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  Current Issue
 
2021 Vol.41 Issue.9,Published 2021-09-20
Air Pollution Control
Water Pollution Control
Solid Waste
Soil Pollution Control
Environmental Microbiology
Environmental Ecology
Environmental Impact Assessment and Management
Environmental Toxicology and Health
Biodiversity
Carbon Emission Control
Air Pollution Control
3969 Long term characteristics and potential sources of PM2.5 in Rizhao City from 2015 to 2019
WANG Zhong-jie, HUO Juan, DU Hui-yun, WANG Da-wei, LI Jie, ZHANG Chuan-bing, ZHANG Tao, WANG Wei, WANG Hai-bo, YANG Wen-yi
Based on the hourly data of PM2.5 concentrations and meteorological elements in Rizhao City during 2015 to 2019, the seasonal characteristics of PM2.5 and its relationship with wind speed and wind direction were analyzed. Also, the characteristics of sea-land in Rizhao City were summarized. Combined with HYSPLIT model and GDAS data, the 48h backward trajectories of PM2.5 concentrations at 02:00, 08:00, 14:00 and 20:00 (BTC) every day in five years were calculated. The main transport pathways and potential source contribution of PM2.5 concentrations in different seasons were discussed by cluster analysis and potential source contribution analysis. The influence of sea-land wind on pollutants in Rizhao City was also analyzed. The results showed that the seasonal characteristics of PM2.5 concentrations in Rizhao City was the highest in winter and the lowest in summer. The particles concentrations of the monitoring station is higher under the influence of northwest wind. There are differences in the main transport routes in different seasons in Rizhao:in spring, it is mainly affected by the easterly and northerly airflow; in summer, it is mainly affected by the cleaner easterly airflow from the sea under the influence of subtropical high system; in autumn, it is mainly affected by the northwest and easterly airflow; in winter, it is mainly affected by the northwest and northerly airflow. On the whole, the PM2.5 concentrations of Rizhao City is higher in different seasons affected by the westerly to southerly airflow. The sea-land wind days are more in spring and autumn,less in summer and winter. Under the influence of sea-land wind, the PM2.5 and ozone pollution in Rizhao City present different distribution characteristics, and under different PM2.5 pollution levels, the daily variation characteristics of PM2.5 concentrations are also different from those in normal days.The results show that the main potential source areas of Rizhao are Linyi City, Weifang City, Qingdao city and Lianyungang City of Jiangsu Province.
2021 Vol. 41 (9): 3969-3980 [Abstract] ( 398 ) [HTML 1KB] [ PDF 2298KB] ( 1631 )
3981 Comparative analysis of the relationship between PM2.5 and O3 in plain and mountainous cities in North China
LUO Yue-han, ZHAO Tian-liang, MENG Kai, WANG Hong, GONG Kang-jia, XIN Yu-shan, LU Shuo
By using the environmental monitoring data from 2015 to 2019, This study presented a comparative analysis of PM2.5 and O3 changes and their relationships between the plain city Baoding (BD)and the mountainous city Zhangjiakou (ZJK) in North China. In BD, PM2.5 concentrations were low in summer and high in winter, O3 was high in summer and low in winter with a diurnal single-peak in afternoon, while in ZJK, the low PM2.5 concentrations oscillated diurnally with a weaker amplitude. And the wintertime O3 presented the bimodal peak in the afternoon and around 5:00 in the morning. The O3 concentrations in ZJK in winter and during nighttime in spring, summer and autumn were significantly higher than those in BD. Even in summer, nighttime O3 exceeded the air pollution standard, with the highest concentration reaching up to 202μg/m3, reflecting the distinct influence of changes in atmospheric physical and chemical processes in plain cities and clean mountains. PM2.5 and O3 were positively and negatively correlated respectively from April to September and from November to following March; the daily change of the correlation coefficient of PM2.5-O3 in BD is unimodal, and bimodal, each in the early morning and afternoon in ZJK The obvious differences were found in the diurnal and seasonal variations of the relationship between atmospheric compound pollutants PM2.5 and O3 in the plain polluted area and the relative clean mountainous area in North China.
2021 Vol. 41 (9): 3981-3989 [Abstract] ( 363 ) [HTML 1KB] [ PDF 1834KB] ( 1899 )
3990 Spatial and temporal distribution characteristics and transport path analysis of regional particulate matter over Gansu Province
GUO Chun-ye, WANG Ying, LIU Hao, LIU Yang, WANG Si-tong, LI Bo
Based on the monitoring data of particulate matter mass concentration, the spatial-temporal variation and emission characteristics of atmospheric particulate matter concentration were analyzed across the Gansu Province for the time period of 2018~2019, with a focus of the transport path of particulate matter using the HYSPLIT backward trajectory model. The results suggested that:Different spatial distribution of PM10 and PM2.5 were shown across the Gansu Province with a significant regional dependency. The peak value of PM10 concentration was located at the Hexi Corridor area, with a strong step-decreasing from north to south. While, the high value center of PM2.5 concentration was observed over Longzhong region, which experienced a extending decreasing to the north and south. Furthermore, Longnan region was identified as the noticeable clean area of particulate matter across the Gansu Province. Significant discrepancies were found in the seasonal variation of PM10/PM2.5 concentrations among different regions. The similar seasonal patterns of PM10/PM2.5 concentration were found over central Gansu, eastern Gansu and southern Gansu, with the concentration of PM10 and PM2.5 both peaking in winter (winter) but plunging in summer (autumn) at Longzhong and Longdong (Longnan). However, different seasonal variations of PM10 and PM2.5 concentrations were found over Hexi Corridor, where PM2.5 was found to be experiencing high concentration in winter and low in summer, but high concentration of PM10 was shown in spring and low in summer. The backward trajectory clustering results showed that the Gansu province was strongly governed by the west air current which come from central Asia and Xinjiang, especially in spring and winter time. This path is considered to be a typical dust transport pathway across the Gansu Province when considering the higher concentration of PM10 than others, with which affecting. the four regions in the order of Hexi > Longzhong > Longdong > Longnan. The eastern path from Shanxi, Sichuan & Chongqing with PM2.5/PM10 ratio over 0.5which is significantly higher than the western one was deemed to be the dominant transmission path in Longnan area, which indicated that the contribution of man-made source pollution along the eastern path is significant. The results of this study can serve as a scientific reference for comprehensively understanding the characteristics of particulate pollution in the Gansu Province, formulating regional particulate pollution prevention and regional cooperative governance policies.
2021 Vol. 41 (9): 3990-4000 [Abstract] ( 333 ) [HTML 1KB] [ PDF 3449KB] ( 1045 )
4001 Source analysis of PM2.5 in the typical mixed functional zone of Shenzhen
LAN Zi-juan, JIANG Jia-hao, LIN Li-liang, HUANG Xiao-feng, HE Ling-yan
In order to accurately identify the source of PM2.5 pollution in the typical commercial, residential and industrial mixed functional areas of the Shenzhen, this study selected five points in the northern part of Shenzhen to be located in the northern part of Shenzhen from September 2017 to August 2018. The sample collection and composition analysis of particles with a dynamic diameter of less than 2.5μm, using the optimized multivariate linear engine model (ME-2) to explore its main sources and their temporal and spatial characteristics. The results show that the study period of the study area The annual average concentration of PM2.5 in the atmosphere is 29.0μg/m3, and 10 sources of SO2 secondary conversion(19.9%), motor vehicles(15.1%), biomass combustion(11.2%), etc. are analyzed, of which SO2 secondary conversion, biomass combustion, NOx secondary conversion, VOCs secondary conversion, industrial emissions, aged sea salt and ocean-going ship sources have significant regional transmission characteristics, while motor vehicle sources, coal burning and dust have local source characteristics and are subject to local emissions. The impact is greater. Motor vehicle sources, NOx secondary conversion sources, industrial emissions and biomass combustion sources have increased most significantly under heavy pollution weather. Strengthening the control of these sources is the key to the refined prevention and control of PM2.5 pollution in such mixed functional areas.
2021 Vol. 41 (9): 4001-4008 [Abstract] ( 335 ) [HTML 1KB] [ PDF 815KB] ( 1446 )
4009 Source identification and volatility characteristics of ambient organic aerosols in Shenzhen in autumn
LI Meng-lin, ZHU Qiao, CAO Li-ming, WEI Jing, HUANG Xiao-feng
Using a thermodenuder coupled with a long-time-of-flight aerosol mass spectrometry system, we conducted online measurements of submicron aerosols in Shenzhen in the fall of 2020. In addition to obtaining chemical compositions of PM1 and analyzing their volatility characteristics, we used positive matrix factorization (PMF) method to apportion sources for organic aerosols (OA). The results showed that during the sampling period, the average mass concentration of aerosol was (28.3±11.11)μg/m3 (9.5~76.8μg/m3). Among the chemical compositions, organics contributed most to PM1 (57.9%), sulfate was the secondary dominant composition, which accounted for 24.7% in total PM1. PMF analysis for OA resolved four OA factors:hydrocarbon-like OA (HOA), cooking-related OA(COA), less-oxidized oxygenated OA(LO-OOA), and more-oxidized oxygenated OA(MO-OOA). The mass fractions of HOA, COA, LO-OOA and MO-OOA were 9.1%, 27.2%, 31.8% and 31.9%, respectively. Furthermore, we used two methods including NO+/NO2+ ratio and PMF methods to estimate organonitrates (ON). The average concentration of ON was 0.17~0.25μgm-3, accounting for 1.5%~9.7% of OA, indicating ON made a substantial contribution to aerosols in Shenzhen. Correlation analysis shows that ON were correlated bestwith LO-OOA(R=0.80), suggesting ON maybe formed via localsecondary formation. The volatility analysis revealed that the volatility sequence of the main chemical components was chloride≈inorganic nitrate>ammonium>organic matte>ON>sulfate, and the volatility sequence of the OA factors was LO-OOA> HOA> COA> MO-OOA. Except LO-OOA, the volatility sequence of other OA factors was consistent with their oxidation states. LO-OOA evaporated most from 50℃to 70℃, suggesting the significant difference of volatility existed among its compositions.
