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2022 Vol.42 Issue.1,Published 2022-01-20
Air Pollution Control
Water Pollution Control
Solid Waste
Soil Pollution Control
Environmental Microbiology
Environmental Ecology
Environmental Impact Assessment and Management
Environmental Toxicology and Health
Carbon Emission Control
Advanced Wastewater Treatment Technology Column
Air Pollution Control
1 The establishment of double-layer PCT classification method and its application
CAI Xu-zhang, WANG Cheng-gang, WANG Hua-qing, LAO Xiu-feng
This paper proposes a new double-layer PCT weather classification method. This method separately classifies weather data from the high-level background field and the low-level ground field, and then combines, classifies, and adjusts all initial classes to form the final classification. The winter weather information over the lower reaches of the Yangtze River from 2014 to 2019 was collected and used in this study. As a result, 8 main weather patterns were classified as: weak pressure field, cold front transit, high pressure front, high pressure bottom, high pressure control, high pressure rear, inverted trough front and inverted trough rear. Among them, the weak pressure field had the highest proportion (26.6%) and the lowest ventilation coefficient (3518m2/s in daytime, 1373m2/s at night), and the pollution rate was higher in common weather types. We observed four main moving paths of the winter high pressure over the lower reaches of the Yangtze River of which the "high pressure front-high pressure bottom-high pressure rear" path was the most frequent (accounting for 42.9%), and this kind of path has been proven to be most unfavorable for accumulating atmospheric pollutants through quiet and stable weather. Our typing results finally verify that the double-layer PCT weather classification method has better accuracy and stability than the traditional one.
2022 Vol. 42 (1): 1-10 [Abstract] ( 529 ) [HTML 1KB] [ PDF 1991KB] ( 2630 )
11 Hg0 oxidation of modified Ni-Al catalysts and its anti-ammonia interference mechanism
QIU Lei, GUO Lei, HAN Jin-chi, YU Jie, CHANG Hua-zhen
NiAlO and NiAlMO (M=Zn、Ba、Mn、La、Cr) catalysts were prepared to evaluate the efficiency of Hg0 oxidation of NiAlZnO catalyst using urea hydrolyzation, Raman and XPS experiments, etc. The results indicate that NiAlZnO catalyst exhibited the highest Hg0 oxidation activity in the presence of NH3 and the Hg0 oxidation efficiency of NiAlZnO catalyst was above 80% at 250℃ and reached 90% at 350℃. Doping Zn enabled the NiAlZnO catalyst to form Ni-O-Zn solid solution and generate Jahn-Teller distortions which could increase the content of surface chemisorbed oxygen and promote the activation of O2, and thus increase the surface chemisorption oxygen content of catalyst. The incorporation of Zn could improve the redox and Hg0 adsorption performance of NiAlZnO catalyst, even in the presence of NH3. NH3-TPD and NH3-DRIFT experiments also proved that the addition of Zn introduced the new Hg0 adsorption site (B acid site) for NiAlZnO catalyst. Obviously, NiAlZnO catalyst can greatly promote Hg0 oxidation and possesses the resistance to NH3 interference.
2022 Vol. 42 (1): 11-19 [Abstract] ( 236 ) [HTML 1KB] [ PDF 799KB] ( 1505 )
20 The characteristics of CuSnZr catalyst applied to NTP enhanced catalytic desulfurization process
ZHOU Zheng-hua, JIANG Lian-shuang, ZHANG Zhen-yu, HUANG Rui, NING Jing-yuan, NING Zhi-yuan
In order to efficiently process a large amount of low-concentration electrolytic aluminium flue gas at low temperature, the Sn Zr type metal oxide was prepared by the impregnation method with Cu added as a catalyst, and this desulfurization effect of CuSnZr catalyst was the first time to be tested in low temperature plasma (NTP) technology. The best desulfurization performance results when the catalyst was loaded with 20wt% Cu and when the aging temperature was 40℃. Compared with the fresh catalyst, the X-ray diffraction analysis (XRD) results showed that the discharge basically did not affect the crystal form of the catalyst; the scanning electron microscopy (SEM), nitrogen adsorption and desorption (BET) indicated that the discharge will greatly improve the adsorption capacity, the desorption capacity and the pore structure of the catalyst; X-ray photoelectron spectroscopy (XPS) also showed that the discharge will change the valence state of the elements on the catalyst surface, thereby changing its redox performance and deviating the reaction path. For the catalyst performance analysis, theoretical calculations indicate that the increase in copper content will cause changes in the energy band structure of the catalyst, which is better used for exciting gas.
2022 Vol. 42 (1): 20-31 [Abstract] ( 260 ) [HTML 1KB] [ PDF 2632KB] ( 1490 )
32 Air pollutants emission inventory for the main urban area of Tianshui City based on verification by WRF-Chem simulation
LIU Yang, WANG Ying, LIU Hao, QIN Chuang, WANG Si-tong, LI Bo, GUO Chun-ye
An emission inventory, including ten emission categories and nine air pollutants, was developed for the main urban area of Tianshui city (EITS) using emission factor approach. Sector survey, on-site investigation and remote sensing interpretation method have been used to derive the activity data of air pollution sources used in EITS. The rationality of EITS was further validated by comparing with other emission inventories and model verification. The results suggested that: (1)The total emissions in the study area were 2702t SO2, 8829t NOx, 82670t CO, 10460t VOCs, 7551t NH3, 14221t PM10, 8252t PM2.5, 1682t BC and 2814t OC in 2019. Fossil fuel burning was the major contributor to SO2、CO and PM emissions, traffic was the main source of NOx and VOCs emissions, while agriculture was the dominate contributor to NH3 emission; (2) High-emissions of SO2、NOx、PM、CO and VOCs appears in river valley, while NH3 emission maximizes outside of the river valley where cultivated lands were dominate; (3) Spatial allocation of residential fuel consumption sources had an important effect on model simulations, with more reasonable results when the location of village outside of the river valley region was used for spatial allocation; (4) Correlation coefficients between WRF-Chem modeled and observed daily averages of SO2、NO2、O3、CO、PM10 and PM2.5 concentrations were 0.767、0.502、0.618、0.462、0.647 and 0.654, respectively, indicating the reasonability of the EITS.
2022 Vol. 42 (1): 32-42 [Abstract] ( 479 ) [HTML 1KB] [ PDF 2623KB] ( 1534 )
43 Aerosol acidity and its influencing factors at different PM2.5 pollution levels in ammonia-rich area in autumn and winter
CHEN Ying, XU Rui-xin, HAO Qi, JIANG Nan, LIU Yang, ZHANG Rui-qin, CHEN Jing
This study was conducted to understand the aerosol acidity at different levels of air pollution and its influencing factors over ammonia-rich area in autumn and winter. Two non-urban sites in Zhengzhou, Xinmi and Airport, were selected for PM2.5 sample collection from 15th Oct 2018 to 28th Feb 2019. Ion chromatography was used for water-soluble inorganic ions. The aerosol model ISORROPIA-Ⅱ for pH values of PM2.5. The results show that NO3-, NH4+ and SO42- were the three most important ions. With the worsening of the pollution, NO3-, SO42-, NH4+ showed an upward trend and both NO3- and NH4+ increased at a greater rate. The ratio of NH4+/SO42- higher than 0.75 implied that the atmosphere was in an ammonia-rich site. NH4 + mainly existed in the form of (NH4)2SO4, NH4NO3 and NH4Cl in autumn and winter. The PM2.5 pH was moderately acidic, 4.6±0.6 at Xinmi and 4.6±0.7 at Airport, respectively. With the aggravation of pollution, the variation in pH value became smaller. TNH3, SO42- and T were identified to be the main driving factors affecting the PM2.5 pH in winter and autumn. With the aggravation of pollution, the greatest factor manipulating aerosol acidity changed from TNH3 to SO42-. With an increase in pH values, TNO3 tended to become the particle phase, while TNH3 tended to be the gas phase.
2022 Vol. 42 (1): 43-51 [Abstract] ( 301 ) [HTML 1KB] [ PDF 967KB] ( 1519 )
52 Characteristics of hygroscopicity of atmospheric aerosols based on chemical component parameterization
SHEN Zi-xuan, XU Min, HU Bo, WANG Yue-si, ZOU Jia-nan
In order to discuss the hygroscopic characteristics of atmospheric aerosols, the hygroscopic parameters κ were calculated based on the chemical composition of aerosols. The hygroscopic parameters were calculated firstly through PCA analysis, the main influencing chemical factors of hygroscopicity parameters κ were obtained; Secondly, based on the Köhler formula and the ZSR mixing theory, the hygroscopic parameters of each chemical component were weighted to get the corresponding hygroscopic parameters κchemical at each time. Finally, based on the κ-Köhler theory, differences between calculated value of hygroscopic characteristics and the theoretical values were discussed by inverting the characteristic parameters of hygroscopicity (optical and particle size hygroscopicity growth factor f(RH), gf). The iterative algorithm and the empirical formula obtained from previous studies were used to calculate the hygroscopic parameters, which was set to verify the accuracy of the chemical method. In addition, the relation between κchemical and visibility was also discussed. The results showed that the correlation coefficient between κchemical and κköhler was 0.78 and the root mean square error of the two was 0.031, which was at a low level. The ratio of the two was basically distributed in the range of 10% of the linear fitting error from the center. The correlation coefficient between the inversion of f(RH) and the instrument measurement f(RH)measured was as high as 0.99, which further proved a strong linear relationship between them. The gf had a high coincidence degree and correlation with the theoretical value gfNEP. When the visibility was less than 5km, the κNH4NO3 contribution to κchemicalwas 74.63%.
