CHINA ENVIRONMENTAL SCIENCECE
 
 
CHINA ENVIRONMENTAL SCIENCECE
　　　　　　　　    More    
Online Submission
Manuscript Tracking
Peer Review
Editor Work
Office Work
Editor-in-chief
Forthcoming Articles
Current Issue
Archive
Advanced Search
Read Articles
Download Articles
Instruction
Template
Copyright Agreement
More   
  Current Issue
 
2021 Vol.41 Issue.5,Published 2021-05-20
Air Pollution Control
Water Pollution Control
Solid Waste
Soil Pollution Control
Environmental Microbiology
Environmental Ecology
Environmental Impact Assessment and Management
Environmental Toxicology and Health
Carbon Emission Control
Air Pollution Control
1985 Effect analysis of meteorological conditions on air quality during the winter COVID-19 lockdown in Beijing
YIN Xiao-mei, LI Zi-ming, QIAO lin, LIU Xiang-xue, GUO Heng, WU Jin, ZHU Xiao-wan, QIU Yu-lu, WANG Ji-kang, ZHANG Xiao-ye
The influence of meteorological conditions on the pollution processes was investigated in this study by analyzing the changes of air quality as well as the characteristics of two persistent heavy pollution episodes during the Coronavirus Disease 2019 (COVID-19) prevention (January 24 to February 29) of 2020 winter compared with the same period of 2015~2019. Cold air intensity in 2020 winter was weaker with the cold surges frequency decreased by 50%. Air temperature was 0.73℃ higher, and wind speed and mixed layer height were 17.8% and 32.5% lower, respectively. Relative humidity and dew point temperature increased by 60.9% and 48.1%, respectively. Northerly wind frequency reduced 7.5% while both of southerly and easterly wind increased 6.0%. As shown above, all meteorological conditions in 2020 winter were significantly more favorable for air pollution than the same historical period. Moreover, two heavy pollution episodes (January 24~29 and February 8~14) lasted for 59 and 75 hours were analyzed. At the cumulative stage, regional transport that can be divided into east and south channel greatly affected PM2.5, with the contribution of 70% and 58% for two episodes. By contrast, the contribution of local pollution was 67% and 48%, respectively, indicating the increased proportion of hygroscopic growth and secondary generation in the maintenance and aggravation stages. Under the meteorological background of "high humidity and high atmospheric stability", the combined effects of atmospheric vertical dynamics and horizontal convergence accumulated PM2.5 and water vapor in Beijing plain and prevented them from spreading beyond the boundary layer. Further bidirectional feedback between increased pollutants and meteorological factors in stable boundary layer resulting in aggravation of pollution. According to EMI index, meteorological conditions during the epidemic prevention in 2020 winter caused an increase of 70.1% in PM2.5 concentration compared to pre-COVID-19. Emissions reduction caused by emergency measures for COVID-19lockdown offset 53% of the adverse impact induced by meteorological conditions. As for the two episodes in 2020 winter, EMI was 26.9% and 19.7% larger than the average of other nine episodes in the corresponding period of 2015~2019, and PM2.5 concentration was basically unchanged or slightly reduced. Overall, if the current social emission level is not changed, emission reduction caused by city blockade under special circumstances can only partially reduce the pollution concentration, however, cannot completely offset the adverse impact of meteorological conditions.
2021 Vol. 41 (5): 1985-1994 [Abstract] ( 410 ) [HTML 1KB] [ PDF 1038KB] ( 1727 )
1995 Emission characteristics of port tugboat based on working conditions
TANG Yuan-zhi, LOU Di-ming, ZHANG Yun-hua, SUN Xian-chao, TAN Pi-qiang, HU Zhi-yuan
The Portable Emission Measurement System (PEMS) was used to conduct the emission test on a port tugboat under variable sailing operating conditions. Emission characteristics under different operating conditions were studied, including the transient characteristics of CO, THC and NOx, distribution characteristics of particle size, and the emission factors of main engine. The results showed that the particle size of the tugboat main-engine presented a single-peak or double-peak distribution under daily sailing conditions and different engine loads. The first peak of particle size was between 30 and 40nm, while the second peak was 191.1nm. Based on fuel consumption, the emission factors of CO and THC were significantly higher under the entry-and-return condition than other operating conditions; the emission factors of NOx, PM and PN were higher under departure-and-return condition than other operating conditions. Based on distance, the emission factors of pollutants under topping operation were higher than other operating conditions. Based on power, the emission factors of CO and THC were the highest under topping operation condition (4.10 and 1.20g/(kW·h) respectively); the emission factors of NOx, PM, and PN were the highest under the reverse-towing operating condition, with 10.28g/(kW·h), 0.28g/(kW·h) and 13.97×1014 units/(kW·h) respectively.
2021 Vol. 41 (5): 1995-2003 [Abstract] ( 269 ) [HTML 1KB] [ PDF 1002KB] ( 1796 )
2004 Impact of a cold front transport process on haze weather in eastern China in early winter
WANG Li-juan, LIU Xiao-hui, LU Wen, ZHANG Chen, Tang Wei-ya, ZHU Bin
Regular surface observation meteorological data, NCEP/NCAR reanalysis data, and national PM2.5 concentration data, combined with backward trajectory, air pollution transport index, and transport flux analysis, were used to analyze a cold-front induced large-scale haze weather process during December 10 and 11, 2019 in central and eastern China. The results showed that:(1) During the haze period, 500hPa was dominated by the meridional circulation, and accompanied with the upper-air low-pressure trough leading the ground cold front to move to the southeast. The heavy polluted area also moved from North China to Huang-huai and Jiang-huai. (2) Before the cold front passage, PM2.5 concentration in the region from North China to Yangtze River Delta increased significantly. Beijing was dominated by pollutants imported from the south, Jinan was mainly affected by pollutants from the northwest and east, and PM2.5 in Nanjing was mainly influenced by pollutants from north and west. (3) When the cold front passed through, the cold air quickly removed pollutants over Beijing Station, while the Jinan station was affected by the backflow of easterly wind at the bottom of the high pressure, and the PM2.5 concentration was maintained at about 50μg/m3. When the cold front intruded into the Nanjing station, weakened northwest flow had little effect on the removal of pollutants. Taking Jiangsu province as an example. In the whole cold front process, the contribution of local pollutants accounted for 25.8%, and the contribution of pollutants outside Jiangsu accounted for 74.2%, which were mainly transported from North China. (4) After the passage of the cold front, the boundary layer structures over the three stations were slightly different from each other. The inversion layer over the Beijing station was quickly dissipated, the lower boundary layer over the Jinan station changed from the isothermal layer to the inversion layer due to the influence of warm and wet advection from the sea, and the near-surface boundary layer over the Nanjing station changed from the inversion layer to the isothermal layer. This study revealed the impact of upstream pollutants on downstream area during the southward movement of the cold front, as well as the different evolution and removal characteristics of PM2.5 at the stations in the north and south China.
2021 Vol. 41 (5): 2004-2013 [Abstract] ( 314 ) [HTML 1KB] [ PDF 1562KB] ( 1401 )
2014 The characteristics and source apportionments of VOCs at typical background sites during summer in China
XIAO Long, WANG Shuai, ZHOU Ying, CHAI Wen-xuan, DU Li, TANG Gui-gang, LI Jian-jun
57 volatile organic pollutants at four representative background stations, namely, Pangquangou, Shennongjia, Wuyishan and Changdao in China, were collected using SUMMA Canisters and analyzed by GC-FID/MS methods during summer of 2019. Concentration, composition and diurnal variation characteristics of VOCs were discussed and the PMF model was used to identify the source of VOCs and its ozone formation potential (OFP). The results showed that the averaged VOCs concentration at Pangquangou, Shennongjia, Wuyishan and Changdao background sites were (23.06±8.14)×10-9, (8.25±4.27)×10-9, (7.95±11.31)×10-9 and (11.98±8.80)×10-9, respectively. The concentrations of alkane, aromatics, alkenes and alkynes at all background sites but Pangquangou were significantly lower than that in urban sites. The respective proportions of alkane, aromatics, alkenes in background sites were similar with that in urban sites, while the proportions of alkynes at background sites were significantly lower than that in urban sites. The diurnal variations of alkane and aromatics at background sites showed a pattern of declining in the day and accumulating at night, while alkenes reach its peak concentration at 09:00~15:00. Source apportionments by PMF model and components analysis showed that the VOCs concentrations and OFP at four background sites were affected significantly by anthropogenic sources. The contribution from sources of gasoline and organic solvents evaporation, usage of coating material and automobile exhaust at four background sites ranged from 39% to 58% of VOCs and 35% to 58% of OFP. Besides, the sources related to fuel combustions contributed 18% to 21% of VOCs and 13% of OFP, respectively. Sources from plant emission processes contributed 7% to 17% of VOCs and 8% to 33% of OFP at 4 background sites, which were higher than that at urban sites.
2021 Vol. 41 (5): 2014-2027 [Abstract] ( 435 ) [HTML 1KB] [ PDF 2037KB] ( 1602 )
2028 Nonlinear dynamic mechanism of regional air pollution during the COVID-19 lockdown
WU Bo, LIU Chun-qiong, ZHANG Jiao, LI Yan-hui, CHEN Yu-bing, WEN Ye, BAO Bing-yi, DU Juan, SHI Kai
Based on hourly concentration of PM2.5 and O3 during the epidemic period (January 24, 2020 to May 31, 2020) in Changsha, Zhuzhou and Xiangtan, the diurnal patterns, long-term persistence, multifractality and self-organization evolution dynamics of these two pollutants were studied to reveal the internal dynamic mechanism of the occurrence and evolution of heavy pollution events during the epidemic period. Firstly, the diurnal patterns of PM2.5 and O3 concentrations were investigated. It showed that O3 showed a single peak of high concentration in the daytime and low in the night, while PM2.5 showed a single lowest peak concentration in the day and high in the night, which was different from the pattern in non-epidemic periods. Furthermore, detrended fluctuation analysis (DFA), the multifractal detrended fluctuation analysis (MFDFA) and probability statistical analysis were applied to study the long-term persistence, multi-fractal structure of PM2.5 and O3 series. The results showed that PM2.5 and O3 series had significant long-term persistence characteristics and strong multi-fractal structures for the three cities. Meanwhile, detrended cross-correlation analysis (DCCA) and multifractal detrended cross-correlation analysis (MFDCCA) were conducted to estimate the cross-correlations between PM2.5 and O3 series. Long-term persistence as well as multifractal features at different time scales was also observed in PM2.5-O3 cross-correlations. Next, nonlinear analysis results obtained during epidemic period were compared with those obtained in the same periods of non-epidemic years of 2019 and 2018. Finally, based on the self-organized criticality (SOC) theory, the internal dynamic law of spatial and temporal evolution of PM2.5 and O3 series was discussed. Combined with the typical regional meteorological characteristics, it was found that the intrinsic dynamic mechanism of SOC may be one of the leading mechanisms of heavy air pollution episodes during the COVID-19 lockdown period. During the epidemic period, PM2.5and O3 concentrations did not evolve independently but remained complex interactions. Under the stable meteorological conditions, the nonlinear coupling effect inside the air combined pollution might reach the dynamic critical state, thus, lead to the risk of heavy air pollution in Greater Changsha Metropolitan Region during the epidemic period.