2021 Vol. 41 (9): 4009-4015 [Abstract] ( 284 ) [HTML 1KB] [ PDF 1083KB] ( 1730 )
4016 Short-term PM2.5 concentration prediction based on XGBoost and LSTM variable weight combination model: a case study of Shanghai
KANG Jun-feng, TAN Jian-lin, FANG Lei, XIAO Ya-lai
In order to further improve the accuracy of PM2.5 concentration prediction, a variable weight combination short-term 1-hour PM2.5 concentration prediction model based on LSTM network and XGBoost model was proposed. First, analyze the predictive factors, explore the influence of air pollutant factors and meteorological factors on the PM2.5 concentration, to determine the best PM2.5 concentration predictive factors and analysis the variable importance. Then, after data pretreatment the LSTM prediction model and the XGBoost prediction model was built respectively, and adopt the adaptive variable weight combination method based on residual improvement to obtain the final prediction result. The results show that:The relative importance of pollutant variables is higher than the importance of meteorological factors, among which the relative importance of current PM2.5 concentration and CO concentration is higher, while the importance of average wind speed and relative humidity is lower. The values of RMSE, MAE and MAPE of the variable weight combined XGBoost-LSTM (Variable) model proposed in this study are 1.75, 1.12 and 6.06, which are better than LSTM, XGBoost, SVR, XGBoost-LSTM (Equal) and XGBoost-LSTM (Residual) model. The combined model predicts performance best in spring but the forecast accuracy is poor in summer. The variable weight method combination model proposed in this study effectively combines the advantages of the two models, not only considers the time series information of the data but also takes into account the nonlinear relationship between the features, and has higher prediction accuracy compared with other models.
2021 Vol. 41 (9): 4016-4025 [Abstract] ( 508 ) [HTML 1KB] [ PDF 1868KB] ( 1634 )
4026 Research progress of correction algorithm and influence factors for aerosol absorption coefficient from aethalometer measurement
CAI Yuan-qing, XU Xue-zhe, ZHOU Jia-cheng, LIU Qian-qian, ZHAO Wei-xiong, FANG Bo, WANG Shuo, ZHANG Wei-jun
As one of the commonly used techniques for aerosol absorption coefficient measurement, Aethalometer is widely used to investigate aerosol light absorption properties in laboratory and field experiments. However, owing to the constraint of filter-based method, the accuracy of the absorption coefficient measurement is affected by the filter-loading effect, and by the multiple-scattering effects caused by the filter fibers and aerosol particles. The instrument methodology and the developed correction algorithms of Aethalometer were reviewed. The influence factors for absorption coefficient measurement were explored. The influence of mixing state of black carbon (BC) on Aethalometer measurement deviation (Cref') of absorption coefficient were analyzed. The relationship between Cref' and aerosol single scattering albedo (SSA), and the wavelength-dependent relationship of Cref' were discussed. Furthermore, some suggestions for the future research were proposed.
2021 Vol. 41 (9): 4026-4035 [Abstract] ( 314 ) [HTML 1KB] [ PDF 751KB] ( 1642 )
4036 Characteristics of gas-particle partitioning of gaseous nitric acid and particle nitrate in Shenzhen in winter
CHEN Yao, YUN Long, LUO Yao, NIU Ying-bo, PENG Xing, HE Ling-yan, HUANG Xiao-feng
In this study, the dual-channel online gas and aerosol analyzer (MARGA) was used to simultaneously observe water-soluble inorganic ions and their gaseous precursors in PM2.5 and PM10 in Shenzhen in winter, in order to explore the gas-particle partitioning characteristic of gaseous nitric acid (HNO3) and particle nitrate (pNO3-). It was shown that gaseous nitric acid, fine-particle nitrate and coarse-particle nitrate accounted for 9.6%, 56.8% and 33.6% of total nitrate (TNO3,=HNO3+ pNO3-), respectively. The diurnal variation of TNO3 concentration presented a curve of two peaks. The peak in the morning was related to the increase of fine NO3- caused by NOx from vehicles in the morning rush hour. The photochemical reaction in the daytime increased the concentration of three components of TNO3, so the TNO3 concentration reached the highest level of the day at 17:00. The analysis suggested that low temperature was beneficial for NO3- to exist in fine particles as NH4NO3. When the concentration of TNO3 was high, the proportion of NO3- in fine particles also increased.
2021 Vol. 41 (9): 4036-4042 [Abstract] ( 355 ) [HTML 1KB] [ PDF 839KB] ( 2100 )
4043 Tracking the source and contribution of NO3- in precipitation in Nanchang in autumn and winter by dual isotope
AI Wen-qiang, XIAO Hong-wei, SUN Qi-bin, ZHANG Yong-yun, ZHANG Zei-yu, LI Jing-wen
Rainwater was collected from September 1, 2016 to February 28, 2017 in Nanchang, as well as stable isotope of nitrate (δ15N) and chemical compositions of rainwater were analyzed. The results showed that the concentration of NO3- ranged from 7.3 to 99.5μmol/L, and the mean is 36.1μmol/L; the δ15N of NO3- ranged from -6.0‰ to +8.3‰, and the mean is -0.8‰. Combined with chemical composition and isotope analysis, it is shown that NO3- was mainly affected by the region and mainly comes from biomass burning, traffic, coal combustion while biological soil is the secondary source in the sampling period. Bayesian mixing model (MixSIA) which took account of the isotope fractionation wes used to make precise estimations of the contribution of different sources. The results showed that the contribution of biomass burning emissions, traffic and coal combustion was more than 86%. However, in this case, the contribution of biomass burning emissions and traffic was more than 63%, and the coal combustion was only 23.1%, which indicated that a necessity to control NOx from traffic and biomass burning strictly to reduce air pollution.
2021 Vol. 41 (9): 4043-4050 [Abstract] ( 254 ) [HTML 1KB] [ PDF 956KB] ( 1184 )
4051 Identification of ozone pollution control zones and types in China
ZHANG Hong-yu, WANG Yuan, LU Ya-ling, WANG Yan-wei, YU Chao, WANG Jun-xia, CAO Dong, JIANG Hong-qiang
This study is based on the satellite remote sensing indicator method, using 2017~2019 as the base years, by comparing ozone on-site monitoring data, VOCs and nitrogen oxide emission intensity data, and satellite remote sensing data, on the basis of PM2.5 key regulatory areas, reclassifying ozone control areas, which means classifying areas where the annual average concentration of ozone exceeds the standard (above 160μg/m3) into different key zones. Identify the sensitive types of ozone precursors in each key zone, namely VOCs control zone, NOx control zone, and VOCs and NOx coordinated control zone; For each type it is further confirmed into local pollution control zones and joint prevention and control zones. This type of ozone classification method that combines ground monitoring data, statistical data and remote sensing observation data can provide a new idea for the macro-zone classification control of air pollution and also provide decision-making reference for the national level of ozone pollution prevention and control, and PM2.5 & O3 coordinated control related policies.
2021 Vol. 41 (9): 4051-4059 [Abstract] ( 318 ) [HTML 1KB] [ PDF 5193KB] ( 2437 )
4060 Analysis of the ozone sensitivity and source appointment in Xianning, Hubei Province
REN Jun-yu, ZHU Kuan-guang, XIE Min, LIU Wei, GAO Da, CHEN Jia-sheng, JIN Yu-ning, ZHAO Run-qi, ZHANG Lin-tao
This research introduced statistical analysis methods and surface ozone data in 2018 to gain the knowledge about the ozone pollution characteristics in Xianning, Hubei Province. The ozone concentrations exceeded the national standards at days from March to October, especially in June, August, September and October when persistent heavy ozone pollution occurred. From April to July, the daily ozone high concentrations occurred between 12:00 and 20:00, and usually achieved the daily peak around 16:00. The Observation-Based Model (OBM) is designed and tools such as Empirical Kinetic Modeling Approach (EKMA) and Relative Incremental Reactivity (RIR) were included to calculate the ozone chemical sensitivity. It was found that the ozone formation in Xianning was VOCs-limited and seemed to be more sensible to two important anthropogenic VOCs species-xylene (XYL) and alkene (OLEP). After 10% cut of the emissions of xylene and alkene VOC species, the RIR values produced 0.271 and 0.238, respectively. Offline VOCs monitoring data was used in the PMF method and 5types of sources are appointed. It is found that industrial emissions contributed most to ozone pollution. xylene and alkene mainly came from solvent usage and combustion sources, respectively, which were the main VOC pollutants that should be controlled. During the ozone exceeding days, there were 9.8%, 1.8% and 1.9% more contributions from vegetation, solvent and biomass burning, while 2.4% and 10.9% less contributions from vehicles and industrial sections.
2021 Vol. 41 (9): 4060-4068 [Abstract] ( 340 ) [HTML 1KB] [ PDF 2270KB] ( 1398 )
4069 Spatial distribution characteristics of VOCs and key emission reduction species in autumn Shenzhen
CHEN Xue, HUANG Xiao-feng, ZHU Bo, HUANG Pei-rong, CUI Zhuo-yan, HE Ling-yan
Off-line measurements were conducted to obtain 105 VOCs at 11 sites across Shenzhen during November 6~9 in 2019. The spatial distribution characteristics of ozone generation potential (OFP) and secondary organic aerosol generation potential (SOAFP) were further analyzed. The results showed that total VOCs (TVOCs), total OFPs and total SOAFPs were 44.3×10-9, 272.6 and 1.1μg/m3, respectively. The spatial distributions of TVOCs, OFP and SOAFP had a similar trend with a higher level in the west and north region and a lower level in the east and south region, which indicated that mitigating industrial emissions in the northwestern industrial area is essential for VOCs reduction. Among the different VOC species, acetone, dichloromethane and ethane had higher volume concentrations; 1,3-butadiene, toluene, acetaldehyde had higher OFPs; and toluene and xylene had higher SOAFPs. The ratio of toluene to benzene suggested that industrial sources such as solvent emission made a significant effect on VOCs. Additionally, n-butane, toluene and 2, 3-dimethylbutane had larger regional differences. In conclusion, n-butane, isobutane, toluene, xylenes and 1,3-butadiene, as the most active and local emitting species, were the key VOCs for the coordinated control of O3 and PM2.5 in Shenzhen.
2021 Vol. 41 (9): 4069-4076 [Abstract] ( 291 ) [HTML 1KB] [ PDF 1706KB] ( 1218 )
4077 Influence of coking coal ratio on emission characteristics of volatile organic compounds in sintering flue gas
LUO Yun-fei, WANG Yi-fan, LI Jun-jie, YU Zheng-wei, WEI Jin-chao, LONG Hong-ming
The PF-300 portable methane, total hydrocarbon, and non-methane total hydrocarbon tester was used to analyze the volatile organic compound content of the flue gas generated in the sintering cup experiment, and the effect of the sintering fuel coke-to-coal ratio on the emission characteristics of flue gas volatile organic compounds was studied.:Volatile organic compounds are continuously released during the sintering process, and their emission trends are consistent with NOx; the generation of TVOCs and MHC is significantly related to the volatile content of pulverized coal and coke powder. When pulverized coal is used as the main fuel, appropriate mixing Coke powder not only has a physical emission reduction effect on TVOCs and MHC, but also has the effect of coal coke mixing and synergistic emission reduction. At the same time, a domestic steel sintering machine was tested for TVOCs emission concentration and sub-sample composition, which showed that the volatile organic compound emission concentration in the flue gas of the steel sintering machine was higher, and the result was consistent with the curve obtained from the sintering cup experiment; the sintering process VOCs was tested separately. The main compounds are ethyl lactate, acetone, benzene, toluene, n-hexane and so on.