2022 Vol. 42 (1): 52-60 [Abstract] ( 473 ) [HTML 1KB] [ PDF 1137KB] ( 1783 )
61 Effect of mountain-valley wind on PM2.5 concentrations in Yanqing Area
WU Jin, LI Chen, MA Zhi-qiang, MA Xiao-hui, SUN Zhao-bin, HAN Ting-ting, ZHU Xiao-wan
Based on the environmental monitoring data and meteorological data of Beijing from 2015 to 2019, this study analyzed the impact of mountain-valley wind on PM2.5 concentrations in Yanqing and revealed the separateness, the similarities and the differences between (the event 1) initial stage of air pollution event with mountain-valley wind and (the event 2) non-mountain-valley wind and its meteorological mechanism. The result showed that persistent pollution concentrated in September to March of the next year with a total of 63 times, of which 27 times (43%) were accompanied by one or more mountain-valley days and 82% mountain-valley days appeared in the initial stage of the pollution event and 18% appeared in the peak stage. The hourly PM2.5 concentrations in mountain-valley days (the event 1) were higher than those in non-mountain-valley days (the event 2) by 4.5~15.4μg/m3. The maximum diurnal difference was in the stage of valley wind, which was greater than 13μg/m3 from 15:00 to 19:00. The wind frequency center of SSE-ESE was 0.59% with the wind speed about 3.3m/s from 15:00 to 16:00. The wind frequency centers of non-mountain-valley wind days were WSW-SW and SE-ESE with the maximum value of 0.41% and the wind speed was smaller than that of mountain-valley days. In the initial stage of both events 1 and 2, the critical period of PM2.5 concentration change was from 15:00 to 19:00. The wind direction of event 1 was E-SSE and the wind speed was 2~4m/s. In the event 1, the growth rate of PM2.5 was greater than that of event 2, which was basically consistent with the trend of dew point temperature change. The PM2.5 concentration of event 1was significantly higher than that of event 2. The meteorological mechanism can be so summarized: the mountain-valley wind circulation appears in the initial stage of the pollution event, then in the later stage, the southeast wind in the valley from the regional transport of aerosol and water vapor, which have a positive contribution to the increase of PM2.5 concentration. This special type of air pollution events accounted for 20% in the Beijing plain (outside of Yanqing aera and the wind orientation centers were scattered in the daytime with NNW-WNW, SW-SSW and ENE-NNE about 0.7% and S-ESE orientation.
2022 Vol. 42 (1): 61-67 [Abstract] ( 251 ) [HTML 1KB] [ PDF 1788KB] ( 1514 )
Water Pollution Control
68 The vertical migration process of toluene in capillary zone and its response to environmental factors
WANG Jin-sheng, LIU Jia-wei, HAN Ke-xue, XU Dong-hui, XUE Zhen-kun, LI Qiao, PAN Ming-hao, ZUO Rui
In order to explore the migration law of toluene in heterogeneous capillary zone and the response of environmental factors, a one-dimensional soil column leaching experiment with multi-layered monitoring was used. This study simulated the migration process of toluene from the vadose zone to the aquifer under the instantaneous release situation, and the changes of pH, DO, ORP and other environmental factors with the migration of toluene were monitored synchronously. Through Pearson correlation analysis, the relationship between environmental factors and toluene migration was noticeable. The results showed that the migration of toluene in the capillary zone can be divided into four stages, namely, the rapid increase of concentration dominated by gravity; the migration rate decreased and the concentration increased slowly under the action of capillary zone jacking; the concentration of toluene decreased significantly under adsorption and the formation stage of stable pollution distribution. The environmental factors such as pH, DO and ORP were positively correlated with the migration process of toluene and showed obvious stages. Among them, the migration law of ORP was the closest to that of toluene, followed by pH, and the deviation between DO and migration law of toluene was the most obvious, especially in the ascending stage.
2022 Vol. 42 (1): 68-75 [Abstract] ( 279 ) [HTML 1KB] [ PDF 1657KB] ( 1277 )
76 Effect of suspended particles in drinking water on microbial aggregation and disinfection
ZHANG Xin-xin, GU Zheng, YU Chao, CHEN Guo-wei, LIU Li
Considering that the mechanism of disinfection-stressed protection effects of suspended particles on microbes remained unclear, this study investigated the chlorination-stressed protection effects of these particles on microbes in drinking water by analyzing microbial physiological characteristics and aggregation behaviors via a static experimental setup. The results showed that goethite dosage had a minor impact on the logarithmic inactivation rate on microbes in drinking water when the absence of chlorine. However, the presence of goethite stimulated microbial aggregation behaviors and the chlorine decay process, thus goethite playing a protective role when associating with chlorination stress, particularly at 0.5mg/L chlorine.
2022 Vol. 42 (1): 76-82 [Abstract] ( 200 ) [HTML 1KB] [ PDF 577KB] ( 1268 )
83 Research progress of iron-type denitrification removal technology
YU Yan, LIU Ning, LIAO Zu-gang, ZHAO Jian-qiang, ZHANG Qian-qian
Traditional denitrification process with the advantages of fast reaction and high efficiency is a very effective nitrogen removal technology for wastewater treatment, but it is greatly affected by the concentration of organic carbon source in wastewater. The lack of carbon source in wastewater can not meet the requirements of biological denitrification and lead to a lower total nitrogen (TN) removal rate, and the addition of exogenous organic carbon source will increase the treatment cost and easily cause secondary pollution. Therefore, the traditional denitrification process has certain limitations on the nitrogen removal treatment for low C/N wastewater. As one of the autotrophic denitrification technologies, iron-type denitrification technology has the advantages of higher nitrogen removal efficiency, lower operation cost and the product has recycling value, which can effectively solve the shortcomings of traditional heterotrophic denitrification. The sources and harm of nitrate wastewater were summarized, and the reaction mechanism of iron-type denitrification process was elucidated. The effects of pH, temperature and molar ratio of iron to nitrogen (Fe/N) on the denitrification efficiency of iron-type autotrophic denitrification were discussed, and the performance strengthening measures of iron-type denitrification system were summarized.
2022 Vol. 42 (1): 83-91 [Abstract] ( 516 ) [HTML 1KB] [ PDF 554KB] ( 4219 )
92 Phosphorus morphology transformation law and sludge characteristics of AOA-SBR process under different C/P
QU Hong, SHI Xue-ying, NIE Ze-bing, LI Qing-zhe, LIU Wen-ai, YU Ge, MA Yun-guang, BIAN De-jun
Five groups of SBR reactors operating in anaerobic, aerobic, anoxic(AOA) mode were used to investigate the transformation rules of phosphorus morphology and sludge characteristics of AOA-SBR system under different C/P(120, 40, 24, 17, 13). The results showed that the removal effect of COD, TN and NH4+-N all outperformed the primary A standard. As the C/P decreased, the system TP removal gradually increased. When the C/P was less than 24, the removal effect of the TP began to deteriorate and fluctuate violently. When the C/P was 40, the system was the most stable, with an average removal rate of 99.22%. The results showed that with the decrease of C/P, the phosphorus forms in the sludge increased. IP was the main phosphorus form of TP, and IP was similar under different C/P (about 96%). As C/P decreased, the content of sludge TP and IP decreased, while OP content of sludge TP maintained a downward trend. Biological effective phosphorus (the sum of NAIP and OP) had the greatest impact on sewage phosphorus removal effect, with the highest proportion of bioeffective phosphorus in the sludge with C/P 40, and the best sewage TP removal effect. MLSS and SVI increased with C/P, while the risk of sludge expansion the lower C/P systems. High-throughput sequencing showed that with the decrease of C/P, both PAOs and DPB content decreased except for Dechloromonas, and the sewage TP removal effect was poor and fluctuated greatly.
2022 Vol. 42 (1): 92-101 [Abstract] ( 232 ) [HTML 1KB] [ PDF 746KB] ( 2237 )
102 Preparation of ferromagnetic nanomaterials based on molecular imprinting technology and their performance for selective enrichment of 17β-estradiol (E2)
GUAN An-zhe, ZHAO Xu-dong, ZHANG Ting-ting, LI Yi, LI Jian-sheng, LU Rui
Ferromagnetic separation and molecular imprinting technology were combined together. Ferromagnetic oxide nanoparticles were used as core, while 17β-estradiol (E2) was used as the template molecule and (3-Aminopropyl) triethoxysilane was used as the functional monomer E2 molecularly imprinted polymer (MIPs) and non-imprinted polymer (NIPs) were prepared by surface polymerization. Then E2MIPs and NIPs were characterized by FT-IR, XRD, XPS, SEM and other methods. The results showed that MIPs have a regular spherical shape, and the particle size is uniform at about 790nm. In the selective adsorption experiment, the saturated adsorption capacity of MIPs and NIPs for E2 is 9.69 and 6.25mg/g, respectively. These results indicated good selectivity of the material. Freundlich linear fitting was performed on the static adsorption data, and the results proved that MIPs have good adsorption capacity. Meanwhile, MIPs showed excellent reusability as the adsorption capacity only lost 3% after 7 adsorption-desorption processes.
2022 Vol. 42 (1): 102-108 [Abstract] ( 255 ) [HTML 1KB] [ PDF 1393KB] ( 1246 )
109 Occurrences and risk assessment of antibiotics in water bodies of major rivers in Bohai Rim Basin
ZHAO Fu-qiang, GAO Hui, LI Rui-jing, JIN Shuai-chen, ZHANG Hai-bo, LI Shi-sheng, ZHANG Ke-yu, SHU Qin, NA Guang-shui
This study was conducted to characterize the occurrences and accumulation of antibiotics in surface water of each river's downstream in Bohai Rim Basin and to evaluate their ecological risk and human health risk. The results indicate that 50 antibiotics falling into 6 categories were detected in the lower reaches of four major rivers (Xiaoling, Luanhe, Yellow River and Daliao) in Bohai Rim Basin. Off all kinds of antibiotics, β-Ls, MLs and QNs were dominant in those waterbodies of the basin, of which the concentration of Penicillin G was the highest, up to 353.13ng/L. Compared with other rivers in China, The concentration of antibiotics ranged from 124.50ng/L to 489.16ng/L whose average concentration over the study area was rated at a moderate pollution level, but higher than that in other rivers of China. The accumulation level of different rivers was rated in the order as: Xiaoling River>Daliao River>Luanhe River>Yellow River. In addition, amoxicillin, anhydroerythromycin and erythromycin presented higher ecological risk to sensitive aquatic species than did tetracycline, oxytetracycline, enrofloxacin, ofloxacin and cinoxacin which were evaluated at a moderate ecological risk. According to the threshold of the human health risk value of target antibiotics (2.53×10-7~6.79×10-3), the pollution level of the antibiotics in the Bohai Rim Basin did not become a health threat to people yet.
