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  Current Issue
 
2023 Vol.43 Issue.3,Published 2023-03-20
Air Pollution Control
Water Pollution Control
Solid Waste
Soil Pollution Control
Environmental Microbiology
Environmental Ecology
Environmental Impact Assessment and Management
Environmental Toxicology and Health
Air Pollution Control
993 Study on the evolution of meteorological conditions of air pollution in Tianjin based on circulation index
CAI Zi-ying, HAN Su-qin, QIU Xiao-bin, YAO Qing, WANG Jing, FAN Wen-yan, YANG Xu, HAO Jian, TANG Ying-xiao, ZHANG Min
Based on multiple climate system monitoring indices from Beijing Climate Center and the synthesis meteorological condition index for PM2.5 pollution over Tianjin constructed from outputs of Tianjin environmental model, the evaluation methodology for meteorological conditions of air pollution in Tianjin based on circulation indices was established to study the impacts of weather and climatic condition changes on PM2.5 diffusion in Tianjin from 1951 to 2021. Results show that the highly correlated circulation indices with springtime PM2.5 pollution meteorology in Tianjin are East Atlantic teleconnection index, tropical North Atlantic SST index and Scandinavian teleconnection index. In summer, the PM2.5 pollution meteorology in Tianjin is closely correlated with the location of the subtropical high, and the high correlation circulation indices are the location indices of the northern boundary of the Indian subtropical high and the northern boundary of the South China Sea subtropical high. The variations of Asian zonal and meridional circulation indices in autumn and winter are of good significance to the concurrent PM2.5 pollution meteorology in Tianjin. Specifically, the variations of Arctic Oscillation index and polar vortex intensity index in the Northern Hemisphere can reflect the intensity and frequency of cold air activities affecting China in autumn and winter. The temporal correlation coefficient (TCC) with the PM2.5 pollution meteorology in Tianjin in autumn and winter is 0.45 and 0.66, respectively. By using our proposed PM2.5 pollution meteorology index based on large-scale circulations, the TCC between the meteorological conditions for PM2.5 pollution in Tianjin and the estimated meteorological conditions by the numerical model is 0.80. Furthermore, according to the data analyses, the mean interannual variations in meteorological conditions for PM2.5 pollution in Tianjin from 1951 to 2021 was 2.56%. The difference between the extreme peak and valley values and the averaged values were 7%~8%, with the worst one in the 1980s and the best one in the 1950s. Moreover, the difference in the 2010s outperformed the historical average of 1.61%.
2023 Vol. 43 (3): 993-1001 [Abstract] ( 132 ) [HTML 1KB] [ PDF 728KB] ( 467 )
1002 Classification characteristics, circulation background and its effect on O3 of land and sea breeze in Shanghai
MAO Zhuo-cheng, XU Jian-ming, QU Yuan-hao, YIN Chang-qin, YANG Dan-dan, ZHOU Guang-qiang
A comparative analysis was made from meteorological factors (temperature, humidity and wind), six circulation backgrounds that formed sea land breeze and their impacts on O3 concentration of three types of land and sea breeze (North Branch, South Branch and Double Branch) in Shanghai from 2013 to 2019. The results show that there were 237 days of land and sea breeze in Shanghai from 2013 to 2019, of which the North Branch had the most days (209d) and the Double Branch had the least days(88d).The proportion of Double Branch land and sea breeze with the South Branch was the highest (75.9%);Among the three types of land and sea breeze, the North Branch had the earliest starting time, the longest maintenance time and the strongest sea breeze intensity. The South Branch had the highest average temperature, lower average humidity, and the most dispersed wind field; Compared with no sea and land breeze condition, O3 concentration in North Branch, South Branch and Double Branch increased by 20.5, 26.4 and 25.1μg/m3 respectively. O3 pollution concentration in South Branch was the same as that in no sea and land breeze condition, while that in North Branch and Double Branch were slightly lower than that in no land and sea breeze condition. Among the six weak circulation backgrounds forming Shanghai land and sea breeze, the high-pressure central type, the unsystematic type and the pressure equalizing field type were the most important three types, accounting for 70% in total; The results of the combination of circulation backgrounds and land and sea breeze types show that the highest probability of O3 pollution was the South Branch land and sea breeze of pressure equalization field type, reaching 40.0%. The highest combination of O3 concentration and O3 pollution concentration was South Branch land and sea breeze with the unsystematic type and the Double Branch land and sea breeze with the high pressure front type, with the average concentration of 146.6μg/m3 and 211.3μg/m3, respectively.
2023 Vol. 43 (3): 1002-1013 [Abstract] ( 152 ) [HTML 1KB] [ PDF 2146KB] ( 370 )
1014 Aqueous-phase photochemical oxidation of extracted WSOC in PM2.5 from biomass burning
ZHU Long-wei, CUI Yao-jia, GE Xin-lei, YE Zhao-lian, ZHAO Zhu-zi
To explore aqueous-phase oxidation characteristics of extracted water soluble organic carbon (WSOC) in PM2.5 emitted from biomass burning, this study investigated the absorption, fluorescence and the oxidation properties of WSOC from two types of biomass burning (wheat and rice straws) under ultraviolet (UV) and UV+H2O2 (UV+OH) conditions. The results from total organic carbon (TOC) analyzer showed that WSOC removal rates were almost the same in the two conditions. Extra H2O2 adding didn't improve the removal rates of WSOC, indicating direct photolysis was the major degradation pathway of WSOC. The removal rates of WSOC for wheat straw in two types of biomass burning samples were relatively fast, reducing about 70% in 17hours. No significant differences were found in aqueous-phase photochemical oxidation products between rice straw and wheat straw burning samples. With the photolysis process, absorbance decreased gradually due to WSOC degradation, and fluorescence intensity at excitation/emission (Ex/Em)255~260nm/330~340nm also declined. However, new fluorescent peaks at Ex/Em=230/(400~500) nm appeared, which could might be ascribed to the formation of humic-like substance (HULIS). Besides, high-resolution aerosol mass spectra (HR-AMS) was used to investigate aqSOA formation potential and its oxidation characteristics. The results showed that the mass of aqSOA decreased while aqSOA became more oxidative owing to the content of O-containing functional groups increasing as aging. The variation of oxidative potential (OPs) was similar to that of HULIS, with rose at first and then declined in UV+OH condition, which could be attributed to the formation of O-containing functional groups at first stage and subsequent degradation. Based on the above analysis results, we infer that the process of aqueous-phase oxidation of WSOC undergo functionalization to form the first generation products, then to more oxidized second-and third-generation smaller species formed by fragmentation and ring-opening reactions, which in turn indirectly impact climate change and air quality. The study revealed the aging behaviors of WSOC emitted from biomass burning, providing insights into understanding the light absorption, SOA formation and health effects caused by aqueous-phase oxidation reaction.
2023 Vol. 43 (3): 1014-1025 [Abstract] ( 167 ) [HTML 1KB] [ PDF 865KB] ( 246 )
1026 Pollution characteristics and sources of polycyclic aromatic hydrocarbon derivatives in the atmosphere of Tianjin
GAO Yu-zong, JI Ya-qin, YANG Yi, WANG Miao, XIAO Yang, WANG Bing-bing, YANG Xia-wei
To investigate the pollution characteristics and sources of PAH derivatives in the atmosphere of Tianjin, ambient air samples were collected by using quartz fiber filer membranes (QFFs) and polyurethane foam (PUFs), and the concentrations of PAH derivatives were measured by gas chromatography-mass spectrometry (GC-MS). The results showed that the average concentrations of ∑18NPAHs in autumn and winter were 840, 894pg/m3, respectively, and the average concentrations of ∑5OPAHs in autumn and winter were 8.08, 9.36ng/m3, respectively, which were slightly higher in winter than in autumn. In the atmosphere, 9N-ANT, 2N-NAP, 1N-NAP, 2+3N-FLT, BZO and 9-FO were the main PAH derivatives. The concentrations of PAH derivatives in PM2.5 were greater in winter than in autumn, while in the gas phase, they were greater in autumn than in winter. From the perspective of diurnal difference, the night-day ratios of PAH derivatives in PM2.5 were greater than 1 in most sampling days, and the secondary formation of NPAHs in the daytime in the gas phase and PM2.5 was higher in autumn than in winter. Based on the characteristic ratio method, the preliminary source analysis showed that primary emission was the main source of NPAHs in PM2.5 in autumn and winter, and secondary generation also contributed to NPAHs. The secondary generation of NPAHs in PM2.5 was mainly generated by catalytic reaction with OH. The characteristics of gas particle distribution are as follows:most compounds occupied a higher proportion of PM2.5 in winter than in autumn, while the proportion of SPAHs in the gas phase were higher in autumn than in winter.
2023 Vol. 43 (3): 1026-1034 [Abstract] ( 141 ) [HTML 1KB] [ PDF 949KB] ( 268 )
1035 Study on compositions of carbonaceous aerosols emitted by typical construction machinery
XIANG Xuan, KONG Shao-fei, CHENG Yi, HU Yao, SU Wei-feng, YAO Li-quan, LIU Xiao-yong, ZHU Kuan-guang, DING Feng, LIU Wei, QI Shi-hua
This study selected five types of construction machineries, including forklifts, road roller, grader, bulldozer, and excavators, to study the impact of operating condition and emission standard on the composition of carbonaceous aerosols emitted from them. Three running conditions (idling, walking, and working) and three emission standards (pre-stage 1, stage 2 and stage 3 of the national emission standard) were considered. Fine particulate matter (PM2.5) were collected, and the carbonaceous components were analyzed using a thermal/optical carbon analyzer. Results showed that the average proportion of organic carbon (OC) and element carbon (EC) were (70.1±13.2)% and (11.9±7.5)%, respectively. For OC emitted from forklifts, road roller, bulldozer, and excavators, OC1 accounted for the highest proportion of 58.0%±9.5%, while OC2 was the main component emitted from grader, occupied by (42.3±8.1)%. The average value of OC/EC was 12.7±9.5, indicating that the minimum ratio method would overestimate the secondary organic aerosol contribution for the air impacted by construction machinery emissions. The OC/EC ratio varied in 3.0~36.3 for different types of construction machinery. The OC/EC ratios for forklift 3, roller, grader, and bulldozer reached the maximum values of 24.9,15.7,36.3 and 5.3 in walking state, respectively. The ratio for forklift 2 and excavator 2 peaked under operating condition, as 18.1 and 14.9, respectively. The maximum ratio for forklift 1and excavator 3 was for the idle state. From stage 2 to stage 3 of National emission standard, the OC and EC concentrations for forklift decreased by (36433.8±4528.6)μg/m3 (24.6%) and (4209.9±151.4)μg/m3 (19.8%), respectively. The carbonaceous aerosol emission concentrations of excavators decreased by 10582.8 μg/m3 (36.2%) and 2641.1μg/m3 (38.4%), respectively. For the source apportionment and emission inventory of carbonaceous aerosol, the influence of working conditions and emission standards should be considered. The data here can be used to assess and improve the feasibility of source apportionment and emission inventory establishment of carbonaceous aerosol.