2021 Vol. 41 (9): 4077-4084 [Abstract] ( 313 ) [HTML 1KB] [ PDF 561KB] ( 1271 )
4085 Variation and global pattern of major meteorological elements during 1948~2016
NING Zhong-rui, ZHANG Jian-yun, WANG Guo-qing
The variation and global distribution of precipitation, temperature and evaporation over 70years were investigated by using Mann Kendall test and R/S analysis. The results showed that:(1) During 1948~2016, the precipitation in 72.7% regions showed an insignificant increasing or decreasing trend, and the global precipitation presented an increasing trend with a rate of 1.9mm/10a. Global temperature showed a significant and persistent upward trend with a rate of 0.23℃/10a, and the increasing speed of the trend was found after 1980. During 1980~2016, the evaporation in most regions displayed an insignificant increasing trend and the rate of trend is 8.2mm/10a. The Hurst Index showed the persistent behavior of temperature and evaporation was significantly greater than that of precipitation; (2) Precipitation showed a significant upward trend in many high latitude areas in the northern hemisphere, while in low latitude area presented a fluctuation or downward trend. The significance level for increasing rate for precipitation in DJF and MAM was higher than that of in other seasons while the level for temperature was weaker. Evaporation displays an upward trend in many coastal regions, and in northern America showed a downward trend in DJF, in Greenland and Nile river basin there were decreasing trend in all year round. (3) Temperature in all continents showed a significant increasing trend during 1948 to 2016, and North America had the highest increasing rate among them. Precipitation presented an increasing trend with exception of Africa, while in Africa there was a decreasing trend and in South America there was a downward trend with three stages. Evaporation in all continents showed a significant increasing trend and Europe has the highest increasing rate among them. Comparing with the rate of precipitation, increasing rate for evaporation in all continents were higher except Oceania.
2021 Vol. 41 (9): 4085-4095 [Abstract] ( 314 ) [HTML 1KB] [ PDF 4459KB] ( 772 )
4096 Investigation of cloud condensation nuclei activity under different pollution conditions in spring of Nanjing
LU Wen-tao, MA Yan, ZHENG Jun, JIANG You-ling
Filed observation of cloud condensation nuclei (CCN) activation properties of aerosols were carried out from March 2018 to April 2018 in the northern suburbs of Nanjing. Meteorological data, PM2.5 number concentration, chemical composition and optical properties of particles are also collected for analysis. The CCN activities of aerosols in polluted days and clean days during the observation period were compared, and the characteristics of typical pollution processes and new particle formation days were analyzed. Results showed that the CCN activity of aerosols are generally high during this observation, with an average hygroscopicity parameter (κ) of 0.30under each supersaturation(SS) condition. The lowest κ was observed under the lowest supersaturation (SS=0.17%), and the maximum activation ratio (B) was 0.72, indicating that aerosols contains many substances that are difficult for activation. κ was seen higher in polluted days than in clean days. When compared to that in clean days, the activation ratio in polluted days was relatively lower and the level of external mixing was higher, which was mainly due to the large amount of less hygroscopic particles emitted by traffic and industry. Aging process of particulate matters are observed fast at night, making particles more hygroscopic and leading to higher CCN number concentration. In new particle formation days, κ showed diurnal variation due to particle nucleation, and new particle formation process also made significant contribution to total aerosol number concentration(NCN) and CCN number concentration(NCCN).
2021 Vol. 41 (9): 4096-4106 [Abstract] ( 269 ) [HTML 1KB] [ PDF 1848KB] ( 1370 )
4107 Simulated effect of urbanization on urban thermal environment in Hangzhou
ZHANG Han, ZHANG Xiao-wei, FAN Gao-feng
We conducted high-resolution model simulations in urban areas, to investigate the important effects of urbanization on urban thermal environment. The WRF/UCM model was used to quantify the effect of past urbanization on urban thermal environment at monthly timescale for Hangzhou city, Zhejiang province, China. We also conducted sensitivity simulations to investigate the potential effects of urbanization on urban thermal environment under an idealized scenario in which urban area is tripled. In these simulations, different land use/land cover classification data were used. Simulation results show that urbanization during 2010~2017 doubles urban area at Hangzhou, leading to a 91% increase in the area with urban heat island (UHI) intensity levels stronger than "none" (Ht>0.5℃), and a rise of 0.4℃ in 2-m air temperature in the main urban area in August. If urban area is tripled from year 2017 level, the area that UHI intensity levels stronger than "none" would increase by 157%, and for 1846.4km2 of the central urban area, UHI intensity levels could be elevated from "weak" or "none" (Ht≤1.5℃) to "medium" (1.5
2021 Vol. 41 (9): 4107-4119 [Abstract] ( 276 ) [HTML 1KB] [ PDF 1977KB] ( 1236 )
Water Pollution Control
4120 Room-temperature precipitation synthesis and photocatalysis of Bi5O7I/g-C3N4 Z-scheme heterojunction
LI Dong-mei, LU Wen-cong, LIANG Yi-cong, WANG Yi-zhi, CHEN Hai-qiang, LI Jun-tian, XIE Zhen-yu
In this work, by using Bi5O7 I、KI and g-C3N4 as precursors, a novel Bi5O7 I/g-C3N4 Z-scheme heterojunction has been synthesized successfully by precipitation method at room temperature, its property of light absorption、morphologic structure、efficiency of photogenerated electron-hole were characterized. The visible-light degradation performance on Rhodamine B(RhB)by new type composite photocatalyst、the kinds of radicals and the mechanism in photocatalytic reaction system were studied. The results revealed that:The synthesis conditions of Bi5O7 I/g-C3N4 by precipitation were shown as follow:4.85g Bi(NO3)3·5H2O, 1.66g KI, 1.61g g-C3N4, 50mL glycol, 12 of reaction pH, 200r/min of reaction stirring rate and ambient reaction temperature(25℃).There's no impurity and influence on chemical structure of g-C3N4 and Bi5O7 I during the synthesis process, the recombination of Bi5O7I/g-C3N4 crystallographic plane occured on the {002} crystal plane of g-C3N4 and the {312} crystal plane of Bi5O7 I.The morphologic structure of Bi5O7 I/g-C3N4 was 3D nano petal-like, which furnished a large number of contacting site for the transfer of photogenerated electron-hole. The doping of g-C3N4 on Bi5O7 I can significantly enhance photocatalytic activity, its wavelength edge of light absorption shifted to 462nm from 425nm.The band arrangement structure of Bi5O7 I/g-C3N4 was matched with the Z-scheme heterojunction, which promoted the separation of photogenerated electron-hole, its photocurrent density (11.5mA/cm) is 2.66 and 1.47times than that of g-C3N4 (4.32mA/cm) and Bi5O7 I(7.8mA/cm) respectively. The photocatalytic degradation rate for RhB by Bi5O7I/g-C3N4 under visble light irradiation is 93.9%, which is 1.89 and 1.62times than that of Bi5O7 I and g-C3N4 respectively, the activity of photocatalytic oxidation was attributed to the intermediate radicals including ·OH、·O2- and h+.
2021 Vol. 41 (9): 4120-4126 [Abstract] ( 412 ) [HTML 1KB] [ PDF 595KB] ( 2168 )
4127 Magnetic N-doped graphene with multiple catalytic sites for efficient activiation of peroxymonosulfate
YANG liu, LIU Dan, LIU Shi-ang, WU Xi-lin, CHEN Jian-rong
The Fe2O3, Fe3N, single-atom Fe (SA-Fe) and N-doped magnetic graphene (Fe-MNG) were prepared by a facile one-pot method and applied for the activation of perpxymonosulfate (PMS). The results show that Fe-MNG/PMS system was efficient for the oxidative degradation of sulfisoxazole (SIZ) over a wide pH range (3~10) with the removal percentages over 99%. After five cycles, degradation percentages of SIZ maintain over 95% by using the recycled Fe-MNG catalyst. The multiple catalytic sites such as SA-Fe and N of Fe-MNG can effectively activate PMS for the generation of various reactive oxygen species (ROS). Quenching experiment and electron paramagnetic resonance spectroscopy showed that SO4·-, HO· and 1O2 were produced in the Fe-MNG/PMS system, demonstrating the co-existence of free radicals and non-radicals processes. In addition, the Fe-MNG possesses large surface area (446.18m2/g), which can pre-concentrate organic micropollutants onto its surface by adsorption, simultaneously producing a large amount of ROS via PMS activation, leading to the in-situ and high-efficiency oxidation and removal of organic micropollutants. The Fe-MNG also possesses magnetic properties which can be easily recycled, indicating its great application potential.
2021 Vol. 41 (9): 4127-4134 [Abstract] ( 195 ) [HTML 1KB] [ PDF 1335KB] ( 1124 )
4135 Study on the distribution and removal effect of resistance genes in integrated system of A2/O-MBR
LI Zhong-hong, DU Cai-li, CHEN Su-hua, ZHANG Lie-yu, LI Xiao-guang, LI Jia-xi, TIAN Zhen-jun
The increase of antibiotic resistance genes among microorganisms has become the main transmission source for sewage treatment plants. The purpose of this study was to explore the removal effect of Antibiotic Resistance Genes (ARGs) and pathogenic bacteria in rural domestic sewage treatment process and evaluate the water quality safety. This study selected a integration A2/O-MBR wastewater treatment system in the village of Beijing, systematic study was implemented in integrated system of A2/O-MBR wastewater treatment system to get the distribution law of ARGs and pathogenic bacteria in the each processing unit. Based on macro genomics, the high-throughput sequencing technology was used to analysis the the ability of removing ARGs and pathogenic bacteria in genus through integrated system of A2/O-MBR. Results showed that the ARGs widely existed in sewage treatment system, 19kinds of ARGs including tetracycline class, aminoglycoside class and sulfonamide class were detected, the relative abundance of the ARGs in influent was much higher than its concentration in the effluent, relative abundance of the ARGs fell by 72.25%, but most of the ARGs in sewage treatment system was not fully removed. The changes of microbial community structure showed that the relative abundance of 32potential pathogens decreased significantly, and most pathogenic bacteria could not be completely removed. The residual ARGs and pathogenic bacteria in the water will lead to the potential pollution risk of receiving water body.