2021 Vol. 41 (5): 2028-2039 [Abstract] ( 266 ) [HTML 1KB] [ PDF 1763KB] ( 969 )
2040 Influence of fume purifier on VOCs emission characteristics and photochemical reaction of catering
JIANG Bao, SUN Cheng-yi, BAI Hua-hua, CHEN Xue, HE Wan-qing, NIE Lei, SHI Ai-jun, LI Guo-ao
21 restaurants in Beijing were selected to examine the concentrations of VOCs before and after fume purifiers. The results showed that the average concentrations of alkane, alkene, oxygenated volatile organic compounds (OVOCs) and benzene series were (714.62±212.17), (264.88±94.58), (374.72±57.48) and (174.93±55.19)μg/m3, respectively. Among alkene compounds, only the concentration of tetrachloroethylene significantly decreased after fume purifying. Interestingly, the VOC-removal efficiency for 35.7% of fume purifiers was negative. As the most important precursors of ozone, ozone formation potential (OFP) of alkene compounds counted for 48.2%~50.7% of total OFP. Benzene series had become the most important precursor of secondary organic aerosol (SOA) in the restaurant emissions, accounting for more than 95% of the total SOA potential.
2021 Vol. 41 (5): 2040-2047 [Abstract] ( 303 ) [HTML 1KB] [ PDF 1199KB] ( 1764 )
2048 Emission reduction scheme based on source apportionment analysis
XU Yun-fan, WANG Da-wei, XIANG Wei-ling, WANG Zi-fa
In order to quantify the relationship between variability of mass concentration of ambient PM2.5 and the reduction in emission sources scenarios, a WRF-NAQPMS/OSAM model was used in this study to simulate the variations in mass concentration of PM2.5 in Beijing-Tianjin-Hebei and surrounding "2+26" cities in December 2017, and various iterative emission reduction experiments were carried out for cities based on the PM2.5 source apportionment. The results showed that reducing local emission sources in each city had the most significant effect on overall decrease in PM2.5 concentrations. Due to the influence of chemical formation, there was a highly non-linear relationship between the emission sources and the PM2.5 concentrations, which resulted in large uncertainties for the linear-reduction scheme. The changes in PM2.5 concentrations caused by the emission regulation in each city were mainly composed of the contributions of primary emissions and the secondary chemical generation. A significant linear relationship was observed between the PM2.5 concentration contributed by chemical formation and the sector source apportionment. With the reduction of emission sources, most of PM2.5 compositions decreased during the clean periods. However, mass concentration of nitrate, secondary organic compounds, ammonium increased during the pollution periods, which indicated that selection of emission reduction species was vitally important in the iterative emission reduction experiments.
2021 Vol. 41 (5): 2048-2055 [Abstract] ( 276 ) [HTML 1KB] [ PDF 1851KB] ( 1266 )
2056 The change of atmospheric ozone formation sensitivity in Fujian Province based on OMI satellite data during the period of COVID-19
DAN Yang-bin, YU Rui-lian, BIAN Ya-hui, CHEN Jin-sheng, HU Gong-ren
Based on the OMI satellite data, the characteristics of atmospheric ozone sensitivity in Fujian province and its nice municipalities during the period of COVID-19 epidemic were assessed with HCHO and NO2 vertical column densities as proxies for ozone sensitivity. The results showed that Fujian Province was dominated by VOCs-limited regime before the pandemic with the controlled area proportion of 46.5%. The other two regimes:NOx-VOCs-limited regime and NOx-limited regime, controlled 25.0% and 28.5% of the area, respectively. The area proportion controlled by VOXs-limited regime was highest in Xiamen and lowest in Nanping. During the period with strict pandemic control policies, VOXs-limited regime, NOx-VOCs-limited regime and NOx-limited regime controlled 29.5%, 21.1%, and 49.4% of the area, respectively. The area proportion controlled by NOx-limited regime was highest in Ningde and lowest in Putian. During the stable period, VOXs-limited regime, NOx-VOCs-limited regime and NOx-limited regime controlled 23.1%, 29.1%, and 47.8% of the area, respectively. NOx-limited regime was the dominant regime with highest area proportion controlled in Nanping and lowest area proportion in Xiamen. Compared with the before pandemic period, the area proportion of Xiamen controlled by VOCs-limited regime was obviously reduced (38.1% less) during the period with strict control policies, and the lowest reduction was in Sanming with a moderate decrease of 7.9%. According to the conversion results, Putian, Quanzhou, and Xiamen were categorized into the first city group where changes in ozone sensitivity were jointly influenced by its precursors including formaldehyde (HCHO) and nitrogen dioxide (NO2), while other cities could be categorized into the second group where ozone sensitivities were mainly affected by NO2 column concentrations. Therefore, effective strategies for ozone reduction would be more complex in the first group of cities.
2021 Vol. 41 (5): 2056-2063 [Abstract] ( 331 ) [HTML 1KB] [ PDF 1610KB] ( 1407 )
2064 Size distribution of water-soluble ions in particles emitted from domestic firewood burning
FAN Ze-wei, KONG Shao-fei, YAN Qin, ZHENG Shu-rui, ZHENG Huang, YAO Li-quan, WU Jian, ZHANG Ying, NIU Zhen-zhen, WU Fang-qi, CHENG Yi, ZENG Xin, QIN Si, LIU Xi, YAN Ying-ying, QI Shi-hua
Six kinds of domestic firewood were burned in a laboratory. The emitted particles in fourteen sizes were collected using a dilution sampling system and an electrical low-pressure impactor. The emission characteristic and size-resolved emission factors (EFs) of eight types of water-soluble ions were identified. Results showed that the EFs of Ca2+ exhibited a bimodal size distribution, with peaks of 0.14 and 0.16mg/kg for particles within 0.25~0.38 and 2.5~3.6μm, respectively. The EFs of other ions were characterized by a unimodal size distribution. The EFs of NH4+, NO3- and SO42- peaked at 0.25~0.38μm, with peaks of 0.41, 0.58 and 0.84mg/kg, respectively. The EFs of K+ and Cl- exhibited highest values at 0.15~0.25μm of 0.89 and 0.99mg/kg, respectively. The mass median diameters of total water-soluble ions from firewood burning were (0.30±0.07)μm, and those of individual ions ranged in 0.24~0.44μm. The EFs of water-soluble ions in PM0.094, PM0.94, PM2.5 and PM10 were 1.04~9.33, 5.00~48.87, 5.46~52.00 and 6.14~53.68mg/kg, respectively. The ratios of K+/Cl-, K+/NO3-, K+/SO42- and SO42-/NO3- in particles emitted from firewood burning varied with particle size. Their primary emission values should be emphasized when they were used in source apportionment and smoke aging researches. The anion/cation equivalent ratios of PM10 from firewood burning were 0.80±0.11. The acidity of PM0.94 and PM2.5 were higher than those of PM0.094 and PM2.5~10. This study is significant to establish emission inventory of size-resolved water-soluble ions, update and improve the parameter settings of corresponding climate and air quality models, and identify the evolution mechanisms of smokes during transport and aging.
2021 Vol. 41 (5): 2064-2072 [Abstract] ( 278 ) [HTML 1KB] [ PDF 703KB] ( 1103 )
2073 Aircraft observations of aerosol properties in Beijing
HUANG Jia-yi, ZHAO De-long, CHEN Bao-jun, CAI Xiao-dong, DING De-ping, TIAN Ping, HE Hui, HUANG Meng-yu
Spatial and temporal characteristic of aerosol in Beijing were analyzed based on 12-year (2007 to 2018) aerosol observation data through aircraft Yun-12 and King Air. It denoted that the aerosol number concentration in early years has a significant negative growth trend, while the effective diameter has a positive trend. The seasonal variation of aerosol vertical profile was closely related to the seasonal meteorology variation and seasonal PBL variation. The vertical profiles of aerosols in each season or under different weather system were affected by PBL height. The aerosols mixed adequately under PBL height. However, the number concentration near ground in summer is lower than that in winter. It was because higher PBL height in summer allows pollutant mixed evenly in a large vertical extent. The vertical variation of scattering coefficients on 550nm was in good agreement with the aerosol number concentration. High values were usually found in polluted days and winter.
2021 Vol. 41 (5): 2073-2080 [Abstract] ( 327 ) [HTML 1KB] [ PDF 1681KB] ( 1140 )
2081 Comparative study on source parameters inversion performance of typical cost functions
HU Feng, LANG Jian-lei, MAO Shu-shuai, XUAN Bo-yuan
Based on Prairie grass experiments, the differences in inversion performance from eight typical cost functions were systematically evaluated with metrics of accuracy, robustness and overestimation rate. It was found that substantial differences in the inversion performance presented cross models with different cost functions. In terms of single unknown source parameter inversion (only for source strength (Q)), the cost function based on logarithm transformation scheme had the highest overestimation rate (79.4%), and that associated with the sum of deviation squares scheme exhibited the best accuracy (PARD<50%=82.3%, ARD=(35.3±9.1)%); while no significant difference (CV<0.01) was found in the robustness from different cost functions. In terms of three unknown source parameter inversion (source strength (Q) and location (x, y)), the cost function based on normalized root mean square error scheme had the highest overestimation rate (98.5%) for source strength, the logarithm transformation cost function performed the best in the measure of accuracy and robustness (PARD<50%=91.1%, ARD=(48.4±9.8)%; CV=0.01); the cost function based on the sum of deviation squares scheme had the highest accuracy for the source location (AD=(36.12±11.39)m), while the logarithm transformation cost function showed the best robustness (CV=0.0018). In terms of four unknown source parameters inversion (source strength (Q) and location (x, y, z)), the cost function based on normalized root mean squared error exhibited the highest overestimation rate (98.5%) for source strength, and the logarithm transformation scheme got the best accuracy and robustness (PARD<50%=61.7%, ARD=(55.2±16.5)%; CV=0.03); the correlation coefficient scheme performed the best in accuracy and robustness for source location (AD=(34.37±10.72)m; CV=0.011). In general, the logarithm transformation cost function had the most stable inversion performance with the increase of the unknown source parameters.
2021 Vol. 41 (5): 2081-2089 [Abstract] ( 321 ) [HTML 1KB] [ PDF 529KB] ( 706 )
2090 Estimation of VOCs and PM2.5 emissions from catering industry in a typical urban area of Beijing
MA Shu-qiong, LIN Wei-li, XIA Jian-xin
Taking the Xicheng District, in which it has the highest distribution density of catering companies in Beijing, as the area of case study, four types of emission factors for VOCs and PM2.5 based on the number of people dining, dining time, edible oil consumption and number of stoves were obtained through on-site inspections and emission activity level surveys. The annual emissions of VOCs and PM2.5 from catering companies before and after the upgrading of exhaust gas purification equipment were estimated. Results showed that VOCs emission before and after the upgrading of exhaust gas purification equipment ranged from 319.03 to 506.38t/a and 92.14 to 109.89t/a, respectively. PM2.5 emissions also decreased from 166.55~211.09t/a to 30.22~36.05t/a. The VOCs and PM2.5 emissions were significantly reduced by 71%~82% and 80%~86%, respectively. Taking street as unit, the VOCs and PM2.5 emission intensities from catering sources were 1.45~4.32t/km2 and 0.47~1.42t/km2, respectively. Using the measured PM2.5 data, the average reduction in PM2.5 concentration was 28.9% by the upgrading of gas purification equipment, which is most coincident with the reduction ratio calculated from edible oil consumption.