2023 Vol. 43 (3): 1035-1043 [Abstract] ( 165 ) [HTML 1KB] [ PDF 864KB] ( 341 )
1044 Selective catalytic reduction of N2O by CO over lanthanum doped Fe-beta zeolite
ZHAO Fei-lin, ZENG Jie, XIAO Rong, QIU Lei, GUO Wen, CHEN Hao-hui, CHANG Hua-zhen
La/Fe-beta zeolite catalyst was prepared by using impregnation method and used for CO selective catalytic reduction of N2O. The results showed that the doping of La could enhance the CO oxidation activity, and thus improved the N2O conversion efficiency of Fe-beta zeolite, reaching higher than 95% at 350℃. H2-TPR results illustrated that the existence of La could influence the distribution of Fe species on La/Fe-beta surface, and reduce the resistance for O2 and H2O. In addition, effects of HCl on Fe-beta and La/Fe-beta zeolites in waste incineration tail gas were also investigated. Combining the results of CO oxidation activities, H2-TPR and O2-TPD, it was found that the formation of stable FeClx species, poor reduction performance and CO oxidation activity were the main causes of HCl poisoning in N2O conversion activity.
2023 Vol. 43 (3): 1044-1052 [Abstract] ( 155 ) [HTML 1KB] [ PDF 981KB] ( 202 )
1053 Spatiotemporal changes of XCO2 and anthropogenic CO2 emission in China based on multi-source carbon satellite fusion product
WANG Zhen-shan, SHENG Meng-ya, XIAO Wei, YANG Feng-zhu, LIN Bin, XU Xing-zhu, LIU Yi-bo
Accurately assess the spatiotemporal changes of atmospheric CO2 concentration and anthropogenic CO2 emission, is critical to mitigate greenhouse gas emissions contributing to climate change. The spatial distribution and interannual change of column-averaged dry air mole fraction of CO2 (XCO2) and anthropogenic CO2 emission in China from 2010 to 2020 were evaluated using the continuous XCO2 dataset (Mapping-XCO2) fused from the Greenhouse Gases Observing Satellite (GOSAT) and Orbiting Carbon Observatory (OCO-2). Results showed that Mapping-XCO2 had a high consistency with in-situ observations from atmospheric background stations, indicating the potential of Mapping-XCO2 to apply for regional analysis. From 2010 to 2020, the annual average XCO2 in China was 400.4×10-6, with a high value in the East and a low value in the West. The annual increase rate of XCO2 was 2.47×10-6. The XCO2 anomalies in the non-growing season were well consistent with anthropogenic CO2 emissions collected from EDGAR and ODIAC, with a correlation coefficient of 0.71 and 0.67 at provincial-level, respectively. The increase rate of anthropogenic CO2 emissions in Beijing-Tianjin-Hebei, Yangtze River Delta and Pearl River Delta was 0.12×10-6/a, 0.08×10-6/a and 0.08×10-6/a respectively. The results demonstrate the reliability and effectiveness of the satellite retrieved XCO2 data in evaluating atmospheric CO2 concentration and anthropogenic CO2 emissions.
2023 Vol. 43 (3): 1053-1063 [Abstract] ( 216 ) [HTML 1KB] [ PDF 1399KB] ( 387 )
1064 Research on the preparation and dust removal mechanism of new PTFE melt-punched fiber microporous membrane filter media
CHEN Yi-hua, QIU Shu-yong, GUO Jing-zhong, Lü Zhen-hu, WANG Pan, JIA Yong
Towards both the problem of poor ash cleaning effect of coated membrane filter material commonly used in metal mine dust treatment and the basic requirements of ultra-low emission of ultra-fine dust, PTFE filter media immersion melt modification method was developed to prepare the melt-jet-punched fiber microporous membranes with a wide range of adaptability and low resistance and efficiency. PTFE melt-punched fiber microporous membrane production process was combined with the FE-SEM fiber structure recombination CFD-DEM coupling numerical simulation technology method, via which the filtration characteristics and dust removal surface characteristics of the microporous membrane filter material were analyzed. The results show that the fiber microporous membrane filter material made by pressure impregnation dyeing and heating baking treatment could provide the fine sericillary structure on the PTFE spray wire skeleton, which increased both the filling rate of the filter material (SVF) and the filtration efficiency of ultra-fine dust, especially for the third group of filter materials, the dust removal efficiency of fine particulate matter below PM10 was increased from 95.5% to 99.3%. We further verified the physical properties of the filter media by numerical simulation, and analyzed the microscopic dust removal performance and dust adhesion state distribution of the new filter media by combining FE-SEM microscopic dust adhesion state distribution.
2023 Vol. 43 (3): 1064-1073 [Abstract] ( 83 ) [HTML 1KB] [ PDF 2451KB] ( 362 )
Water Pollution Control
1074 Recent progress of the global river network patterns and water network constructions
WANG Yi-chu, NI Jin-ren
Under the conditions of uneven spatiotemporal distribution of water resources, unbalanced socioeconomic development and global climate change, water network construction has become an important way to achieve efficient utilization of water resources and promote regional sustainable development in the new era, and thus the key concern has become how to define the scale of water diversion at varying levels of river networks under multiple objectives. This paper reviews the research progress of global river networks in terms of identification and characterization methods, formation mechanism, temporal and spatial distribution and evolution characteristics, analyzes the corresponding basin water endowment and water resource structure characteristics of typical river network patterns, as well as their ecological and environmental impacts. Based on the case study of the relationships between the inter-basin diversion projects and constructions of backbone water networks, the present work prospects the development trend of the ecology-oriented optimization of water system pattern and the construction of backbone water networks.
2023 Vol. 43 (3): 1074-1086 [Abstract] ( 173 ) [HTML 1KB] [ PDF 2167KB] ( 310 )
1087 Treatment of biochemical tail water containing heterocyclic drugs by PAA/cobalt-loaded ceramic granule-based denitrification biofilter at low temperature
MA Jie, ZHU Shan-Shan, ZHANG Xu-Xiang, REN Hong-Qiang, HUANG Hui
A cobalt-loaded ceramic granule-activated peracetic acid (PAA) system (the concentration of PAA was 150mg/L) was constructed in our previous study, and efficient degradations of typical heterocyclic drugs (sulfamethoxazole (SMX), sulfadiazine (SDZ), carbamazepine (CBZ) and trimethoprim (TMP), all of which were 20mg/L) were observed. In order to realize the in-situ upgrading of the function of denitrification biofilter, this study further explored the efficacy of PAA/cobalt-loaded ceramic granule-based denitrification biofilter in the treatment of biochemical tail water containing the above heterocyclic drugs at low temperature. Under the conditions of 15℃, 60mg/L COD, 20mg/L NO3--N and 20 μg/L of the four heterocyclic drugs in the influent, the dosage ratio of cobalt-loaded ceramic granule of 3%, and PAA concentration of 150 μg/L and 300 μg/L, the biofilter achieved good removal of total nitrogen (TN) and heterocyclic drugs and the reduction of effluent acute biotoxicity. The effluent TN met the requirements of first-class A discharge standard of China, and the average degradation rates of SMX, SDZ, CBZ and TMP were 67.20%, 75.17%, 80.90% and 70.26%, respectively. The acute biotoxicity of effluent increased with the shortening of HRT, while they all had low toxicity. The concentration of cobalt ion leached from the biofilter was lower than 1mg/L, which reached the requirements of surface water environmental quality standards of China. The distribution of microbial species was more even in the biofilter, and the key bacteria Paracoccus and Gordonia and the gene expression of napA, narG and nirK, played significant roles in the removal of heterocyclic drugs and TN. Without considering the operation cost of backwashing, the cost for advanced removal of per 5mg/L NO3--N (calculated by 1m3 wastewater) by the PAA/cobalt-loaded ceramic granule-based denitrification biofilter was 0.1567~0.3475Yuan (RMB) per cubic meter wastewater, showing a good technical and economic feasibility.
2023 Vol. 43 (3): 1087-1096 [Abstract] ( 121 ) [HTML 1KB] [ PDF 994KB] ( 226 )
1097 Phosphorus source regulates extracellular polymers and bioflocculation of Chlorella pyrenoidosa
ZHENG Lei, XING Yu-zi, SONG Jian-xin, PENG Zheng, LIU Ting-ting, XIE En
The efficient harvesting of oil-producing microalgae is a bottleneck problem that restricts the use of microalgae to produce biodiesel. Among them, the biological method has become a research hotspot. However, research on how phosphorus affects the growth, oil production, and bioflocculation of microalgae are still limited. In this study, four groups (IP, OP, NMP, and cNMP) of 59kinds of phosphorus were selected to cultivate Chlorella pyrenoidosa, and their growth, oil production, cell settling, and composition of extracellular polymers were studied. It was found that the IP group had the highest growth promotion effect on Chlorella pyrenoidosa (average algal cell density was 2.92×108 cells/mL), and the oil levels of algal cells cultured in the OP group reached 17.45%, higher than the other three groups, while the average settling velocity of cNMP group was the best, reaching 13.79mm/min. In conclusion, methylene piphosphonic acid, triethyl phosphate, and 6-phospho-gluamic acid are the phosphorus with the best comprehensive benefits for cultivating Chlorella pyrenoidosa for oil production.
2023 Vol. 43 (3): 1097-1106 [Abstract] ( 150 ) [HTML 1KB] [ PDF 3551KB] ( 257 )
1107 Removal of bisphenol A by nitrogen-doped reduced graphene oxide foam via adsorption/peroxydisulfate activation
HE Li-jin, LONG Jun-hong, JIN Hua-lei, ZUO Yi-dan, SONG Jie, XIA Li-hong, SHI Miao, LUO Li-jun, DAI Jian-hui
The nitrogen doped reduced graphene oxide foam (N-RGF) was prepared by hydrothermal method followed freeze-drying treatment using graphene oxide and ammonia as starting materials. The structure and surface physical-chemical properties of as-prepared catalysts were investigated and analysed by SEM, XRD, XPS, FT-IR, BET and TG techniques. The N-RGF was used to activate peroxydisulfate (PDS) for BPA removal via adsorption/degradation synergistically. The results showed that the N-RGF catalyst was a three-dimensional structure with average pore size(1~5μm). Its optimal preparation conditions were 6% nitrogen doping amount and hydrothermal treatment at 180℃ for 20h. The degradation rate constant of BPA over N-RGF activated PDS was 4.88 times than that over RGF activated PDS. Active species capture experiment and electron paramagnetic resonance (EPR) results showed that singlet oxygen (1O2) was the main contributor for BPA abatement. The four possible degradation intermediates were confirmed by ultra-high-performance liquid chromatography-mass spectrometry, and possible degradation pathway was proposed. The estrogenic activity of treated solution was reduced by MCF-7cell viability evaluation.
