions indicate that the environmental behaviors of nitrogen-containing organic compounds are closely related to their molecular weights, saturation vapor pressure, ambient temperature and humidity. The main analytical methods now employed for nitrogen-containing organic compounds in atmospheric environments are off-line detection in laboratories and online observation in the field, and the quantum chemistry calculation method is also used for their theoretical research. The pollution characteristics of nitrogen-containing organic compounds showed obvious spatiotemporal variations under the influence of emission sources and meteorological conditions. And the primary combustion emissions and secondary oxidation reactions were the main sources of nitrogen-containing organic compounds. Based on the limitations of the current research on nitrogen-containing organic compounds, this study proposes future research prospects to strengthen the investigation of toxic effects, improve the analytical methods and explore the generation mechanisms.
2023 Vol. 43 (7): 3416-3428 [Abstract] ( 481 ) [HTML 1KB] [ PDF 595KB] ( 3316 )
Water Pollution Control
3429 Effect of long - short term starvation on initiation of CANON process
YANG Zong-yi, LI Jun, ZHANG Kai, GAO Peng, TANG Peng
A sequencing batch reactor (SBR) was used to start the completely autotrophic nitrogen removal over nitrite (CANON) process. The effects of long-term starvation stress and short-term starvation regulation on nitrogen removal were investigated. The activities of functional bacteria before and after short-term starvation were tested to analyze the inhibitory effect of repeated short-term starvation on nitrite oxidizing bacteria (NOB) under shortened recovery time.Microbial sequencing was conducted at different stages of CANON initiation process to analyze changes in community structure. The results show that the TN removal efficiency (NRE) of the system can reach 62.34% when the system is restored 7days after chronic starvation. The short-term starvation-recovery mode can accelerate the start-up speed of the process, and successfully control the ΔNO3--N/ΔNH4+-N in SBR between 0.11. The average removal rate of ammonia removal efficiency (ARE) exceeds 95% and the average NRE reaches 79.45%. After short-term starvation regulation, the NOB activity decreased from 91.32mgN/(gVSS·d) to 45.40mgN/(gVSS·d), and increased to 219.25mgN/(gVSS·d) compared with the anammox activity (SAA), ensuring the CANON nitrogen removal performance. High-throughput sequencing has shown that the Aerobic Ammonia-Oxidation Bacteria (AerAOB) functional bacterium Nitrosomonas can recover quickly after experiencing long-term starvation. Candidatus Kuenenia has the ability to resist long-term starvation, and the relative abundance of Candidatus Kuenenia is as high as 69.04% after 7days of recovery. The relative abundance of Candidatus Kuenenia decreased in the stable recovery, but reached 61.19% after the process was started, thus achieving the enrichment of Anaerobic Ammonia-Oxidation Bacteria (AnAOB). The CANON process was able to recover from long-term starvation stress, and short-term starvation regulation was beneficial for process efficiency.
2023 Vol. 43 (7): 3429-3437 [Abstract] ( 201 ) [HTML 1KB] [ PDF 2824KB] ( 1288 )
3438 Partial nitrification start-up study running alternately between sequential batch and continuous flow
LI Dong, MAO Zhong-xin, LI Ming-run, WANG Qin-yuan, HU Li-jun
Three groups of reactors of the same specification, respectively referred to as R1(operation mode of continuous flow with low dissolved oxygen and low substrate), R2(operation mode of SBR), R3(alternate operation mode of continuous flow and SBR) were set up to investigate the nitrite nitrogen accumulation, pollutant removal, sludge characteristics, and EPS secretion during the operation period. The start-up time for partial nitrification in the R1was 28days, and the NAR was maintained at 49.6%, with a gradual decrease in ammonia removal and nitrite concentration. R2 achieved partial nitrification in 12days, and the NAR was maintained at 95.6%, but it was reduced to 82.6% due to a decrease in bacterial activity by prolonged FA inhibition. It took 18days for R3 to achieve partial nitrification, then R3 was operated for 90d, with a NAR of 92.3% in the SBR stage and 90.2% in the continuous flow stage. The ratio of NO2--N/ NH4+-N in the effluent of R3was basically between 1.10and 1.22, and the sludge had a relatively dense structure, the SVI was between the optimal threshold 70and 100mL/g, the EPS content reached 54.63mg/gVSS, the SAOR and SNPR were 6.7 and 2.5mgN/(gMLVSS⋅h), respectively. The above research indicates that the alternate operation strategy of sequential batch and continuous flow can effectively elute NOB while ensuring functional bacteria such as AOB, achieving stable accumulation of nitrite.
2023 Vol. 43 (7): 3438-3446 [Abstract] ( 236 ) [HTML 1KB] [ PDF 1461KB] ( 1605 )
3447 Effect of ammonia nitrogen concentration on phosphorus enrichment from biofilm
BI Zhen, ZHANG Sheng, FU Hao, DING Ruo Ling, HUANG Yong
In this paper, the effects of ammonia concentration in synthetic sewage on the phosphorus (P) enrichment performance, P uptake and release rate of biofilm were investigated in an anaerobic/aerobic polyphosphate accumulating organisms biofilm reactor. The results showed that an increase of ammonia from 15mg-N/L to 30mg-N/L stimulated the P uptake rate of denitrifying polyphosphate accumulating organisms while weaken the PAOs, which resulted in the phosphate uptake rates (PUR) of 11.25mg-P/(L·h),and phosphate release rate (PRR) of 12.02mg-P/(L·h) for the biofilm system. The P concentration in enriched stream reached 52mg-P/L. The uptake and release of P mainly depended on DPAOs when further increase of ammonia to 40mg-N/L, whereas the PAOs metabolism was almost suppressed. As a consequence, the P concentration in enrichment stream was only 40mg-P/L with 8.65mg-P/(L·h) of PUR and 8.81mg-P/(L·h) of PRR. Stoichiometric analysis showed the Prel/HAcupt(the P released per organics uptake) of the biofilm system witnessed a rising and decent trend, with an increase of ammonia from 15mg-N/L to 40mg-N/L. The average values of Prel/HAcuptunder different ammonia concentrations were 0.06, 0.11and 0.07P-mmol/C-mmol, respectively. The adverse effect of ammonia (40mg-N/L) can be eliminat by decrease the volume ratio of sewage stream and enrichment stream (from 3:1 to 1.5:1). Specifically, the PUR and PRR of biofilm reached 16.25mg-P/(L·h) and 15.60mg-P/(L·h) respectively, resulting in a enrichment stream of 70mg-P/L. Meanwhile, the Prel/HAcupt rised up to 0.29P-mmol/C-mmol. The resuls of present study showed that the P enrichment performance in PAOs-biofilm was not affected by ammonia (< 40mg-N/L), also, the nitrogen removal efficiency reached 95%. Therefore, PAOs-biofilm-based technology is of great potential in simultaneous P enrichment and nitrogen removal from sewage.
2023 Vol. 43 (7): 3447-3453 [Abstract] ( 196 ) [HTML 1KB] [ PDF 674KB] ( 1409 )
3454 A review on the mechanism of adding iron and iron compounds to control volatile sulfur compounds during anaerobic digestion of sludge
JIAO Ling-jie, LI Yong-mei, WEI Hai-juan, CHEN Guang
Anaerobic digestion is an effective method for sludge reduction and resource recovery. However, volatile sulfur compounds (VSCs) formed during the anaerobic digestion of sludge have caused many problems, such as reducing digestion efficiency, causing equipment corrosion, and damaging human health. In-situ sulfide control technologies like using iron or iron compounds are effective in controlling VSCs emissions. To deeply understand the role of iron in the anaerobic digestion process, this review summarized the formation mechanism of VSCs and focuses on the mechanism of controlling VSCs by adding iron salts, scrap iron, and iron ore. The practical applicability of adding iron and iron compounds to control VSCs in anaerobic digestion is evaluated, and the future research direction is prospected. This review provides ideas and strategies for cost-effective in situ VSCs control during anaerobic digestion processes.
2023 Vol. 43 (7): 3454-3463 [Abstract] ( 246 ) [HTML 1KB] [ PDF 646KB] ( 1857 )
3464 Research on the rapid cultivation of Feammox sludge, nitrogen removal characteristics and microbial community structure of Feammox process
LI Zhe, LI Jun, ZHENG Zhao-ming
In this study, the effect of pH value on Ferric ammonium oxidation (Feammox) performance was investigated under the micro oxygen environment through short-term experiments. The initial NH4+-N and Fe3+concentrations in the batch experiment were 70.0 and 300.0mg/L, respectively. When no ferric iron was added, the activated sludge could use dissolved oxygen for ammonium oxidation, and the removal amount of NH4+-N was 8.8mg/L. After adding ferric iron, the removal amount of NH4+-N increased to 76.9mg/L. Compared with the experiment without adding ferric iron, the removal amount of NH4+-N in activated sludge increased by 7.7times. Moreover, the nitrogen removal performance and functional microorganisms of the activated sludge-Feammox reactor were investigated through long-term experiments. After acclimation, the average NH4+-N removal rate of the Feammox reactor reached 1.6mg N/(g VSS·d). In a typical cycle, the pH value decreased from 9.0 to 7.8, and the NH4+-N concentration decreased from 35.5mg/L to 1.9mg/L. The NO2--N concentration increased from 11.2mg/L to 18.1mg/L, and the NO3--N concentration increased from 8.1mg/L to 13.4mg/L. The total inorganic nitrogen (TIN) concentration decreased from 54.8mg/L to 33.3mg/L. In mature Feammox sludge, the dominant iron reducing bacteria were unclassified Acidobacter (1.92%) and Pseudomonas (0.22%), which might play an important role in ferric ammonium oxidation.