2021 Vol. 41 (5): 2090-2096 [Abstract] ( 347 ) [HTML 1KB] [ PDF 590KB] ( 1178 )
2097 Vertical distribution and regional transport of aerosols in Zhejiang Province
ZHANG Yi-shu, XU Da, HE Qin, LI Dong-hui, QIN Kai
The interannual and seasonal changes of aerosol vertical distributions in Zhejiang Province from 2017 to 2018 were studied using Micro Pulse Lidar (MPL) measurements in six sites. Air quality data were combined to analyse the dominant particulate matter types in terms of seasonal differences. Aerosol extinction coefficients of most sites in 2018 were lower than that in 2017. Spatially, the extinction coefficient within the boundary layer was high in central Zhejiang and low in the eastern and western Zhejiang. Seasonally, the extinction coefficient was the highest in winter, second in autumn, and lower in spring and summer; aerosols were concentrated within 1~2km above the ground in spring and summer, and mainly distributed below 1km in winter; in autumn, affected by high-altitude aerosols, the six stations showed different vertical distribution patterns. Furthermore, the aerosol sources and transmission mechanisms of two trans-regional transport episodes in April and July 2018 were revealed, by using the CALIPSO and MODIS satellite data, as well as the backward trajectory, PSCF and CWT models. It was found that air masses from high AOD areas can significantly increase local pollution in Zhejiang.
2021 Vol. 41 (5): 2097-2107 [Abstract] ( 322 ) [HTML 1KB] [ PDF 9449KB] ( 1692 )
2108 Study on gas pollutants emission characteristics of Fenton/CaO conditioned municipal sludge and biomass mixed fuels combustion
XU Gui-ying, HU Tuan-qiao, WEI He-tao, OU Jiang-bo, GUO Xiao-long, YANG Kai-dong, FANG Bai-zeng
The SO2 and NOx emission characteristics during combustion of municipal sludge conditioned with Fenton/CaO and rice husk (RH) blended briquette fuels were studied. The effects of the mixing ratio, temperature and Fenton/CaO dosage on SO2 and NOx emission characteristics were analyzed. The results showed that with the increase of RH addition in the sludge mixed fuel, the emission of SO2 and NOx gradually decreased, fuel-S conversion rate first decreased and then increased, and fuel-N conversion rate increased continuously. When the temperature gradually increased, the total emissions of SO2 and NOx in the combustion process increased correspondingly. Compared with the SO2 emissions from the unconditioned sludge combustion, the SO2 generated by the Fenton/CaO conditioned mixed molding fuel combustion was nearly 3.5 times lower; while the NOx generation was reduced by 1.3 times. The results showed that the mixed combustion of SS2 and 50% RH had the best emission performance at a combustion temperature of 800℃.
2021 Vol. 41 (5): 2108-2116 [Abstract] ( 289 ) [HTML 1KB] [ PDF 2091KB] ( 1106 )
Water Pollution Control
2117 Effect of C/N/S on nitrate reduction process in activated sludge system
ZHANG Peng-cheng, LI Xiao-ling, WANG Xiao-ting, ZHANG Yu-hao, ZHANG Jia-ying, LIU Xin-yi, ZHANG Wen-bo
The effect of different electron donors (organics or S2-) on denitrification and nitrate nitrogen reduction to ammonium (DNRA) was explored by adjusting inlet C/N and S/N ratios in an activated sequencing batch reactor (ASBR). The results showed that higher C/N ratios improved denitrification process, while higher S/N ratios were more beneficial to DNRA process. NH4+-N, the characteristic product of DNRA, greatly yielded when C/N/S were 2:2:3 and 2:2:4, with the highest effluent NH4+-N concentration of 10.65mg/L at C/N/S of 2:2:4. It indicated that when the electron acceptor was limited, the excess electron donor could increase the activity of DNRA and promote the conversion of denitrification to the DNRA process. 16SrRNA microbiological analysis clarified that Proteobacteria, Anaerolineae, Bacteroidia as well as Actinobacteria were closely related with nitrate reduction process, and Actinobacteria was corelated with the DNRA. Overall, this study provided alternative strategies for the simultaneous removal of carbon, nitrogen, and sulfur in the sewage treatment process.
2021 Vol. 41 (5): 2117-2122 [Abstract] ( 339 ) [HTML 1KB] [ PDF 466KB] ( 1104 )
2123 Degradation of bisphenol S by photo-assisted electrolysis manganese slag/H2O2 heterogeneous system
XU Zi-hao, LI Ying-jie, XIONG Yu-lu, HOU Zhi-chao, LI Jin-suo, TIAN Sen-lin
Electrolytic manganese slag was used as photocatalyst to construct heterogeneous photo-Fenton reaction system. Bisphenol S was used as a model compound to study the degradation mechanism and influencing factors for bisphenol S in the reaction system. The formation rate model of •OH were constructed in the photo-Fenton reaction system. Based on ·OH formation rate model, the prediction model of bisphenol S considering the effect of dissolved organic matter (DOM) were established. The results showed that the mass contents of Fe and Mn in electrolytic manganese with catalytic activity were 1.49% and 2.28% respectively. Compared with other degradation system (i.e., UV, UV/electrolytic manganese slag, UV/H2O2 and electrolytic manganese slag/H2O2 system), the electrolytic manganese slag/UV/H2O2 photo-Fenton system exhibited excellent oxidation degradation efficiency for bisphenol S, and the degradation efficiency of bisphenol S was positively correlated with the dosage of electrolytic manganese slag and H2O2 concentration, but negatively correlated with pH and initial concentrations of bisphenol S. The concentrations of Fe and Mn in the solution was negatively correlated with the pH value, and the coexisting active metal components in the reaction leaching from electrolytic manganese slag were not conducive to the degradation of bisphenol S. Electron spin resonance and radical quenching experiments showed that the main active species for bisphenol S degradation in electrolytic manganese slag/UV/H2O2 system was •OH. The formation rate model of •OH in this system was constructed by using isopropanol, and the formation rate of •OH was estimated to be 3.22×10-9~1.1×10-8mol/(L·s), which was consistent with R·fOH (6.5×10-9mol/(L·s)) calculated by nitrobenzene fitting. The degradation efficiency of bisphenol S decreased with the increase of DOM concentrations. Based on the theory of free radical steady-state kinetics, a kinetic prediction model of bisphenol S degradation in electrolytic manganese slag/UV/H2O2 system in the presence of DOM was established. It was found that the predicted values from the model was in line with the experimental data, indicating that DOM mainly affected the degradation of bisphenol S through quenching •OH in the system.
2021 Vol. 41 (5): 2123-2132 [Abstract] ( 239 ) [HTML 1KB] [ PDF 790KB] ( 1152 )
2133 Effects of AHLs at low temperature on the characteristics of mature biofilms in aerobic zone of multi-stage A/O technology
ZHOU Rong-xuan, MA Xiao-ran, LI Jun, ZHANG Lin-Hua, ZHANG Jing, ZHANG Ya-chao, HAN Hao
Aiming at the problem that the ammonia nitrogen in the effluent of the multi-stage A/O technology is likely to exceed the standard under low temperature conditions, the effect of exogenous addition of acyl homoserine lactone signal molecules (AHLs) on the characteristics of the biofilm in the aerobic zone of the multi-stage A/O technology at low temperature was studied. Results showed that the addition of 100nmol/L hexanoyl homoserine lactone (C6-HSL) increased the biofilm nitrification efficiency by 22.34%, and lauryl homoserine lactone (C12-HSL) increased the amount of attachment biomass by 24.47%, both C6-HSL and C12-HSL had long-term effects on the nitrification efficiency and biological adhesion of biofilm. This was because C6-HSL can increase the aerobic biofilm nitrification activity by 17.56% at low temperature, while C12-HSL could increase the content of protein (PN) in EPS by 67.37%. In addition, both C6-HSL and C12-HSL could promote the endogenous release of the same signal, thus having a long-term positive impact on the nitrification activity and adhesion performance of biofilm. The high-throughput sequencing analysis showed that C6-HSL can increase the abundance of Nitrosomonas, and thus enhancing the nitrification activity of biofilm in R2; while the addition of C12-HSL had a greater impact on the abundance of Rhodobacter, which was an important reason for the increase of PN content in EPS of R5 biofilm.
2021 Vol. 41 (5): 2133-2140 [Abstract] ( 315 ) [HTML 1KB] [ PDF 1575KB] ( 806 )
2141 Adsorption and desorption properties of degradable microplastic for Cu2+ and Zn2+
FAN Xiu-lei, CHANG Zhuo-heng, ZOU Ye-feng, LIU Jia-qiang, LI Ying, HOU Jun
In order to evaluate the carrier effects of degradable microplastics on co-existing pollutants, the adsorption and desorption behaviors of heavy metals (Cu2+, Zn2+) by degradable microplastics was explored, and conventional microplastics PP were selected for control experiments. During the UV ageing process, microplastics (MPs) showed surface cracks, pits, increased specific surface area, increased of negative charge, increased strength of oxygen-containing functional groups and enhanced hydrophilicity. Compared with PP, the physical and chemical properties of PLA were significantly changed during UV ageing. The adsorption capacity of MPs after ageing was much higher than that before ageing, and the maximum adsorption capacity of Cu2+ by aged PLA was 5.56mg/g, which was about 2.5 times that of original PLA (2.27mg/g). The adsorption capacity of PLA to heavy metals before and after ageing was better than that of PP. In the desorption experiment, the desorption rate of MPs to heavy metals after ageing were both lower than before ageing. The desorption capacity and desorption rate of Cu2+ and Zn2+ by PLA were higher than that of PP. Compared with gastric fluid environment, MPs desorption of metal ions was easier in intestinal fluid environment before and after ageing. The results showed that PLA had a stronger carrier effect on heavy metals than PP. At the same time, the results of desorption experiments (simulating human stomach and intestinal environment) showed that PLA was more likely to release heavy metal pollutants into the human body, thereby posing a threat to human health.
2021 Vol. 41 (5): 2141-2150 [Abstract] ( 488 ) [HTML 1KB] [ PDF 3076KB] ( 1847 )
2151 The influence of input data precision and accuracy on SWAT model simulation
CHEN Hai-tao, WANG Xiao-yan, NAN Zhe, HAN Xiao-meng, WU Ai-pu, HUANG Jie-yu, PANG Shu-jiang
The influence of input data precision and accuracy (DEM resolution and precipitation interpolation) on runoff and total nitrogen simulation was studied with runoff and water quality monitoring data of Chaohe watershed from 1990 to 2013 as samples. The results showed that there were different effects of the DEM resolution change (30~300m) on runoff and total nitrogen simulation results. No significant impact on runoff simulation were found, with ENS and R2 above 0.87. While greater effects on total nitrogen simulation results were found. The finer the resolution, the better the simulation accuracy. Under different hydrological years, heterogeneous impacts on simulation performance were found on total nitrogen (TN) load with the change of DEM resolution. There were more significant differences in wet years than in dry years. The influence on the spatial distribution of the annual average (1993~2002) total nitrogen load were much less with the change of DEM resolutions. The high load areas were located in the midstream of the Chaohe watershed, and low load areas in the upstream and downstream. There were larger discrepancies in the spatial distribution of precipitation in the watershed under different distribution and density of monitoring sites, and accuracy of precipitation input data. In general, the runoff and total nitrogen simulation results based on the interpolation data of the fewer weather stations were close to results based on monitoring data of rainfall stations, and the simulation performance based on interpolation data of SWAT official rainfall stations was relatively poor. The spatial distribution of simulated total nitrogen intensity load were obviously different with different precipitation data inputs. The higher the precipitation, the higher total nitrogen load intensity. In different hydrological years, the simulation performance of total nitrogen load also differed with different precipitation data inputs. In wet and dry years, simulation results of TN based on the interpolation data of the weather stations were closer to results based on the rainfall station data, while large simulation deviations were found with the official SWAT rainfall station data. In the normal years, the simulation performance based on official SWAT rainfall station data was better than those based on the interpolation data of the weather stations. This research provided a scientific reference for watershed modeling applications regarding input data accuracy and precision.