2023 Vol. 43 (3): 1107-1121 [Abstract] ( 183 ) [HTML 1KB] [ PDF 2349KB] ( 305 )
1122 Pre-deposition of biochar layer improves the performance of gravity-driven membrane(GDM) filtration system for polluted surface water treatment
HE Qiang, ZUO Qing-yang, CHEN Zi-wei, LIU Cai-hong, ZHANG Tang-long, ZHI Yue
In this study, pre-deposition of biochar (BC) was conducted to strengthen gravity-driven membrane (GDM) performance for treating contaminated surface water, and the effect of pre-deposited biochar on water flux and decontamination efficiency was investigated. The applied BC was a mesoporous material prepared by pyrolysis of corn stalk powder at a high temperature of 600℃. The obtained BC possessed rich pore structure and abundant oxygen-containing functional groups, with specific surface area and total pore volume of 181.09m2/g and 0.12cm3/g, respectively. The feed water was realistic Jialing River water polluted by domestic sewage, and the filtration operation period was 50d. The pristine membrane in the absence of BC deposition served as a control group (i.e., GDM). During membrane filtration process, we systematically investigated the flux stability, removal efficiency on main water quality parameters including turbidity, dissolved organic carbon (DOC), UV254, fluorescent organics and ammonia of both control GDM and BC-GDM systems. The results show that the stable flux (4.82L/(m2·h)) of BC-GDM was slightly higher than that of control GDM (4.72L/(m2·h)) under long-term operation. The pollutants removal performance indicate that the BC-GDM system slightly improved the removal of turbidity and ammonia, accelerated the start-up process of ammonia removal, and significantly improved the organic removal such as DOC, UV254 and fluorescent organics. Specifically, after BC pre-deposition, the average removal efficiency of DOC and UV254 increased from 16.7% and 10% to 34.1% and 39.9%, respectively. Our results reveal that pre-deposition of BC in GDM could effectively improve the water purification efficiency without compromising membrane water flux.
2023 Vol. 43 (3): 1122-1130 [Abstract] ( 133 ) [HTML 1KB] [ PDF 2816KB] ( 206 )
1131 Influence mechanisms of BC filters of different pyrolysis temperatures on BAFs treating aquaculture wastewater
LIU Si-qiang, XIN Xin, YANG Wen-yu, YAN Xue-hua, DAI You-xue, HU Jin-tao
To improve the removal efficiency of nitrogen, phosphorus and antibiotics in aquaculture wastewater by traditional biological aeration filter (BAF), biochar (BC) derived from different pyrolysis temperatures (400, 500, 600 and 700℃) were filled in the BAFs (No 2#~5#) to treat artificial aquaculture wastewater containing sulfamethoxazole (SMX), sulfadiazine (SDZ), enrofloxacin (ENR) and ciprofloxacin (CIP), for revealing the removal performances of COD, ammonia nitrogen, TN, TP and four antibiotics during the start-up and operation period of the BAFs, with the traditional BAF loading zeolite as the control group (No.1 #). Several test methods were utilized to analyze the removal characteristics of the typical periodical target pollutants, and to detected the Extracellular polymeric substances (EPS) and microbe Electron transport system activity (ETSA) in the late period. Simultaneously, the key microbial population composition in each BAF were investigated by High-throughput sequencing technology. Results showed that the nitrogen, phosphorus and antibiotics removal performances in 2#~5# BAFs were enhanced by BC, and BC pyrolyzed at high temperature was more conducive to the removal of pollutants. The microbial EPS content and PN/PS value in the 2#~5# BAFs were higher than those in the control group, and increased with the increase of BC pyrolysis temperature. Although the ETSA was negatively correlated with the pyrolysis temperature of BC, the ETSA of 2#~5# BAFs were still higher than that of 1#BAF (the control group), filling BC could increase the electron transport in BAF. Meanwhile, functional genera related to antibiotic degradation and nitrogen and phosphorus removal were also detected in 2#~5# BAFs, such as Micropruina (relative abundance 0.42%~8.18%)、Rhodobacter (0.63%~2.94%)、norank_f__Chitinophagaceae (0.23%~3.98%) and Microbacterium (0.37%~1.66%) etc., whose relative abundances were positively correlated with BC pyrolysis temperature. During the stable operation time, the 5# BAF with BC pyrolysis temperature of 700℃ achieved the best decontamination efficiency, in which the average removal rates of TN and TP were 51.99% and 41.00%, and the average removal rates of SDZ, SMX, ENR and CIP were 71.84%, 75.01%, 62.91% and 69.62%, respectively.
2023 Vol. 43 (3): 1131-1141 [Abstract] ( 90 ) [HTML 1KB] [ PDF 1858KB] ( 203 )
1142 Application of modified microbial flocculants in wastewater treatment process and mechanisms for membrane fouling mitigation
SHEN Yu, MAO Xin, SHEN Jing, ZHANG Bing, SHI Wen-xin
The application of pre-coagulation in the treatment of wastewater with bacterial-algal granular sludge membrane bioreactor (ABGMBR) and the mechanisms of membrane fouling mitigation were systematically investigated by using polymerized aluminum chloride (PAC) and modified microbial flocculant (MMF) as a composite flocculation system. Membrane filtration tests showed that PAC/MMF pre-coagulation effectively alleviated the membrane fouling compared with other flocculation systems. When the concentration of MMF was 20mg/L, the optimal flocculation capacity and membrane fouling control performance were achieved. The extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory clarified that the PAC/MMF system possessed superior antifouling properties. The PAC/MMF flocculation system greatly inhibited the adhesion and accumulation of foulants on the membrane, thus forming a loose, porous, and thin cake layer on the membrane surface. Correlation analysis showed that the mitigation of membrane fouling was mainly attributed to the decrease in the concentration of suspended solids and the increase in zeta potential in the raw wastewater.
2023 Vol. 43 (3): 1142-1151 [Abstract] ( 146 ) [HTML 1KB] [ PDF 1857KB] ( 228 )
1152 Microbial protein production by using nitrogen extracted from microbial fuel cells
LI Xiao-yue, WANG Yue, JIA Pei, LI Ya-jie, CHEN Jia-qi, JIN Li-jun, WANG Wen, YANG Zi-yi
In this experiment, ammonium nitrogen in organic wastewater was recovered via microbial fuel cell (MFC). In MFC system, the recovery efficiency of ammonium nitrogen could reach 41.3%, along with electric energy of about 95.5J. The migration tendency of ammonium nitrogen matched well with Levenberg-Marquardt equation (R2>0.95). Subsequently, microbial protein (MP) was synthesized by hydrogen oxidizing bacteria (HOB), using CO2 and the extracted nitrogen from MFC. The CO2 sequestration rate was about 1.1LCO2/(L×d) and dry cell weight in HOB system was 2.41g/L. The protein content was 49.4%, and the production of amino acids was 1.19g/L. The amino acid content of MP produced in this experiment was higher than that of the Clupanodom punchtatus. Also, the amino acid species were more abundant than that of the plant protein feeds. Thus, MP performs the potential on market competitiveness and practical application. In this experiment, CO2 and nitrogen from wastes could be used for providing green and sustainable protein supply source, which played a positive role in promoting the resource utilization of organic wastewater.
2023 Vol. 43 (3): 1152-1159 [Abstract] ( 121 ) [HTML 1KB] [ PDF 540KB] ( 207 )
1160 Enhancing Se(IV) reduction in the wastewater with a low-carbon source by Fe3O4 coupling with anaerobic microorganism
SUN Jie, HOU Bo-wen, TANG Jing-yao, HU Liang-hui, LI Hai-ming, LIANG Yue-gan
In order to strengthen the removal efficiency of wastewater containing Se(IV) by anaerobic microorganisms, anaerobic sequencing batch reactor (ASBR) was used to study the effect of Fe3O4 on the removal of Se (IV) by anaerobic microorganisms, and the changes of selenium concentration in the effluent, selenium form and distribution, selenium reductase activity and microbial flora were analyzed. The results showed that Fe3O4 had no effect on the removal of Se(IV) at the wastewater with a high carbon source concentration by anaerobic microorganisms, but Fe3O4 could significantly improve the efficiency and rate of Se(IV) reduction at the wastewater with a low carbon source concentration by anaerobic microorganisms. Compared with the control group, the removal efficiency of Se (IV) in the magnetic group increased from (97.3±0.5)% to (98.2±0.5)%, and the maximum removal rate raised by 3.6 times. Compared with the control group, Fe3O4 decreased the proportion of Se (IV) and Se(0) in the supernatant and increased the proportion of Se (-II), and Fe3O4 strengthened the reduction process of Se(0)-Se(II) by anaerobic microorganisms. Fe3O4 improved increasing selenite-reduction activities, such as sulfite reductase, glutathione reductase, peripheral fumarate reductase and nitrite reductase. High-throughput sequencing results showed that Fe3O4 increased the relative abundance of iron-reducing bacteria Rhodococcaceae as well as the abundance of Anaerolineaceae and Dechlorobacter related to electron transport. Therefore Fe3O4 enhanced Se(IV) reduction by increasing reductase activities and inducing Fe(III) reduction to accelerate electron transfer. This study's results can provide technical support for the treatment of Se(IV) containing wastewater with low carbon source.
2023 Vol. 43 (3): 1160-1165 [Abstract] ( 143 ) [HTML 1KB] [ PDF 874KB] ( 377 )
1166 Adsorption characteristics and mechanism of W(VI) from aqueous solution using MgAl layered double hydroxide and its calcined product
YUAN Xiu-juan, ZENG Ping, REN Si-li, LUO Wu-hui
A nitrate-type layered double hydroxide (LDH) with the Mg/Al molar ratio of 2:1 was prepared via microwave aging method. The adsorption characteristics of W(VI) using LDH and its calcined product (CLDH) were systematically studied, and the involved mechanisms were elucidated through the structural characterization of LDH and CLDH before and after adsorption. The adsorption kinetics of LDH and CLDH to W(VI) was well fitted with the pseudo-second order model, indicating that chemisorption was the key process determining the adsorption rate. Both LDH and CLDH showed high affinity to W(VI), showing the maximum uptakes of 176.0 and 124.5mg/g, respectively, which are far higher than the analogous LDH. The optimum pH range for W(VI) adsorption on LDH was 4.0~10.0, while the acidic condition was conducive to W(VI) adsorption by CLDH. Compared with CLDH, LDH showed the higher adsorption capacity, faster adsorption rate, and less influences on water qualities (e.g., less releases of Mg and Al and change of pH), suggesting that the original LDH is more applicable for W(VI) adsorption. The main mechanisms of W(VI) adsorption on LDH include ion exchange, outer-sphere complexation, and inner-sphere complexation, while for the case of CLDH, the intercalation of paratungstate (W7O246-) during the reconstruction of layered structure was also involved. The above results indicate that both LDH and CLDH synthesized via the microwave radiation are favorable adsorbents with the superior performance in removal of W(VI) from the polluted water.