2021 Vol. 41 (9): 4135-4141 [Abstract] ( 242 ) [HTML 1KB] [ PDF 861KB] ( 1251 )
4142 Effect of dissolved organic matter in runoff on the removal of Cu2+ and Pb2+ by bioretention medium
DU Xiao-li, YIN Zi-jie, CHEN Meng-yao, YU Zhen-ya
The effect of dissolved organic matter (DOM) in the road runoff on the removal of Cu2+ and Pb2+ by inert medium (soil and sand) and enhanced medium (sludge from drink water purification plant, iron-manganese binary oxides) were investigated respectively, and the major response DOM fractions and mechanisms were also detected. The results showed that runoff DOM, different DOM molecular weight fractions and chemical fractions could inhibit the removal of Cu2+ and Pb2+ by inert medium and promote the adsorption of them by enhanced medium. The DOM fractions with <1kDa molecular weight and hydrophilic fractions had the most obvious inhibitory effect or promotion effect on the adsorption of Cu2+ and Pb2+ by inert medium or enhanced medium, respectively, indicating these two DOM fractions were the key componentsaffecting the adsorption of Cu2+ and Pb2+ by bioretention medium. The existence of DOM fractions with <1kDa molecular weight reduced the adsorption capacity of Cu2+ and Pb2+ by sand medium by 62.96% and 83.70%, and increased the adsorption capacity of Cu2+ and Pb2+by iron-manganese binary oxides medium by maximum 81.16% and 4.67%, respectively. The existence of hydrophilic fractions reduced the adsorption capacity of Cu2+ and Pb2+by soil medium by 41.43% and 69.12%, and increased the adsorption capacity of Cu2+ and Pb2+by sludge from drink water purification plant by maximum 32.35% and 39.06%, respectively.
2021 Vol. 41 (9): 4142-4148 [Abstract] ( 217 ) [HTML 1KB] [ PDF 589KB] ( 951 )
4149 Stable operation of aerobic granular sludge continuous flow system——by controlling reflux ratio and organic load
LI Dong, YANG Jing-wei, LI Yue, ZHANG Jie
Inoculate mature aerobic granular sludge at room temperature in an anaerobic/aerobic alternate continuous flow system composed of independent anaerobic tanks and aerobic tanks, control the effect of mixed liquid reflux ratio and organic load on the removal of COD, TN and TP by anaerobic and aerobic alternating continuous flow process. The results showed that the two-stage continuous flow process can achieve better nitrogen and phosphorus removal performance by adjusting a lower reflux ratio when the influent organic load was low. The average concentration of COD, TN and TP in the effluent was 18.78, 5.79 and 0.49mg/L. The average removal rate was 93.76%, 84.3% and 83.12% respectively; when the organic load was higher, the long-term two-stage continuous flow system lacked the environmental stress of feast and famine, resulting in filamentous bacteria growth, deterioration of system performance. The model was used to characterize the granular sludge and system effluent at different stages. The results showed that the organic load has a greater impact on the production of intermediate products related to the utilization of foreign substrates. The influent with lower organic load could effectively reduce the generation of intermediate products in the effluent. In summary, in the actual secondary urban sewage treatment plant, the anaerobic/aerobic alternating continuous flow process was not suitable for long-term operation under the organic concentration (500mg/L) of the emission limit.
2021 Vol. 41 (9): 4149-4156 [Abstract] ( 255 ) [HTML 1KB] [ PDF 1185KB] ( 983 )
4157 Study on rapid detection of beam deflection method for detecting metabolic status of activated sludge from printing and dyeing wastewater
ZHANG Luo-hong, LI Rui-ying, CAO Min, CHENG Jing-jing, WANG Xun-tao, ZHAI Ying-bo, XIONG Xin
Considering that limitation that cumbersome process, time-consuming and lagging detection of current activated sludge testing process, a rapid detection of beam deflection method were provided in this study. The polyvinyl alcohol gel beads with a particle size of 4mm and microporous structure of 20μm were put in the printing and dyeing wastewater complete mixed activated sludge treatment system with a sludge load of 0.33KgCOD/(kg MLSS·d) and a hydraulic retention time of 15h. The light spot analyzer was used to detecte light deflection which reflect the surface concentration gradient changes due to the exchange of external solutions and microbial metabolites after the beads reached a stable state. The corresponding COD of effluent after 15h were also measured, meanwhile the COD removal rate were calculated. After ten consecutive months of testing, it was found that the predominant microorganism is bacteria in the PVA-gel beads. The light deflection value of the beads increased from 229.51μm to 299.97μm when the influent COD increased from 91.95mg/L to 519.4mg/L, and The COD removal rate also increased from 16.03% to 66.99%. The light deflection of the beads increased with dissolved oxygen concentration and reached to the higest value 309.3μm at DO=4mg/L, meanwhile, the corresponding COD removal rate reached to the maximum which is 61.18%, when the dissolved oxygen concentration range from 1.5mg/L to 5mg/L. The light deflection of the beads increased with dissolved oxygen concentration and reached to the higest value 293.96μm at pH=7, meanwhile, the corresponding COD removal rate reached to the maximum which is 64.83%, when the pH range from 6to 9. The light deflection value of the beads decreased with the concentration of Cr3+ and reached to 269.7μm when the Cr3+ concentration at 20mg/L. The light deflection value increased with Cr3+ concentration continiued increased to 50mg/L, but the corresponding COD removal rate decreased form 52.5% to 25.73%, for the reason that the microbial cells are damaged and the intracellular substances are dissolved. The results show that the changes information of metabolic state in activated sludge can be quickly obtained by this method. And the changes of light deflection value of beads can be used to predict the subsequent COD concentration removal effect of printing and dyeing wastewater under specific conditions. Three-dimensional fluorescence spectroscopy were also used to explore the mechanism of microbial metabolism triggering light deflection. And the results showed that the main organic substances involved in microbial metabolism are tyrosine, aromatic proteins and tryptophan.
2021 Vol. 41 (9): 4157-4166 [Abstract] ( 230 ) [HTML 1KB] [ PDF 1229KB] ( 821 )
Solid Waste
4167 Biochemical degradation index test and liquid-gas production evaluation of waste landfill
KE Han, XU Xing, HU Jie, ZHANG Mei-Lan, LAN Sheng-Ze, XU Hui, ZHANG Chen-Sheng, XIAO Dian-Kun
Taking a comprehensive waste landfill in Shanghai as the research object, the municipal solid waste samples were drilled for testing of biochemical degradation index. The results showed that the waste in the testing area has begun to produce methane stably, and it entered the slow degradation stage. Among them, the C/L(the ratio of cellulose and lignin) values of solid waste samples range from 0.72 and 1.53; pH values of leachate were between 7.91 to 8.92; BOD values were between 1050 and 5780mg/L, COD values were between 2640 and 15200mg/L, NH3-N values were between 2110~4360 mg/L. The normalized indexes β1, β2, and β3 for solid, liquid and gas phases were introduced to evaluate the degradation stage of the landfill. Among them, β1 values were between 0.56 and 0.83; β2 values were between 0.65 and 0.76; β3 values were between 0.97 and 1.02. β1 and β2 could be used as the indicators determining the degradation stage of landfill, but β3 could only be used to determine whether it is in the stable methane production stage. In addition, the calculation method of leachate production considering the coupling effect of compression and seepage was established. The leachate production rate from waste was around 70%~80%. The landfill gas production was calculated using the two-stage degradation model. As the waste stops landfilling, the landfill gas production rapidly decreased, and it would drop to 3.88% of the peak value by 2025 and would reduce to 0.08% of the peak value by 2040.
2021 Vol. 41 (9): 4167-4175 [Abstract] ( 265 ) [HTML 1KB] [ PDF 746KB] ( 1029 )
4176 Application of modified metal salt hydrates containing SO42-/Cl- in the production of biodiesel from sewage sludge
ZHU Fen-fen, HU Bo, HAN Mei-ling, ZHANG Rong-yan
The catalytic performance of two kinds metal salt solid acid catalysts (NaHSO4·H2O that mainly were Bronsted acid sites and AlCl3·6H2O that mainly were Lewis acid sites) for biodiesel production from sludge was compared. The results showed that NaHSO4·H2O dehydrated at 130℃ had better performance than AlCl3·6H2O. The optimal catalytic conditions of the two catalysts were as follows:catalyst dosage of 1.2g/10g freeze-drying sludge, reaction temperature of 130℃, reaction time of 4h. The esterification rate of crude fat catalysed by NaHSO4·H2O (63.4±2.6)% was lower than that of AlCl3·6H2O (68.9±1.4)%, the corresponding biodiesel yields were 9.73%~10.69% and 10.80%~11.39% (sludge dry base). However, the GC-MS analysis showed that the biodiesel catalysed by NaHSO4·H2O had higher purity and better quality. The reusability of the two catalysts was <3~5times. Therefore, both of the two catalysts were excellent in biodiesel production from sludge with low cost, high performance and environmental friendliness.
2021 Vol. 41 (9): 4176-4183 [Abstract] ( 193 ) [HTML 1KB] [ PDF 1623KB] ( 928 )
4184 Removal of chloride from MSWI fly ash: a comparison of accelerated carbonation and water flushing
WEI Yun-mei, YAO Rui-xuan, CHEN Shuang, ZHOU Hong-li, LIU Si-jie
MSWI fly ash samples from two incineration plants in China were sampled and used (TX fly ash and JX fly ash). The physical and chemical properties of the ash samples were analyzed, and three Cl removal methods (water flushing, water flushing with CO2-ventilation, and water flushing with CO2-ventilation + carbonate salts addition) were adopted to remove Cl from MSWI fly ash. The results revealed that the two fly ash samples contain a high content of Cl (16.95% for TX fly ash and 20.52% for JX fly ash). When treated with pure water, the maximum Cl removal ratios were 87.54% and 90.12%. Elevated temperature posed no significant influence on Cl removal using water flushing. CO2-ventilation during water flushing improved Cl removal, reaching maximum removal ratios of 93.69% and 99.19%. In spite of the higher removal ratios of Cl with CO2-ventilation, the high content of Ca2+ in the flushing solution remains a problem. Addition of carbonate salt after CO2-ventilation effectively reduced the concentration of Ca2+ in the solution. XRD analysis of the treated fly ash revealed an enhanced decomposition of the hardly soluble Cl-containing salts by CO2-ventilation, and calcite and gypsum became the major minerals after accelerated carbonation. The content of Cl in the CO2-treated fly ash was below 1%, which satisfies the utilization standard in Technical Specification for Pollution Control of Fly Ash from Municipal Solid Waste Incineration (HJ1134-2020).