2021 Vol. 41 (5): 2151-2160 [Abstract] ( 335 ) [HTML 1KB] [ PDF 1093KB] ( 1260 )
2161 Spatial-temporal characteristics of groundwater quality and its environmental driving factors of Steppe Basin—taken Balaguer river basin of Inner Mongolia for instance
FANG Li-jing, GAO Rui-zhong, JIA De-bin, YU Rui-hong, LIU Xin-yu, LIU Ting-xi
In order to find out the hydro-chemical characteristics, formation and environmental significance of groundwater in Inner Mongolia steppe basin, Balaguer River basin was selected as the typical study area, in which 92 groundwater samples of 46 wells were sampled in the wet and dry seasons of 2018~2019. The Piper trigram, Gibbs graph, principal component analysis (PCA), Nemerow index were adopted to analyze groundwater water quality and the results showed that the groundwater were weakly alkaline, most of which were brackish water and a few were fresh water. Overall, the ion concentrations were higher in wet seasons than dry seasons, and higher in the west area than the east area. Groundwater hydro-chemical types were complex and diverse, including HCO3--Ca2+·Na+, HCO3--Ca2+, HCO3--Ca2+·Mg2+, HCO3--Na2+ and HCO3--Ca2+·Na+·Mg2+. There were no significant hydro-chemical distinctions in different river sections during the dry seasons, while the ion concentrations possessed spatial characteristics and the sources were complicated during the wet seasons. The ions in groundwater were mainly controlled by rock weathering, and Ca2+、Mg2+ mainly came from the dissolution of carbonate, silicate and evaporation, while Na+、K+ came from the dissolution of salt rock. The groundwater quality was better in the whole basin, and the proportion of extremely poor and excellent water was relatively small. The main driving factors of the evolution of groundwater hydro-chemical characteristics were carbonate rock weathering, water karst filtration and human activities. The research results could be taken as a technical reference for protection and restoration of regional grassland ecological environment, exploitation and utilization of water resources and study of watershed eco-hydrology.
2021 Vol. 41 (5): 2161-2169 [Abstract] ( 348 ) [HTML 1KB] [ PDF 1184KB] ( 1057 )
2170 Carbon aerogels: Preparation and adsorption properties to polar pesticides
SONG Dong-bao, XUE Bing, HUANG Peng, ZHANG Peng, SUN Hong-wen
The wood pulp fibers were pretreated with the mechanical ball-milling combined with TEMPO oxidation technology, and then were applied to prepare the carbon aerogels under the high-temperature pyrolysis. The morphology, element composition, special surface area, pore structure and surface functional groups of carbon aerogels were all analyzed, and their adsorption properties were evaluated by cationic imidacloprid (IMI) and anionic 2,4-D. The results showed that modification with mechanical ball-milling combined with TEMPO oxidation could significantly increase the contents of pores, surface C=O functional groups, and polarity of carbon aerogels, and reduce their layer thickness and aromaticity. Their highest specific surface area was over 2631m2/g. The adsorption isotherms of IMI and 2,4-D on carbon aerogels could be well described by the Freundlich model. The main adsorption mechanism of IMI on carbon aerogels was cation/p/π-π electron donor-acceptor interactions, hydrogen bonding, pore filling, electrostatic attraction, while the adsorption of anionic 2,4-D on prepared carbon aerogels was mainly restrained by the electrostatic repulsion. The maximal adsorption capacity of IMI and 2,4-D of the prepared carbon aerogels were 437mg/g and 286mg/g, respectively. Therefore, carbon aerogels modified with the mechanical ball-milling combined with TEMPO oxidation technology had the great potential in the field of adsorption removal of organic pollutants in water.
2021 Vol. 41 (5): 2170-2178 [Abstract] ( 317 ) [HTML 1KB] [ PDF 1015KB] ( 1836 )
2179 Preparation and activity evaluation of heterogeneous magnetic nano-CoFe2O4 activators
LIU Jia-lu, ZHANG Feng-jun, PENG Xin-jing
The magnetic nanoscale cobalt ferrite (CoFe2O4) solid particles were prepared by the sol-gel method. These samples were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), fourier transform infrared spectrometer (FT-IR) and vibrating sample magnetometer. The activity of CoFe2O4 particles was evaluated with the removal experiments of tetracycline hydrochloride (TCH) in the activated persulfate oxidation system. The results showed that the particles calcined at 600℃ had the higher activity and lower metal ion leaching rate on the particle surface. The CoFe2O4 particles prepared at the optimized temperature had high activity in a wide pH range (4.4~9.0) in activated persulfate oxidation system. The TCH removal efficiency reached 82.0% after 4 hours of reaction with the experimental conditions of PDS0 1g/L, CoFe2O4 1g/L, TCH0 50mg/L, 20℃, pH0 4.4. These particles still maintained high activity and structural stability after 10 cycles of reuse, and could be easily recycled due to its special magnetic properties.
2021 Vol. 41 (5): 2179-2186 [Abstract] ( 216 ) [HTML 1KB] [ PDF 1002KB] ( 1489 )
2187 Preparation and optimization of PVDF composite membrane for efficient and selective removal of radioactive cesium
YE Zhao-yong, DING Shi-yuan, YANG Yu, HOU Li-an
In order to achieve the efficient removal of radionuclide cesium (Cs), the FeCN/SiO2/PVDF composite membrane was prepared through the surface grafting between amino functional groups of SiO2 and Fe3+, after SiO2 coating on the hydroxylated PVDF membrane. Loading dosage and particle size of SiO2 were optimized by SEM and XPS analysis to be 0.4% and 300nm, respectively. The Cs removal rate was improved to be more than 99.6% after three times loading of the composite membrane. In addition, XPS results illustrated that the prepared membrane was stable even under strong acid and ultrasound conditions. In the complicated water solution, the coexisting cations competed with Cs adsorption when their hydrated ionic radius were similar in the early stage of filtration. In the later stage, the extent of Cs removal rate decline was positively correlated with the ion radius of coexisting cations due to the influence of Donnan effect. Additionally, natural organic matter (NOM) had a larger effect on water flux, whereas had a weaker effect on Cs removal than that of coexisting cations.
2021 Vol. 41 (5): 2187-2195 [Abstract] ( 306 ) [HTML 1KB] [ PDF 2165KB] ( 886 )
2196 Improving fermentative hydrogen production of anaerobic sludge by redox mediators
ZHANG Li-guo, AI Bing-ling, LI Jian-zheng, BAN Qiao-ying
To improve the hydrogen production activity of anaerobic sludge, the effects of redox mediators (ROMs) on the hydrogen production efficiency of anaerobic sludge using glucose as substrate were investigated by batch culture. The microbial community structure was revealed by Illumina MiSeq sequencing. The results showed that the cumulative hydrogen production and maximum hydrogen production rate (Rmax) of the control were respectively 11.0mL and 0.28mL/h under conditions of the fermentative volume of 100mL and the initial glucose concentration of 500mg/L. When humic acid and anthraquinone-2-sulfonic acid (AQS) as ROMs were added to the system, the hydrogen production capacity of anaerobic sludge was significantly improved. The cumulative hydrogen production was higher than the control by 56.4% and 13.6%, respectively. While Rmax was increased by 53.6% and 10.7%, respectively. On the contrary, the hydrogen production capacity of anaerobic sludge was inhibited when graphene oxide (GO), hennaquinone and anthraquinone-2,6-disulfonic acid (AQDS) were used as ROMs. Illumina MiSeq sequencing revealed that the dominant microbial groups from each sample were different. Thermomarinilinea, Longilinea, Defluviimonas, Gimesia and Planctomicrobium were the dominant genera in control. The major genera were shifted to Thermomarinilinea, Longilinea and Ottowia in humic acid, AQS and hennaquinone fermentation systems. While Thermomarinilinea, Longilinea, Ottowia and Defluviimonas became the predominant genera in AQDS and GO fermentation systems. Redundancy analysis indicated that hydrogen production was positively correlated with Longilinea, Macellibacteroides, Trichococcus, Thioflavicoccus and Ottowia, whereas negatively correlated with Defluviimonas, Pirellula, Gimesia and Ignavibacterium.
2021 Vol. 41 (5): 2196-2202 [Abstract] ( 304 ) [HTML 1KB] [ PDF 538KB] ( 1476 )
2203 Solubilization and desorption effect for tetrachloroethylene of in-suit microemulsion containing Brij35
ZHANG Jing-yi, FU Yu-feng, YAO YU, YUAN Fang, QIN Chuan-yu
A microemulsion was in-situ formed in the aquifer by using binary solutions of non-ionic surfactant Brij35 and cosolvant butanol, and tetrachloroethylene (PCE). The solubilization and desorption ability of the microemulsion toward PCE as well as the formation process and the PCE repair effect in the simulated aquifer were investigated. The results showed that the maximum solubility of microemulsions for PCE was 61.1g/L, which was 9.7 and 2.3 times higher than that of a single Brij35 solution and its conventional mixture. In addition, the solubility of PCE was positively correlated with the volume fraction of n-butanol. The results of desorption experiments showed that in-situ formed microemulsion could play a good role in desorption of pollutants in different types of media. The desorption rate was 3 times higher than that of a single surfactant. Meanwhile, the higher the volume fraction of n-butanol, the larger the particle size of the medium and the lower the viscosity of microemulsion, the higher the efficiency of pollutants desorption. And the optimum desorption capacity was achieved with 250g/L Brij and 35%~30% n-butanol. The simulated flushing experimental results confirmed the in-situ formation of microemulsion in the aquifer. During the early stage, the solubilization was mainly caused by the microemulsion, and in later stages, the solubilization was mainly by the surfactant. After flushing, 94% of the PCE was removed, and the tailing phenomenon in the later stage of washing was effectively reduced.
2021 Vol. 41 (5): 2203-2210 [Abstract] ( 293 ) [HTML 1KB] [ PDF 1310KB] ( 1709 )
2211 Action effects of tetracycline and copper ion on the microorganisms during biological phosphorus removal
ZHANG Hua, JIANG Wei, LIU Ya-li, WANG Jin-hua, HUANG Jian, TAO Hai-tao, CAO Xue-feng, FANG Nan
This paper focused on the specific phosphorus absorption rate to characterize the combined effect of tetracycline and copper ion binary mixtures on the biological phosphorus removal by microorganisms. Three mixtures with different concentration ratios (ratio 1, ratio 2, ratio 3) were designed by the linear average ray method. The relationship curves between the concentration and the action effect were obtained by fitting the experimental data with logistic equations. The combined effects of mixtures on the phosphorus removal microorganisms were analyzed by the concentration addition model. The results showed that the inhibition effect of mixtures on phosphorus removal microorganisms increased gradually with time. The concentration addition model revealed that the combined effect of mixtures with different ratios on the microorganisms gradually changed from antagonistic effect to additive effect and synergistic effect as the treatment time increased. However, there were obvious differences in the composition of these effects. In ratio1and ratio3, there were significant differences in the proportions of each effect, and the antagonistic effect was obvious. However, the antagonistic effect was relatively weak in ratio2 where each effect had similar proportions.