2023 Vol. 43 (7): 3464-3471 [Abstract] ( 294 ) [HTML 1KB] [ PDF 606KB] ( 1835 )
3472 Effect of NaCl concentration on hydrogen and vivianite recovery from sludge fermentation liquid enhanced by iron anode
LIU Zhi-hong, YIN Xiao-yun, XING Jian-bo, GUO Zheng-tong, ZHAO Ting, YUE Xiu-ping, ZHOU Ai-juan
Based on the resource attribute of waste activated sludge (WAS), A novel electro-fermentation (EF) system mediated by iron anode was constructed to investigate the effect of NaCl concentration (10mmol/L, 30mmol/L and 60mmol/L) on synchronous hydrogen and vivianite recovery from simulative sludge fermentation liquid. Results showed that hydrogen yield peaked at (387.8±14.2) mL under 10mmol/L, promoted by 23.5% and 286.6% compared with that of 30mmol/L (312.2±18.6) mL and 60mmol/L (100.3±10.4) mL. The corresponding utilizing efficiency of short-chain fatty acids (SCFAs) reached 81.2%, which was much higher than that obtained in other groups. Soluble phosphate was completely removed within 3d in each group, Fe2+ content was reduced with NaCl concentration increase, accounted for 77.6% in 10mmol/L group. Scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) showed that the recovered precipitate was vivianite, and the crystallinity was negatively related with NaCl concentration. Meanwhile, the charge-discharge property of biofilm was promoted by the low electrolyte concentration, the dominating microbial consortia attached to the bio-cathode in 10mmol/L group, i.e., electrochemically active bacteria (EAB), anaerobic fermentation bacteria (AFB) and dissimilatory iron reducing bacteria (DIRB, e.g, Bacteroides, Pseudomonas and Sphingomonas), accounting for 22.10%, 42.37% and 9.17%, respectively.
2023 Vol. 43 (7): 3472-3480 [Abstract] ( 192 ) [HTML 1KB] [ PDF 933KB] ( 1551 )
3481 Effects of aluminum ions on acid production and organic substance release in waste activated sludge diges-tion by Autothermal Thermophilic Micro-Aerobic Digestion (ATMAD)
LIU Yi-wei, GAO Chun-di, BI Hao-hua, OU Jia-li, XING Yi-yan, PENG Yong-zhen
In order to exploit and use the organic matter in the fermentation liquid, the study added various dosage of AlCl3•6H2O to the sludge digestion system which using the technology of Autothermal Thermophilic Micro-Aerobic Digestion (ATMAD), the thesis discussed about the impacts of aluminum ions (Al3+) on transformation rule of organic substance, volatile fatty acid (VFA), ammonia nitrogen (NH4+-N) and orthophosphate (PO43--P) in the course of ATMAD. The results promoted that the conversion and degradation of organic substance was inhibited, meanwhile, the content and composition of dissolved organic substance in sludge digestion solution was changed when Al3+was existing in the system of ATMAD. The maximum production of VFA in contrast group was 6.9 multiple than experimental group with the concentration of Al3+ was 1.0g/L. When the process of ATMAD digestion ended, the concentration of NH4+-N was 502.06mg/L in the reactor which the concentration of Al3+ was 1.0g/L, in the contrast group the concentration of NH4+-N just was 334.41mg/L. The activity of microorganisms declined when Al3+ present in the system of ATMAD. It can be concluded that Al3+ have negative impacts on sludge digestion and stabilization. It's advisable to avoid adding excessive aluminum ions in sludge ATMAD system to ensure the digestion system can fully produce acid and release organic substance, which will be used as high-quality carbon for biological nitrogen removal.
2023 Vol. 43 (7): 3481-3488 [Abstract] ( 206 ) [HTML 1KB] [ PDF 917KB] ( 1307 )
3489 Effect of inoculum and cultivation mode on the performances of denitrifying biocathodes
ZHAO Ting, FENG Yong, XIE Bei-zhen, LIU Hong
This study investigated the effects of inoculum and cultivation mode on denitrifying bioelectrochemmical systems (BESs). Firstly, several inocula, including freshwater sediment, activated sludge and heterotrophic denitrifiers, were used to construct directly start-up BESs (DS-BESs). All the DS-BESs could reduce nitrate with electrodes as electron donors, but the nitrate-N removal rates were only 11.9~25.2mg/(m2·d). Among them, the DS-BESs inoculated with freshwater sediment showed relatively high nitrate-N removal performances. Then, the BESs obtained by polarity reversal (PR-BESs) were constructed with freshwater sediment and anaerobic activated sludge as inocula. The nitrate-N removal rates of the PR-BESs achieved 227.4mg/(m2·d)and 160.6mg/(m2·d), respectively, which were much higher than those of the DS-BESs. 16S rDNA sequencing analysis revealed that inocula had no significant effect on the dominant microbial species growing on BES electrode surfaces. Afipia and Aquamicrobium were enriched and became dominant genera in both the DS-BESs and PR-BESs. Moreover, biomass analysis showed that the DNA contents on the electrode surface of PR-BESs were much higher than those on the electrode of DS-BESs, indicating that the enhanced nitrate removal performances by the PR mode can be mainly attributed to the increased biomass on BES electrode surfaces.
2023 Vol. 43 (7): 3489-3498 [Abstract] ( 202 ) [HTML 1KB] [ PDF 2684KB] ( 1239 )
3499 Determination of the total phosphorus content in activated sludge by ultrasonic pretreatment assisted wet method
ZENG Shang-jing, PENG Jia-xi, SUN Xue-jian, WANG Fan, AI Sheng-shu, BIAN De-jun
The total phosphorus (TP) content of activated sludge was determined by an ultrasonic cracking assisted wet method. This study investigated the individual and interactive effects between three factors of sampling volume, sonication time, and sonication power, using the response surface methodology with the TP content as the response value, based on the single-factor test. Meanwhile, four sludge TP determination methods were compared, i.e., ultrasonic cracking wet method, microwave digestion method, SMT method, and improved national standard method. The results showed that the ultrasonic cracking wet method had the highest accuracy and stability in determining the TP content of sludge under the conditions of 15mL of sludge mixture sampling volume, 22min of ultrasonic time, and 720W of ultrasonic power. The results of the sludge TP determination followed the order of ultrasonic cracking wet method > microwave digestion method > SMT method > improved national standard method. There was a significant linear correlation between the ultrasonic cracking wet method and the other three methods (correlation coefficients of 0.9997, 0.9977, and 0.9969, respectively) with the fitted function slope values of 0.9436, 0.9183, and 0.8295, respectively. The RSDs for the determination results of TP in sludge samples by the ultrasonic cracking wet method were £3.6% and the spiked recoveries were 96.5%~104.8%. This study demonstrates that the ultrasonic cracking wet method is of good reliability, economy, and ease of operation in determining TP. Furthermore, ultrasound can save chemicals and extraction time.
2023 Vol. 43 (7): 3499-3508 [Abstract] ( 230 ) [HTML 1KB] [ PDF 2577KB] ( 1753 )
3509 Effect of pretreatment though acidification combined with persulfate catalyzed by steel slag on dewaterability of sludge
LI Wen-xiu, SONG Xiu-lan, WU Yu-qi
The acidification combined with steel slag-catalytic persulfate (PS) pretreatment technology was applied to sludge conditioning and the sludge dewatering performance was investigated by the single-factor experiment. The optimal pretreatment conditions for sludge were temperature of 25℃, pH 3, mixing time of 30min, and dosing levels of 100mg/g TS and 280mg/g TS for steel slag and PS, respectively, the sludge specific resistance and sludge cake water content decreased from 9.23×1012m/kg and 85% of the raw sludge to 1.89×1012m/kg and 77% respectively. Fourier transform infrared spectroscopy, three-dimensional fluorescence spectroscopy, polysaccharide, protein and free radicals quenching experiments were characterizated mechanism for steel slag-catalytic PS pretreatment promoting sludge dewatering performance: The SO4−• and •OH generated by slag-catalytic PS can destroy the sludge extracellular polymeric substances and biological cell structure, thereby reducing the content of hydrophilic functional groups and promoting the release of bound water.
