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  Current Issue
 
2022 Vol.42 Issue.6,Published 2022-06-20
Air Pollution Control
Water Pollution Control
Solid Waste
Soil Pollution Control
Environmental Microbiology
Environmental Ecology
Environmental Impact Assessment and Management
Environmental Toxicology and Health
Advanced Wastewater Treatment Technology Column
Air Pollution Control
2481 Spatial and temporal distribution characteristics of ozone in Urban agglomerations in China
LIN Wen-peng, GUO Xin-tong
In order to reveal the temporal and spatial distribution law of ozone in major urban agglomerations, the concentration data of 1215 stations in 243 cities of 2019, released by air quality monitoring website were used. The results showed that ozone pollution mainly occurred in June and July in summer, followed by late spring and early autumn, and almost no ozone pollution occurred in winter. The variation trend of ozone concentration with increases above 100μg/m3 in urban agglomerations roughly presented two categories of irregular "V" and "W". In 2019, two high-value concentration centers could be obviously extracted, which appeared in summer and autumn respectively. Further, the high-value concentration center in summer could be divided into two levels according to the severity of pollution. The concentration distribution of ozone in urban agglomeration showed autocorrelation characteristics:the hot spot area overlaping with the high value center in the north in summer, and being consistent with the high value center in the south in autumn, simultaneously, the area of the cold spot area reaching its maximum. Due to the complexity of the causes of ozone pollution, it is inappropriate to classify ozone pollution solely according to the existing circumstances of urban agglomerations classification. Formulating corresponding pollution prevention and control measures for different urban agglomerations according to the actual distribution is the key point.
2022 Vol. 42 (6): 2481-2494 [Abstract] ( 393 ) [HTML 1KB] [ PDF 3592KB] ( 2176 )
2495 Influence of thermal circulation on air quality near-ground under the prevailing gradient wind
XU Jia-jia, JIA Hong-Wei, ZHONG Ke, KANG Yan-Ming
As a representative coastal city in mid-latitude in China, the diffusion and transportation characteristics of air pollutants emitted by pollution sources near Shanghai coastline are analyzed by numerical simulation with the coupling effect of prevailing gradient wind and thermal circulation, and compared with the ideal situation that the sea-land temperature difference (SLTD) is ignored. The results show that the thermal circulation caused by the SLTD still has an important influence on the flow field near the coastline with the condition that the prevailing gradient wind dominates the urban wind field, and the spatiotemporal distribution of pollutant concentrations near-ground is quite different from that without SLTD. Pollutants are merely dispersed to the downwind direction areas of the prevailing gradient wind without SLTD. While the SLTD exists, the diffusion of pollutants is bi-directional. The time of the highest and lowest temperature on land in coastal cities corresponds to the most unfavorable releasing moment of pollutants (RTS-16:00 and RTS-04:00), and the total contaminated time and daily averaged concentration are both the largest. Pollutants near-ground are not only carried to the upwind areas of the prevailing gradient wind, but also increase the pollution concentration in the downwind areas, up to 4to 5times that without SLTD. Therefore, even when the speed of the prevailing gradient wind is high, the actual intensity and range of pollution on non-sea-land breeze day can significantly be underestimated when neglecting the influence of the thermal circulation.
2022 Vol. 42 (6): 2495-2503 [Abstract] ( 223 ) [HTML 1KB] [ PDF 1318KB] ( 908 )
2504 Characteristics of carbonaceous aerosols and estimation of secondary organic carbon in Chengdu
LI Zhao-yang, YUAN Liang, ZHANG Xiao-ling, WEI Rong, LI Shuang-zhi
To investigate the diurnal and seasonal characteristics of carbonaceous aerosols in Chengdu, mass concentrations of total carbon (TC), organic carbon (OC), elemental carbon (EC), and secondary organic carbon (SOC) were continuous hourly measured from June 2020 to May 2021. The results showed that the annual mean values of m(TC), m(OC) and m(EC) during the observation periods were (9.5±4.4) μg/m3, (6.4±3.2) μg/m3 and (3.2±1.1) μg/m3, respectively, with the ratio of r(OC/EC) at 2.2±0.5. The m(TC), m(OC) and m(EC)in Chengdu peaked in winter ((15.8±8.2), (11.1±5.8), (4.6±2.5) μg/m3), followed by spring and autumn, and reached to the lowest level in summer ((6.1±0.9), (4.5±2.0), (2.7±1.4) μg/m3).The seasonal means of r(OC/EC) were in the range of 1.9~2.6, and the diurnal variations in m(TC), m(OC) and m(EC) followed the "bimodal" pattern which peaked in the morning (07:00~09:00) and the evening (22:00~01:00).This indicated significant contributions of motor vehicle emissions on carbonaceous aerosols in Chengdu. The correlation between OC and EC wasweaker in spring and summer than in autumn and winter, indicating that the sources of OC and EC were quite different in spring and summer. The m(SOC), which was estimated by the EC-tracer method and the Minimum R-Squared method, and the r(SOC/OC) was the largest in summer (40.4%) and the smallest in winter (27.3%). The significant positive correlation between SOC and O3 in spring and summer revealed that photochemical reactions contributed significantly to the formation of SOC. The continuous high m(TC) periods in each season were selected for comparison with the seasonal averages. The results showed that carbonaceous aerosols had obvious nocturnal accumulation process. The m(OC) increased significantly higher than that of m(EC) due to the secondary production during the high concentration periods in summer, and the r(OC/EC) also increased rapidly during these times.
2022 Vol. 42 (6): 2504-2513 [Abstract] ( 350 ) [HTML 1KB] [ PDF 1259KB] ( 2038 )
2514 Vertical profiles characteristics of near surface layer ozone in Shangyu Economic Development Zone of Hangzhou Bay based on unmanned aerial vehicle
DAI Shang, ZHOU Cheng-xiang, PANG Xiao-bing, LI Jing-jing, CHEN Lang, WU Zhen-tao, YUAN Kai-bin, HAN Zhang-liang, WANG Qiang, WANG Shuai-qi, CHEN Jian-meng
In order to understand the air pollution in chemical parks, the vertical profiles of ozone (O3) in chemical park were studied bya self-developed miniature atmospheric detector combined withan unmanned aerial vehicle(UAV), a 12-day UAV field observations was carried out in Shangyu Economic Development Zone of Hangzhou Bay during August 2020 to January 2021. Flight observations were conducted every 1h from 08:00 to 18:00 on each observation day, the concentrations of O3, TVOCs and NO2 were obtained at 0, 50, 100, 200, 300, 400 and 500m above the ground for each observation. The results showed that the concentrations of TVOCs and NO2 usually decreased with increasing height due to meteorological factors, ground-level plant emissions and peak travel, and the concentrations of NO2 decreased more significantly with increasing height, ranged from 19.7~59.1μg/m3 at 0m to 5.9~21.7μg/m3 at 500m, with a decreased rate of 40%~70%.The concentrations of TVOCs and NO2 showed a daily trend of high in the morning and evening, low in the noon. In addition, the concentrations of NO2 increased at 400~500m in some days caused by inversion layer. The concentrations of O3 increased with height affected by the photochemical reaction of precursors, solar radiation intensity and stratospheric input, the average concentrations were 49.2μg/m3 at 0m and 98.4μg/m3 at 500m, and the peak value of daily variations reached at 15:00~17:00. TVOCs and O3, NO2 and O3 were negatively correlated at all heights. The seasonal change of O3 concentrations were summer>autumn>winter, and the concentrations of TVOCs and NO2 were winter>autumn>summer, affected by the difference of meteorological factors in different seasons and the increase of heating emissions in winter. Backward trajectory cluster analysis showed that the local O3 concentrations in chemical industry park would be affected by regional transport, and the local O3 concentrations in winter was less influenced by the regional transport than in summer because the low temperature was not conducive to the generation of O3 from precursors.
2022 Vol. 42 (6): 2514-2522 [Abstract] ( 329 ) [HTML 1KB] [ PDF 860KB] ( 1718 )
2523 Simulation of daily PM2.5 based on MODIS data and multi-machine learning method
XU Fa-zhao, LI Jing, CHU Xin-de, MAN Yuan-wei
In order to further understand the spatial distribution of PM2.5 on the ground, based on the PM2.5 measured data in 2019, MCD19A2 aerosol optical depth product of the Moderate Resolution Imaging Spectroradiometer (MODIS) at the L3 level, taking Shandong Province as the study area, and fully considering the factors including population, terrain, and weather. The daily PM2.5 in 2019 was simulated by using the four machine learning algorithms of Random Forest (RF), Support Vector Regression (SVR), Back Propagation Neural Network (BPNN), and Deep Neural Networks (DNN). The result shows the RMSE and MAE values of the RF are 12.67 and 6.62, respectively, which are better than BPNN, SVR and DNN models. RF is most suitable for the daily PM2.5 simulation in Shandong Province.
2022 Vol. 42 (6): 2523-2529 [Abstract] ( 264 ) [HTML 1KB] [ PDF 2088KB] ( 1161 )
2530 Review on key structure design of bag filter based on numerical simulation of flow field characteristics
ZHANG Jia-qi, DONG Zhong-hong
Flow field characteristics are the key factors affecting the purification effect, dust removal efficiency and service life of bag filter, and are the basis for optimizing or evaluating the rationality of equipment design. Based on the analysis of the working principle of the bag filter, this paper clarifies the key problems to be solved in the current research and development of the bag filter, expounds the numerical simulation method of the internal flow field of the bag filter, the evaluation index of the flow field characteristics, and the key influencing factors of the flow field distribution, and emphatically summarizes the basic influence law of the common structural design factors on the flow field characteristics of the bag filter. It is hoped that this review can provide reference structural design methods for users to improve the internal flow field performance of bag filter.
2022 Vol. 42 (6): 2530-2540 [Abstract] ( 287 ) [HTML 1KB] [ PDF 687KB] ( 1202 )
2541 Removal of nitrogen oxides by adsorption-discharge plasma decompositionprocess
DU Meng-wei, FAN Xing, CHEN Li, LI Jia, SONG Li-yun, LI Jian
Effects of adsorbent type, operating conditions of discharge, and cyclic operation on the removal of NOx in adsorption-discharge plasma decomposition process were investigated. Among the four kinds of zeolites (ZSM-5, MOR, SAPO-34 and SSZ-13) investigated, SSZ-13 showed the highest NOx adsorption capacity and lowest adsorption strength, which were beneficial to prolong the adsorption period and promote the desorption and decomposition of NOxby plasma. The results of temperature-programmed desorption and infrared spectroscopy showed that NOx was mainly physically or weakly chemically adsorbed on the surface of SSZ-13, while a small amount of NOx was converted into strongly adsorbed species such as NO3− and NO2−.The removal of NOx adsorbed on SSZ-13 by plasma is significantly affected by the operating conditions of discharge. Compared with N2-purge discharge and sealed-discharge, higher NOx removal efficiency and energy efficiency, less residual NOx on the adsorbent, and lower N2O selectivity can be obtained simultaneously by using sealed-discharge first and thenN2-purge discharge. The removal performance of NOx can be maintained during cyclic operation of the adsorption-plasma decomposition process, without significant changes to the crystal and pore structures of SSZ-13 after six cycles.