2021 Vol. 41 (9): 4184-4192 [Abstract] ( 286 ) [HTML 1KB] [ PDF 636KB] ( 1507 )
4193 Comparative study on filtration of PM2.5 in combustion flue gas of organic solid waste
ZHU Fen-fen, WANG Huan, Xu Zhi-min, YAN Fa-wei, LI Xue-mei, HU Bo, LI Sheng-hong
Waste incineration is one of the important sources of PM2.5. At present, there is no control unit for the effective removal of PM2.5 in the flue gas system. In this paper, the removal effect of several filter media on PM2.5 produced by the combustion of three kinds of organic solid wastes, namely sawdust, pork and sludge, was studied. These filter media are polyester knitting fabric, polytetrafluoroethylene (PTFE) fabric, polyvinylidene fluoride (PVDF) micro-filtration membranes, graphene and their combinations. The combination of PTFE fabric and PVDF micro-filtration membrane has the best filtration effect on PM2.5 produced by sawdust burning, which can reach 97.45%. The filtration effect of double layer PVDF micro-filtration membrane on PM2.5 of pork and sludge burning are 99.39% and 98.03%, respectively. According to the experimental results and SEM-EDS analysis, PVDF micro-filtration membrane has a high selectivity retention effect on particles made of C. The combined use of filter can greatly improve the filtration efficiency of PM2.5. However, double-layer filtration may increase resistance, which is not conducive to a large number of exhaust gases for dust treatment.
2021 Vol. 41 (9): 4193-4203 [Abstract] ( 221 ) [HTML 1KB] [ PDF 1547KB] ( 1421 )
Soil Pollution Control
4204 Preparation of montmorillonite-humic acid complex and study on the adsorption properties for strontium
LIU Bing-yi, LUO Min, SHAO Yang, ZHENG Nan, XU Dian-dou, LIU Zhi-ming, MA Ling-ling
In order to explore the adsorption mechanism of soil colloids on radionuclide strontium, montmorillonite, one of the typical inorganic minerals, and humic acid were selected to prepare for an organic-inorganic complex, and to explore the adsorption properties. It was found that the humic acid loaded on the complex with a loading of 2.97% can change the morphology of montmorillonite. The adsorption capacity of the artificial complex for strontium was up to 6.86mg/g. By fitting the kinetics of the adsorption of strontium on the complex, the adsorption process was found to be more in line with the second-order kinetic model with the adsorption equilibrium time of 10min. The removal rate was high at low temperature of 15℃ with a rate of 72.29%. When the pH increased from 5 to 9, the removal rate varied between 1%~2%. Ionic strength had a significant effect on adsorption with the removal rate at 0.1mol/L, which was obviously lower than 0.001mol/L with a decreasing rate of 20%~60%. Meanwhile, the removal rate increased with the increasing concentration of humic acid. The removal rate increased rapidly from 0 to 60mg/L, and the highest rate reached 75.36% at 60mg/L, then the rate reached an equilibrium.
2021 Vol. 41 (9): 4204-4210 [Abstract] ( 310 ) [HTML 1KB] [ PDF 558KB] ( 834 )
4211 Spatial pollution characteristics and magnetic response of surface soil heavy metals in Jinchuan mining area
WANG Guan, XIN Qian, MA Li-juan, WANG Yang-yang, YAO Wen, ZHU Xin-yu, REN Fei-fan
26surface soil samples were collected from the Jinchuan mine area. Environmental magnetism and heavy metal element (Cu, Ni, Cr, Fe, Sr, Ti, Pb and Mn) content analysis were related analysis on the samples, and carried out by using single factor pollution index and Nemero pollution index evaluation methods to evaluate the heavy metal pollution degree. The magnetic characteristics of the surface soil and the content of heavy metal elements showed obvious spatial distribution differences:mine area> outer processing area> high traffic section> gate area> other areas. The samples were contaminated up to100% by Cu and Ni, showing the high levels of pollution. While metal pollution of Cr, Pb, Ti, and Sr was between the warning line and moderate pollution. Then, the values of χl、SIRM、χARM and HIRM were relatively high, indicating that the content of magnetic mineral particles was extremely high, and the magnetic particles were dominated by ferrimagnetic mineral types. The magnetic grain size characteristics of the surface soil samples were dominated by coarser pseudo-monodomain (PSD) and multi-domain (MD) particles. Correlation analysis results were shown that there was an excellent correlation between Cu、Ni、Cr、Fe、Pb and Mn, especially, the correlation of Cu、Ni was excellent (R=0.91) among them. χlf, SIRM, and χARM had an excellent correlation with various metals(0.52≤R≤0.78), it showed that the heavy metal pollution of urban surface soil was effectively monitored by magnetic parameters, quickly delineating the area and scope of heavy metal pollution, and providing rapid and effective data support for urban surface soil pollution monitoring.
2021 Vol. 41 (9): 4211-4220 [Abstract] ( 257 ) [HTML 1KB] [ PDF 997KB] ( 1000 )
4221 Effect of sodium salt with varied anions on Cd fractions and microbial community in soil
WANG Li-fu, ZHAO Shu-wen, LI Shan-shan, QIN Lu-yao, SUN Xiao-yi, LEI Xiao-qin, CHEN Shi-bao, WANG Meng
In order to explore the impact of saline-alkaline stress on soil microbial community structures and Cd availability, different Cd-contaminated soils from wastewater-irrigated agricultural land were collected, the actual saline-alkali environment was simulated by adding the neutral and alkaline salts in different proportions. Soil microcosm incubations were conducted, Illumina high-throughput sequencing of 16S rRNA genes was used to estimate microbial community structures, and basic soil physiochemical properties and Cd content were determined. The results showed that salt addition positively affected sodium adsorption ratio (SAR), alkalinity (ESP), but reduced the content of soil organic carbon (SOC), cation exchange capacity (CEC). Increased soil salinity and alkalinity increased the proportion of small soil aggregates (<0.002mm), and promoted Cd translocation from large aggregates into clay/silt size fractions. Treatment T1 (mainly contained ions of SO42- and Cl-) enhanced exchangeable Cd content in both test soils by 27.06% and 11.00%. Soil saline-alkali stress decreased bacterial abundance and diversity, comparatively, soil microbial community in T1 showed the highest difference. Meanwhile, salt addition changed major soil bacterial taxa, for example, increased saline stress enriched saline-alkali tolerant taxa Nitriliruptoraceae, Staphylococcaceae, Pseudomonadaceae and heavy-metal resistant taxa Bacillaceae, microbial structure difference under different treatments probably depended the components of soil anions. For instance, comparatively, the abundance of Proteobacteria, Gemmatimonadetes and Bacteroidetes was significantly enriched in T1treatment. Redundancy analysis (RDA) of the abundant bacterial phyla and soil properties suggested that soil pH, exchangeable Cd content, SAR and ESP were the most influential environmental factors driving the changes in community composition, the abundances of Bacteroidetes, Gemmatimonadetes, and Proteobacteria were positively correlated with pH, and the abundances of Chloroflexi and Acidobacteria were strongly positively correlated with soil exchangeable Cd content, SAR. Therefore, saline-alkali stress increased soil Cd availability, significantly altered soil bacterial community.
2021 Vol. 41 (9): 4221-4230 [Abstract] ( 236 ) [HTML 1KB] [ PDF 681KB] ( 905 )
4231 Progresses in microbial degradation of agricultural soil mulches
DING Hao-jie, SU Qi-qian, LI Lin, LI Xiao-feng, XU Qi-jing, RENSING Christopher, LIU Xue
Plastic film mulching can increase crop yields by maintaining soil moisture, regulating soil temperature and limiting weed growth, thus plays an indispensable role in modern agricultural production. However, its predominant component polyethylene (PE) is stable and resistant to degradation thus being accumulated in farmland soils. In addition, phthalates (PAEs) are added as plasticizers during plastic film production, which are readily being accumulated and transported in soil and water environment, together with the high biotoxicity, posing great threats to the environment, plant, animal and human. The multi-contamination of PE and PAEs is one of the most difficult form in soil organic pollution remediation. Therefore, how to remediate plastic film mulching soils attracts increasing attention in scientific researches and plays an important role in ensuring crop production safety and human health. Compared to physical and chemical methods, bioremediation using microbial degradation shows advantages in high efficiency, no secondary pollution risk, lower cost, and less environmental disturbance. As such, the present status of agricultural film mulching application and residue in soils, and the research progress of biodegradation were reviewed in order to provide basic information and technical supports for bioremediation of organic film pollutants in farmland soils.
2021 Vol. 41 (9): 4231-4244 [Abstract] ( 384 ) [HTML 1KB] [ PDF 631KB] ( 1476 )
Environmental Ecology
4245 Study on the cooling effect of urban parks base on the case of Changzhou, Jiangsu, China
WANG Xin-jun, FENG Xing-ying, CHEN Kai-li, GAO Ji-xi
This research selected parks in Changzhou, a rapidly urbanizing city in the Yangtze River Delta, to study the relationship between the composition of parks and their cooling effect. The park composition indicators and cooling effect indicators were extracted from high-spatial-resolution images created by Landsat 8TIRS and Tianditu. Land surface temperatures of the researched area were retrieved by the radiation transfer equation, and buffer analysis of ArcGIS, piecewise regression were used to analyze cooling effect indicators of each surveyed park, including the land surface temperature, the temperature drop range and the temperature drop amplitude. The perimeter, area and integration index of the parks were measured as their composition indicators. Afterwards, park land cover indicators, namely, the green coverage, water coverage, impervious surface coverage, and tree coverage were extracted from high-definition remote sensing images of Tianditu. Correlation analysis and the regression model between the park indicators and the cooling effect revealed that the temperature drop amplitude was nonlinearly related to the area and perimeter of a park, and the threshold were 26hm2 and 3600m respectively, which means that a park has a strong cooling effect with its area and perimeter within the threshold, while the cooling effect decreases with its area and perimeter exceeding the threshold. A second finding was that the integration index of a park had a linear correlation with the cooling rate, meaning greater cooling effect for parks with a lower integration index. The third finding was that the tree coverage and water coverage of a park were strongly correlated with the surface temperature inside the park, while the impervious surface coverage rate and green space coverage rate showed no significant correlation with the land surface temperature inside the park. Based on the three findings, it was concluded that to give full play to an urban park's cooling effect, planners and designers need give a thorough consideration of its area and perimeter thresholds, integration index value, and tree and water coverage.