2023 Vol. 43 (7): 3509-3517 [Abstract] ( 223 ) [HTML 1KB] [ PDF 1059KB] ( 1314 )
3518 The efficiency and mechanism of biochar addition to mitigate membrane biofouling
XIA Si-lian, YANG Xiao-huan, HAO Li-tu, CHEN Rong
In order to study the mitigation effect of biochar on membrane biofouling, Escherichia coli was selected as the model microorganism, and the effects of static adsorption, antibiofouling experiments and biochar on microorganisms and the extracellular polymers substances (EPS) released by microorganisms was analyzed,combined with the effect of biochar addition on membrane properties. The results showed that compared with the control group,the addition of biochar mainly alleviates the adhesion of microorganisms on the membrane surface by increasing the electrostatic repulsion between foulant and the membrane surface, increasing the hydrophilicity and roughness of the membrane surface, the number of bacteria on the membrane surface decreased by nearly 30% after adding biochar. In addition, in the antibiofouling experiment, the time to effectively delay the flux decay (6.5h) after adding biochar, the flux of dosing biochar at the end of filtration was 3.7times that of the control group, and to further alleviate the membrane pollution by absorbing microorganisms and extracellular polymeric substances. The adsorption capacity of biochar for Escherichia coli, protein-like and polysaccharide-like was 2.4x105CFU/mL/g、3.729mg/g、1.135mg/g respectively, among which the effect on protein was more remarkable.
2023 Vol. 43 (7): 3518-3525 [Abstract] ( 246 ) [HTML 1KB] [ PDF 1586KB] ( 1635 )
3526 Selective detection of catechol by boronized perovskite quantum dots
LIU Xin-ni, WEI Xiao, YANG Yu-yu, WANG Feng-jie, HE Hong-zhu, QIN Fang, LIU Jia-li, WANG Fei
Boronized perovskite quantum dots (APBA-PQDs) were prepared using an aqueous emulsion method. Based on the borate affinity mechanism between APBA-PQDs and catechol, a new method for the efficient and rapid detection of catechol in water was established, which solved the difficult problem that PQDs sensor was easy to condense and quench in water and had low selectivity. The morphology and optical properties of APBA-PQDs were characterized by transmission electron microscopy (TEM), fluorescence spectrum and UV-Vis spectrum, and the detection performance and mechanism of APBA-PQDs fluorescence sensor for catechol were explored. It was shown that the best detection was achieved when n (PQDs: APBA)=1:1, the response time was 7min, and the pH was 7. Under the optimal detection conditions, the relative fluorescence intensity ratio (F0/F) of APBA-PQDs had a good linear relationship with the concentration of catechol, and the detection limit was 72nmol/L. In addition, APBA-PQDs sensor had good selectivity and anti-interference, and can be used for the rapid detection of catechol in actual water samples, which provides a reference for the subsequent application of perovskite quantum dots in the detection of water phase pollutants.
2023 Vol. 43 (7): 3526-3532 [Abstract] ( 193 ) [HTML 1KB] [ PDF 1468KB] ( 1834 )
3533 Nanoscale PBA-Fe1Mn2 activated peroxymonosulfate for degradation of Azo organic
ZHANG Ting, ZENG Jing, YE Xiao-zhen, LAN Yan-yan, WANG Yong-quan, HONG Jun-ming
The nano-scale Fe-Mn bimetallic catalyst of Prussian blue analogue PBA-Fe1Mn2, was prepared by a two-step oil bath-hydrothermal method. The large contactable area and many active sites of the nanoscale catalyst was utilized to activate peroxymonosulfate (PMS) for reactive black 5 (RBK5) degradation. Serious catalyst were characterized by X-ray powder diffractometry (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR), indicating that the synthesized catalyst PBA-Fe1Mn2 had structure of Prussian blue cubes. The synergistic effect of FeMn bimetal with the active site on the cubic structure effectively enhanced the degradation efficiency of RBK5. Under the optimal conditions of initial pH=7, catalyst dosage of 0.2g/L and PMS concentration of 2mmol/L, the decolorization efficiency of 10mg/L RBK5 could reach 100% within 60min. The free radical quenching experiments and EPR showed that HO• and SO4-• in this system were involved in the degradation of RBK5 and the hydroxyl radicals on the catalyst surface were the main acting groups. XPS reflected the changes of FeMn valence states, proved the synergistic interaction between bimetals, and identified the promotion of activity via FeMn valence cyclizing process. Finally, the degradation mechanism was analyzed according to XPS and 3D-EEM, which indicated that RBK5 was degraded in the system.
2023 Vol. 43 (7): 3533-3544 [Abstract] ( 185 ) [HTML 1KB] [ PDF 1420KB] ( 1345 )
3545 Preparation and anti-biofouling performance of vanillin-modified ultrafiltration membrane
HOU Bing-qian, CHEN Xin-yu, GENG Ru, WANG Dan-ni, ZHOU Xiang-tong, WU Zhi-ren, WEI Jing
To enhance the anti-biofouling performance of polyacrylonitrile ultrafiltration membrane in wastewater, quorum sensing inhibitor, vanillin, was used to modify the membrane by surface coating. The surface morphology, chemistry, hydrophilicity, surface charge, and water permeability of the modified membrane were systematically characterized. Escherichia coli (E. coli) was used to assess the impact of vanillin on bacterial colony growth and biofilm formation on vanillin modified membrane. Effluent from the bioreactor was used as feed to test the anti-fouling performance of vanillin modified membrane. The results showed that vanillin could effectively inhibit the formation of bacterial colonies on agar plates. The initial adhesion and growth of E. coli on the modified membrane were decelerated, and there was no mature biofilm on the membrane surface after being cultured for 48h. Membrane fouling experiments showed that the flux reduction of the modified membrane was 15.6% less than that of the unmodified membrane. The extracellular polymeric substances content in the biofilm of the modified membrane was 15.9% less than that of the unmodified membrane, further demonstrating the enhanced anti-biofouling property after modification. The results indicated that the modified membrane reduced the accumulation of N-acyl homoserine lactones (AHLs) signal molecules in the filtration system, and inhibited the participation of dominant Enterobacteriaceae bacteria from feed in biofilm formation, which affected the structure of bacterial community in biofilm.
2023 Vol. 43 (7): 3545-3553 [Abstract] ( 223 ) [HTML 1KB] [ PDF 1649KB] ( 1947 )
3554 The electron transfer research of biogenic nano-palladium by Klebsiella strain
JU Cheng-jia, WANG Zi-yang, CAO Wen-ying, YU Lei, QIU Xu-hai, ZHOU Shao-hua, WANG Quan, CHEN Rong-ping
Chem-Pd (chemically synthesized palladium nanoparticle) and Bio-Pd (biosynthetic palladium nanoparticle) were prepared using chemical and biological methods, respectively, with sodium formate serving as the electron donor. The TEM and XRD results revealed that the Chem-Pd was agglomerated with an average particle size of 12nm, while Bio-Pd was evenly distributed inside the cell and in the extracellular polymeric substance (EPS), with an average size of 5nm. The reduction curve of bivalent palladium showed that the rate of bivalent palladium reduction by the biological method was 70% higher than that by the chemical method, indicating that the intervention of microorganisms can effectively promote the formation of nano palladium. By exploring the effect of intracellular electron transfer and extracellular polymer on the synthesis of Bio-Pd, the synthesis mechanism of Bio-Pd was clarified: the Klebsiella oxytoca strain transferred electrons to extracellular palladium divalent via its respiratory chain. Meanwhile, the presence of redox active groups in EPS may enhance Bio-Pd production outside the cell. Additionally, the test of live/dead bacteria showed that Bio-Pd remained harmful to cells.
2023 Vol. 43 (7): 3554-3561 [Abstract] ( 230 ) [HTML 1KB] [ PDF 3026KB] ( 1449 )
Solid Waste
3562 Influence of thermal ventilation system on biodrying of sludge in food industry
LIU Yi-si, ZHOU Zi-an, SUN Xiao-ting, QI Guang-xia, YU Su-ping, DONG Li-ming
The combined heat treatment of dewatered sludge in food industry was carried out by preheating and thermal ventilation to simulate industrial waste heat. The biodrying effect and mechanism of dewatered sludge were studied under different thermal ventilation conditions (30,40,50℃). The results showed that the high temperature period of biodrying can be maintained for 62h(>45℃) at 40℃ of thermal ventilation based on preheating and the daily cumulative temperature TD was 15.77℃/d. The moisture content of the material decreased from 68.95% to 41.28% after 166 h of biodrying period. Three-dimensional fluorescence spectrum analysis showed that the organic matter in the initial material was mainly tyrosine. TC decreased from 243.6~243.8g/kg WM before biodrying to 182.9~191.7g/kg WM after biodrying, mainly decomposed in the form of CO2and finally stable in the form of humic acid. TN changed little in the whole process, and NH4+-N decreased from 0.867~0.877g/kg WM to 0.43~0.55g/kg WM. In the process of biodrying, NO3--N content was low, and the final content remained at 2.94~6.54mg/kg WM. The analysis results of energy balance and fuel characteristics of product showed that the energy utilization efficiency of water evaporation was the highest when the thermal ventilation reached 40℃ based on preheating, accounting for 85.34% of the total heat consumption. The obtained product had the best fuel value index (75.52).