2022 Vol. 42 (6): 2541-2551 [Abstract] ( 202 ) [HTML 0KB] [ PDF 878KB] ( 1357 )
2552 Numerical simulation of diffusion characteristics of high-temperature particles generated by multiple pollution sources in welding process
HAN Kun, ZHUANG Jia-wei, DIAO Yong-fa, REN Mei, ZHANG Li-an
In order to explore the migration law of particles under the action of hot airflow in the process of hot working, the diffusion characteristics of high-temperature particles associated with multiple buoyant jets are numerically studied based on the gas-solid two-phase discrete particle model (DPM). The instantaneous changes of the temperature and velocity of the hot airflow and the particle group during the two-phase flow are discussed. The results show that for the high-temperature particle group with 473K£T0£673K, the temperature attenuation trend is similar, and the temperature distribution of the particle group is centrosymmetric. When the particle size is between 5μm and 20μm, the followability between particles and airflow decreases as the particle size increases.Thermal plumes have undergone independent development and merging processes over time.The disappearance of the vortex structure between the plumes causes the particles with a particle size of 10mm emitted by the central pollution source to settle moreeasily.
2022 Vol. 42 (6): 2552-2560 [Abstract] ( 179 ) [HTML 0KB] [ PDF 3129KB] ( 684 )
2561 Emission characteristics of light duty vehicle in RDE tests under different environmental conditions
WANG Xin, GE Yun-shan, JIANG Ping, WANG Xian-gang, ZENG Jun, GU Dong-lin, XU Chang-jian, LI Jia-chen
The effect of different ambient temperatures and altitudes on the tailpipe emissions from the RDE test was measured on a China-6emission standardlight-duty direct-injection gasoline vehicle. The results showed that the 30ºC ambient temperature increased the heat load on the aftertreatment devices compared to the 23ºC ambient temperature test, resulting in an increase in CO and PN emissions and a slight decrease in NOx emissions from the test vehicle. It is found that at 30ºC, the increase in test altitude reduced the vehicle's road resistance requirements, which in turn reduced the frequency of fuel enrichment, resulting in a trend of decreasing CO and PN with increasing altitude. The results also show a relatively high sensitivity of CO and PN emissions in the urban phase to changes in RDE testboundary conditions, indicating that further refinement of the vehicle's emissions calibration is still necessary.
2022 Vol. 42 (6): 2561-2568 [Abstract] ( 254 ) [HTML 0KB] [ PDF 705KB] ( 1829 )
2569 Emission characteristics of fine particles from direct-injection gasoline vehicles
LI Jia-chen, GE Yun-shan, WANG Xin, JIANG Ping, WANG Xian-gang, ZENG Jun, XU Chang-jian
Three direct-injection gasoline vehicles meeting China-6 emission standard were selected for cold start WLTC tests. The emission characteristics of solid particles above 23nm and particles containing volatile/semi-volatile components above 6nm were measured on the three vehicles. The test results showed that particles containing volatile/semi-volatile components in the particle size range of 6~30nm were mainly produced in the WLTC cycle deceleration condition, high-speed section, and ultra-high-speed section. Volatile/semi-volatile particles in the particle size range of 30~2500nm were mainly produced in the ultra-high-speed section. Solid particles above 23nm accounted for the bulk of the emissions in the rest conditions. GPF had limited effectiveness in intercepting particles in the 6~30nm particle size range. Moreover, GPF regeneration produced high concentrations of particles in the range of 6~30nm. Analysis of the carbonaceous composition of particles showed that volatile/semi-volatile particles had little effect on PN emissions of solid particles above 23nm measured by the emission regulation but had a significant impact on PM emissions.
2022 Vol. 42 (6): 2569-2576 [Abstract] ( 203 ) [HTML 0KB] [ PDF 609KB] ( 1001 )
2577 Source apportionment and seasonal variation characteristics of atmospheric dustfall in Taiyuan by two receptor models
ZHANG Zhong-cheng, XIE Yu-qi, ZHANG Zhi-jie, GAO Gang-shuan, XU Bo, TIAN Xiao, XU Han, WEI Yu-ting, SHI Guo-liang, FENG Ying-chang
Dustfall sampling and chemical composition analysis were carried out from November 2019 to December 2020 in Taiyuan, a typical industrial city. During the sampling period, the average amount of dust fall was 7.9t/km2·30d and was higher from April to June in Taiyuan. Among the 8selected monitoring areas, Qingxu and Julun had higher average amounts of dustfall, 10.7t/(km2·30d) and 10.6t/(km2·30d), respectively. Crustal elements (Ca, Si, and Al) accounted for a large proportion in the concentrations of dustfall, and the content of Fe in dustfall in Julun and Taoyuan monitoring areas was significantly higher than that in other monitoring areas. Datasets containing the amount of dustfall and its chemical composition were incorporated into two receptor models, respectively, positive matrix factorization (PMF) and partial target transformation-positive matrix factorization (PTT-PMF), to analyze the sources of dustfall in Taiyuan. By comparing the performance and source profiles of the two receptor models, it was found that the PTT-PMF receptor model which incorporated into the measured source profiles could better distinguish two similar sources (urban dust and construction dust) than the PMF model. According to the results from the two receptor models, dustfall in Taiyuan was mainly from six sources:urban dust (PMF:35%, PTT-PMF:35%), construction dust (PMF:29%, PTT-PMF:28%), steel industry (PMF:14%, PTT-PMF:14%), coal combustion (PMF:13%, PTT-PMF:12%), secondary inorganic compounds (PMF:5%, PTT-PMF:6%), vehicle emissions (PMF:4%, PTT-PMF:5%). The source contributions obtained by the two receptor models were similar, but the seasonal variations of the construction dust and steel industry were different. The contribution of coarse particles (urban dust and construction dust) to dustfall was greater than 60% (the main source in Taiyuan), and its contribution was higher in spring (from April to June).
2022 Vol. 42 (6): 2577-2586 [Abstract] ( 262 ) [HTML 0KB] [ PDF 1806KB] ( 1855 )
Advanced Wastewater Treatment Technology Column
2587 Development and comprehensive application of mathematical simulation in sewage treatment system under the trend of carbon neutralization
CHEN Zhi-chi, HE Qiang, CAI Ran, LUO Hua-rui, LUO Nan, SONG Chen-xin, CHENG Hong
Mathematical simulation technology (MST) has been widely applied in wastewater treatment, therefore, in order to systematically summarize these related technologies, this study reviewed the development of MST in sewage treatment system, and the application of activated sludge model (ASM) and machine learning (ML) in water quality prediction and parameter optimization; In addition, this paper mainly discussed the models of greenhouse gas emission in sewage treatment system, and the trade-off of multi-objective optimization model in sewage treatment system with the objectives of greenhouse gas emission (GHG), effluent quality (EQI) and operating cost (OCI). Furthermore, this paper also summarized the development of MST to achieve the energy self-sufficiency and resource recovery of sewage plant. The results from this study showed that MST can accurately predict the effluent quality, quickly optimize the process parameters, weigh the relationship among greenhouse gas emission, effluent quality and the operation cost, and improve the resource recovery efficiency. Overall, MST can effectively guide the operation optimization and management of sewage treatment process, and ultimately provide technical supports for the synergy of pollution reduction and carbon reduction in sewage treatment industry.
2022 Vol. 42 (6): 2587-2602 [Abstract] ( 416 ) [HTML 0KB] [ PDF 1239KB] ( 9759 )
2603 Effect and mechanism of C.vulgarisintensified treatment of kitchen wastewater
JIA Yan-ping, DING Xue, SHAN Xiao-qian, LI Shuo, ZHANG Jian, ZHANG Hai-feng, LI Zheng, ZHANG Lan-he
Chlorellavulgaris(C.vulgaris) was used to treat the coagulation effluent and the effects of C.vulgaris inoculation amount on the removal efficiencies of COD, DTP and TN were investigated. The changes of morphology and structure of C.vulgaris were analyzed using the scanning electron microscope (SEM), infrared spectroscopy and specific surface area micropore analyzer. The component changes of organic matters in kitchen wastewater were studied using ultraviolet visible spectrum and three-dimensional fluorescence spectrum. Mechanism of C.vulgaris degrading kitchen wastewater was explored. The results showed that when the inoculation amount of C.vulgaris was 25%, the removal efficiencies of COD and TN were the highest (79.73% and 78.28%, respectively), while the highest DTP removal efficiency (85.55%) was achieved at the inoculation amount of 35%. Before inoculation, the surface of C.vulgaris cells was relatively smooth, while it became rougher after application. The specific surface area of C.vulgaris increased with the attachment of a large amount of particulate matters. The carboxyl, amino and phosphate groups on the surface of C.vulgaris cells involved in the adsorption and precipitation of the pollutants. C.vulgaris destroyed the structure of humus and reduced the aromaticity of humus. Aromatic protein substances were produced when C.vulgaris degraded the soluble microbial by-products and humic acids.
2022 Vol. 42 (6): 2603-2610 [Abstract] ( 251 ) [HTML 0KB] [ PDF 881KB] ( 1627 )
2611 Operation and recovery performance of anaerobic ammonia oxidation process after long-term starvation
MA Bing-bing, ZHANG Xiao-jing, ZHANG Han, ZHANG Nan, WEI Deng-hui, ZHANG Hong-li, HOU Yu-lin
In order to study how to rapid recover the activity of Anammox process which had been interrupted under emergency situation for a long-term, the nitrogen removal performance and microbial variations of three Anammox reactors were comparatively analyzed. The reactors were named as R1 (biofilter), R2 (membrane bioreactor, MBR), and R3 (MBR), where R1 and R2 had the same influent concentration, R2 and R3 had the same reactor type but different influent concentration. The results showed that the Anammox activity in R1, R2, and R3 was recovered after 39, 93, and 76days, with the total nitrogen removal efficiency returned to 87.0%, 83.4%, 87.6%, and the total nitrogen removal rate restored to 0.359, 0.114, 0.244kg/(m3·d), respectively. Compared R1 with R2, the Anammox biofilter could withstand higher hydraulic load, showed higher stability after long-term interruption, and was easier to recover. Compared R2 with R3, the higher influent concentration supplied sufficient substrate for Anammox bacteria, and formed concentration pressure for promoting the transformation of ammonia and nitrite inside the sludge, thus led to better recovery performance. The results of high-throughput sequencing showed that the relative abundance of Candidatus Kuenenia before (after) recovery of the three reactors were 17.3% (32.0%), 1.6% (2.6%), 1.8% (6.0%), and the abundance in R1after recovery was the highest.