2022 Vol. 42 (1): 109-118 [Abstract] ( 397 ) [HTML 1KB] [ PDF 1157KB] ( 2872 )
119 Characterizing the estrogen content in cow feces based on gestation crate experiment
LI Yan, PAN Jie, LIANG Zi-wei, HU Jia-wu, LIU Jiang-yan, HE De-chun, LI Ting-zhen
To explore characteristics of estrogen content in cow feces, fecal samples were collected from the gestation crates to quantify the contents of 4 natural estrogens (including estrone, 17α-estradiol, 17β-estradiol, estriol) and 2 synthetic estrogens (17α-ethinylestradiol, diethylstilbestrol) with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results showed that the detection frequency (DF) of 6 estrogens ranged from 8.33% to 98.89%. The DF of detected natural estrogens was higher than 90%, except for estriol (8.33%); while the DF of synthetic estrogens were 52.22% and 64.44% for 17α-estradiol and diethylstilbestrol, respectively. The total content of 6 estrogens was in the range of 1.15~658.91μg/kg (dry weight, dw). The total estrogenic activity was equivalent to the content of 3.76~478.50μg/kg (dw). A significant difference in the total content (median) of 6 estrogens among different growth stages was observed in the order of: lactating cows (79.21μg/kg)>calves (47.20μg/kg)>heifers (25.72μg/kg). The content of estrogens in fecal samples demonstrate large seasonal variations: relatively higher in winter and spring than in summer and autumn andthe lowest concentration of 6 estrogens was observed in autumn. The total concentration of 6 estrogens in the feces collected from fecal stock dump ranged from 7.63 to 3921.92μg/kg which were significantly higher than that in fresh feces from gestation crate. Clearly, cow growth stage, sampling time (season) and sampling sites influenced the content of estrogens in cow feces, which should be fully considered in the investigation and risk assessment of estrogen emissions for cow breeding.
2022 Vol. 42 (1): 119-126 [Abstract] ( 255 ) [HTML 1KB] [ PDF 536KB] ( 1040 )
127 Effect of freezing on drying and combustion characteristics of dewatered sludge
MENG Qi, YANG Tao, YANG Cheng-jian, AN Miao, LI Zhi-hua
This work explored the effect of freezing operation on the drying and combustion characteristics of dewatered sludge and different freezing temperatures on the characteristics of the drying process for the sludge. In addition, the effect of different freezing temperatures and heating rates on the combustion characteristics of dewatered sludge were investigated by thermogravimetric analysis (TG-DTG). Then the dynamics analysis was carried out. The results indicated that compared with the original sludge, freezing turned the dewatered sludge into a hard structure that can be crushed, and when the temperature was dropped to –20℃, the drying rate of the crushed sludge was improved by 41.46%, and the drying time was shortened by 41.67%. Three degradation stages, dehydration, combustion of volatile and combustion of the fixed carbon were identified in the combustion process of the freezing dewatered sludge. As the temperature decreased, the ignition point, the volatile releasing index, the flammability index, the burnout index, and the general combustion index increased. According to the dynamics analysis, the reaction order of pre-peak was 0.9 and post-peak was 1.1. The apparent activation energy of the frozen sludge was higher than that of the original sludge, and as the temperature decreased, the apparent activation energy would decrease.
2022 Vol. 42 (1): 127-134 [Abstract] ( 249 ) [HTML 1KB] [ PDF 448KB] ( 1000 )
135 Simultaneous recovery of nitrogen and phosphorus in wastewater by MgO modified red mud composite material
ZHAO Cong, PENG Dao-ping, LI Qin, WAN Qing-li, HUANG Tao, ZHAO Rui
To treat high-concentration wastewater while realizing the utilization of red mud as a resource. The modified red mud composite material (MgO-RM) was prepared through the red mud loaded with magnesium oxide for efficient simultaneous recovery of nitrogen and phosphorus in wastewater. The effects of the initial pH, the mass ratio of nitrogen to phosphorus and the dosage of MgO-RM on the recovery performance were investigated, and kinetic models and isothermal adsorption models examined the recycling characteristics. Meanwhile, the recovery mechanism was revealed by characterizing the MgO-RM before and after the reaction through FTIR, XRD, SEM, and BET testing methods. The results showed that magnesium oxide was effectively loaded on the surface of red mud under an optimal condition: initial pH=3, nitrogen and phosphorus mass ratio=3:5 and MgO-RM dosage=4g/L. The ammonia nitrogen and phosphate recovery efficiency can be reached as 65 % and 90 %, respectively. Such a recovery process can be explained by the Langmuir model and the quasi-two-order kinetic model. The adsorption behavior was in line with the monolayer adsorption, in which chemical adsorption plays a dominant role. The maximum ammonia nitrogen and phosphate recovery capacity can be achieved as 61.50mg/g and 140.66mg/g, separately. The above results concluded that the recovery mechanism may include physical adsorption, ion exchange, complexation reaction and chemical precipitation, in which struvite precipitation is the dominant process.
2022 Vol. 42 (1): 135-145 [Abstract] ( 194 ) [HTML 1KB] [ PDF 2038KB] ( 1353 )
Advanced Wastewater Treatment Technology Column
146 Synthesis of Ag3PO4/Cu-BiVO4 p-n heterojunction and enhancement of its visible-light photocatalytic degradation of tetracycline
GUO Ji-feng, LI Jing, SUN Ze-xin, LI Ze-en, LU Chang-yu
The Ag3PO4/Cu-BiVO4 heterostructure was successfully synthesized using hydrothermal and in-situ precipitation methods to load Ag3PO4 nanoparticles onto the Cu2+ doped monoclinic BiVO4 microspheres, and was used as the photocatalyst for the efficient degradation of tetracycline (TC) under the visible light. Materials characterization was carried out. The techniques such as SEM, TEM, XPS, FTIR, UV-Vis DRS and EIS were applied to characterize the samples. Our results showed that Cu2+ modification and Ag3PO4 nanoparticles increased the specific surface area and visible light response performance, which could provide more active sites on the heterojunction interface. Ag3PO4/Cu-BiVO4with Bi/Ag at 2:1 ratio demonstrated the highest photocatalytic removal performance (91.68%) of TC (20mg/L) within 120min, and the degradation rate remained at about 86.1% for a five-consecutive cycle. h+ and ·O2- were experimentally confirmed to be the main active species. The enhanced photocatalytic activity could be mainly attributed to the formation of p-n heterojunction between Cu-BiVO4 and Ag3PO4 and the band regulation of Cu2+ doping, which could effectively improve the separation and migration efficiency of photogenerated carriers during the photocatalytic reaction.
2022 Vol. 42 (1): 146-159 [Abstract] ( 248 ) [HTML 1KB] [ PDF 1476KB] ( 1644 )
160 Efficient adsorption of BPA by alginate-based porous carbon with the preparation of synchronous activation and nitrogen doping
CHEN Ai-xia, GUAN Juan-juan, WEI Xiao, XIE Ya-ping
This study aims to further improve the adsorption performance of porous carbon materials, with sodium alginate (SA) as carbon precursor, K2CO3 as activator and melamine as nitrogen dopant, so the sodium alginate-based porous carbon materials (SAC/N) were prepared by one-step synchronous activation and nitrogen doping. This study measured the influence of nitrogen mixing ratio on the adsorption performance of porous carbon. The samples were characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS). The results showed that when the mass ratio of SA, K2CO3 and melamine was 1:1:0.2, the optimal product obtained was SAC/N-0.2. Its specific surface area was 2017.98m2/g, and the total pore volume reached 1.23cm3/g, which was 0.88 times and 1.1 times higher than that of non-nitrogenous porous carbon (SAC/N-0), respectively. The adsorption process was in accordance with the pseudo-second-order kinetics and Langmuir model. At 308K, SAC/N-0.2 could reach the adsorption equilibrium of bisphenol A (BPA) within 30min, and the saturated adsorption capacity was as high as 1180.02mg/g, which was double compared with SAC/N-0. The carbon material doped with nitrogen obviously exhibited layered porous structure, which fully indicated that melamine played a synergistic role in the pore formation during SA activation. In addition, SAC/N-0.2 had strong resistance to acid-base, ion and organic interference, and had good regeneration performance.
2022 Vol. 42 (1): 160-171 [Abstract] ( 249 ) [HTML 1KB] [ PDF 2049KB] ( 1254 )
172 Effect of carbon source types on denitrifying phosphorus removal and microbial community in the A2/O - BCO process
FAN Ya-jun, ZHANG Miao, JI Jun-jie, CHENG Ji-lin, WU Qi-chao, HE Cheng-da
The anaerobic/anoxic/aerobic-biological contact oxidation (A2/O-BCO) process was used (1) to treat low carbon/nitrogen ratio (C/N) wastewater, (2) to monitor the effect of single factor of carbon source (Phase Ⅰ: sodium acetate; Phase Ⅱ: Sodium acetate + sodium propionate; Phase Ⅲ: sodium propionate) on organic matter, and (3) to investigate the simultaneous nitrogen and phosphorus removals were investigated. The research explored the transformation and utilization of internal carbon sources (PHA and Gly) and the mechanism of denitrifying phosphorus removal (DPR) under the mixed carbon source conditions of sodium acetate and sodium propionate. Meanwhile, the evolution rules of microbial community structure at different phases were compared through high-throughput sequencing. The results showed that the mixed carbon source improved the simultaneous removal efficiency of organic matter, nitrogen and phosphorus, and the transformation amount of internal carbon source was 226mg/h with the phosphorus release amount of 30.58mg/L in the anaerobic section, and the DPR efficiency was above 90%. The batch test showed that the proportion of denitrifying phosphorous accumulating bacteria (DPAOs) to phosphorous accumulating bacteria (PAOs) was 72.42%, which basically realized the enrichment of DPAOs. The results of high-throughput sequencing showed that the mixed carbon sources were more conducive to the formation of unique OTUs bacterial genus, and the total amount of PAOs (including Accumulibacter and Acinetobacter) and DPAOs (including Dechloromonas and Pseudomonas) was up to 29.13%(> 16.18%(Phase Ⅲ) > 14.34%(Phase Ⅰ)), thus efficiently promoting the utilization of carbon source and efficiently denitrifying phosphorus removal. In the BCO reactor, the total amount of ammonia-oxidizing bacteria (AOB, including Nitrosomonas and Nitrosomonadaceae) and nitrite-oxidizing bacteria (NOB, mainly Nitrospira) increased from 3.89%(N1) to 23.09%(N2) and 37.23%(N3), which provided sufficient electron receptors for denitrifying phosphorus removal. In addition, the operation regulation strategy based on the efficient utilization of carbon source was established, in order to provide theoretical reference for the application of A2/O-BCO process.