2023 Vol. 43 (7): 3562-3570 [Abstract] ( 168 ) [HTML 1KB] [ PDF 1205KB] ( 1401 )
Soil Pollution Control
3571 Quantitative assessment methodology and case studies on environmental impacts of passivation remediation of agricultural land pollution
Meng, MENG Hao, DONG Jing-qi, ZHANG Hong-zhen, ZHOU Tong, WU Long-hua, LI Xiang-lan
The environmental impact and carbon footprint of passivation remediation technology for polluted farmland in Nujiang Prefecture, Yunnan Province, were quantified using the life cycle assessment method. The results showed that the environmental impacts of passivation remediation technology were finally classified into human health, ecosystems, and resources, with global warming impact being the main environmental impact. In the entire passivation remediation process, the chemical production stage and the project implementation stage were the hot spots of carbon emissions, with carbon emissions of 2103and 2091t, respectively. Carbon emission per unit cubic meter of contaminated soil remediation was 87.80kg. The environmental impact single score of passivation remediation technology was 949.94kPt, suggesting low environmental impact. This paper quantitatively evaluated the environmental impact score and carbon emissions of farmland pollution passivation remediation technology to provide a data basis for comparing the environmental impact of different remediation technologies and to promote green and sustainable remediation development of farmland contaminated site.
2023 Vol. 43 (7): 3571-3581 [Abstract] ( 298 ) [HTML 1KB] [ PDF 2174KB] ( 1175 )
3582 Contamination characteristics of polycyclic aromatic compounds in soils of typical coal mining areas
XU Zhen-peng, YUAN Ke-yue, QIAN Ya-hui, LIANG Han-dong
The sources of polycyclic aromatic compounds (PACs) and carcinogenic risk in soils from three typical coal mining areas were analyzed with positive matrix factorization analysis (PMF) and Monte-Carlo simulation. The results showed that the soil in Shizuishan coal mine, Qipanjing coal mine and Shitanjing coal mine ΣPACs were 21862, 6226 and 2278μg/kg, respectively. PACs species were abundant and dominated by low rings, which was significantly affected by the coal mining area. Meanwhile, the concentration of alkyl polycyclic aromatic hydrocarbons (aPAHs) was significantly higher than that of parent polycyclic aromatic hydrocarbons (16PAHs). The results of PMF showed that coal and gangue particles were the primary pollution sources in the coal mine areas, followed by traffic sources. Monte-Carlo simulation showed that the three coal mining areas have potential carcinogenic risks to local residents. Although the study area was significantly affected by coal pollution sources, coal combustion was the main contributor to carcinogenic risks. In addition, Monte-Carlo simulation was more accurate than incremental lifetime cancer risk (ILCR), and the traditional risk assessment used ILCR significantly underestimates the actual cancer risk of adults.
2023 Vol. 43 (7): 3582-3591 [Abstract] ( 276 ) [HTML 1KB] [ PDF 1553KB] ( 1952 )
3592 Characteristics of microplastics and potential pathogenic microorganisms in the soil surrounding a rural garbage dump
JIANG Juan, LONG Yun-chuan, HU Jing, WANG Long-yan
To explore the microplastic pollution and potential pathogen risk in the surrounding soil caused by rural garbage stacking, the soil samples around a typical rural garbage dump in Guizhou province were collected for analysis. The microbial community and functional changes in soil, including viruses and pathogens, were studied by metagenomic technology. Combined with the distribution characteristics of microplastics, the potential interaction between microorganisms and microplastics was explored. The results showed that microplastics were detected in all soil samples with the abundance ranging from 1796~13702 /kg. A total of 20 kinds of microplastics were detected, including polypropylene (PP), silicone resin and polyurethane (PU), etc. The microplastics particle size were mainly£100μm with a proportion of 88.55%. The soil microbial community belonged to 214 phyla, and 1336 families, of which Proteobacteria was the dominant phyla. The main soil viruses were Siphoviridae and Podoviridae. A total of 191 potential soil pathogens have been found, including Salmonella enterica, Pseudomonas aeruginosa, Xanthomonas oryzae, etc. LefSe analysis showed that β-proteobacteria and γ-proteobacteria were the indicator bacteria in the proximal area, while α-proteobacteria were key bacteria in the distant area. Iridovirus and Pandoravirus were the biomarkers of the proximal region. The results of correlation analysis showed that microplastics in the garbage contaminated soil might affect the composition of microbial community and the aggregation of pathogens, while PET had the most significant effect on microbial community and metabolic function.
2023 Vol. 43 (7): 3592-3603 [Abstract] ( 246 ) [HTML 1KB] [ PDF 3078KB] ( 2470 )
Environmental Ecology
3604 Analysis of recognition and transmission path for organic nitrogen and phosphorus pollutants in representative cities section of lower Yangtze River
YU Ming-xing, SU Hai, LI Ming-yang, WU Xiao-jian, ZHANG Kai, MA Pan, MA Yu-ning, HU Guan-jiu
The study investigated water samples from eight sampling sites along the main urban river path, tributaries, and the merger of ditch gates of the lower course of the Yangtze basin. The profiles, sources and transport pathways of nitrogen, phosphorus, and related organic pollutants in the selected part of the river were analyzed using high-throughput non-targeted screening technology combined with multivariate statistical analysis. A total of sixty organic pollutants were identified in the research area including eleven organic nitrogen compounds, such as aminomethanesulphonic acid, carbamide, and benzonitrile, and two organic phosphorus compounds, 4-hydroxyphenylphosphonic acid and trimethyl thiophosphate. Most of the discharges were from the production of pharmaceuticals and pesticides, the daily use of pharmaceuticals and personal care products, and the manufacturing of raw and auxiliary materials. The chemicals travelled down the watershed via three routes, dominated by inorganic phosphorus transport with certain amount of organonitrogen involved, dominated by organonitrogen transport with certain amount of organophosphorus involved, or dominated by the transport of organonitrogen in combine with organophosphorus compounds. The inflow of the screened organics was predominantly influenced by hydrological factors and consistent with the water flow direction. The source apportionment from upstream inflow and regional input needs to be considered as well.
2023 Vol. 43 (7): 3604-3615 [Abstract] ( 187 ) [HTML 1KB] [ PDF 1952KB] ( 2042 )
3616 Characterizing Nitrogen and Phosphorus Transport and Source-Sink Interactions at the Lake Sediment-Water Interface During the Freezing Period
ZHU Yin-ze, ZHAO Ke, DONG Xiang-qian, ZHANG Jing-han, WANG Qi-chen, WANG Ying-xue, TIAN Xue, YUAN Yu-xiang, ZHU Xiao-yan
Based on the in-situ high-resolution Diffusive Gradients in Thin-films (DGT), the study aimed at analyzing the spatial distribution of key nutrient elements (N and P) at the submillimeter scale and their source & sink characteristics. Our findings indicate that the concentrations of DGT-NH4+-N and NO3--N in overlying water were higher than those in sediments during frozen period, whereas liable P demonstrated a contrasting trend. Under the sediment-water interface, liable N and P showed different distribution characteristics. The concentrations of NH4+-N and NO3--N gradually decreased with the increase of sediment depth, and P concentration firstly increased and then decreased with the increased sediment depth. The average exchange fluxes of NH4+-N and NO3--N in Chagan Lake were -0.135 and -0.333mg/(m2·d) respectively, showing the features of “Sink”; the average exchange fluxes of P was 0.084mg/(m2·d), showing the features of “Source”. Redundancy Analysis (RDA) showed that dissolved oxygen explained 32.8% of nitrogen and phosphorus release fluxes at sediment-water interface (P<0.05). Through estimating the contribution rate of overlying water, we found that the diffusion of P nutrients in sediment played a great role on the overlying water, and the contribution rate of individual sampling points reached 2,297%, possibly due to the presence of local micro-niches.