2021 Vol. 41 (5): 2211-2218 [Abstract] ( 336 ) [HTML 1KB] [ PDF 865KB] ( 966 )
2219 Inhibition mechanism of phosphine biological purification system
YU Shuo, LIU Shu-gen, LI Ting
Two electron transport inhibitors (rotenone and anti-mycin A) were introduced to phosphine bio-purification systems, then comparative experiments were conducted to investigate the variations of the microbial growth and metabolisms, phosphorus transport and transformation, the production of reactive oxygen species (ROS), and oxidase activities. When rotenone and anti-mycin A were respectively added to R1 and R2 bioreactors, the average O2-· content in these two systems increased to 0.68 and 0.96 mmol/g during the operation time of 14~17 days, which was significantly higher than control group (i.e. R0 reactor). Besides O2-·, another kind of reactive oxygen species, i.e. HO·, was also detected in bio-purification systems. In addition, due to the ROS accumulation, the malondialdehyde (MDA) content in microorganisms kept at a high level, caused the purification efficiency of phosphine less than 75%. The average phosphine removal efficiency in the R1 and R2 bioreactors decreased to 65.1% and 59.5% respectively, after 15~17 days operation. The factors, e.g., pH, ROS, and oxidase activity, had significant effects on phosphine biological purification. As metal cations such as Mg2+ and Cu2+ migrated into the microbial cells, the enzyme activities of superoxide dismutase and catalase were dramatically improved, which led to the alleviation of the oxidative stress derived from the reactive species such as O2-· and HO·. As the consequence, the purification efficacy of phosphine was improved moderately.
2021 Vol. 41 (5): 2219-2225 [Abstract] ( 300 ) [HTML 1KB] [ PDF 524KB] ( 1319 )
2226 Impact of initial concentration distribution on solute transport in the one-dimensional aquifer
CAO Meng-xiong, CHEN Gang, HU Cheng
This paper developed a novel mathematical model to study the impact of arbitrary initial condition on solute transport in the one-dimensional aquifer. The new mathematical model was developed by including the arbitrary initial condition and three types of boundary conditions (continuous solute input condition、instantaneous solute input condition and pulse-type boundary condition), and analytical solution was derived using the Green's function method. To test the assumptions used in the mathematical model, a laboratory experiment was conducted. Results showed that:The influence of initial conditions on the solute transport results could not be ignored. The experimental results showed that the new model could simulate the one-dimensional solute transport process under arbitrary initial conditions; The new model could be used to study the solute transport process in unsteady flow by linearizing the flow velocity change; The new model improved the previous model by including three different types of inner boundary conditions and arbitrary initial conditions, it could also provide theoretical basis for improving geothermal exploitation and utilization.
2021 Vol. 41 (5): 2226-2231 [Abstract] ( 227 ) [HTML 1KB] [ PDF 752KB] ( 1277 )
2232 Purification effect of non-dynamic cascading bio-filter on domestic sewage in a mountainous village
HAN Yang, DONG Zhi-xin, XIAO Qian-ying, LU Chuan-hao, HU Lei, ZHU Bo, WANG Tao
The present study investigated the performances of a set of non-power cascade bio-filter system constructed based on the low mountains and hills terrain on rural sewage. A continuous one-year monitoring of the performances of this system had been carried out in the typical rural village in low mountainous areas of the Sichuan Basin. The results showed that the average concentrations of chemical oxygen demand (COD), total nitrogen (TN), ammonium nitrogen (NH4+-N) and total phosphorus (TP) in the rural domestic sewage were 147.33, 32.52, 14.39 and 3.03mg/L, respectively. The average removal efficiencies of COD, TN and TP in the cascading bio-filter were 59.6%, 60.8% and 67.4%, with the multi-stage bio-filter units being 39.1%, 44.1% and 54.1%, respectively. The seasonal reduction rates of TN and TP were in the order of summer (autumn) > spring > winter. Influent concentrations, air temperature, plant biomass and hydraulic loading (HL) were regulators of the purification efficiency. Thus, the low-temperature-resistant plants and rain-sewage separation in the later stage to optimize purifying efficiency and improve the general applicability were recommended to improve domestic sewage purification to protect water environment in mountainous villages of the upper reaches of the Yangtze River.
2021 Vol. 41 (5): 2232-2239 [Abstract] ( 267 ) [HTML 1KB] [ PDF 486KB] ( 1085 )
2240 Microbial mechanism of A2O process for wastewater treatment in plateau habitat
HAO Kai-yue, LI Yuan-wei, ZONG Yong-chen, YOU Jun-hao, GUO Ming-zhe
Based on Illumina MiSeq high-throughput sequencing technology, the structure, abundance and correlation of the microbial community at different temperatures were discussed in the A2O process activated sludge under the plateau habitat. Combined with the role of the main functional proteins, functional genes, enzymes and their abundance in the metabolic pathways of carbon, nitrogen, phosphorus, sulfur and other pollutants during the decomposition, adsorption and transformation of pollutants, the microbial mechanism of A2O process for sewage treatment in plateau area was analyzed from the perspective of biochemistry and molecular level. The results showed that the dominant bacterial Phylum were Proteobacteria, Bacteroidetes, Actinobacteria, Firmicutes and Chloroflexi, and the dominant bacterial genus norank_f_AKYH767, norank_f_Saprospiraceae, Ottowia, unclassified_f_Burkholderiaceae, IMCC26207, and Novosphingobium. The optimum temperature for pollutant removal and microbial community was 15℃, and the optimum temperature for COG, metabolic pathway, gene and enzyme activity of microbial community was 20℃. The main functional proteins were general function prediction only, amino acid transport and metabolism, transcription. The main metabolic pathways were ABC transporters, two-component system, purine metabolism, ribosome and pyrimidine metabolism. The main functional gene products (enzymes) were enoyl-CoA hydratase, acetyl-CoA C-acetyltransferase, aldehyde dehydrogenase (NAD+), thiosulfate and exopolyphosphatase.
2021 Vol. 41 (5): 2240-2251 [Abstract] ( 419 ) [HTML 1KB] [ PDF 1850KB] ( 6715 )
2252 Effect of polypropylene microplastics on the performance of sludge anaerobic digestion
JIANG Xiao-ying, LIU Yong-xi, QIN Yan, GAO Pin
Polypropylene (PP) microplastics (MPs) were used to investigate their effects on the production of methane (CH4) and volatile fatty acids (VFAs) in sludge anaerobic digestion. The abundances of acetate kinase (AK) and mcrA genes under stresses of different amounts of PP MPs were determined by quantitative real-time PCR methods. The results showed that production of CH4 and VFAs was enhanced by addition of PP MPs. The cumulative productions of CH4 and acetic acid increased with increasing dosages of PP MPs. When the addition of PP MPs was 0.2g/g VSS, the cumulative productions of CH4 and acetic acid increased by 148.2% to 227.1mL/g and 15.2% to 1291.2mg/L, respectively, compared with the controls. Correspondingly, the abundance of mcrA genes increased by 98.2%, which indicated that PP MPs had a promoting effect on the growth of methanogens, thereby enhanced CH4production during sludge anaerobic digestion.
2021 Vol. 41 (5): 2252-2257 [Abstract] ( 387 ) [HTML 1KB] [ PDF 358KB] ( 1820 )
2258 Adsorption and desorption behavior of 17α-ethinyl estradiol on microplastics
JIANG Hui, LIU Xin, SUN Jiao-xia, HU Ying, ZHOU Jin-shan, LIU Xiu-li, QUE Si-si
The endocrine disruptor 17α-Ethinylestradiol (EE2) was used as the target pollutant to study the adsorption kinetics, adsorption isotherm and desorption of five kinds of microplastics:polyamide (PA), polyethylene (PE), polyurethane (TPU), polyvinyl chloride (PVC) and polystyrene (PS). The results of adsorption kinetics and adsorption isotherm showed that the adsorption capacity of five kinds of microplastics for EE2 was in the order of PA > TPU > PE > PVC > PS. TPU and PA had the largest adsorption capacity, which was mainly due to the chemical adsorption of hydrogen bonds; while PE, PS and PVC mainly depended on the interaction of van der Waals force. Because PA and TPU had stronger adsorption capacities for EE2, their desorption capacity was also higher than the other three substances. When the desorption rate was used to reflect the desorption performance of different microplastics, it was found that the desorption rate of EE2 in PS was the highest, while that in PA and TPU were relatively low. Single factor repeated measurement ANOVA was used to analyze the analytical characteristics of EE2 on five kinds of microplastics. There was significant difference between PS and the other four kinds of microplastics, but no significant difference was found in pairwise comparison among these four kinds of microplastics. Although the desorbing rate in gastrointestinal juice was higher than that of deionized water, there was no statistical significance between them.
2021 Vol. 41 (5): 2258-2267 [Abstract] ( 292 ) [HTML 1KB] [ PDF 1172KB] ( 1326 )
2268 The use of kitchen waste fermentation liquid as carbon source for denitrification based on facultative treatment system
ZHU Zi-han, ZHOU Tao, ZHAO You-cai, YU Yi, OUYANG Chuang, CAO Rui-jie, CHEN Shan-ping, ZHANG Rui-na
The fermentation liquid of kitchen waste was used to adjust the ratio of carbon and nitrogen (C/N) in the denitrification system with facultative condition. Results showed that there was no accumulation of organic matter in the system, while the maximum accumulation concentration and efficiency of nitrite under high C/N conditions were higher than those of low C/N conditions. With the increase of C/N, the nitrogen removal rate and denitrification rate continued to increase. When C/N was 13, the denitrification rate achieved the maximum of 9.79mg/(gVSS·h), and the denitrification rate exceeded 95%. Besides, the denitrification rate and the maximum accumulation concentration of nitrite were directly proportional to influent nitrate concentration under the same C/N conditions. For facultative system, the removal of unit nitrogen required more organics, and the denitrification and nitrite reduction rate were lower than that of anaerobic system, although there was no COD residual occurring in the denitrification process.
2021 Vol. 41 (5): 2268-2274 [Abstract] ( 319 ) [HTML 1KB] [ PDF 576KB] ( 960 )
2275 Effect of colloids on the mechanism of chloroform formation during managed aquifer recharge （MAR)
ZHANG Wen-jing, WEN Zong, LIU Dan, CHAI Juan-fen, CHEN Xue-qun
To investigate the secondary formation of chloroform under the influence of colloidal effect during managed aquifer recharge, this paper used batch experiments to study the formation of chloroform under different hydrochemical conditions with and without colloids. The synergistic mode between chloroform and silica colloids was analyzed by tangential flow ultrafiltration technique combined with atomic force electron microscopy(AFM). The results indicated that the formation of chloroform increased with the increase of contact time. High chloride/TOC ratios, high pH, and low ionic strength promoted the formation of chloroform in a specific contact time. The presence of silica colloid affected the adsorption of the reaction precursor, which inhibited the formation of chloroform at all contact times and had a strong adsorption effect on chloroform in water. These results can provide a scientific understanding of the secondary formation of chloroform during artificial recharging processes.