2021 Vol. 41 (9): 4245-4252 [Abstract] ( 296 ) [HTML 1KB] [ PDF 1794KB] ( 1793 )
4253 Effects of marine engineering construction on environmental factors and phytoplankton in the coastal area of Lianyungang
ZHANG Jing-jing, Wang Yi-bin, WANG Ying, WANG Tian-tian, Lü Qi-ming, GAO Yan-jie, Lü Zhen-bo
Comprehensive investigations were conducted on the spatial distribution characteristics of chlorophyll a (Chl a), phytoplankton community structure and the environmental factors in the coastal area of Lianyungang in May 2009 (before marine engineering construction) and 2016 (after marine engineering construction), with the purpose of understanding the effects of marine engineering construction on environmental factors and phytoplankton community in this area. The results show that the environmental factors of the studying area changed significantly after engineering construction. An obvious high temperature zone was formed near the inshore area after engineering construction, with 3℃ higher than the offshore area. The nutrient concentrations were significantly decreased, and especially the dissolved silicon (DSi) which reduced by 70%. The concentration of Chl a and the biomass of phytoplankton increased obviously, with the dominant community shifting from diatoms alone to the co-dominant of diatoms and dinoflagellates. The main dominant species before engineering construction (e.g., Coscinodiscus asteromphalus and Noctiluca scientillans) were significantly decreased in 2016, while dominance of Skeletonema costatum was significantly increased. Redundancy analysis (RDA) showed that chemical oxygen demand (COD), dissolved inorganic nitrogen (DIN) and salinity (negative correlation) were the main factors affecting phytoplankton community before marine engineering construction, while the influence of temperature (T) was significantly increased after marine engineering construction. The increase of T, BOD5 and DO may be the main factors that promoted the increase of phytoplankton in spring.
2021 Vol. 41 (9): 4253-4262 [Abstract] ( 259 ) [HTML 1KB] [ PDF 3817KB] ( 823 )
4263 Hydrochemical characteristics and its controlling factors of Basong Lake in cold season in Tibet
LUO Zhen, RENZENG LaMu, CHEN Hu-lin, HUANG Xiang
In Dec. 2018, study on hydrochemical characteristics and its controlling factors of Basong Lake was carried out. Water samples were collected from the lake surface, vertical layers, inlets and outlets river and, on-site measurement were performed for various physicochemical parameters. The results showed that the Basong Lake overall was slightly alkaline. The measured TDS were relatively low, with an average value of 107mg/L. The average water temperature in the lake area was 5.7℃, with a thermocline appeared at the depth of 45~60m. However, since the temperature variation was minor, there was no significant difference between these measured physicochemical parameters at each sampling sites (P>0.05). Among major ions, Ca2+and HCO3- were the two dominants,account for 80.35% and 72.95% of the total cations and anions, respectively. Spatially, contents of the major ions in the inlet rivers were generally higher than that of lake surface, then after showed a homogeneous feature over the lake surface. In contrast, vertically, the contents of the major ions were slightly increased with an increasing water depth. The water chemistry type of the Basong lake was HCO3·SO4-Ca type. Weathering of rocks in the lake catchments, especially carbonate weathering was the major controlling factor that determined the composition and distribution of ionic contents in the lake area.
2021 Vol. 41 (9): 4263-4270 [Abstract] ( 322 ) [HTML 1KB] [ PDF 576KB] ( 1685 )
4271 Pollution characteristics of four-type antibiotics in typical lakes in China
ZHANG Jing-jing, CHEN Juan, WANG Pei-fang, WANG Chao, GAO Han, HU Yu
Based on existing literature data, we analyzed the pollution characteristics of four-type antibiotics used commonly, including tetracyclines, sulfonamides, quinolones and macrolides, in 38 typical lakes, which are distributed in eastern plain lake region (31), Mengxin lake district (4), Erlong Lake, Qinghai Lake and Fuxian Lake. The results showed that the four-type antibiotics were ubiquitous in waterbody and sediments of these lakes, and the pollution concentrations decreased as follows:SAs (2147ng/L)> quinolones (QNs, 1458ng/L)> tetracyclines (TCs, 481 ng/L)> macrolides (MLs, 205 ng/L). The antibiotics in sediments exhibited vertical difference, with higher pollution concentration in surface sediment than that in deep sediments. The antibiotics concentrations varied among different lake regions, and in the eastern plain lake region showed higher contamination level. Compared with the inflow rivers, lakes, such as the Gonghu Bay in Taihu Lake and Qinghai Lake, generally showed relatively higher contamination levels, suggesting that lakes serve as a reservoir of antibiotics. Seasonal comparison in pollution levels in waterbody of lakes showed that the antibiotic concentrations in pring, summer and winter was significantly higher than that in the autumn. For example, Poyang Lake, Baiyangdian Lake and Erlong Lake' antibiotic pollution was higher in dry season (April) than in rainy season (August). However, antibiotics concentrations in lake sediments were comparable between different seasons, probably resulting from the migration of antibiotics in sediments.
2021 Vol. 41 (9): 4271-4283 [Abstract] ( 356 ) [HTML 1KB] [ PDF 558KB] ( 14806 )
4284 Occurrence characteristics and transport fluxes of nitrogen and phosphorus at sediment-water interface of Panjiakou Reservoir in spring
WANG Hong-wei, WANG Shao-ming, ZHANG Min, HU Xiao-kang, TANG Meng-yao, YANG Fan-yan, ZHONG Ji-cheng
The sediments from Panjiakou Reservoir were selected as the research object. The overall status of nutrient pollution and the release characteristics of internal loading of the reservoir were analyzed. The vertical distribution characteristics and spatial differences of nutrient were analysed by obtaining interstitial water in sediments via high-resolution interstitial water samplers (HR-Peeper). The transport fluxes of nutrient at the sediment-water interface were obtained by static release test of intact sediment cores, and the internal loading characteristics of Panjiakou Reservoir were analysed. The release risk of nutrient in the sediments was relatively high, and the TN and TP content was 3701.59~8221.28 mg/kg and 756.28~1696.15 mg/kg, respectively. According to the C/N ratio, the main cause of eutrophication in Panjiakou Reservoir was the residual feed and fish manure from cage culture before 2017. The static release results of the intact sediment cores showed that the exchange fluxes of NH4+-N、NO3--N、NO2--N and SRP were 23.71~156.80, -7.37~-161.78, 1.64~33.4, and 0.56~2.86mg/(m2·d), respectively, and the internal loading of Panjiakou Reservoir was relatively high. The results are related to the high contents of organic matter, nitrogen and phosphorus, oxygen consumption by biological decomposition and gradually increasing water temperature in spring, which leads to the accelerated release of nutrient into the overlying water column. The internal loading of Panjiakou Reservoir can accelerate the process of eutrophication, and measures should be taken to control the internal loading of Panjiakou Reservoir.
2021 Vol. 41 (9): 4284-4293 [Abstract] ( 285 ) [HTML 1KB] [ PDF 642KB] ( 1214 )
4294 Characteristic of radon in typical karst water systems and its indicating significance in Guangxi, China
GUO Fang, WEI Li-qiong, JIANG Guang-hui
The radioactive isotope radon originates from decay of uranium in the stratum. 222Rn has a half-life of 3.82 days, and the activity of 222Rn has significant difference in groundwater and surface water. The application of 222Rn in understanding hydrological process grows quickly in recent years, while it has less study in karst environment. Three karst water systems in Guangxi were taken as examples to study the characteristic of 222Rn in karst environment and its indicating meaning. It was found that the activity of 222Rn was less than 500Bq/m3in the upper aeration zone, while it had local anomaly high in unsaturated zone, which is related to local geological structure. In saturation zone, the residence time of groundwater, the mixing proportion of different groundwater components, and the length of the radon transport along the flow paths causes the different of 222Rn activity. In general, 222Rn in karst conduit media is higher than that in fissure media, and 222Rn in thick soil covering layer is higher than that in thin soil covering. In the discharge zone of big karst water systems, groundwater usually flows to river, and sometimes river can flow back into the spring outlet. Because the significant difference between 222Rn in groundwater and surface water, 222Rn might be an ideal tracer of quantifying groundwater-surface water interaction.
2021 Vol. 41 (9): 4294-4299 [Abstract] ( 318 ) [HTML 1KB] [ PDF 435KB] ( 765 )
4300 Reliability analysis of a method to rapidly concentrate and fix phytoplankton
LI Ya-li, YANG Zheng-jian, TIAN Pan, LIU Yi, WANG Cong-feng, JI Dao-bin, LIU De-fu
In order to verify the reliability of a membrane concentration method to rapidly concentrate and fixe phytoplankton in the field, the "Lugol's solution fixed sedimentation method (LSM)" and "membrane concentration method (MCM)" were comparatively used here to authenticate different phytoplankton samples. The results show that:(1) 7 phyla and 32 genera were both identified by the two method, but using the MCM could authenticate more phytoplankton species than the LSM method; (2) There was no significant difference not only in phytoplankton abundance between the two methods except Euglenophyta (P<0.05) at the phylum level (P>0.05), but also in phytoplankton relative abundance within 99% at the genus level (P>0.05). Which meant that, at the phylum and genus levels, the MCM was feasible to identify the phytoplankton abundance; (3) There was no significant difference in the slope of fitting equation of different algae biomass gradients (P>0.05), and they showed a high correlation coefficient (R2=0.958, P<0.01), however, algal biomass of the MCM seemed to be a little larger. On a conclusion, the results of the MCM was consistent with the LSM, and the MCM had more advantages in less environmental condition requirement, easier for field monitoring, and save time.
2021 Vol. 41 (9): 4300-4309 [Abstract] ( 304 ) [HTML 1KB] [ PDF 1917KB] ( 1698 )
4310 Variation characteristics of vegetation characteristics, biological crusts and soil nutrients under the main vegetation configuration modes in the process of sand control in the Yarlung Zangbo River valley
LIU Lin, ZHANG Bao-jun, XIONG Dong-hong, TANG Yong-fa, YUAN Yong
In order to understand the impact of ecological project for sand control on the vegetation, biological crusts and soil characteristics of the middle reaches of the Yarlung Zangbo River valley. The characteristics of understory vegetation, surface biological crusts, and soil fertility properties during the implementation of the project with different vegetation configuration modes and ages were analyzed. 4 modes which restoration ages were approximately 10 years were selected, including Populus+Sophora moorcroftiana (YS+SSH), Sophora moorcroftiana (SSH), Hedysarum scoparium (HB) and Artemisia wellbyi (ZSH). Because of the most widely implemented of YS+SSH and SSH, three ages were studied (i.e. 6, 10 and 30 years old). The results showed that:The arbor+shrub (YS+SSH) and shrub (SSH and HB) plots with 10 years were more conducive to increasing species diversity than the herb (ZSH). The above-ground biomass, litter volume, underground biomass, soil organic matter, total nitrogen and total phosphorus content of the YS+SSH plot were significantly higher than the other three plots. The biological crusts of the ZSH plot were the most developed, followed by the HB plots, and the YS+SSH plot had no crust. The species diversity index, litter storage, underground biomass, soil organic matter, total nitrogen and total phosphorus content of the YS+SSH plot increased with the increase of years, but the biological crust was only in 6 years. The aboveground biomass, underground biomass, and biological crusts of the SSH plot gradually increased with the increasing of years, but the species diversity index and total nitrogen content showed a downward trend. The litter storage, organic carbon and total nitrogen content increased first and then decreased. Among the different modes, the YS+SSH plot had the best comprehensive near-surface characteristics. With the increasing of the project years, it had stronger effects on promoting the succession of vegetation on the sandy land in this area, increasing the productivity of the vegetation, and enhancing the fertility of the sandy land. Therefore, it is suggested that the vegetation configuration mode of arbor+shrub(YS+SSH) should be promoted in the ecological project for sand control in this area.