2023 Vol. 43 (7): 3616-3624 [Abstract] ( 253 ) [HTML 1KB] [ PDF 839KB] ( 1542 )
3625 Accumulation characteristics and risk assessment of heavy metals in sediments of Fuxian Lake
BAI Guang-yi, ZHAO Ke-liang, LIU En-feng, ZHANG En-lou
Combining with the 210Pb and 137Cs dating results of typical core FX12, this study investigated the spatial and temporal variations of heavy metal concentrations and pollution in sediments from different areas of Fuxian Lake by analyzing the heavy metal concentration, grain size, and magnetic susceptibility of 9 short sediment cores. The results showed that the grain size compositions of sediments in Fuxian Lake were mainly composed of clay (<4μm) and fine silt (4~16μm). The heavy metal concentrations exhibited certain spatial variations, with higher concentrations of Zn, Pb, and Cd in the northern and southern lake areas and higher concentrations of Hg, Cu, and As in the southern lake area. Generally, heavy metal concentrations were higher in core FX4 than in others, which were related to the higher clay content and pollution. The vertical variation trends of metal concentrations were similar in the sediment cores from different lake areas. Before 1950, concentrations of metals were relatively stable. Since 1950, concentrations of Al, Cr, Ni and Cu gradually decreased, while concentrations of As, Hg, Zn, Pb and Cd have shown varying degrees of increase. Based on the results of enrichment factors, As, Cd, Pb, and Zn were identified as the main pollutants, and the pollution began at around 1980 and gradually increased. Among the pollutants, Cd reached a strong pollution level in the near-surface sediment. The accumulative amount of anthropogenic As, Cd, Hg, Pb, and Zn showed spatial differences in the sediment cores, with relatively higher values for As in the central and southern lake areas. Due to anthropogenic pollution inputs, the ecological risk of heavy metals in sediment cores increased from low to medium, with Hg and Cd posing a medium to high ecological risk in near-surface sediments and the other metals posing low ecological risks.
2023 Vol. 43 (7): 3625-3633 [Abstract] ( 203 ) [HTML 1KB] [ PDF 946KB] ( 1781 )
3634 Characteristics of phosphorus fractions distribution and release risk of sediment in the cascade reservoirs in the middle and lower reaches of Lancang River
SUN Meng, BAO Yu-fei, WANG Yu-chun, HU Ming-ming, LI Shan-ze, WEN Jie, ZHANG Di
The physical and chemical properties of sediments and overlying water were studied to elucidate the spatial distribution characteristics and potential release risk of phosphorus fractions in four cascade reservoirs in the middle and lower reaches of the Lancang River. The results showed that the total phosphorus content in the sediment of each reservoir varied from 266.66mg/kg to 842.87mg/kg, with an average of 533.18mg/kg. The spatial distribution of organic phosphorus (OP) fraction exhibited that sediment of Gongguoqiao Reservoir was mainly composed of bioavailable OP, while the OP fractions in other reservoirs was mainly composed of Residual OP. The correlation analysis showed that organic matter and environmental factors of overlying water were the important factors affecting the distribution of phosphorus fractions in sediments. The analysis of orthophosphate (PO43--P) concentration at the sediment-water interface indicated that the PO43--P concentration of pore water ranged from 0.017 to 0.258mg/L and the PO43--P concentration of overlying water ranged from 0.015 to 0.055mg/L. The sediments acted as the P source to the overlying water, which ranged from 0.010 to 0.116mg/(m2·d). Seasonal hypoxia and regional sedimentation might lead to a large risk of PO43--P release in the downstream reservoir.
2023 Vol. 43 (7): 3634-3643 [Abstract] ( 307 ) [HTML 1KB] [ PDF 869KB] ( 1297 )
3644 Evolution of water quality risk and dispatching strategy of the tidal sluice at the typical sluice-controlled Estuary in South China
ZHAO Chang-jin, CHEN Gang, YANG Han-jie, WANG Wen-cai, YE Ying-xin, FANG Huai-yang, ZENG Fan-tang, FAN Zhong-ya
Lianjiang Estuary, located at east Guangdong province, is a typical heavily polluted and tidal sluice-controlled estuary in south China. This study utilized a numerical modelling to analyze the seasonal variations of water quality risks and the corresponding rational scheduling strategies of tidal sluice. Based on the Environmental Fluid Dynamics Code (EFDC), a three-dimensional coupled hydrodynamic and water quality model for the Lianjiang-Haimen Bay area was established. Aiming at differentiating the seasonal characteristics of water quality risks and comparing the improvements in varied dispatching schemes of the tide sluice, several scenario cases corresponding to dry and wet seasons were simulated. When the concentrations of pollutants in the dry season continued to exceed the water quality standards, the tide receiving should be scheduled at high tide to dilute the pollutant content. However, in the dry season, due to the high risk of saltwater intrusion, it is not advisable to keep opening sluices for a long time. The major pollution risk in the flood season was induced by the heavy rainfall and the sudden increase of ammonia. After the major polluted water mass was quickly discharged by opening the sluice, the sluice should be arranged to stay open at neap tides period in succession to discharge the remaining water body, preparing for the rapid down-rush of flood water potentially in coming days. By releasing and tracking Lagrangian particles in the numerical model, the total exposure time of the polluted water mass in the flood and dry seasons and the water exchange status of different river sections were calculated. The total exposure time in the flood seasons is in the range of 10~15 days, and in the dry season is about one month. The middle reaches of the river are characterized by the long exposure time. Considering the climate and eutrophication level of the Lianjiang River, the middle reaches are susceptible to algal blooms.
2023 Vol. 43 (7): 3644-3654 [Abstract] ( 209 ) [HTML 1KB] [ PDF 1707KB] ( 1327 )
3655 Nitrogen migration characteristics of dry and wet depositions in roofing rainwater
LI Jie, GAO Zan, WANG Yu-fei, ZHENG Wen-hao, ZHANG Qiong-hua
In this study, correlation analysis and nonlinear fitting were adopted to explore the migration and transformation of nitrogen pollutants during dry and wet depositions of roof rainwater based on data collected from 15rainfall events for one year. The results show a significant correlation between the load reduction of all nitrogen pollutants in the process of wet deposition and runoff.However, no strong correlation was observed between rainfall intensity and COD, especially in the early rainfall period. An analysis of the first flush effect of nitrogen pollutants found that all, except TON, had a weak first flush phenomenon, and the wash-off intensity of the wet deposition varied as follows: NO3--N>NH4+-N> NO2--N>TON, whereas that in the runoff varied as NO3--N> NO2--N >NH4+-N >TON. In addition, the average TN contribution rates of dry and wet depositions to roof runoff were 23.7% and 76.3%, respectively, among which the NH4+-N comprehensive proportion was the highest, exceeding than 50%. Overall, the characteristics of dry and wet depositions and migration of nitrogen pollutants in roof rainwater were systematically elucidatred in this study, which can provide a reference for the formulation of urban roof runoff pollution control measures.
2023 Vol. 43 (7): 3655-3663 [Abstract] ( 219 ) [HTML 1KB] [ PDF 915KB] ( 1701 )
3664 Groundwater pollution sources inversion based on local-global hybrid adaptive surrogate model
LUO Jian-nan, LI Xue-li, WANG He, MA Xi, SONG Zhuo
A local-global hybrid adaptive surrogate model was proposed based on optimal solution criterion and cross validation- Voronoi (CV-Voronoi) criterion to improve the inversion accuracy and computational efficiency of groundwater pollution source. The local-global hybrid adaptive surrogate model combined with genetic algorithm was applied to groundwater pollution sources inversion case. The inversion results were compared with those of the local and the global adaptive surrogate model. The comparison results reveal that the local-global hybrid adaptive surrogate model combined genetic algorithm had the highest inversion accuracy and the lowest computational cost. The pollution sources inversion results can identify the actual pollution source characteristics, and the maximum relative error was only 3.51%. The results of the paper prove the robustness of the proposed local-global hybrid adaptive surrogate model in improving the accuracy and computational efficiency of groundwater pollution sources inversion.
2023 Vol. 43 (7): 3664-3671 [Abstract] ( 212 ) [HTML 1KB] [ PDF 979KB] ( 1306 )
3672 Evaluating the importance of habitat patches using landscape functional connectivity for grassland in Poyang Lake
ZHANG Cheng, CHEN Wen-bo, HUANG Fang-fang
Taking the grassland of Poyang Lake as a case, and comprehensively considering the ecological processes of water level change and species dispersal, this study firstly identified the range and patch composition of grassland under different water levels. Then, the graph theoretical approach was applied to analyze the dynamics of functional connectivity of grassland with different water levels and dispersal distances. Finally, the delta value for probability of connectivity (dPC) and betweenness connectivity (BC) were respectively used to identify the important grassland patches and key grassland nodes. The grassland presented the characteristics of "expanding when water falls while shrinking when water rises". The grassland patches faced both the segmentation effect and the inundation effect of water. With the increase of water level, the distribution of grassland decreased from 1813.61km2 at the water level of 7.54m to 182.36km2 at the water level of 17.17m, and the fragmentation of large patches and the disappearance of small patches coexisted. From the perspective of water level change, with the increase of water level, the number of links in ecological function between patches decreased, the number of independent components increased, the probability of connectivity decreased, and then the functional connectivity of grassland has progressively decreased. From the perspective of species dispersal, the species dispersal distance had an absolutely positive impact on landscape connectivity. With the increase of dispersal distance, the functional connectivity of grassland increased dramatically. The 124 important grassland patches were identified and mapped. They were all consistently large and primarily distributed in the center of Poyang Lake, especially concentrated in the two national nature reserves. The 16 key grassland nodes were determined and mapped. They were very small in size and mainly scattered in the central and southern margin of Poyang Lake. Giant patches and large patches play an extremely vital role in maintaining the functional connectivity of grassland. However, small patches in a pivotal location can not be ignored as stepping stones or connecting elements.