2022 Vol. 42 (1): 172-182 [Abstract] ( 240 ) [HTML 1KB] [ PDF 1175KB] ( 2681 )
183 Effect of drainage rate on the stability of a constructed rapid infiltration system with CANON process at the low temperature
SUN Feng, YU Xin-jie, ZHAO Zi-jian, WANG Ning, PING La-mei, WANG Zhen
The constructed rapid infiltration (CRI) system with the complete autotrophic nitrogen removal over nitrite (CANON) process, which had been launched at (35±2)℃ and high NH4+-N concentration of (459.98±36.98)mg/L, was used to treat domestic sewage at (10±2)℃. It was conducted to explore the nitrogen transformation mechanisms and the related microbiological characteristics in the CRI system under drainage rate (vd) constraints. The results showed that the oxygen-limiting microenvironment could be restored and optimized in the CRI system as a result of appropriate vd. Subsequently, recovery of the CANON process was achieved in the system, as well as its nitrogen removal performance. At the vd of 0.50L/min, the proliferation and the increased activity of nitrite oxidizing bacteria (NOB) made the nitrification/denitrification process instead of the CANON process became the primary total nitrogen (TN) removal route in the CRI system, resulting the deterioration for nitrogen removal of the system. When the vd decreased from 0.50 to 0.20L/min, the CANON process could be recovered largely accompanied by the dominance of anaerobic ammonium oxidation bacteria (AnAOB) in the system, and the mean TN and NH4+-N removal rates could reach up to (72.07±5.62)% and (81.51±2.74)%, respectively. However, as the vd was lower than 0.20L/min, the activity and the quantity of aerobic ammonia-oxidizing bacteria (AOB) was inhibited because of the insufficient of dissolved oxygen (DO) in the bed, thus the reduction of nitrogen removal rate in the CRI system was detected resulting from the unsatisfactory enhancement of the CANON process.
2022 Vol. 42 (1): 183-193 [Abstract] ( 195 ) [HTML 1KB] [ PDF 1813KB] ( 1129 )
194 Evaluation of sludge characteristics and microbial community of anammox sludge during exposure to perfluorooctane acid and perfluorooctane sulfonate
TANG Lin-qin, SU Cheng-yuan, HUANG Xian, LI Ru-ting, WANG An-liu, FAN Cui-ping, XIAN Yun-chuan
The sequential batch experiments explored the influence mechanism under different concentrations (0.5mg/L and 1mg/L) and types of perfluorinated compounds (PFCs) on the denitrification performance and microbial community of anaerobic ammonia oxidation (anammox) sludge. Results indicated that perfluorooctanoic acid (PFOA) (at 0.5mg/L, 1mg/L) and perfluorooctane sulfonate (PFOS) had no obvious inhibitory effect on the denitrification performance of the anammox sludge. The addition of 1mg/L PFOA (OA1) and PFOS (OS1) to the anammox sludge for one day resulted in removal rates of respectively 47.68% and 92.7%. X-ray photoelectron spectroscopy (XPS) analysis of the sludge showed the presence of C-F, MgF2, CaF2 functional groups in the OA1 and OS1 groups. The addition of PFOA and PFOS reduced the concentration of heme c in the anammox sludge by respectively 21.05% and 7.5%. The high-throughput sequencing analysis of the anammox sludge in different experimental groups showed that the addition of 1mg/L PFOA and PFOS could reduce the relative abundance of anammox bacteria and promote the relative abundance of denitrifying bacteria. The relative abundance of Candidatus Brocadia in the OA1 and OS1 groups decreased by respectively 1.08% and 0.28%, while the relative abundance of Acinetobacter increased by 1.73% and 0.06%. In general, the negative effects of PFOA on the anammox sludge were more significant than PFOS.
2022 Vol. 42 (1): 194-202 [Abstract] ( 314 ) [HTML 1KB] [ PDF 1858KB] ( 2711 )
203 Photoassisted MIL-101(Fe) activated hydrogen peroxide system for oxidative degradation of roxarsone and adsorption of in-situ formed arsenate
SANG Lin-feng, SU Shan-shan, GAO Zi-wei, JIN Wei, ZHAO Ya-ping
An iron-based-organic framework (MIL-101(Fe)) was prepared using a simple one-pot method, aiming to simultaneously oxidize ROX through activating hydrogen peroxide and adsorption formed arsenate under simulated sunlight. The photoassisted MIL-101(Fe) (250mg/L) activating H2O2 (1.0mmol/L) system could remove 95.27% of ROX within 120min. Moreover, the arsenate (As(Ⅴ)) formed in this system could be adsorbed onto the surface of MIL-101(Fe) with 84.14% of the total arsenic removal ratio. The main formed reactive oxygen species ·OH and O2·– free radicals, attacked the As-C bond of ROX, generated As(Ⅴ) and o-nitrophenol compounds and accelerated the removal process. The actual environment water matrix significantly promoted the removal ratio of ROX in this system.
2022 Vol. 42 (1): 203-212 [Abstract] ( 234 ) [HTML 1KB] [ PDF 733KB] ( 3507 )
Solid Waste
213 Effects of Na+ in leachate on initial adsorption of biofilm
LIU Feng, WANG Qian, WU Hua-nan, XU Qi-yong
A quartz crystal microbalance with dissipation (QCM-D) was used to investigate the initial adsorption behavior of biofilm under four kinds of Na+ concentrations. The rigid model and viscoelastic model were fitted to explore the changes in adsorption mass and viscoelasticity with time. The results indicate that both reversible and irreversible adsorption processes occurred in the initial adsorption of biofilm. The formation of irreversible adsorption was promoted when Na+ concentration was 150mmol/L, due to increased zeta potential and net charge reduction in bacterial surfaces. With an increase in Na+ concentration from 2.5mmol/L to 50mmol/L, the adsorption rate increased gradually, which is consistent with the electrostatic double-layer theory. No significant change in the adsorption rate was observed when the concentration was increased to 150mmol/L. The softness of the absorbed layer in the 150mmol/L group was the highest, followed by the 2.5, 10 and 50mmol/L groups. An increase in the viscoelasticity of the layer was also observed during the early adsorption process. With an increase in Na+ concentration, the adsorption mass kept increasing and the viscoelasticity first increased and then remained unchanged.
2022 Vol. 42 (1): 213-219 [Abstract] ( 230 ) [HTML 1KB] [ PDF 572KB] ( 1245 )
220 Removal of fluoroquinolone antibiotics generated from the sludge using hyper-thermophilic composting and its degraded products
SONG Xiang-tong, YANG Ming-chao, ZHANG Jun, GUO Ya-li, DONG Bin
The removal performance of NOR, OFL and their degradation products from traditional thermophilic composting (TC) and from hyper-thermophilic composting (HTC) were compared. The results showed that after 25 days' hyper-thermophilic composting, the removal rate of NOR with TC and HTC was 91.8% and 92.1% with the residual NORP of 628 and 668μg/kg, respectively, while the removal rate of OFL was 92.1% and 88.1%, respectively with the residual OFLP and 191 and 675μg/kg, respectively. Compared with TC, HTC reduced the ecological risk of NOR and OFL by 3.1% and 30.5%, respectively, indicating that HTC could more effectively remove the ofloxacin and its degradation products and thus reduced the risk of environmental exposure to OFL in composting products. At the same time, the DOC/DON of hyper-thermophilic composting products was lower with the higher seed germination index and the plant toxicity of composting products was also lower, which is must be beneficial to the safe land use of sludge.
2022 Vol. 42 (1): 220-226 [Abstract] ( 263 ) [HTML 1KB] [ PDF 468KB] ( 2161 )
227 Advances in research and application of intelligent municipal solid waste classification technologies
LIANG Rui, CHEN Guan-yi, YAN Bei-bei, SUN Yu-nan, TAO Jun-yu
The growing annual disposal volume of municipal solid waste (MSW) is causing serious environmental problem worldwide. Different components in MSW have their own appropriate treatment and utilization techniques, thus effective MSW classification is significantly important. While current classification methods in China is primarily artificial classification, which have a lot of disadvantages such as low efficiency, high cost and low accuracy. These bottlenecks could be excellently solved by intelligent and automatic classification technologies. The recent distribution feature and growing trend of MSW in China's representative cities were briefly introduced, and the existing intelligent MSW classification technologies in six categories of principles were analyzed. These categories included density, electricity, magnetism, image, acoustic and spectrum. The practical applications of intelligent MSW classification technologies were also introduced. Finally, the threats and opportunities faced with intelligent MSW classification technologies were analyzed.
2022 Vol. 42 (1): 227-238 [Abstract] ( 515 ) [HTML 1KB] [ PDF 903KB] ( 6707 )
239 The product distribution of hydrothermal carbonization of food waste and the characteristics of liquid-and solid-products
ZHANG Ying, GU Meng, SUN Jie, ZHOU Yi-ran, ZHU Wei, WANG Xiao-ming
The food waste (FW) collected from a canteen was treated by hydrothermal carbonization (HTC) under three different process conditions: mild (180℃-1h), intermediate (220℃-2h) and severe (260℃-4h), to explore the effects of process severity on the distribution of HTC three-phase products and the characteristics of liquid and solid products. The results showed that the process severity significantly influenced the product distribution. With the increase of the process severity, the yield of hydrochar increased initially and then decreased, the yield of carbonization liquid decreased initially and then stabilized, while the yield of gas product kept increasing. However, despite of different process severities, the HTC products were mainly in the form of hydrochar (40.4%~52.1%), of carbonization liquid (38.3%~57.5%), with a small fraction of gas products (2.1%~13.3%). In addition, the process severity also significantly affected the characteristics of carbonization liquid and hydrochar. With the increase of the process severity, the pH level of the carbonization liquid gradually increased, while COD and sCOD gradually decreased, and the conductivity showed an initial decreasing and then increasing trend. Further qualitative analysis found that the carbonization liquid contained a variety of ketones, aldehydes and volatile fatty acids (VFAs). As the reaction intensity increased, the surface of the hydrochar became more rough and complex, and the specific surface area gradually increased. Meantime, the hydrothermal carbonization reaction contributed to the enrichment of the carbon element from the FW into the hydrochar, and the degree of enrichment increased remarkably with the increasing process severity. Due to the low ratios of H/C and O/C, the calorific values of hydrochar is 23.9MJ/kg, similar to the bituminous coal value of 28.3MJ/kg, and the high ignition temperatures from 267.5℃ to 302.3℃, the hydrochars produced from FW exhibited the potential of safe and clean fuel for energy production.