2021 Vol. 41 (9): 4310-4319 [Abstract] ( 270 ) [HTML 1KB] [ PDF 547KB] ( 1683 )
4320 Spatial distribution characteristics of heavy metals in the soil-groundwater system around an integrated waste management facility
ZHU Shui, SHEN Ze-Liang, WANG Yuan, WU Hao-Ran, XIN Jia
The concentrations of heavy metals (Cr, Cu, Ni, Pb, Zn, As, Cd, and Hg) in the soil-groundwater system around an integrated waste management facility were determined. The results showed that an obvious vertical migration of heavy metals was observed with the highest concentration levels found at the depth of 150~200cm, which was attributed to the convection and diffusion of soil water and the adsorption and interception of the soil media. In spite of clues for heavy metals accumulation in the soil, the concentrations of heavy metals were lower than the critical limit of national soil quality standard. In soil samples, the contents of heavy metals at the upstream site were higher than those of the other two closer downstream sites, which was mainly caused by atmospheric deposition. In groundwater samples, the values of Zn and Ni adjacent to the integrated waste management facility were significantly higher that those at other further sites and the content of Zn even exceeded the groundwater quality standard, which was contributed by the infiltration of landfill leachate. Through high-throughput sequencing analysis, significant differences were found between soil and groundwater samples (P<0.01) in terms of microbial community structure:there was no significant correlation between most microbial communities in the soil and heavy metals, while the microbial community in groundwater was closely related with the enrichment of heavy metals Zn and Ni. These results would be helpful to assess and manage the environmental risks of the soil-groundwater system adjacent to the integrated waste management facility.
2021 Vol. 41 (9): 4320-4332 [Abstract] ( 245 ) [HTML 1KB] [ PDF 1664KB] ( 1771 )
4333 Analysis on slow-release of residual ammonium in ion-absorbed type rare earth tailings
XIE Fang-fang, WANG Guan-shi, LUO Si-hai, YIN Sheng-hua, WEN Teng, ZHANG Shil-iang, LIU Jian
In order to explore the slow-release of residual NH4+, ion-absorbed type rare earth ore from Xinfeng (Jiangxi Province) was taken as the research object. The leached tailings were prepared by column leaching, and then drip washing with deionized water. Follow the steps of drip washing → sealing and storing → re drip washing, NH4+ amount in drip washed tailings with different water content (1.3%, 15%, 35%, 250%), under different time (15, 30, 60, 120, 180, 195, 210, 240d), different mass transfer mechanisms (convection, diffusion) were investigated. The results show that NH4+ can still be washed out from the drip washed tailings after being sealed and preserved for a long time. NH4+ washing amount is affected by water content, time and mass transfer mechanism. NH4+ washing amount, as a whole, increase with time proceeding, when the water content is ≥15%, and increase with the increase of water content, in the same preserved time. When other conditions are the same, NH4+ washing amount under convective is greater than diffusion. NH4+ re-washed out from the tailings is the result of transformation of NH4+ from exchangeable to water-soluble.
2021 Vol. 41 (9): 4333-4340 [Abstract] ( 196 ) [HTML 1KB] [ PDF 924KB] ( 890 )
Environmental Microbiology
4341 Application of metatranscriptomics in environmental microbial ecology
LI Ying, WU Xing-Jie, HE Zhi-Bin, BEI Shui-Kuan, MA Ke, PENG Jing-Jing
In this review, the pipeline for metatranscriptomics workflow and data analysis were systematically summarized. Then, the strategy of research in environmental microbial ecology was discussed. Based on the above, the prospects of metatranscriptomics application were proposed. Metatranscriptomics has been useful in analyzing the function of environmental microbiomes. It provides a powerful tool for us to better understand the dynamic evolution of the functional microbial community and its relationship with environmental factors and ecosystem function.
2021 Vol. 41 (9): 4341-4348 [Abstract] ( 441 ) [HTML 1KB] [ PDF 539KB] ( 4957 )
4349 The influences of petroleum pollution on the microbial population distribution in Northern Shaanxi Province of China
XU Yin-rui, WU Man-li, WANG Li, GAO Huan, LIU Ze-liang
Oil-contaminated soil and uncontaminated soil from oil well sites in ten oil-producing counties in Northern Shaanxi were collected. Chemical analysis and molecular biology techniques were used to determine the physicochemical properties and bacterial community structure of soil. Methods such as Pearson correlation analysis and redundancy analysis were used to study the impact of oil pollution on physicochemical properties, microbial population distribution and diversity of soil. Results showed that compared with uncontaminated soil, nitrate-nitrogen, total organic carbon, total carbon, total sulfur and carbon-nitrogen ratio of oil-contaminated soil increased, while the pH value decreased. The richness of soil bacterial community did not change significantly, but the evenness decreased significantly. The relative abundance of some dominant bacterial changed obviously after oil contamination in different regions. Changes in relative abundance of Proteobacteria and Chloroflexi were significantly positively correlated with petroleum hydrocarbon content, and changes in relative abundance of Candidatus Saccharibacteria were significantly negatively correlated with petroleum hydrocarbon content. The relative abundance of Pseudomonas, Nocardioides, Arthrobacter, Acinetobacter, Alkanindiges, Gaiella and GP4 increased significantly in Dingbian, Jingbian, Zichang, Suide, Wuqi, Ansai and Fuxian. The relative abundance of Ohtaekwangia, Pseudonocardia, Ramlibacter, and Sacchariacteria_genera_incertae_sedis decreased significantly in Dingbian, Jingbian, Zichang and Suide. Pseudomonas, Nocardioides, Arthrobacter and Alkanindiges were the main oilphilic bacteria in Northern Shaanxi Province. Physicochemical properties such as pH, moisture content, total petroleum hydrocarbon and total organic carbon were the key factors affecting the microbial population structure of oil-contaminated soil in Northern Shaanxi oilfield.
2021 Vol. 41 (9): 4349-4359 [Abstract] ( 264 ) [HTML 1KB] [ PDF 780KB] ( 1123 )
4360 Isolation and screening of piperazine degrading bacterium PIPA-6 and its degradation characteristics
GUO Jun-jun, YAO Wen-qin, LOU Li-li, LEI Xin-hua, ZHANG Xin
Piperazine-degrading strain PIPA-6was isolated from the soil around a pharmaceutical plant in this study, the strain could grow in medium with piperazine as the sole energy source, and the degradation rate for 100mg/L of piperazine reached 100% within 30h. Strain PIPA-6 was finally identified as Paenarthrobacter nicotinovorans based on the analysis of morphological observation, physiological and biochemical tests, as well as 16s rDNA sequencing. Strain PIPA-6 could grow in a wide range of temperatures (10~40℃) and pH (5~10), with excellent sodium salt tolerance (50g/L) and high piperazine resistance (300mg/L). The optimum degradation was achieved at 35℃, pH,8. The degradation efficiency of the strain could be significantly improved by adding organic carbons.Simulation experiments showed that strain PIPA-6played a vital role in piperazine degradation in 50L simulation tank, the parameter of chemical oxygen demand(COD) and the content of ammonium nitrogen in pharmaceutical wastewater were significantly reduced(P<0.05).Degradation rate of strain PIPA-6 for piperazine was up to 98% in 30d. Metagenomics analysis confirmed that the strain could successfully colonize in the wastewater and shape new microbial community structure compared with the initial one. The strain obtained in this study enriched the resource of the piperazine-degrading strains, and the experimental results provided a preliminary theoretical basis for the development and practical application of the strain.
2021 Vol. 41 (9): 4360-4366 [Abstract] ( 230 ) [HTML 1KB] [ PDF 982KB] ( 1199 )
Biodiversity
4367 Species diversity and phylogenetic analysis of bdelloid rotifers in Guangdong Province
WANG Qing, LI Ying, WANG Wen-bo, YANG Yu-feng
In order to investigate species diversity of bdelloid rotifer in Guangdong Province, 98 samples from different habitats in Guangdong Province were collected, and 66 species (including subspecies) of bdelloid rotifers were recorded belonged to 3 orders, 4 families, 12 genera. Fifty-six species of bdelloid rotifer were identified in terrestrial environment, including 42 species in bryophyte habitats, 40 species in deciduous habitats, 12 species in lichen habitats, and 15species in aquatic habitats. The species number of bdelloid rotifer in terrestrial habitats was significantly more than that in aquatic habitats. To verify the accuracy of morphological identification, 37 COI gene sequences of 16 species belonged to 4genera were obtained, and the genetic distance among them ranged from 8.59% to 23.17%. The COI gene sequences of Adinet cuneata and Philodina rapida were first reported in the world. The total content (71.2%) of adenine (A) and thymine (T) was higher than that (28.8%) of guanine (G) and cytosine(C). The cluster results of phylogenetic tree were consistent with those of morphological species identification; the species with similar morphology belonged to the same genus have higher homology. The results showed that the combination of morphological identification and DNA barcoding technology could improve the accuracy of species identification for bdelloid rotifers, explore their phylogenetic position at molecular level, and promote the species diversity and ecological research of bdelloid rotifers.