2023 Vol. 43 (7): 3672-3687 [Abstract] ( 216 ) [HTML 1KB] [ PDF 2205KB] ( 1671 )
3688 Characteristic analysis of bacterial community in water and sediment in typical urban rivers
ZHANG Wei, WANG Min, GUO Xiao-yu
Using high-throughput sequencing, we investigated the diversity, structure and function of water and sediment microbial community in the Chaobai River, and discussed the difference in the vertical distribution pattern between Chaobai River and natural river. The results showed that the microbial communities in water and sediment not only had obvious distribution boundaries and ranges in the NMDS, but also the richness, evenness and comprehensive diversity index of the microbial communities in water were significantly lower than those in sediment. Proteobacteria and cyanobacteria were dominant phyla and subdominant phyla in water and sediments, respectively, and their relative abundance in water was significantly higher than that in sediments. Functions related to the light reaction, represented by chloroplasts, had a higher abundance in the water. In contrast, sulfur_respiration, a function related to the sulphur cycle, and methanogenesis, a function related to methane production, were highly abundant in sediments. The solid-liquid phase exchange process resulted in bacteria in the following sediment and water being more diverse and of similar composition compared to natural rivers. Cyanobacteria were encouraged to survive and grow in sediments due to the high ability of water and sediment to exchange materials. Therefore, the incubation process of pathogenic microorganisms in solid phase can be effectively controlled by managing the input of pathogenic microorganisms in reclaimed water supply, thus reducing the secondary release risk of pathogenic microorganisms in the river.
2023 Vol. 43 (7): 3688-3695 [Abstract] ( 189 ) [HTML 1KB] [ PDF 2682KB] ( 2025 )
3696 Study on the effect of bioturbation on the efficacy of lanthanum modified bentonite for phosphorus control
YAO Jing-mei, TAN Qiu-jun, SHI Si-jie, HAN Le, ZHI Yue
Two dominant benthic species in eutrophic lakes—Chironomus flaviplumus and Branchiura sowerbyi—were selected as representative benthos. Microcosm experiment was conducted to investigate the effect of bioturbation on the efficacy of endogenous P control by lanthanum modified bentonite(LMB). Moreover, La dissolution and its ecological risk were also assessed. Chironomus flaviplumus significantly increased the release of endogenous P in the overlying water in the absence of LMB, while this effect was negligible with branchiura sowerbyi; after the application of LMB, Chironomus flaviplumus and Branchiura sowerbyi both showed a negative inhibitory effect on the P control efficiency of LMB; the concentration of phosphate (PO43-) in the overlying water were 2.50 and 2.23 times higher than that in the control groups; during LMB application, bioturbation has significantly reduced the La concentration in the overlying water; however, La was found accumulated in benthic organisms.
2023 Vol. 43 (7): 3696-3703 [Abstract] ( 232 ) [HTML 1KB] [ PDF 735KB] ( 1394 )
3704 The effect mechanism of K-Birnessite on denitrification in sediments
XU Wei-mo, ZHANG Long, LI Run-jia, CAO Li, LONG Dan, LIU Dan-yang, ZHANG Li-pan, AI Hai-nan
The effect mechanism of K-Birnessite on denitrification were investigated by exposing the sediments of Qingshuixi Section, a tributary of Jialing River, Chongqing, to different contents of δ-MnO2 (0,2,4,7g/kg). The findings revealed that δ-MnO2 inhibited the activity of microbial electron transport system (ETS) in the sediment, resulting in a decrease in key enzyme activities in the denitrification process [nitrate reductase (NAR): 9.62%~43.64%; nitrite reductase (NiRs): 29.13%~69.39%; nitric oxide reductase (NOR): 22.55%~44.87%; nitrous oxide reductase (NOS): 20.48%~68.80%, whereas inhibited the entire denitrification process, specially significantly decreased the sediment NO3--N reduction rate (23.47%~89.30%) in each experimental group during 0to 3h. Additionally, δ-MnO2 significantly decreased the ratio of NiRs/NOS, which may have contributed to the N2O release reduction (2.65%~28.55%) observed. The results of the microbiological investigation showed that δ-MnO2 alters the makeup of the microbial community, causing it to evolve towards an environment adapted to high Mn content. Manganese redox-related species were enriched, including Exiguobacterium_sibiricum_255-15 of Firmicutes, Bacillus simplex of Firmicutes and Pseudomonadales of Proteobacteria. However, the abundance of Trichococcus linked to sediment heterotrophic denitrification decreased, which may be the underlying cause for the deterioration of sediment denitrification performance after δ-MnO2 exposure.
2023 Vol. 43 (7): 3704-3712 [Abstract] ( 140 ) [HTML 1KB] [ PDF 912KB] ( 1597 )
Environmental Toxicology and Health
3713 Human health risk assessment of antibiotics in the water environment of Yangtze River Economic Belt
CHEN Yu-ru, DUAN Yan-ping, ZHANG Zhi-bo, TU Yao-jen, GAO Jun
In this study, 33 surface water and 50 fish samples were collected from 5 cities (Yibin, Chongqing, Yichang, Wuhan, and Shanghai) from the upstream to the downstream of the Yangtze River Economic Belt. The concentration levels of 26 antibiotics in the samples were determined by high performance liquid chromatography tandem mass spectrometry (HPLC/MS-MS). The distribution characteristics, sources, and influencing factors of target antibiotics in surface water and fish in the Yangtze River Economic Belt and their relationship with urban characteristics were analyzed in detail, and the health risks of target antibiotics were evaluated according to risk entropy (RQ). The results showed that a total of 18 kinds of antibiotics were detected in surface water and fish, with a total range of 0.01~80.37ng/L and n.d.~8.93μg/kg, respectively. The surface water was dominated by sulfonamides, tetracycline, and chloramphenicol antibiotics, and the flufenicol (FF) had the highest average value (61.33ng/L). The fish body was dominated by tetracycline and fluoroquinolone antibiotics, and aureomycin (CTC) had the highest average value (17.35μg/kg). The spatial distribution of total antibiotic volume showed the trend of upper reaches > middle reaches > lower reaches. The antibiotic content was positively correlated with the body size (body length and body weight) of fish, and the antibiotic content of fish with different ecological habits and feeding habits was in the order of middle lower layer > middle upper layer > benthic fish and herbivorous > carnivorous > omnivorous fish. The correlation analysis results between antibiotic concentration level and urbanization characteristics showed that antibiotic content was positively correlated with the proportion of primary and secondary industries in GDP. The results of principal component analysis and redundancy analysis showed that the main pollution sources of antibiotics were aquaculture wastewater and domestic sewage discharge. The results of the health risk assessment showed that the total health risk entropy (RQ) of people of all ages was less than 0.1through drinking water and eating fish exposure routes, indicating that they were at low risk. The risk in Wuhan and Yibin was relatively high, and the risk degree increased with the decrease in age. RQ values of fish with different feeding habits and ecological habits showed that the risk of herbivorous, lower-middle, and bottom-dwelling fish was relatively low.
2023 Vol. 43 (7): 3713-3729 [Abstract] ( 338 ) [HTML 1KB] [ PDF 2554KB] ( 3079 )
3730 Target and nontarget analysis of PFASs in mothers and newborns and related health risks of newborns
BAO Jia, QU Wen-e, SHAO Li-xin, LIU Yang, WANG Xin, WU Yu-qing
50 paired samples of maternal and newborn serum, as well as placenta were collected from pregnant women at delivery around Fuxin fluorochemical facilities, and all the samples were analyzed through the target and non-target screening strategies. In the target analysis, 21 legacy per- and polyfluoroalkyl substances (PFASs) in the whole samples were analyzed through high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), revealing that perfluorobutane sulfonate (PFBS), perfluorobutanoic acid (PFBA), and perfluorooctanoic acid (PFOA) were the dominant PFAS contaminants observed in all the samples. In the suspect screening based upon high-resolution mass spectrometry (HRMS), 49 novel PFASs in 11classes were identified in the Fuxin samples, and 20 novel congeners assigned to 4 classes were determined in human sera and placentas for the first time. In addition, the coefficients for mother-placenta transfer (Rm/p) and mother-newborn transfer (Rm/n) of legacy PFASs could be estimated with the median values of 1.7 and 2.0 individually, and Rm/pand Rm/nof novel PFASs were also calculated with the median values of 0.9 and 0.8, respectively. Accordingly, the average contribution rate of all novel PFASs increased from 90% in maternal serum to 96% in neonatal serum. Moreover, the linear regression analysis determined significant correlations among the neonatal growth parameters (gestation and head circumferences of newborns) and serum levels of thyroid hormone, sex hormone, and glucocorticoid, together with the levels of certain legacy and novel PFASs in neonatal sera, and the most representative compounds included perfluorocarboxylic acids (PFCAs), perfluorosulfonic acids (PFSAs), H-substituted perfluorocarboxylic acids (H-PFCAs), H-substituted perfluorosulfonic acids (H-PFSAs), and chlorinated polyfluorinated ether sulfonates (Cl-PFESAs). The results above demonstrated that legacy and novel PFASs could potentially contribute to certain health risks of newborns.