2023 Vol. 43 (3): 1166-1176 [Abstract] ( 106 ) [HTML 1KB] [ PDF 1110KB] ( 234 )
1177 Orthogonal experiment to optimize vertical subsurface flow constructed wetland for short-cut nitrification
YAN Yuan, MA Jiao, DANG Hong-zhong, WU Xin-bo, ZENG Tian-xu, LI Wei-wei, CHEN Yong-zhi
Vertical subsurface flow constructed wetland (VSFCW) was used to treat domestic wastewater and short-cut nitrification was achieved. When the temperature, pH value, dissolved oxygen (DO), and hydraulic retention time (HRT) were maintained at (30±2)℃, (8.4±0.2), (1.5±0.2) mg/L, and 12h, respectively. The removal efficiency of COD and ammonia removal efficiency (ARE) were 73.14%, 98.15%, respectively. However, nitrite accumulation rate (NAR) was 65.18%. The NAR can be improved further by adding hydroxylamine (NH2OH) to VSFCW. A 4-factor, 5-level orthogonal experiment was designed to determine the optimal control conditions of the NH2OH concentration, DO, temperature, and pH value. In this study, the analysis of variance (ANOVA) results revealed that the effects of NH2OH concentration and temperature on NAR were extremely significant (P≤0.01). DO and pH value had no significant effect on NAR (P>0.05). Even if the temperature was dropped from 30℃ to 23℃, the NAR could reach 89.15% by adding 1.0mg/L NH2OH. And the removal efficiency of COD and ARE were 75.67% and 88.76%, respectively. The abundance of Nitrosomonas increased from 1.62% to 4.06%, and the abundance of Nitrospira declined from 1.65% to 0.95%.
2023 Vol. 43 (3): 1177-1185 [Abstract] ( 104 ) [HTML 1KB] [ PDF 1333KB] ( 252 )
1186 Degradation of bisphenol A by Fenton-like system using trace copper ions combined with bicarbonate in water
XIN Li-hong, YAN Cai-xia, NIE Ming-hua, ZHANG Yi-min, YUAN Yu-long, DING Ming-jun, WANG Peng
Higher Cu2+ dosage is typically needed for Fenton-like systems based on copper ions (Cu2+), which could result in secondary pollution. In the current study, an effective system for degrading bisphenol A(BPA) was built using bicarbonate-activated hydrogen peroxide and trace copper ions (Cu2+/H2O2/HCO3-). According to the findings, increasing the Cu2+ dosage boosted the removal efficiency of BPA, while increasing the H2O2 or HCO3- dosage caused the trend to grow initially before declining. BPA can be effectively removed within the range of the initial pH value of solution 5.06~11.02, and the degradation efficiency was improved with increased temperature. The presence of Cl-、HPO42- and humic acid (HA) were found to delayed the elimination of BPA, while other anions like NO3- and SO42- had no obvious effects. Quenching and trapping experiments showed that the identified single oxygen and Cu3+ were the predominant reactive species responsible for BPA degradation. CuCO3(aq) was the major complex with a high reactivity for H2O2 activation to form reactive oxygen species (ROS) and Cu3+. At the same time, there is a good removal effect of BPA in the natural water matrix of the Cu2+/H2O2/HCO3- system. In addition, the mechanism of possible degradation of BPA in Cu2+/H2O2/HCO3- has been proposed from the five identified intermediates.
2023 Vol. 43 (3): 1186-1196 [Abstract] ( 110 ) [HTML 1KB] [ PDF 769KB] ( 295 )
1197 Study on leachate nanofiltration concentrate treated by a coagulation-heterogeneous fenton process
SUN Yue, ZHANG Cong-hui, BAI Hao, LIU Xin, LIU Si-zhuo
An experimental study on the landfill leachate nanofiltration concentrate with a high organic content was performed using a coagulation-heterogeneous Fenton combined process. The effect of different treatment conditions on the removal of organic matter from nanofiltration concentrate was investigated. The working conditions of the combined process were optimized through the orthogonal test, and the feasibility of the effluent reaching the standard under the optimal working conditions was analyzed. The changes in dissolved organic matter and nitrogen pollutant content in the reaction process of the combined process were discussed. The cost of adding chemicals for the combined process was also elaborated. The results show that the optimal treatment conditions of the combined process for COD removal are:the dosage of PFS is 6g/L, the initial pH of coagulation is 7, the dosage of PAM is 25mg/L. The mass ratio of H2O2 to COD is 10, the initial pH of the Fenton reaction is 4, and the mass ratio of catalyst to COD is 16, reaching a COD removal rate of 98.62% under the optimal conditions. After the combined process treatment, the quality of the effluent can be discharged according to the related standard. In the reaction process, the coagulation and sedimentation units can reduce the processing load of the heterogeneous Fenton unit and ensure the discharge of TN and NH4+-N in the effluent of the combined process. The removal rate of HA, FA, and TON from the concentrate is 93.54, 86.80, and 83.98%, respectively. The heterogeneous Fenton unit further oxidizes and decomposes HyI, exhibiting a slightly poor removal effect during the coagulation process, to achieve the COD effluent standard, and its removal rate is 86.02%. Under optimal working conditions, the cost of adding chemicals for the combined process is 47.10yuan/t.
2023 Vol. 43 (3): 1197-1207 [Abstract] ( 118 ) [HTML 1KB] [ PDF 1288KB] ( 378 )
1208 Insights into photocatalytic degradation of diethyl phthalate over BaSnO3 perovskite
YE Quan-yun, LI Xiang, MA Xiao-rui, LI Pei-ran, LIU Wang-rong, HE De-chun, SHE Lei
The photocatalytic degradation potential of BaSnO3 stannate perovskite was investigated under simulated sunlight, where diethyl phthalate (DEP) was selected as the probe pollutants. The results of modern spectral analysis showed that BaSnO3 perovskite with abundant oxygen vacancies, structural defects, and excellent photocatalytic activity could effectively degrade 91.8% of DEP through pseudo-first-order reaction kinetics, and it also remained good degradation efficiency in the pH from 3.0 to 9.0. The photogenerated holes (h+), superoxide (O2·-), and hydroxyl radicals (·OH) participated in the photo-degradation, among which O2·- played the most important role. Furthermore, the degradation mechanism was explored using density functional theory (DFT) calculations, proving that the reactive oxygen species (including O2·- and ·OH) were responsible for the hydroxylation of benzene ring and the breaking of the aliphatic chain, while h+ was prone to break the aliphatic chain.
2023 Vol. 43 (3): 1208-1215 [Abstract] ( 100 ) [HTML 1KB] [ PDF 1314KB] ( 228 )
1216 Analysis of pollution load characteristics and assimilative capacity in Shahe watershed based on Load Duration Curve Method
LIU Xiao-rong, DU Xin-zhong, HAN Yu-guo, LI Ze-li, LEI Qiu-liang, LIU Hong-bin
The Load Duration Curve (LDC) method was used to investigate the characteristics of pollution load export under different hydrological conditions in Shahe watershed located in Tianjin city, northern China. In addition, the influence of point source and non-point source pollution on water quality and load capacities and reductions for total phosphorus (TP), total nitrogen (TN) and chemical oxygen demand (COD) was also estimated based on LDC. In this study, the water quality target of water pollution prevention and control (surface water environmental quality Ⅲ) and the hydrological and water quality data of Shaheqiao monitoring section from 2006 to 2018 were used for the LDC method. The results showed that the average maximum daily loads of TP, TN and COD in flood season of Shaheqiao section are larger than those in non-flood season, indicating a stronger assimilative capacity. The concentrations of TP and TN in each month exceeded class Ⅲ for surface water quality standard, while the concentrations of COD were within the class Ⅲ standard. Under the objective of class Ⅲ water quality standard, the TP load of shaheqiao section didn't exceed load capacity in low flows, but exceeded the capacity in other flow conditions and the load reductions were 0.086, 0.011, 0.014 and 0.001 t/d, respectively for high flow, medium high flow, medium flow and medium low flow conditions. The TN loads in each flow condition exceeded the load capacities, and the load reduction amounts were 11.811, 4.386, 2.327, 0.466, 0.008t/d, respectively for different flow conditions. The COD load was not required for load reduction since it didn't not exceed the load capacity for all flow conditions. The water quality is mainly affected by point source load when the flow guarantee rate is greater than 75% during the low flow conditions. The pollution loads of Shaheqiao section were within the load capacity for low flow condition, indicating that the influence of point source in Shahe watershed was not significant. Non-point source pollution mainly affects the river water quality during medium and high flow conditions when the flow guarantee rate is less than 75%. For medium and high flow conditions, the current TN and TP loads all exceeded the load capacities and need to be reduced to meet the water quality target, which indicated that nitrogen and phosphorus non-point source pollution has an obvious impact on the water quality of Shahe watershed. This study can provide useful reference for investigating pollution load characteristics based on observed hydrological and water quality data and estimating assimilative capacity of pollutants in different hydrological conditions.
2023 Vol. 43 (3): 1216-1224 [Abstract] ( 125 ) [HTML 1KB] [ PDF 897KB] ( 516 )
Solid Waste
1225 Measuring the recycling potential of spent aircraft in China
XIONG Xin, ZENG Xian-lai, HU Zhao-ji
To clarify the obsolescent mechanism and recycling potential of spent aircraft in China, we considered the five typical aircraft types in this study. First, the retention coefficient method is used to measure the generation of spent aircraft and then to estimate the recycling potential of valuable resources (e.g., ferrous, nonferrous, and rare metals) in spent aircraft. The main findings were identified as follows:the potential weight of spent aircraft grew rapidly from 472 tons in 2015 to 1034 tons in 2020; the economic potential of spent aircraft increased from 6.3million tons in 2015 to 15million tons in 2020. Among all aircraft types, Boeing 737 and Airbus A320 have the largest scrap volume, and nonferrous metals account for the majority proportion of aircraft. Therefore, the relevant recycling enterprises can focus upon these two types of aircraft when planning the future capacity allocation, and foster the recycling technology of nonferrous metals.
2023 Vol. 43 (3): 1225-1234 [Abstract] ( 158 ) [HTML 1KB] [ PDF 2590KB] ( 263 )
1235 Study on the influence of sewage sludge coke expansion characteristics on the inhalable particle emission
JIA Li, ZHANG Liu, CHENG Peng, CHEN Shi-hu, WANG Chen-xing, YU Yue, WANG Jian-cheng, ZHANG Jian-chun, JIN Yan
The constitutive relationship between combustion conditions and the expansion characteristics of sewage sludge was established by using a self-built fluidized bed experimental system, with influencing factors including combustion temperature, heating rate and sample particle size. Based on the evolution of the sewage sludge combustion mechanism obtained by differential scanning calorimetry (DSC), the emission characteristics of submicron particulate matter (PM1) and supermicron particulate matter (PM1-10) were investigated, and the microscopic characteristics of the formed particulate matter were combined to reveal the extended influence of the coke expansion characteristics of sewage sludge on the particulate matter emission pattern and the key mechanism of particulate matter formation. The results showed that the combustion process of sewage sludge under different heating conditions showed a similar pattern of variation with temperature, both consisting of two significant exothermic peaks and two gentle heat absorption peaks. The expansion rates of sewage sludge coke formed by combustion all showed a trend of increasing and then decreasing with increasing heating rate, mainly influenced by the volatile analysis process. There was an inverse relationship between the sample particle size and the expansion rate, and the combustion temperature influenced the expansion characteristics of sludge coke mainly by affecting the catalytic evolution of the internal structure of the particles. As the combustion temperature increased, the overall emission of particles tended to increase gradually.