2021 Vol. 41 (5): 2275-2282 [Abstract] ( 333 ) [HTML 1KB] [ PDF 873KB] ( 1031 )
Solid Waste
2283 The analysis of dominant factors in enhancing municipal sludge bioleaching efficiency by quartz sand
SONG Yong-wei, MA Ying-ying, WANG rui, WU Yi-qian, WANG He-ru
Major factors affecting the improvement of bioleaching efficiency with the participation of quartz sand were investigated. Results showed that the bioacidification of A. ferrooxidans was the dominant factor in the first 0~72h. After 72h, the formation of secondary minerals was more significant than the bioacidification of A. ferrooxidans in improving sludge dewaterability, thereby became the major factor. The gradual increment in the yield of secondary minerals could be attributed to the continuing bioleaching process, and further increased the dewaterability based on bioacidification. The specific resistance to filtration (SRF) of municipal sludge declined from the initial value of 17.13×1012m/kg to a minimum of 3.56×1012m/kg at 48h under the joint action of bioacidification and secondary minerals. By comparison, the minimum sludge SRF under each single factor could be observed at 72h, i.e., 3.89×1012m/kg for bioacidification and 4.77×1012m/kg for secondary minerals. Thus, the joint action of these two factors was more efficient in reducing the bioleaching time and further improving sludge dewaterability.
2021 Vol. 41 (5): 2283-2289 [Abstract] ( 250 ) [HTML 1KB] [ PDF 609KB] ( 559 )
2290 Performance of AnMBR for the co-digestion of food waste and waste activity sludge
LU Bin, GONG Kai, JIANG Hong-Yu, LI Qian, CHEN Rong
Continuous experiments and activity experiments were conducted to systematically explore the effect of anaerobic membrane bioreactor (AnMBR) on the efficiency, stability, and kinetic characteristics of the treatment of food waste and waste activated sludge under different organic loading rates (OLRs). The results indicated that AnMBR can operate stably under various working conditions (OLR:3.22~12.92gCOD/(L·d)). When the OLR was 6.48gCOD/(L·d), the methane production was (4335±2)mL/d, the methane yield (calculated as COD) was (361.2±0.2)mLCH4/gCODremoval, the COD removal efficiency was maintained at (98.6±0.9)%, and the pH was stable at 7.71±0.03. When the OLR exceeded 12.92gCOD/(L·d), the volatile fatty acid in the reactor reached 6108mg COD/L. Membrane fouling was dominated by cake layer fouling. High-throughput sequencing was used to characterize the evolution of microorganisms in the system. Levilinea was the dominant genus of bacteria, and its relative abundance was highest (20.1%) when the OLR was 6.48gCOD/(L·d). Methanosarcina was the dominant genus of archaea, and its relative abundance was maintained above 67% as the OLR increased. Specific methanogenic activity experiments showed that with the increase of OLR, the ability of methanogens to degrade acetic acid continues to increase.. The results of this research provide useful information for the selection of optimal working conditions of AnMBR treatment for the co-digestion of food waste and waste activated sludge.
2021 Vol. 41 (5): 2290-2298 [Abstract] ( 336 ) [HTML 1KB] [ PDF 1350KB] ( 998 )
2299 Application of 3D printing technology in the resource recycling of solid wastes
ZHANG Wan-bing, ZHANG Fu-shen
Printing material is the bottleneck problem limiting the development and industrial application of 3D printing technology. Thus far, it had been found that some solid wastes had high compatibility with 3D printing, which could be used to prepare 3D printing material. This paper reviewed four types of solid wastes which could be applied in 3D printing, including Si-Al based waste, agricultural and forestry waste, plastic waste and scrap metals. The methods of preparing 3D printing materials from these four types of wastes and the influence of wastes additions on the original printing materials were discussed emphatically. Meanwhile, the problems needed to be solved in the preparation of 3D printing materials from wastes were analyzed, and the development prospects of waste-based 3D printing materials was also articulated.
2021 Vol. 41 (5): 2299-2310 [Abstract] ( 656 ) [HTML 1KB] [ PDF 743KB] ( 3858 )
Soil Pollution Control
2311 The process of organic acid chemical leaching of radionuclide thorium polluted soil
JIANG Wen-bo, GAO Bai, SHEN Wei, ZHANG Hai-yang, WANG Juan, YI Ling, YANG Bing, LIAN Guo-xi
Oxalic acid, citric acid and tartaric acid were selected to study the leaching effect on typical radioactive thorium contaminated soil with different particle sizes. The changes of fluidity and stability of leaching solution after leaching were analyzed in terms of soil extractable forms, and the soil remediation mechanism and the destruction degree of soil crystalline phase were characterized with leaching kinetics and X-ray diffraction analysis (XRD). The experimental results showed that for oscillating leaching of oxalic acid, citric acid and tartaric acid, the optimal parameter was oscillating for 8hours with concentration of 0.5mol/L, and the leaching effect was in the descending order of oxalic acid > citric acid > tartaric acid > malic acid > acetic acid. On the premise of achieving the purpose of remediation, the whole crystalline phase of the soil after leaching was less damaged, the diffraction peaks of silica was obviously enhanced, the proportions of residual state in each soil sample were increased by 19.39%~27.20% and 0.63%~8.45%, the fluidity was obviously lowered by approximately 10%, and the stability was slightly enhanced. The results provided guiding references for chemical leaching remediation of radioactive contaminated soil.
2021 Vol. 41 (5): 2311-2318 [Abstract] ( 293 ) [HTML 1KB] [ PDF 939KB] ( 1474 )
2319 Source apportionment of lead pollution in soil based on the stable isotope and multi element characteristics
XIAO Wen-dan, YE Xue-zhu, ZHANG Qi, ZHAO Shou-ping, CHEN De, HUANG Miao-jie, HU Jing, GAO Na
Farmlands near electroplating factories and mining areas were selected as the research objects in this study, the single factor index method and Nemero index method were used to evaluate the pollution status of soil heavy metals, and the source of soil Pb was investigated based on the Pb stable isotope and multi element characteristics analysis combined with principal component analysis and cluster analysis. The contribution rate of each pollution source was further quantitatively identified. The results indicated that the farmland soil samples near the electroplating factories and mining areas were seriously polluted by heavy metals, and the lead pollution in both areas reached the severe pollution degree. According to the Pb isotope ratios (207Pb/206Pb、208Pb/206Pb) in samples from different pollution sources and the farmland soil, the contribution rates of each pollution source were calculated by Isosource software. The results showed that the cumulative contribution rates of electroplating waste effluents and solid waste to the Pb pollution in farmland soil nearby was 70.5%, the corresponding contribution rate of ore and tailings piled up in mining area was 71.7%. To further identify the sources of lead pollution in soil, the contents of 28 multi-element in samples from different pollution sources and the farmland soil were studied by principal component analysis and cluster analysis. The results revealed that the multi-element composition of different sources was quite different. The multi-element composition of farmland soil near electroplating factory had the highest similarity with electroplating waste effluents and solid waste, and the multi-element composition of farmland soil near mining areas had the highest similarity with the ore and tailings. Therefore, it could be concluded that the waste effluents and solid waste discharged from the electroplating factory, and ore and tailings piled up in the mining area were the major sources of Pb pollution in farmland soils nearby, respectively. Our analysis also suggested that source apportionment of Pb based on Pb stable isotope ratio and multi-element composition combined with principal component analysis and cluster analysis had the high accuracy and reliability.
2021 Vol. 41 (5): 2319-2328 [Abstract] ( 361 ) [HTML 1KB] [ PDF 564KB] ( 2110 )
2329 The acid dissolution characteristics of arsenic fixed by iron-silicon material
JU Lin, GUO Xiang, YAO Ai-jun, QIU Rong-liang, TANG Ye-tao
In order to assess the environmental stability of As immobilized by IS (IS-As) under acidification conditions, the acid dissolution characteristics of IS-As were investigated by using acidimetric titration method and X-ray powder diffraction (XRD) analyses. The results showed that IS was strongly resilient to the acid dissolution. The As fixed by IS was the most sensitive to acid dissolution in the pH range of 7.68~11.48, in this range the acid dissolution rate of AsO43- was fast, this non acid-stable As accounted for 37.5% of total dissolved As. The As dissolution rate was relatively low in the pH range of 7.68~4.10. In this range, the proportion of weak acid-stable As accounted for 7% of total As and of acid-stable As was 55.5% of total As. XRD results showed that the dissolution order of major As containing minerals in IS under acidic conditions (ranked from high pH values to low pH values) was:Ca3(AsO4)2 > AlAsO4 > As2O3 > Ca4SiAs4 > FeAs3O9·4H2O > Mn2As2O7/SiAs2. The acid dissolution rate of elements from IS-As was in the order:S(94.8%)>Na(93.0%)>Ca(78.8%)>As(44.5%)>Mg(41.7%)>Al(37.6%)>Mn(37.5%)>Fe(5.5%). Results demonstrated that the non acid-stable As in IS was mainly Ca bound As, the weak acid-stable As was primarily and weakly binding with Mg-, Mn-,Fe bearing minerals, and the acid-stable As was dominantly and strongly binding with Fe-Mn-Si containing minerals. The results provided some basis for the safety risk evaluation of applying IS on soils for the remediation of As contamination. It also provided a new reference for the selection of remediation materials for As contaminated soils as well as studies of soil As speciation.
2021 Vol. 41 (5): 2329-2335 [Abstract] ( 194 ) [HTML 1KB] [ PDF 554KB] ( 776 )
2336 Crops planting on improvement of saline soil in coastal reclamation area: A case of sorghum planting under covering conditions
CHEN Li-hua, SU Wei-xia, YAO Yu-tian, GUO Shi-wei, HAN Rui, SHANG Hui, ZHOU Long-xiang, WANG Dong, ZHANG Feng-ge
To investigate the effect of sorghum planting on coastal saline soil physicochemical properties, biological characteristics and surface biomass, a field experiment was carried out during single growth period (from middle April to middle August) in coastal reclamation area. The results showed that sorghum planting significantly (P<0.05) improved the soil physicochemical properties. Compared with NP (without covering and sorghum planting) and NPC (only covering), salt content and bulk density were significantly (P<0.05) decreased, while the water content, total porosity, maximum moisture capacity, field water capacity and organic matter content were significantly (P<0.05) increased in the treatment of PC (covering and sorghum planting). The populations of culturable microorganism (soil bacteria, fungi, actinomycetes, cellulose decomposition bacteria and nitrogen fixation bacteria) were significantly (P<0.05) increased in the PC treatment. Before sorghum harvest, soil respiration intensity in the PC treatment was significantly (P<0.05) increased by 35.71% and 26.67%, respectively, as compared with NP and NPC. Surface biomass in the PC was 3.86 and 3.16 times higher than that of NP and NPC, respectively. In conclusion, sorghum planting efficiently improved soil quality and biological function, which provided an ecological and feasible way for agricultural utilization of land in new reclamation area.