2021 Vol. 41 (9): 4367-4377 [Abstract] ( 315 ) [HTML 1KB] [ PDF 727KB] ( 2284 )
4378 Relationship between geographical pattern of plant diversity and environmental factors in Beiluo River Basin
TIAN Qi-long, XU Xiao-ming, LYU Du, WANG Hao-jia, LEI Si-yue, YI Hai-jie, HE Jie, HE Liang, XUE Fan, ZHOU Ya-dong, WANG Miao-qian, ZHANG Xiao-ping
The diversity of seed plants in Beiluo River Basin was identified through field investigation and statistical analysis of historical documents. Result:There were 1671 species of seed plants belonging to 581genera and 123 families in this area, accounting for 83.67%, 67.24% and 51.83% of the total seed plants in the Loess Plateau. of all the detected 1671 species, the majority (>65%) belonged to large (>50 species) and larger family (21~50 species), and more than half (~56%) belonged to single species genus and small genus (2~5 species). According to cluster analysis of the plant similarity for the 11main streams, 5groups were obtained, with Huanglong County as the firstly separated category, and the largest category including four geographical units, i.e. Fu County, Heshui County, Yijun County and Huangling County, which were all affected by the connection of Ziwuling mountains. The SD values of floristic richness of Fu County, Heshui County and Huanglong County were highest, while those of Luochuan County, Huachi County and Ganquan County were the lowest. There were 15 areal types and 16forms of geographical elements at the genus level in this area, which were dominated by the temperate distribution and its forms (287genera, accounting for 49.40%) and closely related to the tropical distribution and its forms (115 genera, accounting for 19.79%). There was a significant positive correlation between SD value of plant richness and temperate components. Huangling County, Luochuan County and Huanglong County had the highest R/T value and the strongest tropical property, while Huachi County and Dingbian County had the lowest R/T value and the weakest tropical property. The R/T value was affected by altitude and had a similar distribution pattern with temperature and precipitation decreasing from the southeast to the northwest. It is concluded that the plants in this area are important plant germplasm resources, because they have an ancient origin, a high degree of differentiation, rich species diversity and complex geographical elements. The transition pattern of plant species diversity zone is significant, which reflects the niche demands of these groups. Species of the six dominant families (Asteraceae, Poaceae, Rosaceae, Fabaceae, Lamiaceae and Ranunculaceae) that are suitable for the land and trees and grasses (temperate in nature) can be selected for vegetation restoration and soil erosion control.
2021 Vol. 41 (9): 4378-4387 [Abstract] ( 307 ) [HTML 1KB] [ PDF 936KB] ( 1700 )
Environmental Toxicology and Health
4388 Pollution status and ecotoxicity of organophosphate esters (OPEs) in aquatic environment
ZENG Jia-min, ZHONG Shi-hua, QIAN Wei, YUAN Sheng-wu, ZHU Xiao-shan
To effectively assess the potential ecological health risks of organophosphate esters (OPEs), this study gave an overview of the global OPE pollution in water and sediment with a focus on their toxic effects on aquatic organisms. The potential toxicity mechanisms were also analyzed in different kinds of biota including plankton, nekton and benthos, and the future research directions and scientific issues in aquatic environmental studies were finally prospected. This study would be helpful for effective assessment of ecological effects and health risks of OPEs. It would also positively promote the food safety monitoring and ecotoxicology research of OPEs, and provide reference for regulating their green applications.
2021 Vol. 41 (9): 4388-4401 [Abstract] ( 393 ) [HTML 1KB] [ PDF 1014KB] ( 6041 )
4402 Research advances on the cytotoxic effects of zero-dimensional carbon-based nanomaterials
LI Yi-meng, LIU Xi, WU Tian-shu
The main pathways of carbon-based nanomaterials entering into cells were introduced in this paper, and the analysis of different forms of cell death caused by several commonly used zero-dimensional carbon-based nanomaterials and their potential toxic mechanisms was focused on. The physical and chemical factors affecting the cell death induced by carbon-based nanomaterials were elaborated as well. Finally, the prospects of toxicity study of carbon-based nanomaterials based on our findings were provided in this review, which benefits the design optimization and wider application of carbon-based nanomaterials in the future.
2021 Vol. 41 (9): 4402-4414 [Abstract] ( 226 ) [HTML 1KB] [ PDF 1273KB] ( 1367 )
4415 Influence of BC, PM2.5, temperature and their synergy on mortality of cardiovascular diseases in Xi'an
OU Yi-han, ZHANG Xiao-ling, ZHANG Ying, KANG ping
Daily death data of cardiovascular diseases during 2014~2015, daily average of BC(black carbon) and PM2.5 and meteorological data during the same period in Xi'an were collected. Three semi-parametric Generalized Additive Models (GAMs) based on the time series, including an independent model, a non-parametric bivariate response surface model, and a temperature stratification model, were adopted to this study. The results showed that BC and PM2.5 had a lag effect on the daily mortality of cardiovascular diseases in Xi'an. With the optimal lag period, when concentrations of BC and PM2.5 increased by interquartile range (IQR), the excess risk of cardiovascular diseases increased by 3.53%(95%CI:1.86, 5.23) and 2.01% (95%CI:1.06, 2.97), respectively. The exposure-response relationship between ambient temperature and mortality of cardiovascular diseases both exhibited "V" type and the most comfortable temperature was 26℃. Low temperature and high pollutant concentration had a synergistic strengthening effect on cardiovascular diseases. When the temperature lower 26℃, the modulating effects of temperature on BC-mortality relationship became more pronounced than that on PM2.5-mortality relationships with temperature cutoff increasing. For cardiovascular diseases, different susceptibility showed in different subgroups, and female groups was more sensitive to the health risks of BC and PM2.5. When BC and PM2.5 were included in one or more other gaseous pollutants at the same time, the excess risk had no major impact. The adverse effect of BC on human health should not be neglected in the future. BC may be used as an important air quality indicator to assess the health risks of air pollutants.
2021 Vol. 41 (9): 4415-4425 [Abstract] ( 246 ) [HTML 1KB] [ PDF 745KB] ( 1314 )
Carbon Emission Control
4426 The CO2 emission trading system for road transport collaboratively governed by the government, enterprises, and residents
LI Wen-xiang, LI Ye, CAI Jin-jin
This study designed an emission trading system for road transport (ETS-RT) which is collaboratively governed by the government, enterprises, and residents. In the ETS-RT, the upstream fuel producers, midstream vehicle manufacturers, and downstream vehicle users are all involved as regulated entities. The scheme of the ETS-RT includes cap and allocation of the carbon quota, setting of industry benchmarks, examining of compliance, trading of carbon quota, monitoring, reporting, and verification (MRV) of carbon emission. Through case and scenario analysis, the multi-agent collaboration mechanism of the ETS-RT was revealed:under the government's regulation on carbon quota and industry benchmark, fuel producers change the fuel composition to reduce the emission factor of automotive fuels, vehicle manufacturers improve the fuel economy and increase the production of new energy vehicles to reduce the energy consumption intensity of vehicles, while vehicle users decrease the annual vehicle miles to reduce the travel demand or choose the new energy vehicles. The proposed ETS-RT can promote the collaborative optimization of fuel emission factors, vehicle energy intensities, and traffic activity demand, which are the key influencing factors of the road transport CO2 emissions. As a result, it can effectively control the growth of greenhouse gas emissions from road transport, thereby accelerating the achievement of "CO2 emissions peak" and the transition to "carbon neutrality".
2021 Vol. 41 (9): 4426-4438 [Abstract] ( 272 ) [HTML 1KB] [ PDF 992KB] ( 1542 )
4439 Study on operation efficiency and carbon emission characteristics of A2/O + MBR process
HU Yong-feng, LIANG Mei, ZHANG Yong-xiang, WANG Kun
The operation effect and carbon emission characteristics of the A2/O+MBR process in the H reclaimed water plant of Tongzhou District, Beijing, were studied in this paper. The results showed that the average removal rates of BOD5, CODcr, NH4+-N, TN and TP were 97.3%, 94.1%, 98.6%, 77.0% and 96.2% respectively. The total carbon emission and carbon emission per ton of water of the H reclaimed water plant decreased gradually in spring and summer and increased slowly in autumn and winter, the total carbon emission per ton of water was about 2.26kgCO2e/t. In the total carbon emissions, energy consumption carbon emissions accounted for the leading position, while CH4, N2O carbon emissions, and drug consumption carbon emissions accounted for a relatively small proportion. The statistical analysis results showed that the carbon emissions of CH4 ton water, energy consumption ton water, and material consumption ton water were significantly correlated with BOD5, TN influent concentration, and BOD5 removal rate. The carbon emission of N2O per ton of water was significantly correlated with the influent concentrations of TN and BOD5. There is no significant correlation between direct and indirect carbon emissions per ton of water and water quantity.
2021 Vol. 41 (9): 4439-4446 [Abstract] ( 340 ) [HTML 1KB] [ PDF 853KB] ( 3019 )
Environmental Impact Assessment and Management
4447 Net anthropogenic nitrogen input from human activities and its impacts from parameters in Henan Province
PEI Wei, DU Xin-zhong, LEI Qiu-liang, YAN Tie-zhu, LI Ying, ZHANG Tian-peng, CHEN Mei-jun, WU Shu-xia, LIU-Hong-bin
In order to explore the characteristics of net nitrogen input of human activities and the influence of its parameters on the estimation results in the main grain producing areas of plain area. The county-level statistical data from 1990 to 2015 in Henan province was collected and the relevant parameters of NANI model were selected and defined. The characteristics of temporal and spatial distribution, change trend and the influence of parameters on the estimation results of NANI were analyzed. The results show that:(1) From 1990 to 2015, the NANI of Henan province showed an increasing trend. The NANI of 1990, 1995, 2000, 2005, 2010 and 2015 were 14347, 19146, 21466, 24251, 23711 and 26156kg/(km2·a), respectively. For spatial variation, the counties with higher NANI were mainly distributed in the central and eastern plain areas, while the counties in the western hilly areas had lower NANI. (2) Among the input components of NANI model, the net nitrogen input of food/feed was the most affected by the parameters. Compared with the calculation and estimation results of selecting appropriate parameters, the variation range of this parameter was-23.1%~71.3%, the variation range of crop nitrogen fixation was -31.2%~41.2%%, and the variation range of fertilizer nitrogen input was -2.8%~4.5%.
2021 Vol. 41 (9): 4447-4456 [Abstract] ( 262 ) [HTML 1KB] [ PDF 1210KB] ( 1203 )
4457 Water quality warning method based on canonical correlation coefficient and random forest
LI Ruo-nan, WANG Qi, LIU Shu-ming
This study proposed a high-precision early-warning method for detecting sudden water pollution incidents. Firstly, a database of sudden water pollution incidents containing 22common pollutants was established through simulation experiments. Secondly, the canonical correlation coefficients were used to accurately reveal the synergetic feedback law among various water quality parameters after pollution incidents. Finally, a water quality early-warning model, called "canonical correlation coefficients-random forest", was developed based on the multi-parameter synergetic feedback law identified above. Results show that the early-warning model's average true positive rates for known and unknown pollutants are 96.78% and 98.33%, respectively, while the average false positive rate under baseline status of water quality monitoring is 0.16%. The proposed early-warning model can provide practical technical support for reducing the loss of sudden water pollution incidents and ensuring the drinking water supply's safety.
2021 Vol. 41 (9): 4457-4464 [Abstract] ( 295 ) [HTML 1KB] [ PDF 856KB] ( 1025 )
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