2022 Vol. 42 (6): 2611-2618 [Abstract] ( 215 ) [HTML 0KB] [ PDF 587KB] ( 819 )
2619 Effect of nanoscale zero-valent iron on the denitrification performance of anaerobic ammonia oxidation
MA Jiao, ZENG Tian-xu, SONG Jun, DANG Hong-zhong, LI Wei-wei, CHEN Yong-zhi
The effect of nanoscale zero-valent iron (nZVI) powder on the denitrification performance of anaerobic ammonia oxidation (ANAMMOX) reaction was investigated by adding nZVI into ASBR. When the concentrations of nZVI were 0, 10, 50, 100, 200, 500, and 1000mg/L at the temperatures of (25±0.5)℃, and the pH value of 7.5±0.5, the total nitrogen removal efficiencies (NRE) were 70.27%, 74.25%, 83.45%, 90.16%, 68.59%, 57.18%, and 50.93% under the influent NH4+-N and NO2--N concentrations of 30.35mg/L and 37.89mg/L, respectively. The kinetic analysis was carried out by the modified Boltzmann, Gompertz, and Logistic models,the R2 values were 0.9963, 0.9944, and 0.9851, respectively. The mean square errors of the effluent concentration of total nitrogen (TN) and NRE compared with the actual values were 2.13, 6.31, 8.48, and 6.93, 7.47, 10.95, respectively.Key words:nZVI;ANAMMOX;nitrogen removal efficiency;kineticmodels
2022 Vol. 42 (6): 2619-2627 [Abstract] ( 220 ) [HTML 0KB] [ PDF 563KB] ( 974 )
2628 Synergistic enhancement mechanism of nano-TiO2/ZJ-01 composite promoter on the removal efficiency of high-concentration ammonia nitrogen
ZHANG Jia-cheng, LIU Yong-jun, LIU Pan, ZHANG Ai-ning, QI Hao, LIU Zhe
In order to enhance the air-stripping removal efficiency of high concentration ammonia nitrogen (500~7000mg/L) from coal chemical wastewater and reduce thealkali consumption noticeably, a nano-TiO2/ZJ-01 composite promoter was prepared, and its stability, efficiency and promoting mechanism were further investigated. The results showed that the nano-TiO2/ZJ-01 composite promoter had the highest cost-efficient at the proportion of 6.0% and 0.4% (w.t) for organic fraction and 5nm TiO2, respectively within 30min ultrasonic dispersion. The ammonia nitrogen air-stripping rate was up to 95.14% at the Nano-TiO2/ZJ-01 dosage of 7.5mg/L as well as increasing by17.02%~32.46% under any pH values in the presence of the nano-TiO2/ZJ-01. The ammonia nitrogen removal rate for original coal chemical wastewater when the nano-TiO2/ZJ-01 existed in 40min was higher than that of the wastewater by adjusting alkalinity to pH=11.5using direct air-stripping method, indicating that the alkali consumption reduced sharply. Moreover, the mechanism of ammonia removal by the nano-TiO2/ZJ-01 was investigated that the occurrences of the decreased liquid film resistance and the increased mass transfer contact area together with the reduced bubble size in the mass transfer process have arisen due to the great reduce of surface tension between gas and liquid phases, resulting in the escape of ammonia from wastewater accelerating. Meanwhile, the role of the nano-TiO2/ZJ-01 existed in the air-stripping process contained the enhanced actions of the interfacial turbulence and convection and the accelerated renewal of liquid film side in bubble surface as well as the reduced thickness of effective mass transfer boundary layer, therefore the reduction of the ammonia-nitrogen mass transfer resistance and strengthening of the mass transfer between gas and liquid were occurred.
2022 Vol. 42 (6): 2628-2637 [Abstract] ( 157 ) [HTML 0KB] [ PDF 1320KB] ( 664 )
2638 Preparation of manganese ferrite activated carbon cathode catalyst and its effect on the electricity generation performance of microbial fuel cells
WANG Lin, WU Ke, WANG Cheng-ye, LI Yan
The oxidation reduction reaction capability of the microbial fuel cell (microbial fuel cell, MFC) cathode plays a vital role in power generation of MFC. In this study, manganese ferrite/activated carbon (MnFe2O4/AC) was prepared and characterized by material science, and it was used as the cathode catalyst of MFC to explore its effects on electricity generation and sewage treatment of MFC. Results demonstrated that when the molarratio of MnFe2O4 to AC was 1:3, the power density of MFC was the highest, reaching 302.7mW/m². The maintenance time near the peak voltage was up to 200h, which was 4times that of the traditional MFC using Pt/C as the catalyst, and the coulombic efficiency reached 17.45%. Moreover, in the reusability test of catalyst, the voltage of the MFC using the Pt/C catalyst dropped significantly, while the voltage of the MFC using the MnFe2O4/AC catalyst remained basically stable during the same running time indicating good cycle stability of the MnFe2O4/AC catalyst. In terms of sewage treatment effect, the highest treatment efficiency was 74.66% when the molar ratio of MnFe2O4/AC was 1:3. Therefore, the MnFe2O4/AC catalyst is simple to prepare, low in price, and stable in electrochemical performance, which has practical significance in improving the durability of MFC power generation.
2022 Vol. 42 (6): 2638-2646 [Abstract] ( 304 ) [HTML 0KB] [ PDF 644KB] ( 1053 )
2647 Parameter optimization for the achievement of nitrite accumulation by denitrifying phosphorus removal process
DI Fei, SUI Qian-wen, GAO Chao-long, ZHONG Hui, XU Dong-yao, WEI Yuan-song
To promote the coupling of denitrification phosphorus removal and anaerobic ammonia oxidation process, and achieve simultaneous efficient removal of nitrogen and phosphorus from wastewater, a sequencing batch reactor (SBR) was constructed to optimized the operational parameters for the nitrite accumulation by denitrifying phosphorus removal process. Under anaerobic-anoxic-microaerobic operational conditions, SBR gradually realized nitrite accumulation during denitrifying phosphorus removal process by feeding synthetic nitrate industrial wastewater in the anoxic section. The results showed that after 142 days of cultivation and domestication, when the influent C/P ratio of 55 and the nitrate concentration in the anoxic section was 23mg/L, the nitrite accumulation rate achieved 51.01%, the NO3--N→NO2--N transformation rate was 40.22%, nitrate removal rate was 72.14% and the highest removal rate of PO43--P was 88.17%. The effluent COD concentration was lower than 25mg/L, and COD removal rate was maintained above 90%. Analysis of the microbial community structure showed that Bacteroidetes, Proteobacteria, Chloroflexi and Acidobacteria were the dominant phylum in the system. Through parameter optimization, the abundance of denitrifying phosphorus accumulating organisms represented by Candidatus Accumulibacter increased (the cumulative abundance increased from 1.49% to 5.08%), and a more remarkable increase in the abundance of glycogen accumulating organisms represented by Candidatus Competibacter (from 1.02% to 15.49%). The combined effects of phosphorus accumulating organisms and glycogen accumulating organisms contributed to the accumulation of nitrite in the phosphorus removal process.
2022 Vol. 42 (6): 2647-2655 [Abstract] ( 249 ) [HTML 0KB] [ PDF 737KB] ( 1037 )
2656 Electrooxidation-electrocoagulation treatment ofthallium containing wastewater based on RuO2-IrO2/Ti and Fe0 electrodes
ZHANG Rui-qi, WU Hong-hui, XU Hai-yin, WANG Ping, ZHU-Jian, LUO Yuan-ling, HE Dong, XU Xin, WE Jie
The present study investigated the integrated treatment of Tl-containing wastewater by electrooxidation-electrocoagulation (EO-EC) based on a dimensionally stable RuO2-IrO2/Ti electrode and a sacrificial Fe0 electrode compared with the single electrocoagulation (EC). Further, the mechanism of Tl removal by EO-EC was discussed. In contrast to the single EC, the EO-EC(1:1) was suitable for the advanced treatment of Tl-containing wastewater in a wide pH (4~10) and current density (5~20mA/cm2) range and was less prone to passivation. Active chlorine and the ORP (oxidation-reduction potential) played a vital role in the indirect oxidation of Tl(I) to Tl(III) by EO-EC. The floc analyses showed that Tl(OH)3(s) was co-precipitated with Fe(OH)3(am), and the residual Tl(I) was adsorbed on the lepidocrocite. This study offered an integrated EO-EC method for remediation of Tl-containing wastewater, which can meet the discharge standard of <2µg/L for Tl is economically feasible.
2022 Vol. 42 (6): 2656-2661 [Abstract] ( 154 ) [HTML 0KB] [ PDF 636KB] ( 937 )
2662 Potential oscillation of cathode in nitrate electrochemical reduction removal process
HU Ling, WU Yan-xiang, SHU Jian-cheng, CHEN Shao-qin, ZHAO Zhi-sheng, TANG Jin-jing, LIU Zuo-hua, CHEN Meng-jun
Nitrate has a polyvalent behavior in electrochemical reduction removal process, it is a typical nonlinear system far from equilibrium. To investigate the electrochemical behavior of nitrate during the removal process, the influence of H2SO4 concentration, current, reaction temperature and NO3- concentration on cathode potential oscillation was systematically studied. The cyclic voltammetry characteristics of the reaction system and the changes of the phase composition, microstructure and surface electron valence state of the cathode Cu surface before and after the reaction were analyzed by cyclic voltammetry, XRD, SEM-EDS and XPS. The results show that the H2SO4-NaNO3 system had obvious potential oscillation under constant current conditions (Pt as anode and Cu as cathode). When concentration of H2SO4 and NaNO3 were separately 0.10, 0.20mol/L, the current 12mA, the temperature 20℃, the oscillation average amplitude was 1.15V and the oscillation average period was 3s. In addition, the periodic potential oscillation of nitrate in the process of electrochemical reduction removal was mainly caused by the continuous dissolution and formation of the dense CuO film on the Cu surface of the cathode, and periodic generation and disappearance of H2 on cathode surface.
2022 Vol. 42 (6): 2662-2670 [Abstract] ( 219 ) [HTML 0KB] [ PDF 2683KB] ( 1233 )
2671 Performance comparison of β-PbO2 and BDD electrodes for treating reverse osmosis concentrate in printing and dyeing industry
LIU Zi-feng, ZHENG Rui-hao, ZHOU Qing-qing, WANG Jia-de, SHI Xue-ru
Two electrode systems of β-PbO2/Ti-Ti and BDD/Si-Ti were systematically compared for the performance in treating reverse osmosis concentrate (ROC) from a real printing and dyeing industry. Kinetics of simultaneous remove chemical oxygen demand (COD) and total nitrogen (TN), as well as the improvement of the biochemical properties of the effluent were also investigated. It is shown that the BDD/Si-Ti electrode system has a high anodic oxygen evolution reaction (OER) potential (2.45V) and chlorine evolution reaction (CER) potential (1.90V), and the absolute values of anodic oxidation potential and cathodic reduction potential are higher than those of the β-PbO2/Ti-Ti electrode system; the degradation of COD and TN followed pseudo-first-order kinetics. The BDD/Si-Ti electrode system is more effective in COD removal and current efficiency while the β-PbO2/Ti-Ti electrode system is more effective in TN removal. Electrolysis at a low current density (5mA/cm2) for 15min resulted in a rise in BOD/COD from 0.18 to 0.42 (a 1.33-fold enhancement) for the ROC for the β-PbO2/Ti-Ti electrode system, while the BDD/Si-Ti electrode system only showed a 0.78-fold enhancement. As a result, the BDD/Si-Ti electrode system is suitable for pollutant mineralization, and the β-PbO2/Ti-Ti system is more suitable for the improvement of wastewater biochemical properties.