2022 Vol. 42 (1): 239-249 [Abstract] ( 219 ) [HTML 1KB] [ PDF 1096KB] ( 1961 )
Soil Pollution Control
250 Leaching remediation efficiency of biodegradable chelating agents for the Cd and Ni contaminated soils
GAO Yi-dan, YUAN Xu-yin, WANG Yi-min, XIONG Yu-ting, ZHANG Hai-yan
For assessing leaching remediation efficiency of different biodegradable chelating agents for remediating heavy metals-contaminated soils, Citric acid (CA), DL-2-(2-carboxymethyl) nitrilotriacetic acid (GLDA)(biodegradable chelating agents) and Ethylenediaminetetraacetic acid (EDTA) (a conventional leaching agent as a check) with different leaching treatments were applied to evaluate the removing efficiency of Cd and Ni from yellow brown soil and red soil that have been highly contaminated with various heavy metals in two mining areas. Our experimental results demonstrate higher efficiencies of both EDTA and GLDA for removing Cd and Ni from these soils comparing with CA to reduce the mobility and bioavailability of soil heavy metals. However, the adverse effects of GLDA and CA leaching remediation on soil enzyme activity are significantly lower than that of EDTA leaching remediation. In view of both leaching efficiency and ecological safety, our study has confirmed that GLDA can be used as a good substitute for the conventional leaching agent EDTA in the acidic soils contaminated with heavy metals.
2022 Vol. 42 (1): 250-257 [Abstract] ( 303 ) [HTML 1KB] [ PDF 453KB] ( 1831 )
258 Enhancement effects of the coupling between AC electric field and Fusarium sp. A-2 on the remediation of uranium contaminated soil by Macleaya Cordata
DING De-Xin, CHENG Hao, LIU Jing-Jing, DONG Xue, LI Ai-Shu, TAN Guo-Chi, MA Jian-Hong, ZHANG Hui, WANG Yong-Dong, HU Nan
Pot experiments were conducted to study the effects of the coupling between alternating current electric field (AC) and Fusarium sp. A-2 (A-2) fungi on the biomass, uranium (U) enrichment and enzyme activity of Macleaya cordata (P), as well as the organic acid content, bioavailable uranium and microbial community structure in the rhizosphere soil. The results showed that compared with AC+P+U, A-2+P+U, and P+U groups, the fresh weight, plant height and total dry weight of Macleaya cordata in AC+A-2+P+U group were significantly increased by 10.67%~45.76%, 26.87%~92.02% and 61.99%~159.98%, respectively, and the contents of the total superoxide dismutase (T-SOD) and catalase (CAT) were increased by 41.24%~133% and 15.35%~63.63%, respectively, and the oxalic acid was increased by 13.03%~157.09%. Compared with the A-2+P+U and P+U groups, the bioavailable uranium in soil in AC+A-2+P+U group was increased by 12.5% and 28.57%, respectively. In the AC+A-2+P+U groups, there were a large number of Fusarium fungi and Acidobacteria in rhizosphere soil, and the proportion of Fusarium fungi was the highest. Compared with AC+P+U, A-2+P+U, P+U, and A-2+U groups, the proportion of Fusarium fungi in AC+A-2+P+U group was increased by 16.67%, 81.03%, 299.23% and 374.47%, respectively. The mechanisms of AC and A-2 coupling enhanced the remediation of uranium contaminated soil by Macleaya cordata may be include that AC improved the mobility of uranium in soil, increased the contact between plant roots and uranium, and promoted the enrichment of uranium by Macleaya cordata; that AC stimulated the physiological activity and increased the biomass of Macleaya cordata, improved the activity of antioxidant enzymes, and enhanced the tolerance of Macleaya cordata to uranium; and that AC stimulated the growth of A-2 fungi and Acidobacteria, increased their proportion, and produced a large number of organic acids which can form chelates with uranium, reduced the stress of uranium on plants, increased the proportion of bioavailable speciation of uranium, and promoted the enrichment of uranium by Macleaya cordata. AC and A-2 coupling exhibited a significant enhancement effect on the remediation of uranium contaminated soil by Macleaya cordata, and there coupling was a promising enhancement method.
2022 Vol. 42 (1): 258-266 [Abstract] ( 225 ) [HTML 1KB] [ PDF 836KB] ( 1681 )
267 Transformation of soil ammonium nitrogen in the process of thermally activated persulfate oxidation
YANG Pei-zeng, YUE Hong-shen, JI Yue-fei, LU Jun-he
In order to explore the transformation and fate of soil NH4+ in the thermally activated PS oxidation process, this study used soil samples collected from Jiangsu and Hebei provinces with different soil organic matter content and NH4+ concentration to conduct experiments, and systematically investigated effects of persulfate (PS) concentration, the addition of NH4+, and reaction time on the formation of nitro by-products. Results show that soil NH4+ could be transformed to nitrated byproducts, including 3-nitrophenol, 4-nitrophenol, 2-hydroxy-5-nitrobenzoic acid, 4-hydroxy-3-nitrobenzoic acid, 2, 4-dinitrophenol, etc. The formation of nitro by-products increased first and then decreased with reaction time. An increased in PS dose would promote the formation of nitro by-products, and the yields of mono-nitrophenols and hydroxy-mono-nitrobenzoic acids reached the maximum after 12h reaction at 30mmol/kg PS dose. However, nitrated byproducts were degraded at higher PS dose. Note that sulfate radicals (SO4·-) played a key role in the nitration process by oxidizing NH4+ to form aminyl radicals (·NH2), and then underwent a series of free radical chain reactions to form nitrogen dioxide radicals (NO2·). Besides, phenol moieties in soil organic matter served as the main reactive sites for SO4·- attack, leading to the formation of phenoxy radicals, which further combined with NO2· to form nitro by-products. NOM is everywhere and NH4+ is ubiquitous in the environment. Thus, the formation of nitro by-products will be widespread when PS is applied for contaminated soil and groundwater remediation, which should be taken into consideration when evaluating the feasibility of this technology. This study reveals that the presence of soil NH4+ in activated PS oxidation processes could induce the nitration of NOM and the formation of nitrophenolic by-products.
2022 Vol. 42 (1): 267-275 [Abstract] ( 265 ) [HTML 1KB] [ PDF 512KB] ( 1101 )
276 Effect of Chinese milk vetch combined with lime on cadmium uptake and translocation in rice
XIAO Min, FAN Jing-jing, WANG Hua-jing, XU Chao, ZHANG Quan, CHEN Xin-sheng, ZHU Han-hua, ZHU Qi-hong, HUANG Dao-you
A plot experiment was conducted to study the combined effects of Chinese milk vetch (CMV) and lime (L) on the availability of Cd in soil, the concentrations of Cd in Fe-Mn plaque on roots and the uptake and transport of Cd in rice plants. The results showed that soil pH value was significantly increased by 2.11~2.43 and 1.68~2.48 units, and DTPA-Cd concentration decreased by 18.88%~40.53% and 20.74%~36.85% in L and CMVL treatments, respectively, while it had no significant effect on them in CMV treatment. The Cd concentration in Fe-Mn plaque on rice roots at maturity in CMV treatment was significantly increased by 86.72%, that in roots was increased by 124.27% while that of Cd in grains was increased by 58.54%, which the transport coefficient of Cd from leaf to grain was increased by 5.58 times. The Cd concentration in Fe-Mn plaque on rice roots at maturity in L and CMVL treatments were significantly increased by 34.86% and 42.42%, while the transport coefficient of Cd from Fe-Mn plaque on rice root to root significantly increased by 170.6% and 158.8%, respectively. However, the transport coefficient of Cd from root to stem in L and CMVL treatments was significantly decreased by 75.87% and 74.71%, while those of Cd from root to grains decreased by 74.38% and 68.13%, respectively. Cd concentrations of rice grains in L and CMVL treatments were significantly reduced by 54.88% and 51.83%, respectively. Pearson correlations indicated that soil pH, DTPA-Cd and Cd concentration in Fe-Mn plaque on roots were the key factors on the Cd concentration of rice grains. Chinese milk vetch combined lime to Cd-contaminated rice fields can significantly reduce the Cd in rice grains.
2022 Vol. 42 (1): 276-284 [Abstract] ( 310 ) [HTML 1KB] [ PDF 415KB] ( 1275 )
Environmental Ecology
285 Adsorption behaviors of fulvic acid onto polystyrene microplastics
SUN Xuan, YU An-qi, WANG Xue-song, LIN Lu-jian, TANG Shuai, LI Meng-yao
Adsorption properties and interaction mechanisms of fulvic acid (FA) onto polystyrene (PS) and HBCD-PS composites (HBCD-PS) microplastics were investigated. Results show that the adsorption amounts of FA onto PS microplastics were negligible, while the presence of HBCD significantly enhanced the adsorption of FA onto HBCD-PS microplastics which, as confirmed by W-M intra particles and Boyd diffusion models, was mainly dominated by intra-particle diffusion. The FA adsorption onto HBCD-PS closely conformed to the pseudo-second-order and the Freundlich models. The solution pH and NaCl contents significantly affected the adsorption amounts of FA onto HBCD-PS. Overall, HBCD-PS mainly combined with FA through hydrophobic and electrostatic interactions. Besides, the presence of heavy metal ions (Cu(Ⅱ), Pb(Ⅱ), Zn(Ⅱ) and Cd(Ⅱ)) enhanced the adsorption capacities of FA onto HBCD-PS, which was positively correlated with their complexation ability.