2023 Vol. 43 (3): 1235-1243 [Abstract] ( 109 ) [HTML 1KB] [ PDF 1447KB] ( 187 )
1244 Driving factors of foaming in anaerobic digestion of food waste
LI Lei, ZHANG Zhi, HUANG Qian, YANG Ping-jin, WANG Xiao-ming, PENG Xu-ya
To investigate the driving factors of foaming in anaerobic digestion (AD) of food waste, overloading, ammonia inhibition, and long-chain fatty acid inhibition were introduced into three semi-continuous anaerobic digesters to induce foaming incidents, during which the responses of process parameters, the variations of digestate' rheological properties, surface properties, foaming potential and extracellular polymeric substances (EPS) concentration were explored. The results showed that with the disturbance enhanced, the three digesters all produced foam with a height of 150~300mm. The volatile fatty acids (VFAs), surface activity (SA), foaming potential, surface tension, and viscosity were 1948~5978mg/L, 8.28~30.15, 312.5~350mL, 37.89~41.04mN/m, and 120~183.6mPa×s, respectively, in the three digesters during the initial stage of foaming. These variations suggested that their foaming thresholds were different, and even the variation trends of some parameters were inconsistent with the development trend of the foaming. In contrast, the EPS-related parameters were significantly correlated with the heights of the foam observed in different reactors. The soluble EPS and its protein concentrations, the polysaccharide concentrations of tightly bound EPS, and the polysaccharide concentrations of total EPS were positively correlated with the foam heights in three reactors (P<0.01, R2:0.64~0.81). Also, tightly bound EPS and total EPS concentrations were significantly (P < 0.05) or highly significantly (P < 0.01) related to the foaming heights in three reactors (R2:0.61~0.81). The interaction analysis of those parameters showed that in the overloaded and long-chain fatty acid inhibition reactors, the increased EPS concentrations were attributed to the accumulated VFAs, while in the ammonia inhibition reactor, free ammonia was the main reason for the increase of EPS concentration. Though the internal causes of EPS accumulation in test reactors were different, the increased EPS always significantly increased the viscosity of the digestates, and even reduced their surface tension, which eventually hindered the elimination of biogas from the liquid phase and resulted in foaming incidents. Further research on the EPS elimination technology may be expected to solve the AD foaming in situ with a high efficiency.
2023 Vol. 43 (3): 1244-1255 [Abstract] ( 114 ) [HTML 1KB] [ PDF 1206KB] ( 209 )
Soil Pollution Control
1256 Remediation of cadmium and pyrene co-contaminated soil by washing with biodegradable chelating surfactant LED3A
DIAO Jing-ru, LIU Xing-rui, ZHANG Lin-lin, DONG Ge-jun, ZHAO Bao-wei, JIANG Yu-feng
In this study, sodium N-lauroyl ethylenediamine tetriacetate (LED3A), a biodegradable chelating surfactant, was used as washing agent to remove cadmium (Cd) and pyrene (Pyr) co-contaminants from soils by batch experiments. The effects of washing time, LED3A concentration, temperature, pH value, water-soil ratio and ionic strength on the removal efficiencies were extensively explored. In addition, the forms of Cd and Pyr in soil before and after washing were analyzed. The results indicated that LED3A could simultaneously removal of Cd and Pyr from the contaminated soil. The pseudo-second order kinetics model was most suitable for describing the desorption processes of the two kinds of pollutants. Compared with the corresponding single contaminated soil, the interaction of coexistence of Cd and Pyr reduced their equilibrium removal rates with 5.13% and 9.91%, respectively. The removal efficiencies of Cd and Pyr were both increased with the increasing of LED3A concentration (0~15000mg/L), temperature (15~35℃) and water-soil ratio (10:1~60:1). Under the optimal (cost-effective) conditions (12000mg/L, 25℃, 30:1water-soil ratio), the removal rates of Cd and Pyr were 57.66% and 51.07%, respectively. The pH value of the soil-solution system was preferably maintained at alkaline conditions (pH=11). Appropriate ionic strength (0.1mol/L Na+ or 0.005mol/L Ca2+) could significantly promote the removal effect. The contents of exchangeable and reducible fractions of Cd as well as the non-desorbing and desorbing fractions of Pyr decreased with 61.09%, 26.35%, 17.26% and 68.44%, respectively, compared with their contents before washing. The residual fraction analysis of contaminants in soil demonstrated that the proportion of bio-available fractions of Cd and Pyr was significantly decreased. Correspondingly, soil environmental hazards and ecological risk induced by co-contaminants could be effectively reduced by the proposed approach. Remediation of heavy metal and organic co-contaminated soil by washing with biodegradable LED3A could be a promising green remediation method.
2023 Vol. 43 (3): 1256-1266 [Abstract] ( 116 ) [HTML 1KB] [ PDF 584KB] ( 223 )
1267 Source apportionment of soil heavy metals in lead-zinc area based on APCS-MLR and PMF
LIU Nan, TANG Ying-ying, CHEN Meng, PAN Yong-xing
This study took a typical lead-zinc mining area in Yangshuo county, Guangxi as the research object, and analyzed the contents of 10 heavy metal elements (Cr, Mn, Ni, Cu, Zn, As, Cd, Sb, Hg, and Pb) in the surface soil. The absolute principal component scores-multiple linear regression (APCS-MLR) model and positive definite matrix factorization (PMF) model were comprehensively used to identify and quantitatively analyze pollution sources and their contribution. The results showed that the means content of Pb, Zn, Hg, Cd, Mn, and Cu were higher than their corresponding local background values by approximately 3.29~13.08 times, Cr, Ni, As, and Sb also exceeded the background value in some areas, indicated that heavy metal pollution existed in the study area. The 10 heavy metals were mainly distributed in strips and spots at various depths, and the high content of Mn, Cu, Zn, As, Cd, Sb, and Pb were mainly distributed in the left bank of the Side river and southeast of the study area. The high contents of Cr, Ni, and Hg were mainly distributed in strip highlands of the central and western of study area. The source apportionment results of the APCS-MLR model and the PMF model were relatively consistent in terms of pollution sources. The metal pollution sources in the surface soil were jointly affected by mining activities, natural sources (such as, soil parent materials, rainfall erosion, etc), and mixed source of mining activities and agricultural activities. There were differences in the contribution rate of the APCS-MLR model and the PMF model. For the APCS-MLR model, the contribution rate of pollution sources in the order of mixed sources of mining activities and agricultural activities (30.95%), mining activities (22.39%), natural sources (15.79%), and unidentified sources (8.35%). The PMF model extracted the contribution of pollution sources in the order of mining activities (35.16%), tailings and waste (28.21%), mixed sources of mining activities and agricultural activities (20.89%), and natural sources (15.74%). The reasons for the difference in the pollution sources apportionment of the APCS-MLR model and PMF model may be attributed to different factor extraction methods, orthogonality constraint of the APCS-MLR model, and the uncertainty consideration and the non-negative constraint of the PMF model.
2023 Vol. 43 (3): 1267-1276 [Abstract] ( 150 ) [HTML 1KB] [ PDF 3206KB] ( 221 )
1277 Availability and interfacial energy characteristics of heavy metal ions in soils solidified by graphene oxide
WU Hai-yan, BAI Bing
Aiming at the remediation of heavy metal pollutants in soils, a soil column penetration test was carried out with quartz sand as porous medium material and graphene oxide as adsorbent under different types of heavy metals, concentrations of heavy metal pollutants, injected concentrations of graphene oxide and seepage velocity. For the case of a single heavy metal, the removal effect of graphene oxide and the curing mechanism were studied. The test results showed that the change of seepage velocity had little effect on the transport of single heavy metal ions (Pb2+ or Cd2+). When graphene oxide penetrates the contaminated soil column, low heavy metal pollution concentration and high seepage velocity promoted the transport of graphene oxide, and then promoted the transport of heavy metals. Graphene oxide had a good removal and immobilization effect on heavy metals (Pb2+ and Cd2+). The maximum curing ratios for lead ion and cadmium ion were 88.2% and 63.9%. In addition, SEM, FTIR and zeta potential tests showed that the adsorption mechanism of graphene oxide for heavy metal ions was mainly attributed to the electrostatic attraction, ion exchange and surface complexation. According to the calculation results of DLVO, the graphene oxide loaded with heavy metals was easier to immobilize in the soil than the graphene oxide not loaded with heavy metals. Among them, the graphene oxide loaded with cadmium ions was easier to immobilize in the soil than the graphene oxide loaded with lead ions.
2023 Vol. 43 (3): 1277-1287 [Abstract] ( 134 ) [HTML 1KB] [ PDF 1079KB] ( 269 )
Environmental Ecology
1288 Influences of freezing temperature on the inter-layer variations of mollisol organic carbon mineralization over progressive thawing
LIU Hui-min, SONG Yuan, LI Xian-wen, HU Ya-xian
The process of soil freezing and thawing, due to the severe changes of temperature and the two-phase transformation of ice and water, can profoundly reorganize the spatial distribution pattern of water, salt, nutrients and microorganisms within the soil matrix. The freezing temperature determines the structure and migration rate of the freezing front, which consequently affects the migration and diffusion efficiency of water, salt and nutrients and hence perturbs soil organic carbon mineralization. In this study, a mollisol (particle size < 2mm) was re-filled into soil columns, rewetted to field capacity (41%), respectively frozen at -10℃, -15℃ and -20℃ for 12h, and then thawed at 10℃. Individual soil columns were gradually peeled from the outside to the inner core into six layers (T1~T6) while progressively thawing, to capture the redistribution patterns of soil water, salt and nutrients during freeze-thaw. The results show that:1) The outmost layer T1had the highest water content (48.9%~61.9%), but the inner core T6 was drier with the lowest water content (29.3%~35%), and such polarized distributions of moisture were most significant in the soil columns frozen at -20℃. On the contrary, the electrical conductivity (EC) was higher in the outer layer T1and inner layer T6 (53.9~66.4μS/cm and 55.0~64.0μS/cm), but lowest in the middle layer T3 (53~56.5μS/cm). The difference of EC among the soil layers was most significant for the soil column frozen at -10℃. 2) The dissolved organic carbon (DOC) gradually decreased, but the soil microbial biomass carbon (SMBC) increased, from the outer layer T1to the inner core T6. Such patterns were more pronounced when the soil columns experienced lower freezing temperature. 3) The CO2 emission rate was higher in the outer layer T1 and inner core T6 (34~40.7μg/g and 33.5~63μg/g), but lower in the middle layer T4 (23.7~25.0μg/g). The soil columns after frozen at -10℃ released significantly less CO2 than those frozen at -20℃. 4) The SMBC was negatively linearly correlated with DOC, but positively linearly correlated with CO2 emission rate, suggesting that freezing can neutralize microbes, and the thus released dissolved nutrients can promote the survived microbes to respire during thawing. Our findings show that, peeling off the progressively thawed soil layers from the frozen core can effectively capture the polarized distribution of biophysiochemical properties and the potential impacts on carbon mineralization. Different freezing temperatures regulated the inter-layer heterogeneity over progressive thawing, further pointing to the limitation and thus partial understanding of freeze-thaw impacts on soil carbon mineralization if merely based on conventional investigations after complete thawing.