2022 Vol. 42 (6): 2671-2679 [Abstract] ( 331 ) [HTML 0KB] [ PDF 607KB] ( 1080 )
Water Pollution Control
2680 Microbialcommunitycharacteristics offilamentous sludge bulking at temperature shocking environment
GAO Chun-di, HAN Ying-lu, CHENG Li-yang, YANG Xiao-yang, BI Hao-hua, OU Jia-li, PENG Yong-zhen
Temperature is the key important factor affecting sludge bulking. To investigate the mechanism of sludge bulking at different temperature shockings, themicrobial community structure and dominant filamentous bacteria in sequencing batch reactor (SBR) treating domestic sewage under abruptly/gradually temperature decreasing conditions were analyzed by Illumina MiSeq high-throughput sequencing technology. The results showed that Microthrix Parvicella was the dominant filamentous bacteria in the abruptly temperature dropping system in which the sludge volume index (SVI) increased up to 291mL/g, while filamentous bacteria Eikelboom Type 0092 was the dominant in the gradually decreasing system in whichthe SVI was maintained at 250mL/g. Therefore, temperature shocking can provide more suitable habitat for Eikelboom Type 0092. The temperature varying process will also lead to significant differences in the community structure. The relative abundance of Proteobacteria maintained at average of 39.3%, and showed little variation, but the Actinobacteria and Chloroflexi showed totally different trends. The mean relative abundance of microorganisms related to organic matter removal was stable at 13.6%, and for Nitrospira it was about 2.48% accounting for more than 80% of the total NOB. Limited filamentous bulking (LFB) of Eikelboom Type 0092 caused by gradually temperature decreasing could not lead to serious deterioration of effluent quality, and removal rate of COD and NH4+-N were better than temperature abruptly dropping system.
2022 Vol. 42 (6): 2680-2689 [Abstract] ( 280 ) [HTML 0KB] [ PDF 1794KB] ( 1924 )
2690 Enhanced reductive dechlorination of chlorinated hydrocarbons in groundwater by emulsified zero-valentiron
SUN Ming-lu, DONG Jun, ZHANG Meng-yue, SUN Chen
The biological reduction is an alternative for the remediation of chlorinated hydrocarbons polluted groundwater. However, some issues limit its effectiveness, such as long start up time for microbial acclimatization, continuous pH reduction and the accumulation of toxic by-products. Aiming at the limits, emulsified zero-valent iron (EZVI) was prepared by nano-zero-valent iron (NZVI) coated with emulsified oil (EVO) to retard NZVI passivation and continuously provide carbon source for anaerobic microbial dechlorination. The static batch experiments were conducted to study the kinetics of TCE reduction by EZVI and the intermediate metabolites of tetrachloroethylene (PCE) reduction by EZVI. The results showed that EZVI could effectively retard the passivation of NZVI and enhance the reaction activity.The removal process of TCE by EZVI was a first-order reaction and the reaction rate constant kobs=0.182d-1. Reduction of PCE by EZVI can inhibit the accumulation of DCE. On the 10th day, 97.2% PCE was removed by EZVI, which was 68.9% higher than that by adding EVO. In the reaction process, pH and ORP maintained at 6.5-7.5 and -50-10mV, respectively, which provided a beneficial reduction environment for the effective enhancement of the anaerobic biological dechlorination reaction.
2022 Vol. 42 (6): 2690-2696 [Abstract] ( 245 ) [HTML 0KB] [ PDF 326KB] ( 1221 )
2697 Identification of chemical characteristics and hydraulic connection of each aquifer in complex mine field driven by coal mining
HUANG Lei, HOU Ze-ming, HAN Xuan, XU Lei, ZHANG Sheng-wei, LI Gang-zhu, LIU Zhi-qiang
By analyzing the numerical characteristics of conventional elements, trace elements, deuterium, oxygenand tritium isotope of different aquifers, the groundwater chemical characteristics and hydraulic connection of each aquifer were judged. The three identification charts (piper and durov identification charts of conventional hydrochemical components and deuterium tritium isotope identification charts) were established to realize the rapid identification of aquifer water source. The results showed that the main recharge source of groundwater in the study area was atmospheric precipitation. There was a significant indigenous connection between Quaternary aquifer and Zhiluo Formation aquifer, limited indigenous connection between the Zhiluo Formation aquifer and the Yan'an Formation aquifer. The three identification charts were established to determine the water inrush source and put forward targeted solutions for water inrush from different aquifers in Bulianta mining area based on the differences in hydrochemical ion characteristics, deuterium-oxygen and tritium isotopes.
2022 Vol. 42 (6): 2697-2706 [Abstract] ( 186 ) [HTML 0KB] [ PDF 1409KB] ( 771 )
2707 Movement and transformation of nitrogen in clay unsaturated zone under shallow groundwater table:In-situ experiment
PU Fang, HUANG Jin-ting, SONG Ge, WANG Jia-wei, LI Zong-ze, TIAN Hua, ZHANG Fang, SUN Fang-qiang
In this paper, the movement and transformation of nitrogen was investigated in clay unsaturated zone with shallow groundwater depth via in-situ experiment. Results show that, The depth to groundwater table fluctuated between 145.9cm and 173.6cm, and the calculated capillary height of groundwater reaches 297.0cm which induces high soil water content in soil profile, varied between 0.30~0.45cm3/cm3 except for near surface layer; The concentration of NH4+-N and NO3--N was of the maximum value at 155cm depth in the soil profile, 1.43 and 23.00mg/kg, respectively, which exceeded the background values of 1.13 and 21.05mg/kg; Under the condition of nearly saturated of the clay soil, the NH4+-N and NO3--N moved from ground surface to the depth of 155cm within one day. The research results indicated that the blocking effect of clay on the movement of nitrogen pollutants is weakened on shallow groundwater table depth.
2022 Vol. 42 (6): 2707-2713 [Abstract] ( 195 ) [HTML 0KB] [ PDF 1051KB] ( 766 )
Solid Waste
2714 Environmental risk characteristics and temporal and spatial differentiation characteristics of fly ash road filling and utilization
SUN Shu-na, CHEN Hong-wei, SHE Kai-lang, PENG Xiang-xun, YU Zhen-yang, YAO Guang-yuan, XU Ya
A comprehensive risk-based method was proposed to assess the potential risk and spatio-temporal differentiation of shallow groundwater resources (in terms of drinking water quality) in the process of recycling fly ash road base materials under the influence of comprehensive consideration of pollutant release changes caused by long-term weathering, regional climate conditions and parameter uncertainty. It could be used to evaluate the recovery potential of alkaline wastes (such as incineration fly ash) to partially replace highway cushion materials. The results of the leaching test for estimating the source concentration were combined with the fate migration model commonly used in the risk assessment procedure. The pollutant release under unweathered and weathered conditions was simulated through the laboratory leaching test. The impact of parameter uncertainty on the risk was simulated by Monte Carlo method, and the impact of different climatic characteristics on the characteristics of environmental risk areas was evaluated. The results showed that under the typical climatic conditions in North China, among the seven identified target pollutants, the predicted concentrations of Zn, Cd and Pb at the exposure points might exceed the standard, with the probability of exceeding the standard of 34%, 96% and 7% respectively. As a result, their exposure concentrations (represented by 95% quantile) exceeded the standard, and the environmental risk could not be ignored; Carbonation would change the dissolution characteristics of some pollutants and led to changes in long-term risks. Specifically, with regarded to the exposure concentration after carbonation, Cd showed a downward trend, Ni and Zn remained basically unchanged or changed slightly, Cr, Cu and as increased significantly but were still significantly lower than the standard limit, while the exposure concentration of Pb ions increased significantly and the exceeding standard increased from 1 to 3. 5 times, which requires special attention; Due to the influence of regional differential parameters such as rainfall, the risk difference between different regions was large, and the exposure concentration difference between the arid and semi-arid regions with the largest difference was nearly 2 times; The common pollutants exceeding the standard in different areas were Zn and Cd. In addition, there were Pb exposure concentrations exceeding the standard in humid/semi humid areas.
2022 Vol. 42 (6): 2714-2723 [Abstract] ( 180 ) [HTML 0KB] [ PDF 877KB] ( 1138 )
2724 Enrichment of caproate bacteria and its application in caproic acid production from food waste
ZHANG Yan-yan, BAI Jia-zhe, ZUO Jian-e
This study investigated three different electron donor combinations to attain maximum enrichment of caproic acid bacteria and the ability of these enriched bacteria to further digest food waste without the addition of external electron donors. Three batch experiments were performed using ethanol, lactate, and ethanol plus lactate as electron donors. The results showed that the highest concentration of caproic acid ((2303.06±499.56) mg COD/L) was reached when ethanol and lactate were both used as electron donors which was justified by the significant increase in the microbial population of caproate bacterial genera such as Clostridium_sensu_stricto_12 (16.04%±0.16%), Caproiciproducens (28.78%±0.15%) and Oscillibacter (2.32%±0.03%). When this enriched culture was inoculated to food waste, the maximum concentration of caproate reached (8657.36±996.21) mg COD/L, and the caproic acid yield and specificity were (230.05±26.47) mg COD/g VS and 27.74%±3.19% respectively. This study proved that caproic acid bacteria are significantly enriched in the presence of the electron donor combination of ethanol and lactate, and that the enriched inoculum can promote caproic acid production from food waste. These results provide theoretical support for the recovery of resources from food waste.
2022 Vol. 42 (6): 2724-2733 [Abstract] ( 171 ) [HTML 0KB] [ PDF 841KB] ( 1315 )
Soil Pollution Control
2734 Distribution characteristics and potential risk of heavy metals in soil around water source:A case study of Shenzhen city
ZHOU Rui, QIN Chao, REN Hen-jun, ZHAO Yan
Zn､Pb､As in three different types of soils (lato-red soil, red soil, and paddy soil) around the water sources in Shenzhen were selected as the research object. Their content and toxicity in the environment were high. And this study aims were exploring their distribution characteristics and existing species in the leaching layer, sedimentary layer and parent material layer (layers A, B and C) in these three soil profiles, analyzing the correlation between the content of heavy metals, the existing species and the physical and chemical properties of the soil. And based on them, we used the potential ecological hazard index and the potential migration index to evaluate the ecological risk of the heavy metals. The results showed:Zn, Pb, As had a higher content in each layer of the three types of soil, but they were all fewer than the background content of the local soil environmental quality, and the content of heavy metals was greatly affected by the local soil diagenetic parent material. The heavy metals were mainly in the residual state in the three types of soils. Relatively, the reducible Pb content in red soil was higher, and it was easy to transform into a weak acid soluable state at low pH, so it was easily release from soil and migrate to the water. Correlation analysis showed that the total amount of Zn and Pb was extremely significantly positively correlated with the organic matter content. The reducible state of Zn was significantly positively correlated with pH, and the weak acid soluable state of Pb and As was significantly positively correlated with the reducible state. The content of clay and powder particles affected the morphological distribution of lead and arsenic. The potential ecological hazards of the three heavy metals were all minor, which had little impact on the potential ecological risks of water source safety. The migration capacity of heavy metals in different soil types was red loam> latosolic red soil> paddy soil. The migration ability of the element in the soil was Zn>As>Pb; In latosolic red soil and paddy soil, the migration ability of Zn in layer A was the strongest, in layer B As was the strongest, and in layer C Zn, Pb, As were all weak. In red soil, Zn in layer A had the strongest migration ability, in layer B Zn, Pb, As were all strong, and Zn, Pb, As were all weak in layer C.