2022 Vol. 42 (1): 285-292 [Abstract] ( 331 ) [HTML 1KB] [ PDF 1091KB] ( 2010 )
293 Distribution and release kinetics of organic phosphorus in phosphorus-rich sediments: A case study of Xibeikou Reservoir in Yichang
MA Xiao-yang, NIU Feng-xia, XIAO Shang-bin, KANG Man-chun, LIU Jia, HU Jie-ming
In order to explore the spatial distribution of organic phosphorus (OP) and its release dynamics in phosphorus-rich sediments of the reservoir, the Ivannoff method was used to extract sequentially different forms of OP in the sediments of Xibeikou Reservoir. Simulation experiments on OP kinetic release were performed the release characteristics of different OP fractions from the surface sediments, as well as the physicochemical properties of sediments and their responses to the OP release. The results showed that the OP content of the sediments in Xibeikou Reservoir was 210.3~455.2mg/kg, with an average content of 322.9mg/kg, accounting for 18.3% of the total phosphorus (TP). The spatial patterns of OP contents were characterized by the midstream (363.2mg/kg)>the downstream (339.3mg/kg)>the upstream of the reservior (266.1mg/kg), and longitudinally the OP contents decreased with the depth increasing. The patterns of different OP forms in Xibeikou Reservoir were shown as: inactive organic phosphorus (NOP)>medium active organic phosphorus (MLOP)>active organic phosphorus (LOP). NOP occupied 65.3% of OP, serving as the main forms of OP in the sediments of Xibeikou Reservoir. The quasi-first-order kinetic model was the optimal equation to describe the OP kinetic release curve of the sediments in the upstream, midstream and downstream of the Xibeikou Reservoir (R2=0.98~0.99, P < 0.01). The 0~1h period was the rapid-release stage, with released OP contents accounting for 55.68%~79.55% of the maximum release content (Qmax). Then it got to the slow-release stage, and gradually the release content reached Qmax, ranging between 1.4mg/kg and 3.1mg/kg. In the sediments of the reservoir, both LOP and MLOP were the main OP forms releasing to the overlying water.
2022 Vol. 42 (1): 293-301 [Abstract] ( 293 ) [HTML 1KB] [ PDF 402KB] ( 1767 )
302 Responses and assessment of water ecological state in restored and unrestored areas of a small urban lake after ecological restoration
SU Xiao-mei, XUE Qing-ju, WAN Xiang, XIE Li-qiang
This research aims to study the long-term variations on aquatic ecological state in different regions of a small urban lake after ecological restoration, and the applicability of using different aquatic organisms to evaluate water ecological state, the water quality and different aquatic communities in Songya Lake, a small urban lake in Hunan Province, this monitoring was performance monthly and quarterly from January 2018 to May 2019, and the water ecological state was evaluated. After restoration, the results showed that the water ecological status of the whole lake was better than that of before restoration. The decrease rates of Chl-a and CODMn were nearly to 90%, and for TP it was more than 70%. The concentrations of TN, NH3-N and TP in the restored area and the un-restored area, all showed a decreasing trend, and the others water quality indexes were also at a low level with relatively small variation during the survey; However, most of the indexes were better in the restored area. The higher contents of CODMn in the restored area were probably related to the exogenous input and more submerged plant residues. In addition, the numbers of species and biodiversity indexes of phytoplankton, zooplankton and zoobenthos in the restoration area were higher than those in the un-restored area, and the densities of phytoplankton and zooplankton were also higher than those in the un-restored area. The evaluated results of water ecology showed that the restored area and the un-restored area performed well in most of the time. Among the different biological indexes, the zooplankton species indicators were the most accurate in Songya Lake, this finding suggested that in order to use a single aquatic biota to evaluate the water ecological state of the water body, an appropriate biota should be selected for this evaluation according to the characteristics of the water environment and the objectives pursued.
2022 Vol. 42 (1): 302-312 [Abstract] ( 293 ) [HTML 1KB] [ PDF 971KB] ( 1454 )
313 Analysis based on GAM model for the relationship between chlorophyll a concentration and environmental factors in Dongting Lake
YAN Guang-han, YIN Xue-yan, WANG Xing, WANG Li-jing, LI Dan, TIAN Ze-bin, LI Hong
From January to December in 2019, the samples were collected in Dongting Lake to analyze the correlation between the chlorophyll a distribution and concentration with environmental factors by using the generalized additive model (GAM). The results showed the strong temporal and spatial variations of chlorophyll a concentration appeared, annual average value was 5.77μg/L ranging from 1.00 to 67.33μg/L for the single influencing factor GAM model. The most influential factors in the variations of chlorophyll a concentration differed among seasons, with CODMn, Cond and TP for spring; CODMn, WT and Cond for summer and autumn respectively; NH4+-N and Cond for winter. For the multiple influencing factors GAM model the explanation result was better with an overall rate for 97.5% for the variations in chlorophyll a concentration. The environmental factors affecting the variations in chlorophyll a concentration ranked as CODMn>TP>Cond>NH4+-N>TN/TP, and all factors exhibited a non-linear relationship with chlorophyll a concentration.
2022 Vol. 42 (1): 313-322 [Abstract] ( 376 ) [HTML 1KB] [ PDF 1005KB] ( 2193 )
323 Response of phenological vegetation wilting period to multi-scale drying-wetting changes in Xilingol
LYU Da, BAO Gang, TONG Si-qin, LEI Jun
Based on the third generation《Global Inventory Monitoring and Modelling Studies》(GIMMS) and the《Normalized Difference Vegetation Index》(NDVI) (1982~2015), this study extracted vegetation EOS (End of Growing Season) data in Xilingol grassland from 1982 to 2015, and analyzed its responses to multi-scale drying-wetting changes derived from the Standardized Precipitation Evapotranspiration Index (SPEI). The results showed that during 1982~2015, the EOS of Xilingol vegetation was 265~280 d, and delayed from northeast to southwest, with a decreasing trend of -0.14 d/a. Generally, the interannual variation in spatially averaged SPEI tended to decrease at -0.10d/10a. In addition, an increasing trend was mainly observed in the northeastern meadows, and a decreasing trend was observed in the southwestern desert grasslands. Over the past 34 years, the frequency of drought in Xilingol has increased, with the large areas experiencing the light to mid-droughts. The sudden change to frequent droughts occurred in the 1990s. There were significant spatial differences in the impacts of multiple SPEI time scales on EOS. In detail, the positive effect of monthly SPEI-1(Index for one month data) on vegetation EOS in the Xilingol was the greatest, suggesting that grassland vegetation EOS could be delayed in a favorable dry-wet environment over a short time scale. The SPEI-3, SPEI-6, SPEI-9, and SPEI-12(Index for many months data), however, had relatively large negative correlations with EOS, indicating that the long-term changes in the drying conditions could advance grassland EOS in Xilingol. The time-lag effect of SPEI-1 in the Xilingol mainly occurs two months before EOS. The long-term SPEI-3, SPEI-6, and SPEI-9 (especially SPEI-3), which are accumulated to June, have particularly considerable lag effects.
2022 Vol. 42 (1): 323-335 [Abstract] ( 235 ) [HTML 1KB] [ PDF 2631KB] ( 1362 )
336 Drought effects on forest greenness anomalies in China from 2003 to 2018
HOU Xin, ZHAO Jie, ZHAO Hong-fei, TA Zhi-jie, YUE Chao
This study was to evaluate the effects of drought on forest greenness anomalies in China. Satellite observations of forest leaf area index (LAI) and climate reanalysis data were used to examine forest canopy damage induced by drought during the period from 2003 to 2018. We assigned the forest Greenness Anomaly index (GAI) as a proxy for the forest canopy damage, defined as cumulative monthly negative LAI anomalies deviated from the long-term monthly LAI trend, then followed by standardization using the standard deviation. Using this index, we analyzed the spatiotemporal dynamics of drought-induced forest damage and the drought sensitivity of different forest types. Our results showed that: (1) The drought-induced forest canopy damage was more widespread in South China than in North China, while high-intensity drought damage mainly occurred in the Northeast and Southwest of China; (2) From 2003 to 2018, the severity of drought-induced canopy damage increased significantly with the GAI change rate of -0.06/a (a lower index means a higher severity), while the forest area ratio subjected to the drought damage decreased with the change rate of -0.0049/a; (3) Forests with a high sensitivity of drought damage mainly occurred in the north of Yunnan and the north part of the Greater Khingan Mountains in China, due to the common effects of geological, climate and vegetation type characteristics of the region; (4) Broadleaf forest was most sensitive to drought, followed by coniferous forest, while mixed forest was the least sensitive forest type and the corresponding regression slopes of GAI and SPEI for these three forest types were 1.8, 1.3 and 1.2, respectively; and (5) from 2003 to 2018, coniferous forest suffered the highest drought intensity and forest damage, with the median of SPEI as -1.65. As a result forest damage was more dominated by the drought intensity than by drought sensitivity.
2022 Vol. 42 (1): 336-344 [Abstract] ( 315 ) [HTML 1KB] [ PDF 1839KB] ( 1494 )
345 Carbon and nitrogen contents and isotopic fractionation in different tissues of Ctenopharyngodon idellus and Anabarilius grahami in Fuxian Lake
GUO Wen, HUANG Lin-pei, WANG Ming-guo, CHEN Zi-dong, ZHAO Shuai-ying, KONG Ling-yang, CHEN Guang-jie
Stable isotope signal and element composition of carbon and nitrogen in lake organisms have been widely applied to identify food sources and trophic structure of lake food webs. This study was conducted to evaluate ecological processes of elemental assimilation and stable isotope fractionation among different tissues by determining carbon and nitrogen contents and stable isotopes of 31 tissues of Ctenopharyngodon idellus and 17 tissues of Anabarilius grahami collected from Fuxian Lake. The results show that there are significant carbon isotopic fractionations among tissues, ranging from -20.66‰ to -11.62‰ for Ctenopharyngodon idellus and from -27.55‰ to -19.71‰ for Anabarilius grahami. Meanwhile, the nitrogen isotope fractionations are relatively moderate for both kinds of fish, with a maximum range of 1.88‰ and 4.60‰, respectively. The δ13C values show a significantly negative correlation with carbon contents of tissues. A 10% increase in carbon content results in a depletion of δ13C value by -1.83‰ for Ctenopharyngodon idellus and -1.35‰ for Anabarilius grahami, indicating that the absorption and synthesis of carbon in tissues are accompanied by significant isotopic fractionation. However, the δ15N values of different tissues may be affected by essential amino acids but not associated with nitrogen content; because a high content of essential amino acids in tissues often leads to a depletion of 15N. The isotopic fractionation coefficients between the dorsal muscle of Ctenopharyngodon idellus and intestinal content (Vallisneria natans) are 0.40‰ for carbon isotope and 2.66‰ for nitrogen isotope, suggesting carbon and nitrogen isotopic compositions of dorsal muscle are a reliable indicator of food source and trophic level. For fish without obvious dietary change over life time, the δ13C value of mucus and the δ15N value of scales (after correction) can be used as alternative indices for dorsal muscles. Obviously, the carbon and nitrogen contents and isotope fractionations of fish tissues can be used to identify the trophic structure and the pathway of trophic flow in lakes of southwest China. The alternative sampling of non-lethal tissues such as mucus and scales can be of great potential for effectively conservation of endangered fish.