2021 Vol. 41 (5): 2336-2342 [Abstract] ( 195 ) [HTML 1KB] [ PDF 432KB] ( 676 )
2343 Uranium isotopes in surface soil in Inner Mongolia and northwest China: level, distribution and sources
HUANG Zhao, HOU Xiao-lin, ZHAO Xue, ZHANG Lu-yuan
In total 132 surface soil samples were collected from Northeast China. The ground and homogenized soil was completely dissolved using mixed acids. Uranium was separated from the sample matrix by extraction chromatography using UTEVA resin, and uranium isotopes in the separated sample were then measured by a triple quadrupole Inductively Coupled Plasma Mass Spectrometry (ICP-MS/MS) to learn the level and distribution of 238U, 235U, 234U concentrations in surface soil of the study. The 234U in surface soil of this area was reported first time, and an obvious isotope fractionation of 234U was observed in some soil samples indicated by the increased 234U/238U ratios. The distribution of 235U/238U atomic ratios in these surface soil samples showed an obvious regional deposition of uranium derived from atmospheric nuclear weapon tests the windward slope of the mountain. Consequently, the level of 235U/238U atomic ratios in the surface soil in west site of Greater Khingan Mountain were higher than other places. The level of uranium isotopes in surface soil was comparable to the environmental background level in other places, indicating negligible impacts from human nuclear activities. The source analysis showed that uranium isotopes in surface soil were dominated by rock weathering, human industrial and agricultural activities also contributed moderately in some areas.
2021 Vol. 41 (5): 2343-2351 [Abstract] ( 330 ) [HTML 1KB] [ PDF 2473KB] ( 1598 )
2352 The interaction between plastics and microorganisms in soil and their ecological effects
JU Zhi-cheng, JIN De-cai, DENG Ye
The pollution of plastics and microplastics in the soil environment attracted lots of attentions in recent years. This paper reviewed the latest research progresses on the interaction between microorganisms and soil plastics. The main contents included, (i) the source and migration of soil plastics and their basic characteristics of long-term storage forms in the soil; (ii) the impacts of soil microorganism on plastics; (iii) the impacts of plastic pollution on soil microbiota, enzyme activities, animals and crop production, and the potential impact on the function of global terrestrial ecosystems. Finally, the future research directions on plastics and microplastics pollution were discussed, topics range from functional microorganisms, experimental design, plastisphere, large-scale and long-term studies on plastics and soil microorganisms. This review provided valuable references for understanding and solving plastic pollution in soil from a microbiological perspective.
2021 Vol. 41 (5): 2352-2361 [Abstract] ( 543 ) [HTML 1KB] [ PDF 425KB] ( 3167 )
2362 The background concentration of rare earth element and its impact factor in soil of Shenzhen City
XI Xiu-ping, ZHAO Shu-hua, YANG Kun, ZHAO Yan, LIAO Man, WU Jing-ya, LI Ting, LUO Fei
For the purpose of studying the environmental background concentration and spatial distribution characteristics of rare earth element in soil of Shenzhen, 450 soil surface sample sites and 50 typical soil depth profile sample sites were selected in the scope of basic ecological control line which was not or little affects by the human being. 500 top soil samples and 100 sectional samples were collected by unit-multi increment sampling method. The results showed that the range of the environmental background concentrations of REE in topsoil of Shenzhen was 23.66~1246.26mg/kg, the arithmetic average value was 285.99mg/kg, which was higher than that in soil of China and Guangdong province. The top soil of Shenzhen was enriched-type of light rare earth element, and the spatial distribution patterns of concentration of REE was high the west and low in the east. The sequence of 95% fraction value of REE concentration in different soil types was lateritic red soil > red soil > yellow soil. The order of 95% fraction value of REE concentration in different parent rocks was metamorphic rock > granite > gneiss > tuff lava > gravel shale > grey limestone. The order of 95% fraction value of REE concentration in different levels of soil profiles was under layer > middle layer > surface layer. The REE background concentration raised with the increase of soil depth, which showed a characteristic of accumulation on the bottom. The parent rocks was probably the first influential factor of REE background concentrations in soil, as which was remarkable higher in soil developed by granite than that by gravel shale. Different soil types also might affect the soil REE background concentration. The REE background concentration was higher in lateritic red soil than in red soil, which were derived from the identical parent rock. Canonical correlation analysis showed a significantly positive correlativity was found between Fe, Al and light rare earth element as well as between Mn and heavy rare earth element, while the correlativity between soil pH as well as clay particle and soil REE background concentration was weak. The result was also indicated the inheritance of soil REE from parent rock.
2021 Vol. 41 (5): 2362-2373 [Abstract] ( 395 ) [HTML 1KB] [ PDF 1600KB] ( 1219 )
2374 In situ immobilization remediation of cadmium-contaminated paddy soil and the characteristics of phosphorus accumulation and movement in water-soil environment
YAO Zhen-hui, TU Li-da, ZHOU Hui-ping, HU Peng-jie, WANG Tian-tian, ZHENG Jia-jun
Two amendments, calcium-magnesium phosphate fertilizer (CaMgP) and calcium-aluminum hydrotalcite (CAH), were selected to immobilize cadmium (Cd) in a Cd-contaminated paddy field in the South Jiangsu Province. The Cd-immobilization efficiency and the characteristics of phosphorus (P) accumulation and movement in water-soil environment caused by using P-containing amendments were studied. The results showed that the application of two amendments both effectively reduced the availability of Cd in the soil. The concentrations of available Cd in all treatments slowly decreased over time and reached the lowest level at the time of 16 weeks from amendments application. Compared to the initial soils, the immobilization efficiency of Cd for different treatments were sorted in descending order as 1500kg/hm2 CaMgP (54.5%) > 6000kg/hm2CAH (50.3%) > 750kg/hm2 CaMgP (46.9%). A significant and negative relationship between soil pH and available Cd at different stages of treatments was also found. The application of CaMgP as an amendment accelerated the accumulation of P in the soil. In addition, the total P and soluble P concentrations in the leakage water at 60~90cm depth tended to increase significantly with the increasing of CaMgP application.
2021 Vol. 41 (5): 2374-2379 [Abstract] ( 331 ) [HTML 1KB] [ PDF 385KB] ( 1149 )
Environmental Ecology
2380 Green vegetation extraction based on visible light image of UAV
ZHOU Tao, HU Zhen-qi, HAN Jia-zheng, ZHANG Hao
Using visible light images taken by unmanned aerial vehicle (UAV) as data source, a new green vegetation index named as Difference Enhanced Vegetation Index (DEVI) was proposed based on the analysis of healthy green vegetation spectral characteristics and the differences of pixel values among different bands of typical ground objects in visible light images of UAVs. DEVI utilized the information of red, green and blue visible bands, which can not only eliminate the interference caused by the difference of pixel values in a single band of green wave of different ground objects, but also enhance the characteristic that the reflectivity of green wave of green vegetation is greater than that of red and blue bands. This new index and 8 other common visible light vegetation indexes were used to extract the green vegetation by the threshold method in the study area, and then the support-vector machine (SVM)-based supervised classification method and the ground truth area of interest (ROIs) were used to evaluate the extraction accuracy. The results showed that the extraction accuracy of DEVI was significantly better than the other eight vegetation indexes. When the threshold method of image histogram visual detection was adopted, the overall accuracy was 98.98%, the Kappa coefficient was 0.9791, and the relative error was 1/83. Meanwhile, the gray image histogram of vegetation index calculated by DEVI had a good bimodal shape, which could quickly determine the threshold value, and the threshold value was generally located between 0.9 and 1. To verify whether DEVI has good applicability and reliability, this study chose three typical areas to conduct the feasibility verification analysis:area with high vegetation coverage, area with dense regions of buildings, and area with discretely distributed vegetation. The results showed that the green vegetation information in regions with dense buildings and discretely distributed vegetation could be extracted with high precisions by DEVI. The overall accuracy was 98.42% and 98.56%, the Kappa coefficient was 0.9610 and 0.9635, and the relative error was 1/125 and 1/91, respectively. However, the extraction accuracy in areas with high vegetation coverages was slightly less accurate with the overall accuracy of 97.40%, a Kappa coefficient of 0.9371, and a relative error of 1/53. Therefore, the new DEVI could extract the green vegetation information from UAV visible light images in typical vegetation covered areas in an effective, high-precision and low-cost way. Therefore, DEVI is a feasible method for the green vegetation monitoring research in terrestrial ecosystems.
2021 Vol. 41 (5): 2380-2390 [Abstract] ( 441 ) [HTML 1KB] [ PDF 3502KB] ( 4299 )
2391 Migration of iron and manganese ions during ice melting
ZHANG Yan, REN Fang-yun, TANG Yuan-qing, ZHAO Wan-li, ZHAO Tong-guo, LIU Tong-shuai, LIU Yu-can, SHEN Hung-tao
In order to explore the migration law of heavy metal ions in the process of ice melting, indoor simulated ice melting experiments were carried out to study the migration law with iron and manganese ions as example metal ions, and the effects of initial concentration and freezing temperature on the migration process were also analyzed. The results showed that under different initial concentrations and freezing temperatures, the concentration distribution of iron and manganese ions in ice was as follows:middle layer < upper layer < lower layer; In the process of ice melting, 51.17%~71.67% of iron and manganese ions were released in the early stage of ice melting (0~25%), and in the middle and late stages, iron and manganese ions were released stably and evenly. In addition, the initial concentration had little effect on the migration of iron and manganese ions during ice melting. When the freezing temperature was low, the concentration of iron and manganese ions increased basically in melt 1. In the process of ice melting, with the increase of accumulated melt water volume, the ratio of the concentration of iron ion and manganese ion in melt water to initial concentration of ice body gradually decreased, and showed an exponential function attenuation mode.
2021 Vol. 41 (5): 2391-2398 [Abstract] ( 339 ) [HTML 1KB] [ PDF 875KB] ( 1366 )
2399 Classification method of swamp vegetation using UAV multispectral data
ZUO Ping-ping, FU Bo-lin, LAN Fei-wu, XIE Shu-yu, HE Hong-chang, FAN Dong-lin, LOU Pei-qing
This paper established machine learning models to classify swamp vegetation communities based on high-resolution UAV multispectral images. In Honghe National Nature Reserve, typical sample areas were selected in the core area, buffer zone and experimental area and ortho-images of these areas were acquired using low-altitude UAVs with RGB and multispectral cameras. Multidimensional datasets were then derived from multiresolution segmentation of ortho-images, and established four classification scenarios. The object-based random forest (RF) algorithm was used to classify vegetation communities after feature selection and parameters (mtry and ntree) optimization and tuning. This algorithm also could rank the importance of each feature in multidimensional datasets and eliminat data redundancy accordingly. The results showed that:The optimized object-based RF algorithm had a high recognition ability for swamp vegetation. The scenario 4 (combination of spectral bands, texture features, geometric features, location features, surface elevation information and vegetation indexes) in the core area obtained the highest overall accuracy (87.12%), and the kappa value was 0.850 at the 95% confidence interval, which was 12.27% higher than scenario 2 (combining spectral bands, geometric features and location features), and the kappa value improved 0.140; For an identification accuracy of typical swamp vegetation, the classification of the reed achieved the highest user's accuracy of above 88%, and its producer's accuracy was higher than 90%. The classification of Calamagrostis angustifolia also achieved over 85% of producer's accuracy, but its user's accuracy (78%) was lower in the core area. This method can be used as an effective method to identify swamp vegetation communities and provide more accurate data support for studying dynamic changes of wetland ecological environment.