2022 Vol. 42 (6): 2734-2743 [Abstract] ( 235 ) [HTML 0KB] [ PDF 478KB] ( 908 )
2744 Study on the accumulation of heavy metals and influencing factors in the soil of facility vegetable fields
LU Wei-hong, LIU Juan, ZHANG Nai-mming, ZHANG Yu-juan, HAO Kang-wei, REN Li-juan, YU Chang, HOU Hong
The accumulation of heavy metals in facility cultivation soil has become a prominent environmental problem. In this study, by collecting soil and fertilizer samples from representative facility vegetable production areas in eight provinces across the country, we systematically studied the effects of facility cultivation years, fertilizer application, and soil properties on the accumulation and activity of heavy metals Cu, Zn, and Cd in facility vegetable soils. The results showed that compared with open-air cultivation, the total and available concentration of Cu, Zn and Cd in the soil showed an obvious accumulation trend with the extension of planting years under facility conditions; when the years of cultivation were more than 15a, the total and available Cu, Zn, and Cd concentration in the facility soils were 1.57, 2.16, 1.67, 3.28, 1.96, and 2.00 times higher than that of the open-air cultivation soil, respectively. Pearson analysis revealed that the Cu, Zn, and Cd concentrations in the facility soil were associated with the soil SOM at an extremely significant level, indicating a high similarity in source among the heavy metals. Further analysis of the content of Cu, Zn, Cd, and soil SOM reached a very significant correlation, indicating a strong similarity in source, and further analyses on the contents of Cu, Zn, and Cd sourced from main agromaterials, showed the concentrations of both Cu and Zn in pig manure, commercial organic fertilizer and soil conditioner were greater than 100mg/kg, and that of Cd exceeded 1.0mg/kg. These agromaterial-sourced Cu, Zn and Cd could be considered the main contributors to the total amount of the heavy metals in the facility soil due to their large inputs to the soil. While the Cu, Zn, and Cd in straw and some chemical fertilizers (such as urea and K2SO4) were at an extremely low level, and their contributions to the accumulated heavy metals in the facility soil were basically neglectable; Both pH and CEC were confirmed as key factors influencing the cumulative activities of Cu, Zn, and Cd in the soil. As the pH increased, the soil Cu activity showed a trend of rising at first and then decreasing, while the soil Cd activity showed a continuous downtrend, reaching a significant correlation level only when pH<6.26; As the increase of soil CEC, the acidity of soil Cu showed a downtrend at first, followed by rising and then downtrend again; and the activity of soil Cd showed rising first, followed by slight downtrend and then rising again. While the activity of soil Zn only showed a significant linear correlation trend when CEC was lower than 5.83 as CEC increased. Therefore, preventing the accumulation and pollution of Cu, Zn, and Cd in the facility cultivation soil, choosing fertilizers with low heavy metal content and regulating the physical and chemical properties of the soil (especially pH and CEC) are effective means to alleviate the accumulation velocity of heavy metals in the facility cultivation soil and ensure the quality and safety of vegetables.
2022 Vol. 42 (6): 2744-2753 [Abstract] ( 233 ) [HTML 0KB] [ PDF 579KB] ( 1001 )
Environmental Microbiology
2754 Biogeographic patterns and assembly mechanisms of bacterial communities in lakes, China-statistical analysis based on the published literature
GAO Peng-fei, WANG Peng, DING Ming-jun, ZHANG Hua, NIE Ming-hua, HUANG Gao-xiang
In order to examine the biogeographic patterns and assembly of bacterial communities in Chinese lakes, data from the published literature on water or sediment bacteria at the phylum level and environmental factors from 228 lakes were collected. Results showed that the dominant taxa of the water bacteria communities in Chinese lakes were Proteobacteria (35.92%), Actinobacteria (25.03%) and Bacteroidetes (10.77%), and the dominant taxa in sediment were Proteobacteria (40.37%), Chloroflexi (8.74%) and Bacteroidetes (8.55%).Distance decay of water bacteria communities was significantly lower than that of sediment bacteria. There was significant spatial difference of lake bacteria communities between Northern China, Southern China and Tibetan Plateau. The distance decay of bacterial communities was not significant in Northern China, but significant in Tibetan Plateau; in Southern China, the distance decay of bacterial communities was significantin lake water, but not significant in lake sediment. The abundance of Actinobacteria (Southern China>Northern China>Tibetan Plateau) and Bacteroidetes (Tibetan Plateau >Northern China>Southern China) in lake waterwere significantly different between the three regions, while Proteobacteria was not. The abundance of Proteobacteria (Northern China>Southern China> Tibetan Plateau), Chloroflexi (Southern China>Northern China> Tibetan Plateau), and Bacteroidetes (Tibetan Plateau >Northern China>Southern China) in lake sediment were significantly different between the three regions. The main environmental factor influencing bacterial communities in lake water of Northern China was dissolved organic carbon, in Southern Chinawas dissolved oxygen, and in Tibetan Plateau was nitrate nitrogen. The main environmental factor influencing bacterial communities in lake sediment of Northern China were total nitrogen and pH, in Southern China was total phosphorus, and in Tibetan Plateauwas pH. Dispersal limitation and variable selection collectively shaped the biogeographic patterns of lake bacteria in China. Dispersal limitation had less impact on water bacteria than sediment bacteria;it had the greatest impact on water and sediment bacteria inTibetan Plateau lakes, and the least impact on water and sediment bacteria in Northern China lakes. Variable selection had the greatest impact on water and sediment bacteria in Tibetan Plateau lakes, andless impact on water bacteria in Southern China lakes and sediment bacteria in Northern China lakes.
2022 Vol. 42 (6): 2754-2763 [Abstract] ( 343 ) [HTML 0KB] [ PDF 1926KB] ( 1845 )
2764 Community structure and gene distribution of the surface and interstitial biofilm in the particle sulfur autotrophic denitrification
Lü Xiao-mei, WU Yi-cong, CHEN Gui-lian, XU Jian-hui, LIU Peng, HU jun-jie
Bioinformation including microbial community structure, functional genes and metabolic pathways of surface and interstitial biofilms in the particle elemental sulfur autotrophic denitrification column were investigated in the present study. Bacterial diversity of microorganisms in the surface biofilm of sulfur particles was lower than that of interstitial biofilm. Differences in the abundance of functional genes for nitrogen metabolism were significant. Abundance of extracellular nitrate and nitrite transportation genes in the interstitial biofilm was much higher than that in the surface biofilm, with the abundance of 0.0792%, 0.109% and 0.0157%, 0.0314%. For reductive denitrification metabolism, the total gene abundance in surface biofilm was significantly lower than that in interstitial biofilm, with their abundance of 0.367%、0.406% respectively. Moreover, abundances of genes participated in denitrification process were remarkably different, especially the genes in the process of reducing nitrate to nitrite and nitrous oxide to nitrogen gas. Regarding sulfur metabolism, no obvious difference was observed. APS (adenosyl phosphosulfate) oxidation was the major pathway for oxidation of sulfite to sulfate, with its gene abundance was much higher than the direct oxidation pathway, and their abundances were 0.137% and 0.0005% (surface), 0.138% and 0.0007% (interstitial). Results indicated that microorganisms in interstitial biofilms cooperated with that in the surface biofilms, contributing to sulfur autotrophic denitrification synergistically.
2022 Vol. 42 (6): 2764-2770 [Abstract] ( 286 ) [HTML 0KB] [ PDF 469KB] ( 2326 )
2771 A study of microbial clogging on the variation of seepage characteristics with biofilm growth in porous medium
WANG Qian-dan, LU Ying, YANG Yue-suo, WU Yu-Hui, XU Zhe, PEI Zi-cheng
The seepage characteristics of porous media varies with the inner biofilm growth irritated by recharge water during groundwater recharge. Indoor soil column experiments were conducted to stimulate the bio clogging process of porous media by continuous injection with nutrient solutions. Growth morphology biofilm and the corresponding seepage parameters of media (including permeability coefficient, water retention and dispersion coefficient) were measured over a series of time periods during experiments. The results showed that the permeability coefficient slightly decreased and rose in the first 5hours. In 5~18 hours, the permeability coefficient decreased sharply, and the hydraulic dispersion coefficient, and greatly increased, but the change of water holding capacity was not obvious. After 18hours, the decrease rate of the permeability coefficient slowed down, whist the water holding capacity began to increase rapidly, and the solute transport in the porous media transited be recharged by dominant mechanism of dispersion. To sum up, the clogging process by the growth of biofilm in the medium can be divided into three stages:(1) First stage is the adaptation period of bacteria, in which the inoculated bacteria did not dramatically grow and reproduce, and the permeability coefficient changed simply because of the retention and migration of bacteria cells; (2) Second stage is the period of mass growth and reproduction of bacteria, in which the increasing bacteria cells occupy more and more pore volume of medium, resulting the decrease in permeability and the increase in dispersion of the porous media; (3) Last stage is the period of extracellular polymer secretion, in which a permeable biofilm is gradually formed, and the growth and shedding of biofilm forms a dynamic balance with the nutrients provided by recharge water.
2022 Vol. 42 (6): 2771-2778 [Abstract] ( 351 ) [HTML 0KB] [ PDF 651KB] ( 1078 )
Environmental Ecology
2779 Identification of key areas of ecological protection and restoration based on the pattern of ecological security:A case of Songyuan City, Jilin province
CAO Xiu-feng, LIU Zhao-shun, LI Shu-jie, GAO Zhen-jun, SUN Bei-wen, LI Ying-xue
From the perspective of ecosystem integrity and structural connectivity in the context of ecological civilization construction, this paper takes Songyuan City, Jilin Province, as the study area. This paper integrated MSPA analysis, landscape connectivity evaluation, and circuit theory to construct an ecological security pattern and identify key areas for ecological restoration in Songyuan City. The results showed that:In Songyuan, a total of 9 ecological sources covering an area of 787.95km2 have been identified, with water and grassland being the main components, that plays an important role in regional ecological security. A total of 23 ecological corridors are identified in Songyuan, including 16 primary corridors and 7secondary corridors, with a total length of 1458.18km. Based on the ecological security pattern, the key areas of ecological restoration in Songyuan City are identified, including 16 ecological pinch points with an area of 180.70km2 and 24 ecological barrier points with an area of 298.11km2. Based on a comprehensive analysis of the spatial distribution and land use status of key ecological restoration areas, targeted ecological restoration strategies are proposed.
2022 Vol. 42 (6): 2779-2787 [Abstract] ( 227 ) [HTML 0KB] [ PDF 2131KB] ( 1825 )
2788 County-levelspatial pattern and influencing factors evolution of carbon emission intensity in China:A random forest model analysis
YU Wen-meng, ZHANG Ting-ting, SHEN Da-jun
To explore the spatial distribution pattern of the county-level carbon emission intensity and the dynamic change in influencing factors, in this paper, ArcGIS spatial statistical model was adopted to measure and analyze the spatial distribution pattern of the carbon emission intensity from 2009 to 2017. Then key influencing factors and their effects change were identified by the random forest model. As results indicated, the average county-level carbon emission intensity fluctuated and decreased from 2009 to 2017. The county-level average carbon emission intensity was 2.02t/10000 yuan in 2017, indicating a significant potential in carbon emission reduction at county-level. Besides, there was significant and rising spatial autocorrelation in carbon emission intensity, but the spatial correlation varied between north-south and east-west regions. The hot-spot area of carbon emission intensity expanded westward, while the cold-spot area expended both southward and northward. Among the key influencing factors, distance to provincial capital, industrial structure, road network density and population played more important role compared with economic development, fiscal revenue and expenditure, number of green patents and high-speed railway. Green patent, total population, and economic development risen in the importance rankings over time, while industrial structure and population density fallen back in the rankings. In addition, most of factors were non-linear correlated with the county-level carbon emission intensity.