2022 Vol. 42 (1): 345-355 [Abstract] ( 421 ) [HTML 1KB] [ PDF 1154KB] ( 2100 )
356 N2O release from the water bodies of typical gate controlling tributaries of Bohai Bay
LI Xiao-zheng, YUE Fu-jun, ZHOU Bin, WANG Xin-chu, HU Jian, CHEN Sai-nan, LI Si-liang
To explore the spatiotemporal variation in N2O in typical coastal zone and its main controlling factors under weak hydrodynamic conditions, water samples were collected from coastal rivers and wetlands (Daqing River-Duliujian River-Beidagang wetland) in July and August (Summer) and November (the beginning of Winter) in 2019. The results show that the concentration of N2O varied between 0.4~184.5nmol/L. The saturation of N2O ranged from 7.2%~2740%, and 90% of the samples were oversaturated, indicating that the study area was a potential source of N2O. The N2O release flux at the water-gas interface ranged from -0.3~6.7μmol/(m2·h), while the N2O exchange flux in summer was higher than that in winter. The study also found that the N2O concentration fluctuated significantly before and after rainfall, and the variation in N2O ranged from -15.2~63.9nmol/L at same sites before and after rainfall. The average increase in N2O concentration was significantly higher in the upper reaches (22.1nmol/L) than in the downstream (1.3nmol/L), indicating that rainfall drove the transportation of nitrogen species and accelerated N2O release. The salinity and NO3--N concentration had significant effect on N2O concentration. The N2O emission factor of the tributaties under the weak hydrodynamic conditions in coastal zone was estimated to be 0.0073, higher than the default value of 0.0026 defined by IPCC. Therefore, the N2O budget in the coastal zone may underestimate the indirect N2O emissions by using the IPCC threshold value.
2022 Vol. 42 (1): 356-366 [Abstract] ( 271 ) [HTML 1KB] [ PDF 2018KB] ( 1147 )
367 Comprehensive assessment and evolution analysis of soil salinization in artificial oasis in arid desert area
LIU Zi-jin, XU Cun-dong, ZHU Xing-lin, ZHOU Dong-meng, TIAN Jun-jiao, GU Feng-you, HUANG Song, LI Zhi-rui, ZHAO Zhi-hong, WANG Xin
To clarify the spatiotemporal variation characteristics of water and salt and the spatial evolution of salinization in artificial oasis in arid desert area, Jingtaichuan electric power irrigation area in Gansu Province was taken as the research area, 2002, 2010 and 2018 were selected as representative years. The soil salinization risk assessment system was constructed based on multi-level fuzzy theory from three driving processes: geological-climatic driven, soil-water environmental driven and natural-human driven. The cloud generator principle, golden ratio method, combined assignment method and queuing theory were integrated to construct a comprehensive spatial risk evaluation model of soil salinization. The long-sequence monitoring data, multi-temporal spatial data, and economic and social data were fused based on the element weights using ArcGIS10.2. The spatial risk state of salinization in each period was visually expressed and flow traced. The results of the study showed that: 1) The overall risks of land salinization in 2002, 2010 and 2018 were "critical", "critical-mild risk" and "mild risk"; 2) The dominant factors in the soil salinization were the depth of groundwater and the mineralization of groundwater; 3) In the irrigation area, the intensity of spatial evolution pattern of salinization risk: continuous change type>early change type>late change type>continuous stable type>repeated change type. The overall salinization risk in the study area showed a transition trend from "risk-free to critical state" and "from critical state to mild risk"; 4) From 2002 to 2018, the salinization in the study area was aggravating with obvious regional differences and generally presented an arcing increase from northwest to southeast.
2022 Vol. 42 (1): 367-379 [Abstract] ( 286 ) [HTML 1KB] [ PDF 1649KB] ( 1508 )
380 Characteristics of phytoplankton functional groups and their relationships with environmental factors in Xinfengjiang Reservoir
ZHANG Hui, PENG Yu-qiong, ZOU Xian-ni, ZHANG Ting-ting, WU Chu, LIN Xiao-ping, QIAO Yong-min, YANG Hong-yun
To understand the structural characteristics of the phytoplankton functional groups (FGs) and the ecological status of Xinfengjiang reservoir, the structure of phytoplankton and physicochemical indexes of water were investigated and analyzed monthly from 2020 to 2021. The results showed that the major water quality indexes of Xinfengjiang reservoir met Ⅰ class standard of "Surface Water Environmental Quality Standard"(GB3838-2002). There were 25 identified phytoplankton functional groups. Among them, FGs A, D, E, F, J, K, Lo, M, MP, NA, P, S1, SN, TB, X1, X2, X3 and Y occurred frequently, and the dominant functional groups were A, E, F, J, Lo, MP, NA, X3 and Y. The main temporal changes characteristics of phytoplankton FGs occurred for Lo/A/E/Y in spring, for Lo/A/F/J/X3/NA in summer, for Lo/NA/F/A in autumn, and for Lo/E/MP/F/A in winter. The main dominant FGs were A, E, Lo, NA and X3, resulting from the oligotrophic factors of the reservoir. Correlation and Multivariate analysis (RDA) between phytoplankton abundance and environmental factors showed that pH, transparency and water temperature were the key factors affecting phytoplankton functional groups in Xinfengjiang Reservoir. The ecological state of Xingfengjiang reservoir is considered as in excellent level, as shown by its Q value with a range of 3.63~4.87.
2022 Vol. 42 (1): 380-392 [Abstract] ( 316 ) [HTML 1KB] [ PDF 1488KB] ( 2867 )
393 Methane diffusion flux and its driving factors in Zhushan Bay of Lake Taihu
LIU Zhen-jing, XIAO Qi-tao, HU Zheng-hua, ZHANG Mi, WANG Wei, XIAO Wei
To identify the influence of input of pollutants and eutrophication on the temporal and spatial variations of the CH4 diffusion flux, monthly field measurements of CH4 flux was conducted in Zhushan Bay from November 2011 to August 2013. For comparison, the CH4 flux in the Central Zone of the lake with less impact from human activities was also determined. Results showed that the CH4 diffusion flux in Zhushan Bay with a mean value of (0.193±0.049) mmol/(m2·d) was significantly (P<0.01) higher than that ((0.024±0.005) mmol/(m2·d)) in the Central Zone. Meanwhile, the highest CH4 flux occurred at the sampling site with river discharge in Zhushan Bay. Further, the CH4 diffusion flux in the Central Zone showed apparent temporal variation, and the flux was positively correlated with water temperature (R2=0.53, P<0.01). However, the CH4 flux showed a poor correlation with water temperature in Zhushan Bay (P>0.05).In addition, both the dissolved CH4 concentration and CH4 flux in Zhushan Bay were positively correlated with the dissolved CH4 concentration in the inflowing river (concentration: R2=0.75, P<0.05; flux: R2=0.64, P<0.05). The results indicated that the external input of pollutants might weaken the effect of temperature on CH4 flux in Zhushan Bay, leading to the eutrophic Zhushan Bay being a significant source of atmospheric CH4.
2022 Vol. 42 (1): 393-401 [Abstract] ( 247 ) [HTML 1KB] [ PDF 690KB] ( 1331 )
Carbon Emission Control
402 Empirical analysis of cost-CO2-energy benefits of distributed photovoltaic-battery storage system-taking (PV-BSS) in a case study in rural Jiaozhou Shandong
WANG Xiao-hu, CHU Chun-li, CAO Zhi, CHU Chun-liang, JU Mei-ting
An integrated assessment model that brought together life cycle cost analysis, life cycle CO2 analysis, and life cycle energy analysis was established. A range of indicators (e.g., static payback period (PBPs), internal rate of return (IRR), carbon emissions intensity (Em), carbon compensation payback period (CPBP), energy payback time (EPBT)) were used to evaluate the economic benefits, carbon emissions reduction benefits, and energy benefits of PV-BSS. The integrated assessment model was applied to installations of 5, 8, 10 and 15kW PV combining with 11kW·h BSS in the rural areas of Jiaozhou, Shandong Province, to establish and examine the cost-benefits ratios in CO2 reduction versus energy benefits. The results showed that adding BSS to these installations would bring negative effects, (1) in reducing mainly the economic benefit (2) in reducing secondly the carbon emission benefit (3) but with only minor energy benefit reduction. Taking the 10kW system as an example, PBPs was extended by 34.7%, IRR reduced by 20%, Em increased by 5.36%, CPBP extended by 5.83%, and EPBT extended by 0.56%. Extending the system use time and the scale of photovoltaic installation could increase the economic benefits, and at the same time, reduce Em, shorten CPBP, thereby reducing the overall negative impact of the energy storage system on the overall economy-CO2-energy efficiency reduction. In the off-grid scenario, the addition of BSS could effectively increase significantly the economic benefits of the system, the overall carbon reduction benefits and energy level benefits were significant.