2023 Vol. 43 (7): 3730-3740 [Abstract] ( 211 ) [HTML 1KB] [ PDF 602KB] ( 1759 )
3741 Assessment of PM2.5-related mortality burden and health economic loss in Shanghai
ZHOU Lu, NIU Yue, CHEN Ren-jie, KAN Hai-dong
Based on the annual average concentrations of fine particulate matter (PM2.5) in 16 districts of Shanghai in 2021. the Global Exposure Mortality Model (GEMM) and the Value of Statistic Life (VSL) method were used in the analysis. This study aimed to assess the PM2.5-related mortality burden and the corresponding health economic losses based on current pollution levels and different PM2.5 pollution control scenarios in Shanghai. The results showed that although the annual average PM2.5 concentration in Shanghai in 2021 (27µg/m3) was lower than the national secondary annual PM2.5 standard (35µg/m3), the excess PM2.5-related deaths still amounted to 13,274 (95%CI: 10,110~21,483) relative to the counterfactual annual average PM2.5 concentration (2.4µg/m3), with an attributable fraction of 9.5% (95%CI: 7.3%~15.5%). The corresponding health economic loss was 66.52billion (95%CI: 50.67~107.66) yuan, accounting for 1.5% (95%CI: 1.2%~2.5%) of the gross domestic product (GDP) of Shanghai. Compared with the current estimates, if the annual average concentration of PM2.5 was reduced to the latest Air Quality Guideline level (5µg/m3) proposed by the World Health Organization (WHO), the number of PM2.5-related deaths would be decreased by 9,873, and the corresponding health economic loss would be decreased by 74.4% in Shanghai. Therefore, it is suggested that more stringent local ambient air quality standards should be established to protect public health from air pollution in Shanghai.
2023 Vol. 43 (7): 3741-3747 [Abstract] ( 196 ) [HTML 1KB] [ PDF 344KB] ( 1823 )
3748 The oxidative polycyclic aromatic hydrocarbons (Oxy-PAHs) facilitated tumor-endothelial cell adhesion through histone acetylation
LI Dan, XUE Mei-ying
On the basis of analyzing the contents of three oxidative polycyclic aromatic hydrocarbons (Oxy-PAHs) in atmospheric PM2.5 samples during heating and non-heating periods in Taiyuan, one of them was selected for in vitro cell exposure. Western Blot and chromatin immunoprecipitation (ChIP) were used to investigate the adhesion of tumor-endothelial cells. The results showed that the content of 9-fluorenone was relatively stable, so 9-fluorenone was used for exposure. Tumor-endothelial cell adhesion was enhanced in a concentration-dependent manner, and the strongest was 3.24times that of control. Moreover, the levels of adhesion molecules E-selectin and VCAM-1 were significantly increased when the concentration of 9-fluorenone was 20 and 100μmol/L. When the concentration of 9-fluorenone was 20μmol/L, the expression of tumor cell adhesion molecule ICAM-1 was also significantly increased. In this process, the E-selectin binding to acetylated histone after 20μmol/L 9-fluorenone exposure was 5.97 times that of control. These results demonstrated a potential mechanism about Oxy-PAHs facilitate tumor metastasis by epigenetic regulation and suggested new research ideas for the treatment of lung cancer caused by Oxy-PAHs environmental exposure.
2023 Vol. 43 (7): 3748-3754 [Abstract] ( 198 ) [HTML 1KB] [ PDF 1016KB] ( 1345 )
Carbon Emission Control
3755 Research on energy saving and emission reduction effect of industrial enterprises' digital transformation
YU Chang, MA Lu-yao, ZENG Xian-gang, MA Dong-yan
To discuss the energy saving and emission reduction effects of industrial enterprises' digital transformation, the digital transformation level was comprehensively measured based on over 130000 big data samples of industrial enterprises from 2015 to 2021, and the fixed panel model and Spatial Durbin Error Model were used to analyze the impact of digital transformation level on the energy intensity and carbon emission intensity. The results indicated that: (1)The level of industrial enterprises' digital transformation increased 1% significantly reduced energy intensity and carbon emission intensity by 1.907% and 1.416%. (2)Provincial heterogeneity from grouped regression demonstrated the obvious heterogeneity among provinces, municipalities and autonomous regions. The level of digital transformation had a strong inhibitory effect on energy intensity and carbon emission intensity in some regions. For example, those with high digital transformation level and developed economic level, or Municipalities with capital and technology and pilot areas related to digitalization. (3)The role of digital transformation level in energy saving and emission reduction had a significant spatial spillover effect. The impact of digital transformation level on energy intensity and carbon emission intensity was negative, and the indirect effect was greater than the direct effect.
2023 Vol. 43 (7): 3755-3765 [Abstract] ( 217 ) [HTML 1KB] [ PDF 563KB] ( 2714 )
3766 Study on carbon transfer characteristics of the North channel of China's West-East Power Transmission
KUAI Peng, XU Meng-xin, LI Ying, DENG Ming-xiang
The research object of this study was the north channel of West-to-East power transmission. Based on the extended embodied carbon transfer decomposition model, the typical characteristics of carbon transfer embodied in electricity trade from the West to the East were explored, and key regions, sectors, and critical transfer paths were identified. The results indicated that Inner Mongolia and Shanxi were identified as the key regions for the roll-out of embodied carbon in western electricity (accounting for 85.8%), while Beijing, Hebei, and Shandong were identified as the key regions for the roll-in (accounting for 91.8%). The embodied carbon primarily transferred through indirect routes (with the indirect transfer from Shanxi and Inner Mongolia to Beijing, Hebei, and Shandong accounting for a high proportion of 85%~98%). Multiple industries in the four eastern provinces and municipalities were recognized as key sectors, including both traditional high-carbon industries such as chemical products, production and supply of electricity and heat, and construction, as well as industries with low direct carbon emissions such as various equipment manufacturing and food and tobacco. Taking the construction industry and food and tobacco industry in Beijing and Hebei as examples, it was found that C2, C4, and C5were the key paths for absorbing the embodied carbon of western electricity, indicating a high level of direct (C2) and indirect (C4and C5) dependence of these two sectors on western electricity. Based on the above findings, recommendations for collaborative carbon reduction in the east and west regions were proposed.
2023 Vol. 43 (7): 3766-3774 [Abstract] ( 226 ) [HTML 1KB] [ PDF 842KB] ( 1046 )
3775 Differential game and multi-scenario simulation of regional carbon emission reduction cooperation
YUAN Liang, QI Yu-zhi, HE Wei-jun, WU Xia
Based on the perspective of multi-stakeholders, a dynamic differential game model of regional carbon emission reduction composed of carbon surplus government, carbon deficit government, and carbon emission enterprises was established, and the strategic equilibrium solution of multi-stakeholders was explored. In addition, the changes in multiple stakeholders' strategic choices, effort level, and social welfare under the two decision-making backgrounds of cost-sharing and no cost-sharing were compared and analyzed. On the basis of the above, a system dynamics model for multi-scenario simulation was constructed. The results show that: (1) Under the cost-sharing policy, the emission reduction efforts, benefits, and social welfare levels of all stakeholders have been improved. (2) The choice of emission reduction strategies of multiple stakeholders has an interactive impact, which is affected by the cost-benefit relationship of each stakeholder, and the change of cooperation income is also affected by the purchase proportion and reward proportion. (3) The increase in marginal income enhances the enthusiasm for emission reduction, and the attenuation coefficient of emission reduction benefits, emission reduction costs are negatively related to the level of effort. (4) Social welfare effect, marginal income, and carbon emission reduction have a great impact on the efforts of carbon deficit governments and carbon emission enterprises. (5) Carbon deficit government's carbon emission purchase proportion has a great impact on the carbon surplus government's emission reduction efforts. (6) Carbon deficit government incentives for emission reduction, corporate social reputation, and the external impact of regional carbon emission reduction have an important impact on the emission reduction efforts of carbon emission enterprises. Based on this, this paper puts forward the policies and suggestions of cooperative emission reduction by multiple stakeholders, which have theoretical value and practical significance for promoting the realization of the "Dual Carbon" goal.