2022 Vol. 42 (6): 2788-2798 [Abstract] ( 472 ) [HTML 0KB] [ PDF 1678KB] ( 2179 )
2799 Study on sustainable development of carbon storage in Guilin coupled with InVEST and GeoSOS-FLUS model
ZHANG Kai-qi, CHEN Jian-jun, HOU Jian-kun, ZHOU Guo-qing, YOU Hao-tian, HAN Xiao-wen
In order to quantify the carbon storage of Guilin and quickly evaluate the impact of hierarchical conservation measures on regional carbon storage function, this study coupled carbon storage module of InVEST model and GeoSOS-FLUS model. Based on land use data and future land prediction results of different scenarios, the spatio-temporal characteristics of carbon storage in Guilin from 2000 to 2040 were analyzed. The results showed that the total carbon storage of Guilin in 2000, 2010 and 2020 was 554.02×106t, 553.58×106t and 550.21×106t respectively, showing a trend of "decreasing year by year". At the same time, affected by human activities and land use type change, the carbon storage level of each district and county in Guilin had a great spatial and temporal difference. The overall carbon storage was higher in northwest, southwest and east, and lower in northeast, southeast and central parts of Guilin. The high-value carbon storage area in Guilin was determined as the priority area for carbon storage resource protection. Compared with the natural change scenario, the forest land in Guilin was effectively protected under the resource conservation scenario, and the expansion of construction land was restricted. After taking resource protection measures, the total carbon storage of Guilin reaches 552.16×106t in 2040, an increase of 1.95×106t compared with 2020. The proportion of medium and low density carbon storage area decreases significantly, and the regional carbon sequestration capacity is greatly enhanced. The research results can provide guidance for the construction of national sustainable development demonstration city in Guilin, and also provide scientific reference for precise protection of carbon storage resources and land use management decisions.
2022 Vol. 42 (6): 2799-2809 [Abstract] ( 349 ) [HTML 0KB] [ PDF 2712KB] ( 2201 )
2810 Temporal and spatial variation and source analysis of biomarkers in surface sediments in the water-level-fluctuating zone of the Three Gorges Reservoir Region
ZHAO Dai-yin, CAI Mao-xue, ZHANG Dai-jun, WANG Feng-wen
Affected by the seasonal "storage-discharge" of the Three Gorges Dam, the water level fluctuation zone (WLFZ) of the Three Gorges Reservoir Region (TGRR) show a periodic change of "submergence-exposure" each year, and the environmental geochemical processes of organic matter in this area changed accordingly. In this study, 16paired surface sediment samples (n=32) were collected from WLFZ inthe TGRR in March and September 2018, respectively. GC-MS were used to analyze several biomarkers (n-alkanes, UCM, hopanes and steranes) to discuss the concentration, composition, sources and spatial-temporal variation. The results showed that the concentration of total n-alkanes (C10~C40) in exposed and submerged period was (14.09±4.05)μg/g and (16.25±3.91) μg/g, respectively, and UCM was 4.28~28.62μg/g, indicating pollution from petroleum hydrocarbon. The average ratios of L/H in exposed and submerged period was (0.90±0.56) and (0.74±0.15), respectively. The exposed period has a mixed input of lower organisms and terrestrial higher plants, while the submerged period was mainly from land sources. The average value of CPI was (1.66±0.32), (1.70±0.33), respectively, indicating the mixed contribution from fossil fuels and higher plants. The Cmax, concentration and composition of n-alkanes revealed that the input from algae, bacteria and aquatic plants in exposed period was higher than in submerged period. The sedimentary organic matter in the upper reaches was mostly from aquatic plants and higher plants, while the downstream was imported from bacteria and planktonic algae. The results of the ratios of hopanes (C27, C29~C32) Ts/Tm, C31 (S/S+R) and steranes (C27~C29) C29 ααα S/(S+R) in the two periods could indicate the input of high-maturity petroleum hydrocarbons. PCA apportion the sources of typical nine n-alkanes and UCM:in exposed period they were mainly from petroleum sources, aquatic and terrestrial plant sources; while in submerged period, they were from a mixture of lower biological sources with aquatic plants contribute higher. As investigating the influence mechanism of seasonal water level regulation on sediment biomarkers in WLFZ, and presenting their tracer information, this study provides basic datasets for further study of environmental geochemical cycle of biomarkers in TGRR.
2022 Vol. 42 (6): 2810-2820 [Abstract] ( 197 ) [HTML 0KB] [ PDF 625KB] ( 2051 )
2821 Effects of soil aggregate preparation methods on the stability and carbon sequestration potential evaluation
ZHENG Nan, SHAO Yang, LUO Min, MENG Dan-yang, XU Dian-dou, LIU Zhi-ming, MA Ling-ling
To investigate the effects of different soil agglomerate preparation methods on the evaluation of agglomerate stability and its carbon sequestration potential, soils were collected from two typical land utilization types-urban road soils and suburban agricultural soils in Beijing. The soil aggregate was prepared by dry sieving and wet sieving methods, respectively, and its composition, organic carbon content and stable carbon isotope were analyzed. The mechanically stable aggregates prepared by the dry sieving method were dominated by the large (>0.25mm) aggregates (urban road soils:69.80%; agricultural soils:71.36%). In contrast, the water-stable aggregates prepared by the wet sieving method were dominated by the micro (<0.25mm) aggregates (urban road soil:57.70%; agricultural soil:52.14%). Infrared spectrum analysis showed that irrespective of the different preparation methods, the relative content of stable organic carbon in micro aggregates was higher than that of active organic carbon for the two types of soils. For the arable soil in the suburbs of Beijing, the relative content of stable aromatic carbon was more, while the relative content of fatty carbon was less. In the case of urban greening soil, the opposite characteristics can be observed, indicating that organic carbon in urban greening soil has higher activity and is easy to be released under certain conditions. Combined with the analysis of stable carbon isotope ratio, it is found that 13C is enriched in the aggregate particle group smaller than 0.053mm prepared by the wet sieve method, which is more fitted the soil aggregate embryo development model, indicating that the wet sieve method has more practical evaluation value than the dry sieve method in the study of soil carbon sequestration potential. This study has reference significance for further evaluating the carbon sequestration potential of urban soils in China.
2022 Vol. 42 (6): 2821-2827 [Abstract] ( 329 ) [HTML 0KB] [ PDF 466KB] ( 2541 )
2828 Research on the ecological compensation standard for river basin based on pollutant allocation
RAO Qing-hua, LIN Xiu-zhu, CHEN Fang, CHEN Wen-hua, LIN Yun-shan, ZENG Yu
In order to reflected "difference fairness", we used the information entropy method to build the pollutant allocation index system and allocation model of a basin. Based on the allocation ratio of different areas and the total pollutant allocation in a basin, the quantity of pollutant allocation in different areas within a basin were determined. Taking the Minjiang River Basin as a case study, the ecological compensation standards values of the water environment from 2010 to 2019 were calculated based on the pollutant allocation in different areas of the Minjiang River Basin. The results showed that the actual COD discharges in Fuzhou city were higher 871 to 20857t than the theoretical COD discharges. Except for 2010, the value of COD discharges in Nanping city were lower than the theoretical COD discharges. The COD discharges in Sanming city were lower than the theoretical COD discharges, and the quantity of emission loss ranged from 1479 to 12507t. From 2010 to 2019, the number of ecological compensations in Fuzhou were 1175×104~28139×104 Yuan. Except for 2010, Nanping needed to pay ecological compensation (the compensation value was 821×104 Yuan). In other years, Nanping should receive ecological compensation from other areas with the compensation values ranged from 1253 to 13157×104 Yuan. Sanming should receive a ecological compensation values, ranging from 1996×104 to 16874×104 Yuan.
2022 Vol. 42 (6): 2828-2834 [Abstract] ( 178 ) [HTML 0KB] [ PDF 445KB] ( 557 )
2835 Optimization and influence of vegetative filter strip's pattern on reduction of runoff and its sediment in the Inner Mongolia farming-pastoral ecotone
SONG Fan-fan, LI Xian-yue, TIAN De-long
In order to improve the performance of vegetative(grass)filter strips(VFS) decreasing runoff and its sediment in the farming-pastoral ecotone,the experiment was carried out at the Jubaozhuang experimental site in central Inner Mongolia, including three stem spacing (0.9cm, 1.2cm, 1.7cm) and three width (3m, 6m, 9m) of VFS treatments plus one control treatment (no VFS). The response of the reduction of runoff and its sediment on VFS's stem spacing and width were studied, the comprehensive benefits of different treatments were evaluated by the entropy TOPSIS model, and the suitable stem spacing and width of VFS were determined. The results showed that the bigger VFS's width caused to the lower runoff and its sediment discharge under the condition of same VFS's stem spacing. Compared to VFS's width of 3m, the treatments of width of 9m and 6m decreased averagely 62.14% and 33.59% runoff, respectively; 80.97% and 60.66% for sediment, additionally, outflow time was delayed by 7min and 2min. Under the condition of same VFS's width, the decrease of VFS's stem spacing can effectively decreased runoff and its sediment. When VFS's stem spacing was 0.9cm, average sediment quantity at the end of VFS was reduced by 35.4% and 48.28% compared with that of 1.2cm and 1.7cm stem spacing, respectively; 16.5% and 18.26% reduction for runoff. So, the runoff and its sediment can be significantly affected by VFS's stem spacing and width, and there was more significant effects for runoff reduction by VFS's width. Additionally, the highly significant reduction for the sediment by their interaction effects appeared. The optimal VFS pattern with stem spacing of 0.9cm and width of 9m was obtained by TOPSIS, and there was best comprehensive benefits. The results has important guiding significance in both theory and practice for VFS construction.
2022 Vol. 42 (6): 2835-2843 [Abstract] ( 178 ) [HTML 0KB] [ PDF 849KB] ( 639 )
2844 Analysis of the source of suspended particulate matter in the Maowei Sea based on composite fingerprint map and Bayesian model
LIU Hai-xia, LI Su-xia, LIU Guang-long, HUANG Kai-xuan, YANG Bin, SU Jing-jun, WANG Jie, ZHANG Jin-yi, HOU Jing-yao
Toreveal the source of suspended particulate matter in Maoweisea, samples of potential sources of suspended particulate matter such as mangrove soil, embankment soil, estuarine particulate matter, Maowei Sea sediment and particulate matter outside the Bay in Maowei Sea Basin were collected. Based on multivariate statistical composite fingerprinting method, the optimal fingerprint factor combination was formatted, and then the contribution rates of five potential sources to suspended particulate matter in Maowei Sea are obtained by Bayesian mixed model. The results show that five fingerprint elements of Mg, Al, Mn, Pb and Fe can be used as the best combination of fingerprint factors, and the cumulative discrimination accuracy rate is 78%. The results of the Bayesian mixed model showed that the suspended particulate matter in Maowei Sea is mainly derived from the estuary and the outer bay transport, and the contribution rate reaches 58.9% and 68.6%. Among them, the area near the estuary is mainly affected by the river inflow, and the contribution rate of estuarine particulate matter reaches 42.2%~58.9%; In the areas close to the outer bay, the contribution rate of particulate matter outside the bay was 44.9%~68.6%. The contribution rate of sediment at each point was low, and the contribution rate of mangrove soil and embankment soil was about 10%. In general, particulate matter brought in by estuarine inflow and tidal action is the main source of suspended particulate matter in the Maowei Sea.