2023 Vol. 43 (3): 1288-1297 [Abstract] ( 173 ) [HTML 1KB] [ PDF 958KB] ( 200 )
1298 Spatial and temporal distribution and driving factors of carbon storage in Zhongtiao Mountain ecosystem in southern Shanxi Province
HAN Yu, DING Su-ting, YANG Tai-bao
In order to explore the role of terrestrial ecosystem carbon storage playing in promoting regional low-carbon construction and realizing carbon peaking and carbon neutrality, our study estimated the carbon storage of the Zhongtiao Mountain ecosystems during 2000 to 2020 using the carbon storage module of InVEST model. The carbon storage was modified according to the net ecosystem productivity (NEP) data. What's more, the geographic detectors were used to analyze the driving factors for the spatial variations of carbon storage. The results showed that the modified carbon storage in Zhongtiao Mountain increased by 2.296×106t from 2000 to 2020. The high carbon storages were mainly distributed in the east, central and northwest regions, while the low values were distributed in the southwest and a small part of the central region. Total carbon sink of terrestrial ecosystem in the Zhongtiao Mountain showed an increasing trend from 2000 to 2020, and the regional average annual NEP was 0.060kgC/(m2·a). The carbon sink was mainly distributed in the east, while the carbon source was distributed in the central and northwestern regions. The spatial variation of carbon storage was mainly influenced by annual average NDVI, human activity intensity and annual potential evapotranspiration, followed by annual average temperature, population and elevation. The interaction effects of different factors on carbon storage showed a double factor and nonlinear enhancement, which indicated that the spatial differences of carbon storage were influenced by the natural and human factors. In the ecological environment protection and regional low-carbon construction of Zhongtiao Mountain, the different influencing factors should be considered comprehensively, and differentiated ecological regulation models and strategies should be adopted to improve the ecosystem stability and enhance the carbon storage capacity.
2023 Vol. 43 (3): 1298-1306 [Abstract] ( 155 ) [HTML 1KB] [ PDF 1715KB] ( 436 )
1307 Changes of organic C and N stable isotope and their environmental implication during the past 130 years of Chen Lake
ZHANG Ya, LIU Li, LI Peng, HU Yuan-ping, LI Lin-jing, SU Ye-wang, XING Xin-li, FENG Jiang, YE Ting
Based on the analysis of total organic carbon(TOC), total nitrogen(TN), organic carbon isotope(δ13Corg) nitrogen isotope(δ15N), and the results of dating(210Pb, 137Cs) from sediment core collected in the center of the Chen Lake in 2020, the source of organic matter in sediments was identified and the evolution process of lake ecosystem during the past 130 years under the influence of human activity was analyzed. These results showed that the average sedimentary rate was 0.52cm/a, showing a slowly increasing tendency. The contents of TOC and TN ranged from 0.89% to 3.65% and 0.04% to 0.20%, respectively. The values of δ13C and δ15N ranged from -29.34‰ to -26.13‰ and 1.67% to 5.48‰, respectively. The rapid increase of TOC and TN in the depth of 38~26cm corresponded to the period of population growth and lake reconstruction projects around the Chen Lake during 1970~1990. The organic matter in sediments was a mixed source, including soil organic matter, terrestrial C3 plants and aquatic vascular plants. Soil organic matter and terrestrial C3 plants dominant the sedimentary organic compositions. After the 1980, due to the weakening of lake hydrodynamic caused by human activities, the contribution rate of aquatic vascular plants to sediment organic matter in wetland increased. Hence, in the future, more attention should be paid to the impacts of human activities on the lake ecological environment for controlling soil erosion and reasonably regulating the hydrological conditions of lakes.
2023 Vol. 43 (3): 1307-1316 [Abstract] ( 172 ) [HTML 1KB] [ PDF 659KB] ( 380 )
1317 Effects of human disturbances on dynamic evolution of ecological vulnerability: A case study over Lanzhou-Xining urban agglomeration
SHI Jing, SHI Pei-ji, WANG Zi-yang, WAN Ya
Taking the Lanzhou-Xining urban agglomeration as an example, this paper uses the spatial principal component analysis (SPCA) method to evaluate its ecological vulnerability, and introduces the human disturbance index (HI) on this basis to explore the impact of human disturbance change on the dynamic evolution of ecological vulnerability. The results show that from 1990 to 2020, the ecological vulnerability of Lanzhou-Xining urban agglomeration decreased from 3.14 to 2.69, and the ecological environment improved year by year. Spatially, the medium, strong and extremely vulnerable areas are mainly concentrated in the valley basins in the central and western regions and the low-altitude areas in the east, while the negligible and light vulnerable areas are mainly concentrated in the higher altitude of the central and western regions. From 1990 to 2020, Moran's I increased slightly from 0.942 to 0.955, indicating an obvious spatial aggregation effect of ecological vulnerability. From 1990 to 2020, the ecological deterioration area decreased by 178.63km2, and the ecological improvement area increased by 7189.08km2. The ecological deterioration area was mainly distributed in the valley basin and the northeast region, while the ecological improvement area was mainly distributed in the southeast and the higher elevation areas in the central and western regions. The human disturbance index increased from 0.245 to 0.252, and the spatial distribution characteristics of the moderate-high interference area and the ecological deterioration area were basically consistent. With the increased level of human disturbance, the ecological environment of the river valley basin and the northeast area deteriorates gradually. The research results can provide useful reference for ecological protection, land resource utilization and sustainable development of Lanzhou-Xining urban agglomeration.
2023 Vol. 43 (3): 1317-1327 [Abstract] ( 140 ) [HTML 1KB] [ PDF 4330KB] ( 280 )
1328 Characterization for nitrogen metabolism of sediments in highland saline lake
YANG Wen-huan, ZHEN Yu, YAO Zhi, YIN Qiang, HUANG Xiao-hui, LI Wei-ping
In order to explore the adaptation strategy of microbiota in saline-alkali lakes under high salt stress, the community structure and functional characteristics of nitrogen-metabolizing microorganisms in Daihai sediments located in Inner Mongolia were revealed by metagenomic sequencing technology. The effects of environmental factors on nitrogen metabolism and the driving mechanism of microbial community construction under salt stress were explored. The results showed that the nitrogen metabolism of sediments was mainly through nitrate dissimilatory reduction, accompanied by five pathways, including nitrogen fixation, nitrification, denitrification, nitrate assimilatory reduction, and complete ammonia oxidation. Proteobacteria, Chloroflexi, and Actinobacteria were the top three dominant phyla in terms of nitrogen metabolism, which accounted for 56.31%~59.19%, 8.26%~12.89% and 3.2%~6.4% of the total microbial community, respectively. There was no significant difference between this microbiota and other sediment of lakes, but the specificity was significant at the genus level. Thiobacillus, unclassified_c_Gammaproteobacteria, and Thiobalkalivibrio were the dominant genera involved in nitrogen metabolism, which accounted for 9.8%~15.22%, 3.49%~4.02% and 3.49%~4.02% of the total microbial community, respectively. Salinity, total nitrogen, total phosphorus, and pH were the main environmental factors affecting the abundance of the gene. The assembly of the nitrogen metabolism microbial community was driven by deterministic processes, and the microbial community composition of each of the six pathways was distinctive under the effect of environmental filtering. Halophilic methane-oxidizing bacteria and nitrate-reducing sulfur-oxidizing bacteria dominated part of the nitrogen metabolism process in salt-stressed, which coupled the carbon, nitrogen, and sulfur cycles, resulting in the particularity of the nitrogen metabolism process in sediments of Dai Lake.
2023 Vol. 43 (3): 1328-1339 [Abstract] ( 120 ) [HTML 1KB] [ PDF 2789KB] ( 333 )
1340 Impact of land use change on the spatiotemporal evolution of the regional thermal environment in the Beijing-Tianjin-Hebei urban agglomeration
XU Hong-chao, LI Chun-lin, WANG Hao, LIU Miao, HU Yuan-man
In this study, the Beijing-Tianjin-Hebei urban agglomeration (BTH), one of the three largest urban agglomerations in China, was selected as the study area. The effects of different land use types on the diurnal regional thermal environment of BTH in summer were investigated by using Getis-Ord Gi* index and contribution index. The results illustrated that the spatial distribution of relative land surface temperature (RLST) varied greatly between day and night in summer. The RLST was higher in the northwest and southeast of BTH during the day. At night, the northwest was dominated by cold spots, while the hot spots were mainly located in the southeast. BTH was mainly dominated by cropland, forest, grassland and built-up area. The cropland and built-up area were mainly located in the southeast, while the forest and grassland were mainly located in the northwest. The cropland was the largest, accounting for about 45.5% of the overall area. However, with the urbanization, the cropland decreased by 5.2% and the built-up area increased by 2.3%. In summer, the RLST of land use varied greatly during the day and night. The RLST of water body was below 0℃ during the day, which had significant cooling effect on the regional thermal environment. At night, the RLST of the water body was 3~4℃, which had significant warming effect. Grassland has no significant cooling effect in the daytime, but it was stronger than that of forest at night. Through analyzing the diurnal impact of different land use types on the regional thermal environment, this study could help to understand the distribution characteristics and impact mechanism of the regional thermal environment, thus expect to provide a theoretical basis for the formulation of mitigation strategies for regional heat islands.
2023 Vol. 43 (3): 1340-1348 [Abstract] ( 135 ) [HTML 1KB] [ PDF 1900KB] ( 357 )
1349 Environmental characteristics and phytoplankton bloom mechanisms in the cold eddy of northern East China Sea in late spring
ZHAO Yu-hang, WEI Qin-sheng, XIN Ming, XIE Lin-ping, SUN Xia, WANG Bao-dong
Based on the survey data obtained in the East China Sea (ECS) in the late spring of 2019, the distribution characteristics and spatial patterns of physical and chemical variables, including temperature, salinity, nutrients and chlorophyll a (Chl-a), were analyzed, and the hydrological environment characteristics, nutrients dynamic processes and phytoplankton bloom mechanisms in the cold eddy of the northern ECS were discussed. The low-temperature zone southwest of Cheju Island clearly showed the location of cold eddy in late spring, and the uplift of cold waters in the boundary area of this eddy indicated the presence of upwelling. The southward horizontal transport of the Yellow Sea western coastal current provided a source of nutrients for the cold eddy-dominated area, while the upwelling near the boundary of cold eddy controlled the vertical transport of nutrients to a certain extent. The high-Chl-a zone (with the highest Chl-a value of 5.69μg/dm3) southwest of Cheju Island implied the phytoplankton blooms in late spring, which generally coincided with the location of cold eddy and high-nutrient zone in the northern ECS. Relatively high nutrient levels, good light conditions, and enhanced water-column stability were favorable for the formation of phytoplankton blooms in the cold eddy of the northern ECS. Its suggested that the northwest-southeast front (formed by the confluence of the cold eddy and the southern high-temperature saline water mass) had an essential impact on the spatial pattern and location of the high-Chl-a zone. The relatively low turbidity in the region southwest of Cheju Island increased the vertical depth that could meet the light conditions required for phytoplankton growth, leading to a subsurface Chl-a maximum within the phytoplankton bloom area in the cold eddy of northern ECS. This study provided an essential scientific basis for further understanding the controlling mechanisms of primary production processes in the northern ECS and conducting regional ecosystem dynamics research.