2023 Vol. 43 (7): 3775-3786 [Abstract] ( 299 ) [HTML 1KB] [ PDF 1347KB] ( 1883 )
3787 Carbon emission monitoring based on analysis from “electricity-carbon” relationship of cement enterprises
ZHANG Shu-han, CHEN Hui, WANG Bin, YU Run-xin, MA Zhi-ting, MIAO Yu-han
Based on the advantages of electrical data-instantaneity, accuracy and wide coverage, this paper establishes the electricity-carbon index for cement enterprises. By exploring the relationship between purchased electricity and total carbon dioxide emissions using the machine learning method, we formulate and investigate both single-sample daily monitoring models and multiple-sample annual monitoring models. The numerical study demonstrates that the Lasso model outperforms the other nine regression models deployed in the monitoring models, with a goodness of fit (R2) of 0.915 and 0.831. The results indicate that the critical factors influencing the electricity-carbon index of cement enterprises are the electricity emission factors in the clinker production and the proportion of electricity consumption in the clinker section, thus underscoring the importance of electrical data in carbon emission monitoring. The proposed model has the potential to significantly improve the efficiency and reduce the cost of carbon emission monitoring for cement enterprises.
2023 Vol. 43 (7): 3787-3795 [Abstract] ( 237 ) [HTML 1KB] [ PDF 716KB] ( 2467 )
Environmental Impact Assessment and Management
3796 The enterprise emission reduction effect of Chinese administrative centralization——Based on the micro analysis perspective of the reform of removing counties and establishing districts
LIU Jun, LUO Shan-yuan, WEI Guang-long
It was of great practical significance to identify the influence path of the upward shift of environmental jurisdiction in the centralized reform between cities and counties on the emission behavior of enterprises, and to solve the negative externality of environmental pollution caused by the localized management mode under the decentralized system, based on the balanced panel data of 1014 industrial enterprises in China from 1998 to 2013. The empirical results showed that the reform of removing counties and setting up districts increased the COD removal and reduced SO2 emission, which showed that the reform played a role in restraining the emission behavior of enterprises. The mechanism research showed that the reform of removing counties and setting up districts could achieve the effect of emission reduction by improving the total factor productivity of enterprises or reducing the output of enterprises. Heterogeneity analysis showed that the enterprise emission reduction effect of the reform of removing counties and setting up districts was more obvious in non-state-owned enterprises, small enterprises, southern regions and central and western regions. A series of robustness tests were passed, such as replacing by county data, deleting special samples, and using the distance between county and city center as instrumental variable. Therefore, appropriate incentives and penalties should be set up to ensure that local governments scientifically implemented the reform plan, and carried out market-oriented reforms in the northern region to create a good business environment, while paying attention to the market demand of small enterprises and providing effective financial and talent support.
2023 Vol. 43 (7): 3796-3807 [Abstract] ( 167 ) [HTML 1KB] [ PDF 559KB] ( 2215 )
3808 The evolution game analysis of enterprise's strategic environmental governance with the effect of different combinations of reward policies and punishment policies
HUANG Xin-huan, BAO Yan-zhen, CHEN Yong-zhi, CAI Bin-qing
The reasonable combination of reward policies and punishment policies was designed to prevent enterprises from conducting strategic environmental governance. In this paper, an evolutionary game model was conducted to analyze the interrelationship between the local government and the enterprise based on the framework of motivation-behavior-performance. Firstly, the impacts of different combinations of reward policies and punishment policies on the evolution of the enterprise's strategic environmental governance behavior were explored. Secondly, the conditions for system's evolutionary stability with the effect of different combinations of reward policies and punishment policies were discussed. Thirdly, the impacts of each parameter on the probability of implementing proactive environmental governance were analyzed in the case of the optimal combination policies. The obtained results showed that if the combination policy of static punishment and static subsidy was implemented by the local government, the system could not gradually stabilize at the central point; the combination policies such as “dynamic punishments and static subsidy”, “static punishment and dynamic subsidies”, and “dynamic punishments and dynamic subsidies” were implemented, there existed the system's evolutionary stability strategy. If the reputation gain obtained by proactive environmental governance was smaller than the threshold value, the combination of dynamic punishments and static subsidy was the optimal collaborative policy. If the reputation gain was greater than the threshold value, the combination of dynamic punishments and dynamic subsidies was the optimal collaborative policy. When the subsidy amount of proactive governance behavior was too high, the incentive effect of the subsidy was distorted, and the subsidy effect was reversed.
2023 Vol. 43 (7): 3808-3820 [Abstract] ( 182 ) [HTML 1KB] [ PDF 1764KB] ( 847 )
3821 Research on the influence and mechanism of the reform of environmental fee-to-tax on energy use efficiency
HUANG He-ping, LI Ying
This paper examines the influence and mechanism of the environmental fee-to-tax policy on energy use efficiency from the perspective of tax differences in 30provinces (municipalities and districts) in China from 2004 to 2020, marked by the enaction of the Environmental Protection Tax Law. The study finds that the reform of environmental fee-to-tax has reduced energy consumption per unit of GDP by 13.2% and increased green total factor energy efficiency by 38.3% in the provinces (cities) where the emission tax levy has been increased, which has a good policy effect of reducing energy consumption and improving energy efficiency, and the findings still hold after a series of robustness tests. There are regional differences in the effect of environmental fee-to-tax on energy reducing consumption and improving efficiency, with the western and northern regions reducing energy consumption per unit of GDP by 15.3% and 23.3%, respectively, and the southern and eastern regions improving green total factor energy efficiency by 39.9% and 60.4%, respectively. The effect of policies to reduce energy consumption and improve energy efficiency is more significant in regions with factor development level higher than 6.205, legalization level higher than 5.689, and in resource regeneration and growth cities. The tax levy should be maintained around the average value of the historical intensity (1.012) to give pollution emission subject time and space to improve the green total factor energy efficiency. In addition, the dynamic spatial Durbin model test founds that the environmental protection fee-to-tax has a negative spillover effect. This spillover effect has a certain continuity, which is not conducive to the function of environmental protection fee-to-tax on reducing energy consumption and improving energy efficiency in the short term, but the environmental protection fee-to-tax will promote the long-term effect of reducing energy consumption and improving energy efficiency by reducing industrial pollution, increasing environmental protection investment and strengthening the level of green innovation mechanism.
2023 Vol. 43 (7): 3821-3834 [Abstract] ( 257 ) [HTML 1KB] [ PDF 1000KB] ( 1632 )
3835 Resource dependence, government integrity and green technology innovation——Evidence from resource-based cities in China
QIN Bing-tao, PENG Cen, GE Li-ming, YU Yong-wei
Based on the panel data of resource-based cities in China from 2000 to 2017, this paper empirically analyzed the impact of resource dependence on green technology innovation in resource-based cities and its mechanism by using a variety of econometric analysis methods, such as fixed effect model, intermediary effect model, regulatory effect model and instrumental variable method. The result showed that resource dependence significantly inhibited the green technology innovation of resource-based cities, which was still valid after a series of robustness tests and control of endogenous problems. Mechanism analysis showed that there was a partial intermediary effect with the level of government integrity as the intermediary variable. Heterogeneity analysis showed that there were significant regional differences in the indirect inhibition of green technology innovation by reducing the level of government integrity. The crowding out effect of resource dependence was only significant in highly corrupt cities, highly resource dependent cities, small and medium-sized cities and traditional mining cities. The intermediary mechanism of government integrity has played a more significant role in expanding resource-based cities. However, the industrial structure of renewable resource-based cities was diversified, and resource dependence was positively affecting green technology innovation. While the government size was too large to reduce the level of government integrity, it played a negative role in regulating the impact of resource dependence on green technology innovation.
2023 Vol. 43 (7): 3835-3847 [Abstract] ( 211 ) [HTML 1KB] [ PDF 576KB] ( 2255 )
3848 National surface water quality classification evaluation based on SMOTE-GA-CatBoost method
XU Ling, JING Xiang-nan, YANG Ying, LI Wei-hua, LIU Yi-xin, YAN Guo-bing
Aiming at the problems such as the high conflict of water pollution feature space and the imbalance of water quality categories in surface water classification evaluation, Synthetic Minority Oversampling Technique (SMOTE) which was combined with Genetic Algorithms (GA) and CatBoost model that used seven water quality indexes of surface water as water quality evaluation factors were respectively employed to evaluate the water quality of major rivers and important lakes-reservoirs in the country. The results were compared with the other four improved ensemble algorithms, which showed that the SMOTE pretreatment could effectively enhance the imbalance of sample categories and increase the accuracy of CatBoost model for the classification of minority water quality samples. The genetic algorithm parameters could effectively improve the convergence speed and classification accuracy of CatBoost model and optimize the classification performance of the model. The SMOTE-GA-CatBoost model showed higher performance of water quality classification compared with the other four improved integrated classification models. The values of accuracy, precision, recall and F1 of the SMOTE-GA-CatBoost model for river water quality classification reached 97.7%, 97.8%, 96.1% and 96.9%, respectively. The value of accuracy, precision, recall and F1 for water quality classification of lakes-reservoirs water were 96.7%, 96.2%, 95.4% and 95.8%, respectively. The proposed model could be used to classify and evaluate the water quality of different water areas.
2023 Vol. 43 (7): 3848-3856 [Abstract] ( 320 ) [HTML 1KB] [ PDF 1283KB] ( 1911 )
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