2022 Vol. 42 (6): 2844-2851 [Abstract] ( 205 ) [HTML 0KB] [ PDF 695KB] ( 1122 )
2852 Fine classification of urban vegetation based on UAV images
LIN Yi, ZHANG Wen-hao, YU Jie, ZHANG Han-chao
The fine classification and information extraction of urban public vegetation based on remote sensing methods hasgreat significance in urban land use change, urban ecological environment monitoring and urban planning. Aiming toreducethe heavy workload, high cost and enhancetheefficiency of traditional vegetation resource survey methods, a multi-dimensional feature space including spectral, spatial and texture features for describing different types of urban vegetation was proposed in this study. Then a comparison experiment of three typical classification algorithms (pixel-based, object-oriented support vector machine and deep learning semantic segmentation model-Mobile-Unet) was accomplished. The experimental results indicate that:The proposed spectrum-texture-spatial feature extraction method can describe different types of urban vegetation effectively, and improve the accuracy of image segmentation and vegetation classification significantly. In terms of classification accuracy, the overall accuracy of pixel-based and object-oriented support vector machine classification exceed 90%, while the overall accuracy of deep learning method is only 84%. In terms of efficiency, traditional machine learning methods are also superior to deep learning method. Therefore, for the fine classification of different vegetation in small urban areas with small samples, traditional machine learning classification methods are more effective than deep learning method.
2022 Vol. 42 (6): 2852-2861 [Abstract] ( 228 ) [HTML 0KB] [ PDF 1625KB] ( 2207 )
2862 Partitioning behavior and influence factors of heavy metals between settled dust and its extracted water phase:a case study of Nanchang city
WANG Xiao, NIE Ming-hua, YAN Cai-xia, SHENG Yan-ru, CHEN Jie, DING Ming-jun
The spatial distribution of heavy metal concentrations in dust and its dissolved phase in different functional areas and bus stations was analyzed in Nanchang City. In addition, the influence of the physicochemical properties of dust and its dissolved phase on the partitioning behavior of heavy metals in the solid-liquid phase of dust was investigated by combining various analytical techniques. Results showed that the concentrations of total heavy metals in the dust and its dissolved phase in Nanchang city were 310~4393μg/g and 2.17~55.62μg/g. The spatial distribution of the heavy metals in the dust and its dissolved phase might be influenced by the traffic arteries with high traffic flow and the wear of automobile tire parts, and the high-value areas were mainly located near Nanchang County Government, some colleges and universities, passenger stations and driving schools. Results of the risk assessment indicated that the comprehensive ecological risk of heavy metals from dust in Nanchang City was generally at a medium level, and Cr and As had a certain carcinogenic risk. The percentage of heavy metals in the dissolved phase in the dust (i.e. K value) was ordered as follows:Ni>Mn>Cu>As>Cr>Zn>Pb. The higher K values were primarily located in the densely populated areas, traffic roads, and near passenger stations. Most of the physicochemical properties of the dust and its dissolved phase had a significant positive correlation with the distribution of Pb, As and Mn, and the higher dissolved organic carbon and humification degree in the dissolved phase had a dominant effect on the release of heavy metals from dust to the dissolved phase.
2022 Vol. 42 (6): 2862-2877 [Abstract] ( 157 ) [HTML 0KB] [ PDF 3195KB] ( 782 )
Environmental Toxicology and Health
2878 Differential Effects of PM2.5from different cities in the induction of hepaticfibrosis in mice
YAN Zhi-peng, LI Shu-yue, XING Qi-song, NAN Nan, QIN Guo-hua, SANG Nan
To clarify the potential mechanism by which PM2.5 exposure causes liver fibrosis and the key components leading to this adverse effect, 10-month-old C57BL/6 female mice were exposed to PM2.5 from different cities of China (Taiyuan, Beijing, Hangzhou and Guangzhou) for 4weeks. And tissue section staining, qRT-PCR and Western-blot technique were used to evaluate the features of liver fibrosis in mice. Pearson correlation coefficient was used to analyse the correlation between the expression level of liver fibrosis-related genes in mice and the typical chemical composition of PM2.5 from different cities. The results showed that a significant decrease in the organ coefficient of liver was found in Taiyuan and Hangzhou PM2.5-exposed group. Taiyuan PM2.5 exposure significantly increased the area of collagen deposition and the relative expression level of fibrosis related genes (Col1a1, Col3a1, TGF-β and MMP2) in the mice liver, and only PM2.5 from Taiyuan induced the significant increase of Col1a1 protein in mice liver, while PM2.5 from other cities except Taiyuan exposure did not cause any of the above changes in fibrosis related factors. In addition, the results of correlation analysis showed that the metal components such as Cr, Mn, Mo, Cs, Pb, Bi, U and Fe were positively correlated with the mRNA expression of Col1a1 and Col3a1. Except for NA, AC and BaP, the other 15PAHs were significantly correlated with Col1a1 mRNA expression, and the sum of 18EPA PAHs was significantly correlated with Col3a1. The above results indicated that PM2.5 exposure induced hepatic fibrosis in mice, especially PM2.5 from Taiyuan. TGF-β and related signal molecules in its pathway has beenshownto play a vital role in mediating liver fibrosis induced by PM2.5. Cr, Mn, Mo, Cs, Pb, Bi, U, Fe and PAHs of PM2.5 were probably critical components to induce liver fibrosis.
2022 Vol. 42 (6): 2878-2885 [Abstract] ( 173 ) [HTML 0KB] [ PDF 871KB] ( 578 )
2886 Toxicological effects and biotransformation mechanism of 6:2fluorotelomer carboxylic acid (6:2FTCA) in earthworms (Eisenia fetida)
ZONGYu-lu, YANG Li-ping, ZHAO Shu-yan
Earthworms (Eisenia fetida) were exposed to the soil spiked with 6:2 fluorotelomeric carboxylic acid (6:2 FTCA) to investigate the toxicological effects and biotransformation mechanisms of 6:2 FTCA in earthworms after in vivo and in vitro exposure. Compared to the controls, no significant effects were observed in malondialdehyde (MDA) contents and peroxidase (POD) activities, while catalase (CAT) activities were increased, and superoxide dismutase (SOD) and glutathione-s-transferase (GST) activities were significantly induced in 6:2 FTCA treatments. This suggested that 6:2 FTCA induced oxidative stress in the earthworm cells. Biodegradation of 6:2 FTCA in the earthworm cytolchrome P450 (CYP450) enzyme extracts and GST enzyme extracts fitted well with the first order kinetics. The biodegradation rate in CYP450 extracts (0.014/h) was much higher than that in GST extracts (0.006/h), indicating CYP450 and GST were involved in the enzymatic transformation and CYP450 contributed more than GST to 6:2 FTCA biotrans formation in earthworms. Three terminal perfluorocarboxylic acid (PFCA) metabolites, including perfluorohexanoic acid (PFHxA), perfluoropentanoic acid (PFPeA) and perfluorobutanoic acid (PFBA) were observed in the enzyme extracts. The results of gut microbial degradation test showed that aerobic microorganisms contributed to 6:2 FTCA biodegradation in earthworms significantly, and the terminal PFCA metabolites were PFHxA and PFPeA, but anaerobic microorganisms didn't contribute to 6:2 FTCA biotransformation in earthworms.
2022 Vol. 42 (6): 2886-2893 [Abstract] ( 281 ) [HTML 0KB] [ PDF 409KB] ( 1585 )
2894 Impact of polyethylene and polylactic acid microplastics on growth, physio-biochemistry and metabolism in soybean (Glycine max)
LIAN Yu-hang, LIU Wei-tao, SHI Rui-ying, WANG Qi, LI Jian-tao, ZHENG Ze-qi
The influence of bio (polylactic acid) and non-biodegradable (polyethylene) at two different concentrations (0.1%, 1%,W/W) on the growth, photosynthesis, oxidation resistance, nutritional quality, and metabolism of soybean (Glycine max) were deeply studied to reveal the ecotoxicological impact of microplastics with different biodegradability on crops. Results revealed that polyethylene microplastics (PEMPs) tend to increase the fresh weight of Glycine max roots. The treatment of 0.1% Polylactic acid microplastics (PLAMPs) inhibited the root length. Whereas, PEMPs enhanced the chlorophyll content of Glycine max significantly. The catalase (CAT) activity was decreased under PLAMPs, while the hydrogen peroxide (H2O2) content was increased by 0.1% PEMPs and 1% PLAMPs exposure. In addition, the Mn, Fe, and Cu content of Glycine max roots also changed, which had the most obvious impact with 0.1% PEMPs. Furthermore, the amino acid metabolisms in Glycine max were up regulated under PEMPs, while organic acid and sugar metabolisms were down regulated under 0.1% PLAMPs. Overall, the phytotoxicity of microplastics is closely related to their biodegradability and concentrations. Biodegradable microplastics at lower doses had the most profound effect on Glycine max. These findings are expected to provide new insights into the effects of microplastics on crop plants in the future.
2022 Vol. 42 (6): 2894-2903 [Abstract] ( 369 ) [HTML 0KB] [ PDF 1019KB] ( 1829 )
2904 Functions of H2S signal in response to SO2 stress in Arabidopsis thaliana
LI Li-hong, GUO Yu-ru, HOU Jun-xin, WU Li-hua
Sulfur dioxide (SO2) is one of the most common and harmful air pollutant. Hydrogen sulfide (H2S), as a new gasotransmitter, is involved in the regulation of plant development and stress adaptation. To reveal the role of H2S in response to SO2 stress, the relation between transcriptional response to H2S and SO2 treatments, and the production and physiological effect of H2S during SO2 fumigation will be studied in Arabidopsis plants. By using high-throughput sequencing, many genes were identified to be differentially expressed in Arabidopsis plants exposed to 30mg/m3 SO2 or treated with 0.1mmol/L H2S. Among these differentially expressed genes (DEGs), 122, 0genes were overlapped between SO2 and H2S treatments, including some genes encoding enzymes involved in sulfur and glutathione metabolism. These results suggested a interaction between H2S and SO2 in regulating sulfur metabolism pathways in plants. Moreover, two H2S-generating genes, L-cysteine desulfhydrase (LCD) and L-cysteinedesulfhydrase1 (DES1) were significantly up-regulated, and endogenous H2S content was enhanced in Arabidopsis plants under SO2 stress. Meanwhile, the activities of superoxide dismutase (SOD) and catalase (CAT), the content of glutathione (GSH) and activities of GSH-related enzymes including glutathione S-transferase (GST) and glutathione peroxidase (GPX) were significantly increased in Arabidopsis plants exposed to SO2. And that H2O2 content was markedly increased in SO2-treated Arabidopsis plants, while malondialdehyde (MDA) content showed no significant difference compared with the control group. Exogenous application of H2S further increased the level of GSH and GSH-related defense enzyme, and reduced the content of H2O2 in Arabidopsis plants under SO2 stress. When scavenged endogenous H2S by spraying hypotaurine (HT) during SO2 fumigation, the content of GSH, the activities of SOD, CAT and GST were reduced, and the content of MDA was significantly increased in Arabidopsis plants. Together, this study indicated that H2S played an important role in response to SO2 stress through improving antioxidant capacity, which would be helpful for better understanding the adaptation mechanism of plants to environmental stress.