2023 Vol. 43 (3): 1349-1359 [Abstract] ( 110 ) [HTML 1KB] [ PDF 3047KB] ( 250 )
1360 The influence of the accumulation of submerged plant residues on the physicochemical properties of sediments——a case study of Malayan cabbage
XU Da, JIN Wei, WEI Yi, WANG Chun-liu, ZHU Bo-song, HUA Ke, ZHOU Pan, LIU Xin
In this study, the influence of the accumulation of submerged plant residues on the properties of surface sediments was clarified by using different contents of Malayan vegetable residues in the sediments and analyzing the changes of physicochemical properties and rheological properties of surface sediments. After one month's experiment, with the increase in the accumulation content of submerged plant residues, the surface sediment density decreased exponentially, accompanied by the formation of fluid sediment. Meanwhile, the results of sediment particle size distribution showed that the decomposition of submerged plant residues in the sediment led to the flocculation and agglomeration of the sediment. And the high values of polysaccharide/protein in extracellular polymeric substances (EPS) in sediments made sediment aggregates difficult to deposit, which is conducive to the formation of fluid sediment. In addition, the yield shear stress of sediments in rheological tests decayed exponentially (R2=0.97) with the contents of submerged plant residues. And when the accumulation content exceeded 0.4%, the values of yield shear stress gradually kept stable, resulting in sediment suspension. Overall, this study deepened the understanding of the impact of submerged plant residues decomposition on sediment properties, and the results can be helpful to sediment management in shallow lakes.
2023 Vol. 43 (3): 1360-1367 [Abstract] ( 107 ) [HTML 1KB] [ PDF 790KB] ( 209 )
Environmental Microbiology
1368 Effect of temperature and humidity on the growth of typical molds in buildings and its kinetics modeling
LU Bing-jie, DU Chen-qiu, GUO Xin-zhu, YU Wei, LI Bai-zhan
A higher air humidity in buildings is easy to facilitate mold growth and spore diffusion, causing building structure damage and allergic symptoms or diseases on human, which is seriously harmful to indoor environment building and people health protection. This study took Aspergillus niger, a typical Aspergillus species in homes as an example, and experimentally studied the influence of environmental temperature and humidity (15/20/25/30℃, 60%/75%/85%) on the growth characteristics of Aspergillus niger, and established the growth kinetics models with time, temperature and humidity. The results showed that when the relative humidity was higher than 60%, the temperature was the main factor and the growth of Aspergillus niger was accelerated with increased temperature; while the influence of relative humidity was not significant. A Gompertz model was developed to quantify the growth of Aspergillus niger through building the relations with the colony diameter and growth time for Aspergillus niger; and the parameter μm was increased and λ was decreased (T≤25℃) with increasing temperature. A response surface model was further adopted as a secondary grade model to explore the growth characteristics of molds under the coupled influence of temperature and humidity. The relations between μm, λ and the temperature, relative humidity were quantified based on the model. The work provides a reference for the mold growth risk evaluation and source control in the real hot-humid environment in buildings.
2023 Vol. 43 (3): 1368-1377 [Abstract] ( 105 ) [HTML 1KB] [ PDF 1511KB] ( 395 )
1378 Cross-tolerance of Nitrosomonas eutropha CZ-4 to high-temperature and high salinity
YANG Rui, GE Hong-mei, CHENG Kai
To study the combined influence of high-temperature and high salinity on the nitrosation activity of Nitrosomonas, the cross-tolerance of Nitrosomonas eutropha CZ-4 to high-temperature and high salinity by short-term cross-experiment at different salinities and temperatures was investigated. Also, stress experiments were performed after long-term preacclimation, and the extracellular polymeric substance content was measured. Results showed the optimal salt concentration increased gradually from 2g/L to 18g/L when the temperature increased from 28℃ to 40℃, and high salinity/high-temperature significantly alleviated the inhibition by high-temperature/high salinity, respectively. The heat tolerance was significantly improved by the high salinity preacclimation, and the salt tolerance also significantly improved by the high-temperature preacclimation. After preacclimation in high-temperature or high salinity conditions, the bound-polysaccharide content significantly increased compared that of cells cultured in low-temperature and low-salinity conditions. The results not only prove the physiological cross-tolerance of CZ-4 to high-temperature and high salinity, but also prove the accumulation of the extracellular bound-polysaccharide of CZ-4 at high-temperature or high salinity conditions.
2023 Vol. 43 (3): 1378-1385 [Abstract] ( 145 ) [HTML 1KB] [ PDF 925KB] ( 188 )
1386 Effect of cadmium-tolerant bacteria on Lolium perenne growth and its cadmium enrichment
SONG Lan-ping, XU Xiao-yang, HONG Wan-yue, AI Yan-mei, WANG Yang, ZHANG Ze-kun, ZHOU Shou-biao, ZHOU Ji-hai
In this study, cadmium was added to the soil, and Cd-tolerant bacteria Cdq4-2 (Enterococcus sp.) was inoculated to conduct a 40-day indoor culture experiment. Finally, the aboveground biomass, underground biomass and total biomass, chlorophyll a, chlorophyll b and total chlorophyll contents of ryegrass, the activities of antioxidant enzymes (SOD, POD) of L. perenne were determined, cadmium concentrations in ryegrass and in soil were measured to explore the effects of cadmium tolerant bacteria on the physiological and biochemical characteristics of ryegrass and the remediation efficiency of cadmium contaminated soil. Four treatments were designed:C1-Cd-contaminated soil (Cd, 4mg/kg), C1B-Cd-contaminated soil (Cd, 4mg/kg) + Cd-tolerant bacteria, C2-Cd-contaminated soil (Cd, 20mg/kg), and C2B-Cd-contaminated soil (Cd, 20mg/kg) + Cd-tolerant bacteria, and soil without Cd was used as control (CK). The results showed that the aboveground biomass, underground biomass and total biomass of L. perenne in the C2B treatment inoculated with Cdq4-2 were 39.57%, 171.88% and 50.15% higher than those in the C2 treatment without Cdq4-2, respectively. Compared with C1, the contents of chlorophyll A, chlorophyll B and total chlorophyll of L. perenne in C1B group were significantly increased by 29.81%, 29.65% and 29.77%, respectively. Compared with C1, POD activity of L. perenne in C1B was significantly increased by 150.75%, and that in C2B was significantly increased by 146.51%; The cadmium concentration of L. perenne in C1B was significantly increased by 58.29% compared with C1, and that of C2B was significantly increased by 30.53% compared with C2. The cadmium concentration of L. perenne in C2B was significantly increased by 24.25% compared with C2. The enrichment coefficient of L. perenne in C1B was significantly increased by 58.29% compared with C1, and that of C2B was significantly increased by 30.53% compared with C2. The transport coefficient of C1B is 74.84% higher than that of C1. The Cd-tolerant bacteria inoculated in the Cd-contaminated soil could enhance the photosynthesis of L. perenne, improve the antioxidant ability of L. perenne, promote the uptake, transport and accumulation of cadmium in L. perenne, so as to improve the efficiency of L. perenne remediation of cadmium contaminated soil.
2023 Vol. 43 (3): 1386-1396 [Abstract] ( 92 ) [HTML 1KB] [ PDF 558KB] ( 197 )
1397 Dynamics of eARGs in activated sludge in response to starvation at different temperatures as revealed by metagenomics
TANG Zhen-ping, LIU Bo-yang, GAO Yuan-yuan, DUAN Yi, YANG Zheng-qing, ZHOU Shuai
Activated sludge is a vital reservoir for extracellular antibiotic resistance genes (eARGs). The metagenomic sequencing technology was used for the first time to examine the impacts of starvation (i.e., substrate deficiency) at different temperatures (12℃, 20℃ and 30℃) on the dynamic of eARGs in activated sludge. The results indicated that the abundance of eARGs after 30-days starvation was effectively reduced by 3.5%~26.0%, 66.1%~81.4%, respectively. The abundance of eARGs after 12℃ starvation was higher than that after 20℃ and 30℃ starvation. The majority of extracellular mobile genetic elements changed little after starvation at 12℃, but their abundance after 12℃ and 30℃ starvation decreased by 41.4%~54.4%, 48.7%~67.4%, respectively. The relative abundance of the dominated hosts of eARGs (i.e., Mycobacterium and Nitrospira) remained stable after starvation at different temperatures. The kinetic studies confirmed that, compared with 20℃ and 30℃ starvation, 12℃ starvation had higher proportion of living cells and relatively lower adsorption or degradation rate of extracellular DNA, which was conducive to maintain the stability of eARGs. The present study was helpful for elucidating the fate of eARGs in activated sludge in response to starvation stress at different temperatures, which could provide a scientific basis for controlling the propagation and dissemination of eARGs in actual wastewater treatment plants.
2023 Vol. 43 (3): 1397-1406 [Abstract] ( 103 ) [HTML 1KB] [ PDF 1888KB] ( 225 )
Environmental Toxicology and Health
1407 Rubber anti-aging agent 6PPD and its ozonation product 6-PPDQ: Environmental distribution and biological toxicity
LI Jia-yao, SHEN Hui-min, XU Ting-ting, GUO Ying
In the present review, we discussed the environmental distribution of 6PPD-quinone (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone) and its precursor 6PPD (N-(1,3-Dimethyl-butyl)-N'-phenyl-p-phenylenediamine) in the air, aquatic environment, and soil, and summarized their cytotoxicity and biota toxicity, as well as potential effect on human health. The present knowledge indicated that 6PPD and 6PPD-Q are mainly from the rubber tire wear particles. They are transported with particles in air, water and soil. 6PPD and 6PPD-Q may inhibit cell proliferation, cause acute death of several fish species, and induce developmental toxicity, and may induce allergic dermatitis for humans. The future researches should pay more attention on the joint toxicity of 6PPD and 6PPD-Q with other rubber tire additives, and the related ecological risk assessment.