2021 Vol. 41 (5): 2399-2410 [Abstract] ( 303 ) [HTML 1KB] [ PDF 6481KB] ( 1331 )
2411 Evaluation of China's forest ecological security based on variable weight theory and DPSIRM
LI Tan, CHEN Tian-yu, MI Feng, MA Long-bo
This study combined the variable weight theory and the DPSIRM causality framework to construct an evaluation system with 6subsystems and 23 indicators for forest ecological security in China. The constructed system was applied to evaluate the status of forest ecological security of 31 provinces (cities, autonomous regions) in China during 2005~2017, drawing on data collected mainly from 2006~2018 China Statistical Yearbook and forestry statistical yearbook and using the K-means clustering method guided by the variable weight theory. The results showed that:(1) During the study period, China's forest ecological security measured by the DPSIRM-based index exhibited an overall increasing yet slightly W-shaped fluctuating trend. (2) The mean value of the variable weight was found to be the highest for the State subsystem (0.0781), followed by the Management (0.0728) and Response (0.0640) subsystems. The mean score of the Management subsystem showed an N-shaped changing trend, significantly interacting with the other subsystems and substantially affecting overall forest ecological security. (3) The comprehensive value of forest ecological security in most provinces showed either a steady increase or a fluctuating upward trend, while the values in Liaoning, Tibet and the other areas fluctuated and declined. There were evident differences in the status of regional forest ecological security, as the mean score of Southwest China was as high as 0.3414 but the mean scores of Northwest China, East China and Central China were much lower than the national average level of 0.2794. (4) The overall situation of forest ecological security in China revealed an improving trend at the national level, albeit with a serious divergence phenomenon across regions at the provincial level. Specifically, areas with traditional forestry advantages possessed relatively benign situation of forest ecological security, while those with rapid economic development entailed higher ecological risk. It was suggested that forest ecological restoration projects should be vigorously implemented and promoted by prioritizing ecologically fragile areas and economically developed areas to strengthen the protection of existing forest resources.
2021 Vol. 41 (5): 2411-2422 [Abstract] ( 266 ) [HTML 1KB] [ PDF 680KB] ( 811 )
2423 Construction of ecological security pattern in Chengdu-Chongqing Twin-City Economic Circle
ZHAO Wei, ZOU Xin-yi, PU Hai Xia
Took Chengdu-Chongqing Twin-City Economic Circle (CCTCEC) as the research object, and the ecological source areas were firstly identified based on Land-use datasets and the evaluation of ecosystem importance. The GIS spatial analysis technology, minimum cumulative resistance (MCR) model and night lighting optimization method then were applied to establish the regional ecological resistance surface.Finally, gravity model was used to identify key ecological corridors and ecological nodes to construct the ecological security pattern of the study area. The results showed that the ecological sources of CCTEC cover 24.8% of the total territory and mainly located on the east, south and west areas. 193 ecological corridors with the length of 6441.81km were successfully identified, and the density decreases from the east to the west in space. The key corridors account for 46.56% of the total identified corridors, which mainly distributed in the Northeast of study area including Dazhou, Wushan and Wuxi. Comprehensively, the "dual cores-two axes-half surrounded" spatial pattern had appeared.
2021 Vol. 41 (5): 2423-2433 [Abstract] ( 314 ) [HTML 1KB] [ PDF 4309KB] ( 1313 )
Environmental Toxicology and Health
2434 Bioaccumulation and biotransformation of perfluorooctane sulfonamide in wheat and earthworms
WU Si-han, WU Yu-meng, WANG Shuang-jie, CHEN Meng, LIU Qing, ZHU Ling-yan
The bioaccumulation and biotransformation of perfluorooctane sulfonamide (PFOSA) in wheat and earthworms was investigated in different culture media by different culture methods. The results indicated that PFOSA was effectively absorbed by wheat roots from the culture media and translocated from roots to shoots. The bioavailability of PFOSA in soil was significantly affected by the soil total organic carbon (TOC) content. The bioavailability of PFOSA in the soil with higher TOC content was reduced, resulting in the bioaccumulation factors in wheat and earthworms decreased from (61.24±8.42) and (21347.91±208.86) to (5.61±0.23) and (1404.92±108.21), respectively. PFOSA could be transformed into PFOS in the earthworms as well as in the roots and shoots of wheat, but the transformation rate of PFOSA in the earthworms ((3.87±1.71)%) was significantly lower than that in the wheat ((26.39±3.02)%). The ratio of branched PFOS isomers (br-PFOS) in the wheat roots was (14.8±2.0)% and (66.1±26.2)% at low and high TOC content, respectively, lower than those in the shoots ((63.0±21.3)% and (85.2±2.4)%), respectively), which might be because it was easier to translocate br-PFOS formed in roots to shoots. The ratio of br-PFOS in wheat, especially in wheat shoots ((85.2±2.4)%), was significantly higher than that in earthworms ((16.5±4.0)%). The presence of wheat enhanced the bioavailability of PFOSA in the soil, thereby promoted the accumulation of PFOSA in earthworms, but had little effect on the transformation of PFOSA. The results provided evidence for the bioaccumulation and biotransformation of PFOSA in wheat and earthworms, and were helpful to explore the indirect sources of PFOS in the environment.
2021 Vol. 41 (5): 2434-2440 [Abstract] ( 326 ) [HTML 1KB] [ PDF 374KB] ( 1426 )
Environmental Microbiology
2441 Isolation and degradation characteristics of highly efficient phenol-degrading bacteria Bacillus sp. L5-1
LIU Qing-hui, LI Jian, YANG Hang, WANG Zhi-yu, LI Yan, ZHANG Wei-chuan, JIA Yin-juan, ZHANG Qiu-gen, LUO Xu-biao
A highly efficient phenol-degrading bacterium named L5-1 was isolated and screened from the activated sludge from a sewage treatment plant. The colony morphology observation and 16S rDNA gene sequencing showed that the strain L5-1 was Bacillus cereus, with the registration number of MN784421 in the US National Center for Biotechnology Information (NCBI). A series of experiments with Phenol as the only carbon source were conducted to study the growth and phenol degradation characteristics of this strain L5-1. The results showed that under the conditions of 10% inoculum, temperature range of 30 to 35℃, pH range of 7 to 8, the strain L5-1 effectively degraded phenol in the culture medium (with the 100mL of medium volume and the initial phenol concentration of 500mg/L), the degradation rate was better than 93% in 14h. Under optimal degradation conditions (10% inoculum, culture temperature at 35℃, pH 7.0, and NaCl concentration at 1%), The phenol degradation rate reached 97.1% within 14 hours when the initial concentration was set at 500mg/L. When the initial phenol concentration was set to 1000mg/L, the strain L5-1 still reached 97.71% degradation rate within 46 hours. The Haldane kinetic model was used to simulate the growth process of strains under different concentrations of phenol. The maximum specific growth rate was 0.355h-1, the semi-saturation constant was 104.27mg/L, the inhibition constant was 322.83mg/L, R2=0.997. This study confirmed Strain L5-1 was a Bacillus strains with strong phenol degradation ability among the reported strains of the genus Bacillus, and provided certain theoretical references for the actual treatment of phenol-containing wastewater.
2021 Vol. 41 (5): 2441-2448 [Abstract] ( 220 ) [HTML 1KB] [ PDF 1047KB] ( 1063 )
2449 Boron carbide promotes the ammonia production by electrocatalytic nitrogen fixation with Psendomonas Stutzeri A1501
DONG Guo-wen, CHEN Piao, REN Guo-ping, WANG Chao, JIN Shu-guang, YE Jie, ZHOU Shun-gui
Pseudomonas stutzeri (P. stutzeri) A1501was used as a model nitrogen-fixing strain and boron carbide (B4C) was selected as a typical electron transfer carrier to construct an electrocatalytic nitrogen reduction system. The effect of B4C addition on the ammonia production under different conditions was explored. The results showed that B4C significantly enhanced the ammonia production of the electrocatalytic nitrogen reduction system mediated by P. stutzeri A1501. With the dosage of 0.4g/L, the addition of B4C (B4C900) prepared at 900℃ calcination temperature improved the ammonia yield by 117%. This was because the abundant activation sites on the surface of B4C900 promote N2 adsorption and activation. In addition, the electrochemical and spectroscopic spectrograms showed that the addition of B4C900 not only triggered P. stutzeri A1501 to secrete more redox active substances, but also drove the construction of highly active cathode biofilms, thereby enhancing the long-distance transfer and utilization of electrode electrons.
2021 Vol. 41 (5): 2449-2458 [Abstract] ( 343 ) [HTML 1KB] [ PDF 2670KB] ( 1000 )
Carbon Emission Control
2459 City population size, industrial agglomeration and CO2 emission in Chinese prefectures
ZHANG Hua-ming, YUAN Peng-fei, ZHU Zhi-shuang
Using the panel data of 286 cities in China during 2009~2018, a spatial econometric model was employed to explore the mechanism between CO2 emissions and the size of city population and industrial agglomeration. The results revealed that CO2 emissions per capita in different cities presented significant spatial spillover effects. Specifically, the impact of the city population size and industrial agglomeration on CO2 emissions per capita presented an inverted U shape. CO2 emissions were synergistically affected by city population size and industrial agglomeration. There were significant differences in CO2 emissions and associated mechanism across different Chinese regions. A series of robustness tests confirmed our main findings. Therefore, for sustainable development policymaking, local governments should rationally formulate policies on energy conservation and emission reduction in accordance with the size of city population and industrial agglomeration.
2021 Vol. 41 (5): 2459-2470 [Abstract] ( 493 ) [HTML 1KB] [ PDF 589KB] ( 2946 )
Environmental Impact Assessment and Management
2471 Energy eco-efficiency measurement and driving factors of China's eight comprehensive economic zones
CHEN Jing-quan, LIU Na, MA Xiao-jun
To promote green and sustainable development of energy, economy, society and ecological environment, the expected outputs of economy and social welfare and the undesired output of ecological environment pollution were included in the energy eco-efficiency measurement framework, and the stochastic frontier model based on Shephard energy distance function was used to study the energy eco-efficiency of China's eight comprehensive economic zones. This realized the analysis of the evolution trend of China's energy eco-efficiency from the perspective of regional research, and explored the mechanism of its driving factors. The results showed that the national average energy eco-efficiency was 0.5839 during the sample period. The overall level was low, and it showed significant spatial imbalanced distribution characteristics. The energy eco-efficiency level of the eight comprehensive economic zones was gradually decreasing from the coast to the inland. The average value of energy eco-efficiency in the southern, eastern, and northern coastal economic zones were 0.6941, 0.6213 and 0.6087 respectively, which ranked the top. Southwest, the middle reaches of the Yellow River, the middle reaches of the Yangtze River and the northeast economic zones followed. The average value of energy eco-efficiency were 0.5803, 0.5720, 0.5623 and 0.5537 respectively. The average value of energy eco-efficiency in the northwest economic zone was 0.5087, which ranked the last. The estimated coefficients of economic development level and energy consumption structure were 0.0459 and 0.0747 respectively, which inhibited the improvement of energy eco-efficiency. The estimated coefficients of industrial structure, urbanization level and environmental regulation were -0.9339, -0.6197 and -0.0387 respectively, which promoted the improvement of energy eco-efficiency.
2021 Vol. 41 (5): 2471-2480 [Abstract] ( 348 ) [HTML 1KB] [ PDF 759KB] ( 1895 )
中国环境科学
  News
More>>  
  下载中心
   Instruction
   Template
   Copyright Agreement
More>>  
  Links
   Ministry of Land and
　  Resources of the People,s
　  Republic of China
    CNKI
    WANFANG DATA
    CNPITC
More>>  
 
CHINA ENVIRONMENTAL SCIENCECE
Links： China Association for Science and Technology　Chinese Society For Environmental Sciences　CNKI　WANGFANG DATA
Copyright © 2010 Editorial By China Environmental Science　　Support by Beijing Magtech Co.ltd, E-mail:support@magtech.com.cn