2022 Vol. 42 (6): 2904-2910 [Abstract] ( 221 ) [HTML 0KB] [ PDF 406KB] ( 712 )
2911 Effects of short-term exposure to PM10 on fasting plasma glucose and blood lipids
HE Ying-qian, WANG Min-zhen, ZHENG Shan, ZHAO Ya-nan, ZHANG Lu-lu, LIU Jing, BAI Ya-na
This study was designed to explore the effects of short-term exposure to PM10 on fasting plasma glucose and blood lipids in population with different glucose metabolism levels based on the platform of "Jinchang Cohort". The pollutant and meteorological data in Jinchang city from 2011 to 2017 were collected. Individual exposure levels were estimated by the nearest neighbor model. Generalized estimating equations were employed to analyze relationships between PM10, blood glucose and blood lipids. The exposure-response relationship curves were drawn by generalized additive mixed model. For every IQR increase in PM10 concentration, it was found that FPG, TC, LDL-C and HDL-C increased by 0.58mg/dL (95%CI:0.35, 0.82), 0.38mg/dL (95%CI:0.25, 0.52), 0.44mg/dL (95%CI:0.31, 0.57) and 0.34mg/dL (95%CI:0.29, 0.40), respectively, TG decreased by 0.67mg/dL (95%CI:-0.86,-0.47). With the increase of PM10 concentration, FPG, TC, LDL-C and HDL-C all showed an upward trend, while TG showed a downward trend. The adverse effects of PM10 on blood glucose and lipid indicators were greater in male and elder people. Findings suggest that PM10 was associated with changed fasting plasma glucose and blood lipid levels among population with different blood glucose states. Male and elder people should pay more attention to personal safety protection.
2022 Vol. 42 (6): 2911-2920 [Abstract] ( 254 ) [HTML 0KB] [ PDF 696KB] ( 699 )
2921 Acute effects of black carbon on respiratory diseases and the modulating effect of air temperature
MA Pan, TIAN Zi-jie, ZHANG Xiao-ling, WANG Shi-gong, YIN Ling
The distributed-lag nonlinear models (DLNMs) and generalized additive models (GAMs) were adopted to reveal the adverse health effects of black carbon (BC) on respiratory emergency room (ER) visits, as well as the potential modifying effect of air temperature. Daily ER visits of respiratory diseases during 2009~2012 in Beijing, daily air pollutants (including BC, PM2.5, SO2, and NO2), and meteorological data covering that period were collected. Moreover, medical data was divided into three sub-groups, including the total respiratory diseases, upper and lower respiratory infections (URI and LRI), respectively. Firstly, we explored the (lag) associations between BC, air temperature and morbidity separately. Secondly, binary interaction models were constructed to explore the synergistic relationship between temperature and BC. Afterwards the effects of BC at varied temperature levels were quantified by hierarchical models. In addition, certain gaseous pollutant (SO2 or NO2) was also included to verify the robustness of basic models. The exposure-response relationships between air temperature and respiratory diseases exhibited an overall "V" type, the thresholds were 24℃, 26℃, and 24℃, respectively for total respiratory diseases, URI, and LRI. The cumulative effects of low temperature were stronger than that of high temperature. BC effect was immediately occurred and lagged for a short-term (within 3days). For each interquartile range (IQR) increase in BC concentration, the corresponding excess risk (ER) of total respiratory disease, URI, and LRI were 1.97%, 2.64%, and 1.34%, respectively. Children (£14years) had the highest excess risk (e.g., total respiratory system, ER=3.40%), while the results were not significant in the elderly group (³60years).Further, the coexistence of BC and SO2 may amplify BC effect on respiratory diseases, especially for URI, while the coexistence with NO2 mightincrease LRI risk. The nonparametric bivariate-response models showed that, the respiratory risk related to BC increased in a logarithmic manner, and high temperature enhanced BC effect strongly. When temperature exceeding its thresholds, an IQR increments in BC associated with5.55% and 1.27% (P>0.05) increase of URI and LRI morbidity,respectively.Whereas the ERs were both approximated 0.55% for both URI and LRI under temperatures lower than the thresholds. In a word, the acute effects of BC on respiratory disease were closely related to infection sites and air temperature levels, differentiations among agegroups were also revealed.
2022 Vol. 42 (6): 2921-2930 [Abstract] ( 208 ) [HTML 0KB] [ PDF 1171KB] ( 1561 )
Environmental Impact Assessment and Management
2931 Cost benefit analysis of implementation of Minamata Convention on Mercury in calcium carbide process polyvinyl chloride industry
CHANG Dun-hu, ZHANG Ze-yang, ZHOU Ji, MA Zhong, WANG Zu-guang
Mercury mass balance has been modelled for the calcium carbide process polyvinyl chloride (CCPVC) production with high-mercury catalyst and low-mercury catalyst respectively to identify the generation, transformation and emission of mercury. Further, cost benefit analysis has been conducted to compare the different responses of a typical enterprise to meet the requirements of the Minamata Convention on Mercury by low-mercury catalyst substitution. The case enterprise will reduce atmospheric and wastewater mercury emissions by 25% and 85.7%~98.9% respectively with the convention compliance, with the net benefits increasing by 50.7%~55.4%. The most profitable option for the case enterprise will be recycling waste catalyst inside plant and improving mercury abatement facilities, but the environmental risks from mercury-bearing solid waste are non-negligible. The reason is that the Minamata Convention on Mercury focuses on the input rather than emission of mercury in CCPVC industry. In addition, the current environmental tax rate on mercury is below the optimal level, indicating the insufficient incentives for the CCPVC enterprises to control mercury emissions. In order to improve the effectiveness of the Minamata Convention on Mercury, it is necessary to promote building mercury mass balance in China's CCPVC industry, strengthen the supervision of mercury-bearing solid waste stockpiles, raise the environmental tax rate levied on mercury emissions, and take the amount of environmental risk substances as the tax basis for solid wastes.
2022 Vol. 42 (6): 2931-2941 [Abstract] ( 242 ) [HTML 0KB] [ PDF 588KB] ( 748 )
2942 Evaluation of China's coal resource energy carbon emission efficiency in the whole life cycle
HU Yan-yong, ZHANG Rui, QIE Xiao-tong, LIU Hong
Based on the LCA, the carbon emission estimation model of coal resources in the development, conversion and utilization stages was constructed, the dynamic network SBM model was used to calculate the comprehensive energy carbon emission efficiency, period energy carbon emission efficiency and phase energy carbon emission efficiency of coal resources in China's 25provinces from 2007 to 2019. The results showed that the comprehensive energy carbon emission efficiency level of China's coal resources was distributed in a "U" shape, with the highest in the east, the second in the west, and the lowest in the middle. There was a large room for improvement in the carbon emission efficiency level of coal resources and energy, the average value of comprehensive energy carbon emission efficiency from 2007 to 2019 was only 0.4726. There were significant regional differences in energy carbon emission efficiency during the coal resource period in China, and the regions with higher efficiency levels were mainly concentrated in East China and Central South China; From the stage energy carbon emission efficiency analysis, it can be found that only the stage 1and stage 3energy carbon emission efficiency of the three provinces of Beijing, Jiangsu and Qinghai at an effective level. The remaining provinces and other stages have efficiency losses, especially stage 2efficiency losses serious. During the study period, the energy carbon emission efficiency of stage 3 showed a "peak-like" fluctuating upward trend as a whole. The comparison of the energy carbon emission efficiency measured by the DNSBM and NSBM models found that the NSBM model would underestimate the comprehensive energy carbon emission efficiency level of coal resources.
2022 Vol. 42 (6): 2942-2954 [Abstract] ( 231 ) [HTML 0KB] [ PDF 1802KB] ( 1815 )
2955 Impact of sustainable development in resource-based cities on carbon emissions:From the perspective of resource dependence
ZHENG He-yun, GE Li-ming
Based on the panel data of 285 cities from 2003 to 2018, the difference in difference models were used to investigate the impact of China's Sustainable Development Plan of National Resource-Based Cities (2013~2020) (here in after referred to as the Plan) on carbon emissions and the effect of the Plan on carbon emissions through the path of resource dependence. In addition, the heterogeneous effects of the Plan on carbon emissions through the path of resource dependence were analyzed based on the perspectives of city region and city scale. Finally, the Plan's spatial spillover effects were examined. The results suggested that the Plan significantly reduced carbon emissions of resource-based cities. The mechanism analysis indicated that the Plan can decrease carbon emissions by reducing the degree of resource dependence. Besides, industrial structure upgrade and technological progress had positive impacts on the Plan's carbon reduction effect. The heterogeneous analysis showed that the effect of the Plan decreased resource dependence to reduce carbon emissions is more obvious in eastern regions, central regions, and large cities. The Plan had a significant carbon reduction effect on local and neighboring areas. This paper had important policy implications for achieving sustainable development of resource-based cities in China under the dual carbon target.
2022 Vol. 42 (6): 2955-2964 [Abstract] ( 283 ) [HTML 0KB] [ PDF 537KB] ( 1030 )
2965 Temporal and spatial variation and prediction of regional carbon storage in Zhongyuan Urban Agglomeration
HE Xiao-hui, XU Ya-ting, FAN Xue-feng, GENG Qing-ling, TIAN Zhi-hui
In order to effectively evaluate the carbon reserve of Zhongyuan Urban Agglomeration, dynamic carbon density data was obtained by using the grey prediction model, combined with the Dyna-CLUE model and the InVEST model, which were used to dynamically evaluate the carbon reserve evolution characteristics under different scenarios of land use change, as well as the impact of urban development on carbon reserve from 2005 to 2030. The results showed that the carbon reserve of the Zhongyuan Urban Agglomeration from 2005 to 2020 were 1689.59×106t, 2035.36×106t, 2066.34×106t and 2093.05×106t, showing a continuously increasing trend; In 2030, the carbon reserve under the economic development scenario, ecological protection scenario and coordinated economic and ecological development scenario were 2162.45×106t, 2179.39×106t and 2174.28×106t, respectively. The carbon reserve was at the minimum under the economic development scenario and at the maximum under the ecological protection scenario. The change of carbon reserve was closely related to that of land use area, which is mainly manifested as follows. The decrease of the cultivated land area resulted in an increase of about 250×106t of carbon reserve, the expansion of forest land resulted in an increase of about 103.4×106t of carbon reserve, and the expansion of construction land resulted in an increase of about 87.77×106t of carbon reserve. The area of cultivated land and grassland had a weak negative correlation with the total carbon reserve, and the area of forest land, water area, construction land and unused land had a strong positive correlation with the total carbon reserve. From 2005 to 2030, the carbon reserve of the 30cities in the Zhongyuan Urban Agglomeration ranged from 11.38×106t to 214.24×106t, respectively. The changes in carbon reserve reflected that urban land carbon emissions has peaked by 2030, and the coordinated economic and ecological development scenario might be more suitable for future cities.
2022 Vol. 42 (6): 2965-2976 [Abstract] ( 395 ) [HTML 0KB] [ PDF 1416KB] ( 2088 )
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