2023 Vol. 43 (3): 1407-1421 [Abstract] ( 619 ) [HTML 1KB] [ PDF 606KB] ( 805 )
1422 Effect of chronic noise-exposure on liver lipid metabolism in high-fat diet mice
XU Dan, CAO Shuang-feng, LIU Li-jie
To explore the effect of chronic noise-exposure on liver lipid metabolism, C57BL/6J mice were randomly divided into control group and noise exposure group (85dB(A) SPL broad-band noise, 4h/d, for 8weeks). Each group was divided into two subgroups that were given a chow diet or a high-fat diet. The body weight growth rate, glucose tolerance, insulin tolerance, the epididymal fat weight, liver weight, the levels of serum interleukin-6, the levels of serum triglyceride and total cholesterol, the levels of triglyceride and total cholesterol in liver, the levels of malonaldehyde in liver and the phosphorylation levels of c-Jun N-terminal kinase in liver of mice were measured at the end of experiment. The results show that noise exposure can significantly decrease the body weight growth rate (23.30±2.54%vs. 37.13±3.05%), significantly increase the metabolic efficiency (545.20±55.06kJ/g/mouse vs. 352.50±20.92kJ/g/mouse) and the levels of serum interleukin-6 (44.68±9.77pg/mL vs. 20.83±0.81pg/mL) of mice fed by chow diet. That noise exposure can significantly increase the levels of triglyceride (0.54±0.07mmol/g protein vs. 0.30±0.03mmol/g protein) and malondialdehyde (1.98±0.13nmol/mg protein vs. 1.24±0.03nmol/mg protein) and the phosphorylation levels of c-Jun N-terminal kinase (1.56±0.19vs. 1.00±0.00) in liver of mice fed by high fat diet. In conclusion, in this study chronic noise exposure can aggravate liver lipid metabolism disorders in high-fat-diet mice, and the activation of c-Jun N-terminal kinase may be involved in the liver lipid metabolism disorders.
2023 Vol. 43 (3): 1422-1428 [Abstract] ( 139 ) [HTML 1KB] [ PDF 1756KB] ( 225 )
1429 Joint acute toxic impacts of 2,6-ditert-butyl-4-nitrophenol and Cd2+ on aquatic organisms and ecological risk assessment
YUAN Yao, ZHANG Ling-han, ZHOU Nan, LIU Hui-hui, YANG Xian-hai
An emerging aromatic disinfection by-products (DBPs) (2,6-ditert-butyl-4-nitrophenol (DBNP)) and a typical heavy metal ion (Cd2+) were selected as model compounds to reveal the potential joint toxic impacts of DBPs combined exposure with other substances on aquatic organisms. Firstly, we tested the acute toxicity of DBNP and Cd2+ on Tetradesmus obliquus, Daphnia magna, and Gobiocypris rarus in single and combined exposure mode, respectively. The experimental results indicated that the acute toxicity values of DBNP on Daphnia magna and Gobiocypris rarus was less than 1mg/L, which implying that DBNP was belonged to the very toxic group substances (hazard level of category 1) according to the classification criteria of acute aquatic hazard defined in Globally Harmonized System of Classification and Labelling of Chemicals (GHS). The combined exposure of DBNP and Cd2+ exhibited antagonistic effect on all the three aquatic organisms. Then, the potential ecological risk of model compounds in single and combined exposure situation were further assessed. Results implied that the concentration addition-based combined risk quotient method would overestimate the real co-exposure risk if the combined exposure exhibited antagonistic effects. While weight-of-evidence (WOE)-based combined risk quotient method could overcome this issue and obtain the more reasonable combined exposure risk in this situation.
2023 Vol. 43 (3): 1429-1437 [Abstract] ( 122 ) [HTML 1KB] [ PDF 738KB] ( 373 )
Environmental Impact Assessment and Management
1438 The spatio-temporal variation and influencing factors of electricity-related carbon emissions in the Yangtze River Economic Belt from the region and industry perspectives
GUO Yi, ZHANG Peng-fei, GE Li-ming, ZENG Gang, WAN Yuan-yuan
The IPCC carbon inventory accounting method and network model were comprehensively used to quantify carbon emissions induced by power production, transmission, and consumption in the Yangtze River Economic Belt from 2005 to 2020, and its spatio-temporal variation was analyzed from the region and industry perspectives. Besides, the LMDI method was applied to quantify the contributions of the economic and technological factors to changes in regional production and consumption side electricity-related carbon emissions. Results showed that the carbon emissions from power generation in the Yangtze River Economic Belt grew continually but with a declining growth rate. Specifically, the total amount increased from 680million tons to 1.225billion tons, and the average annual growth rate decreased from 7.61% from 2005 to 2011 to 1.28% from 2012 to 2020. The spatio-temporal characteristics of electricity-related carbon emissions from the consumption side were similar to those from the production side, but the carbon emissions embodied in the inter-provincial power transmission had grown continually during the research period. Among them, Shanghai, Jiangsu, and Zhejiang had the largest net outflows of electricity-related carbon emissions, with net outflows of 18.94 million tons, 61.20 million tons and 70.21 million tons respectively in 2020. Anhui, Hubei, Sichuan, Guizhou, and Yunnan had the largest net inflows of electricity-related carbon emissions, with net inflows of 27.24 million tons, 23.10 million tons, 10.76 million tons, 30.10 million tons and 22.19 million tons respectively in 2020. The consumption side carbon emissions in the downstream areas mainly came from the resource processing industry, machinery and electronic manufacturing industry, and light textile industry. Machinery and electronics manufacturing, textile, and service industries had the highest growth rate of the consumption side carbon emissions. The consumption side carbon emissions in the midstream and upstream areas were mainly driven by the electric power, heat production and supply industry, and resource processing industry. In the midstream and upstream areas, except Sichuan and Yunnan, the carbon emissions induced by the above industries have increased substantially. Power generation scale was the biggest factor promoting the growth of carbon emissions from the production side. On the contrary, coal consumption rate of power generation and power generation mix were the factors that inhibit its growth. Economic development and household consumption were the main factors to promote the growth of carbon emissions from the consumption side, while industrial power efficiency, carbon emission intensity of power consumed and industrial structure played a negative driving role.
2023 Vol. 43 (3): 1438-1448 [Abstract] ( 110 ) [HTML 1KB] [ PDF 2318KB] ( 263 )
1449 Green for labor: Environmental regulation and employment of heavy polluting enterprises——Based on the green technology innovation in the whole production process
QIN Bing-tao, YANG Kun, GE Li-ming
Based on the data of listed companies in China's A-share heavily polluting industries from 2008 to 2020, this paper empirically examined the impact and mechanism of environmental regulation on employment. The research found that environmental regulation adversely impacted the employment of enterprises, and this result was valid after a series of robustness tests and control of endogenous problems. However, the mechanism analysis revealed that environmental regulation could carry out green technological innovation which alleviated the contradiction between environmental protection and employment. In the heterogeneity analysis, it was found that the adverse impact of environmental regulation on enterprise employment mainly affects non-state-owned enterprises, low-educated people and enterprises in the central region. Furthermore, the research found that the changes in the production process weakened the adverse impact of environmental regulation on enterprise employment. On the contrary, the increase of R&D investment aggravated this negative impact which is not significantly affected by end-of-pipe innovation.
2023 Vol. 43 (3): 1449-1459 [Abstract] ( 195 ) [HTML 1KB] [ PDF 623KB] ( 273 )
1460 Driving factors of agricultural carbon emission: From the perspective of interregional trade carbon emission transfer network
XIN Meng, CHEN Jing-quan, PENG Xue-peng, SHI Lan, QIAN Hui
Using the panel data of 30 provinces in China from 2007 to 2017, the inter-regional agricultural trade carbon emission transfer network was constructed with each province as the node, the carbon emission relationship between provinces as the edge and the carbon emission transfer amount as the weight, and the input-output theory and complex network theory were combined to investigate the influence of each province's role in the agricultural trade carbon emission transfer network on each province's agricultural direct carbon emission. The empirical results show that China's agricultural direct carbon emissions were large in general from 2007 to 2017, and most provinces' agricultural direct carbon emissions were in an increasing trend. According to the results of the inflow and outflow analysis of agricultural trade carbon emissions in the three functional areas, the main grain producing areas were more self-consuming, followed by the main grain marketing areas, and finally the balanced grain production and marketing areas. The main marketing areas consumed more of the main grain producing areas and supply less. The balanced grain production and marketing area consumed more of the main grain producing area and supplies the main grain selling area and the main producing area. The flow of carbon emissions in China was mainly concentrated in the central regions such as the main grain producing regions and the three northeastern provinces. The western provinces of Xinjiang and Inner Mongolia were mainly inflow from developed regions such as the east. The inflow intensity of agricultural trade carbon emissions, urbanization level, agricultural machinery input intensity and average grain production per agricultural labor force have a catalytic effect on agricultural direct carbon emissions; the per capita net income of rural residents and agricultural industry structure have a suppressive effect on agricultural direct carbon emissions; the outflow intensity, transmission medium capacity and influence of agricultural trade carbon emissions have no significant effect on agricultural direct carbon emissions.
2023 Vol. 43 (3): 1460-1472 [Abstract] ( 128 ) [HTML 1KB] [ PDF 942KB] ( 274 )
1473 Research on environmental regulation, reputation appeal and performance of pro-environment behavior
ZHAO Jia-jia, LIU Ling-zhi
Pollution prevention and rational utilization of livestock farming waste is not only an important part of promoting sustainable development of farming and realizing rural civilization, but also an important measure to achieve the synergistic effect of pollution and carbon reduction. In this article, Tobit model was used to analyze the influence of environmental regulations and reputation claims on the pro-environmental behavioral performance of meat duck farmers from the perspective of economics on account of the survey data of meat duck farmers. Then, based on the analysis of the differences between groups of farmers' behavioral performance, the article further explored the non-linear relationship between environmental regulations and reputation claims on farmers' behavioral performance and the path of indirect influence of farmers' behaviors on farmers' behavioral performance. The results as follows:environmental regulations and reputation claims significantly affected farmers' behavioral performance of manure resource treatment. Among all environmental regulations, guidance-type regulations play the strongest role. Among eputation claims, farmers' reputation claims on personal social relationships can better promote farmers' behavioral performance; The effects of environmental regulations and reputation claims on farmers' behavioral performance were different in age and education level. When household income reaches a certain level, the effects of environmental regulations and reputation claims on farmers' behavioral performance were more significant; Environmental regulations and reputation claims directly affect farmers' behavioral performance through interactive effects while indirectly affecting it through influencing farmers' behavior. In order to promote the implementation of rural revitalization, appropriate environmental regulation policies should be formulated on the basis of the heterogeneity of target groups. In addition, in the process of enhancing the effective implementation of policies, technical training on farming pollution control and the reputation effect should be strengthened to enhance farmers' knowledge and promote the implementation of manure resource treatment by farmers, so as to optimize the resource allocation of meat duck farming and realize the sustainable development of meat duck industry.
2023 Vol. 43 (3): 1473-1488 [Abstract] ( 100 ) [HTML 1KB] [ PDF 726KB] ( 282 )
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