2022 Vol. 42 (1): 402-414 [Abstract] ( 336 ) [HTML 1KB] [ PDF 991KB] ( 3180 )
415 The response of heatwave to carbon emission in China
LIU Jin-ping, REN Yan-qun, TAO Hui, LIU Tie, CHEN Hao
Based on the Carbon Emission Accounts and Datasets (CEADs) and meteorological observation, this study aimed to analyze the relationship and change features between carbon emission and heatwaves in eight economic regions (30 provinces) of China during 1997~2017. Moreover, the multi-scale response of heatwaves to carbon emission in different regions was investigated. The results indicate that: i) During the study period, carbon emission in the eight economic regions increased significantly. The middle reaches of the Yellow River and the northwest economic regions had the highest and lowest growth rates, respectively; ii) the severer heatwave appeared less often in term of rate recurrence. The regions with mild and often heatwave encountered the more frequent moderate and severe event. iii) The mild level of heatwave had the earliest onset, termination dates and longer duration comparing other levels; iv) The high consistency of heatwaves and carbon emission in the interannual scale was found in the warm regions, while the cold regions possessed the high consistency in decadal scales. This spatial pattern implied that the response of heatwaves to carbon emission was more robust in warmer regions; v) The response of heatwave duration to carbon emission in different economic zones was significant at different levels. In general, higher emissions leaded to prolonging heatwaves. The results provide scientific support for domestic carbon emission management and regional sustainable development programs.
2022 Vol. 42 (1): 415-424 [Abstract] ( 333 ) [HTML 1KB] [ PDF 2277KB] ( 1691 )
425 Emission of carbon dioxide from Lake Chaohu and the potential influencing factors
LI Yu-yang, ZHU Jun-yu, YU Xiao-qin, CHEN Hui-min, GUO Yan-ni, ZHOU Yong-qiang, ZHOU Lei
Water samples from Lake Chaohu were collected in January (dry), April (wet-to-dry transition), and July (wet) to explore the variability of CO2 emissions from the shallow lake and the corresponding linkage with the sources and optical composition of CDOM. We coupled diffusion coefficient and mass balance approaches to trace the variability of dissolved CO2 concentration (cCO2) and CO2 efflux (FCO2) from Lake Chaohu, and further explore the potential drivers, especially the potential linkage between CO2 emissions and the optical composition of CDOM. Our results showed that the mean cCO2 of the whole lake area in Chaohu was higher in the wet season ((51.9±71.8)μmol/L) than in the wet-to-dry transition season ((48.9±29.0)μmol/L), and further higher than in the dry season ((35.2±15.6)μmol/L). We observed a slight sink of CO2 in the lake in the dry season ((-98.8±20.1)mg/(m2·d)), and there was no significant difference between the mean FCO2 in the wet season ((219.3±275.5)mg/(m2·d)) and the wet-to-dry transition season ((219.9±157.8)mg/(m2·d)). We found higher mean cCO2 and FCO2 in the western than in the central and further higher than in the eastern area of Lake Chaohu. In the western area of Lake Chaohu, dissolved oxygen (DO) was negatively correlated with cCO2(P<0.05) and FCO2(P<0.001); and we further found that both cCO2 and FCO2 increased with increasing dissolved organic carbon (DOC) (P<0.01) and chlorophyll-a(Chl-a) (P<0.001). Parallel factor analysis coupled with excitation-emission matrices revealed four fluorescent components, and both cCO2 and FCO2 increased with increasing humic-rich components C1 (P<0.01) and C4 (P<0.001). No significant correlation was found between cCO2, FCO2 and tryptophan-like C2, or beteween cCO2, FCO2 and tyrosine-like C3. Our results suggested that elevated trophic level potentially drive the emission of CO2 from Lake Chaohu, and the source and composition of CDOM, especially the input of terrestrial humic-rich substances, potentially favors the emission of CO2 from the lake.
2022 Vol. 42 (1): 425-433 [Abstract] ( 346 ) [HTML 1KB] [ PDF 964KB] ( 2538 )
Environmental Toxicology and Health
434 The effects of antibiotic mixtures on bacterial resistance based on “cocktail” exposure
HAN Bao-cang, CHEN Zhi-bin, ZHANG Yue-heng, LIN Zhi-fen, SUN Hao-yu
Three kinds of commonly used antibiotics, i.e., tetracyclines, sulfonamides, and sulfonamide potentiators, were selected as representatives to obtain their concentration for the hormetic maximum promoting effect on Escherichia coli (E. coli) (HCmax). The binary and ternary mixtures of test antibiotics were designed based on equal HCmax rations, and their combined effects on bacterial growth and resistance (mutation and plasmid conjugation) of E. coli were explored. The results showed binary mixtures synergistically inhibited the growth and conjugation frequency, but synergistically stimulated the mutation frequency. The combined effects of ternary mixtures on toxicity and resistance were all synergistic inhibition. Therefore, it could be speculated that binary mixtures might increase the risk of toxicity and resistance, while ternary mixtures might result in an increased toxicity risk but a decreased resistance risk.
2022 Vol. 42 (1): 434-443 [Abstract] ( 338 ) [HTML 1KB] [ PDF 1135KB] ( 1382 )
444 Maternal exposure to ambient air pollution and gestational hypertension in Handan
CAO Lei, WANG Ting, WANG Li-jun, DIAO Rui-ping, YU Li-jing, CUI Xiao-li, MAO Hong-jun
The traditional logistic regression model was used to evaluate the effects of exposure to various pollutants on GH, and the logistic regression model based on principal component analysis was used to evaluate the effects on GH by additionally adjusting parameters of other pollutants. Results of single-pollutant model showed that each 20μg/m3 increment of O3 was significantly positively correlated with the increased risk of GH (OR=1.211, 95%CI: 1.094~1.340) during the first 26 weeks of gestation, and the effect in the first trimester was greater than that in the second trimester. In multi-pollutant model, each 20μg/m3 increment of PM2.5 and PM10 exposure significantly increased the GH risk of pregnant women in the three months before pregnancy, with OR values of 1.021 (95%CI: 1.004~1.038) for PM2.5 and 1.016 (95%CI: 1.002~1.031) for PM10. Consistent with the results of single-pollutant model, each 20μg/m3 increment of O3 exposure also had a significant effect on the risk of GH (OR=1.026, 95%CI: 1.002~1.050) during the first 26 weeks of gestation in multi-pollutant model. The results of subgroup analysis showed that pregnant women aged 25~30 years or those in the first pregnancy were susceptible to PM2.5, PM10, NO2 and CO exposure before pregnancy, while pregnant women over 35 years old or without college degrees were more likely to develop GH due to O3 exposure during pregnancy. In summary, air pollution in Handan has significant impacts on pregnant women inducing suffering from GH. To mitigate the negative impacts of exposure to air pollution, more attention should be paid to the enhancement of air pollution protection awareness for pregnant women before and during pregnancy.
2022 Vol. 42 (1): 444-455 [Abstract] ( 256 ) [HTML 1KB] [ PDF 956KB] ( 872 )
456 Effects of environmental exposure to triclocarban on the neurobehavior of zebrafish (Danio rerio)
ZHAO Chen-xi, WANG Yang, QIAN Qiu-hui, YAN Jin, XIAO Ao, WANG Xue-dong, WANG Hui-li
To evaluate adverse effects of triclocarban (TCC) on vertebrate neurobehavior and their mechanisms, we explored the larval neurodevelopmental toxicity under acute exposure and the adult nervous behavior under chronic exposure by employing zebrafish (Danio rerio) as the model vertebrate. The results show that the TCC acute exposure at the sublethal dose resulted in a decrease in both the autonomous movement activity and the sensitivity to sound and light stimulation of embryonic and larval zebrafish. As indicated by Acridine orange apoptotic staining that TCC induced excessive cell apoptosis in the larval head, kidney, brain and eyes. A series of malformation symptoms were observed with scanning electron microscopy, such as deformed lateral line nerve muzzle, inhibited development, reduced number of hair cell clusters and disordered arrangement. The group of adult zebrafish under the long-term TCC-exposure were observed to suffer from excessive anxiety and panic, decreased risk aversion and vigilance, as well as autism and reluctance to social activity. Overall, TCC exposure can significantly affect zebrafish memory, learning ability and cognitive function.
2022 Vol. 42 (1): 456-464 [Abstract] ( 293 ) [HTML 1KB] [ PDF 1335KB] ( 2351 )
Environmental Microbiology
465 Effects of excess sludge fed by earthworms on microbial community and antibiotic resistance genes in their intestinal functional area
PENG Lan-sheng, GUAN Meng-xin, HUANG Kui, XIA Hui, SANG Chun-lei
This study aimed to investigate the changes of microbial community structure and their antibiotics resistance genes (ARGs) abundances in the intestinal tract of Eisenia fetida, via detecting the sludge passing through different functional areas in earthworms' gut. Prior to the DNA extraction, all fresh samples were pretreated with propidium monoazide (PMA) to characterize active functional microorganisms. The results showed that the abundances of bacterial 16S rDNA and eukaryotic 18S rDNA significantly increased (P<0.05) by 28.2 and 42.2 times in stomach, and they significantly decreased (P<0.05) in the gizzard and hindgut, after 5 days of earthworm digestion. In addition, the sludge digested by earthworms changed dominant proteobacteria to tenericutes in gizzard, and modified dominant bacteroidetes to firmicutes in stomach. However, the digestion process of earthworms had little effect on bacterial community structure in hindgut. For the ARGs, the abundances of ermF, tetX and sul2 significantly increased (P<0.05) by 1.9×102, 8.4×105 and 25.9 times in stomach of earthworm, respectively. While the total abundances of ARGs in gizzard and hindgut significantly decreased (P<0.05) by 11.0 and 45.2 times, respectively. Moreover, network analysis revealed that the feeding behavior of earthworms for sludge could indicate effects on the structural diversity of host bacteria of ARGs in their intestine.
2022 Vol. 42 (1): 465-473 [Abstract] ( 376 ) [HTML 1KB] [ PDF 1094KB] ( 1229 )
Environmental Impact Assessment and Management
474 Design and experimental research of sonic crystal noise barrier with resonance mechanism
QIN Xiao-chun, NI An-chen, CHEN Zheng-hao, MA Bao-long, MENG Fan-tong
In order to reduce the tire-road noise, this study optimized the band structure of the three cavity forms based on the U-shaped model. A "broadband and multi-band" hourglass sonic crystal was designed, then a new type of noise barrier was established and tested for noise reduction performance. The results showed that for the noise characteristic frequency band coverage, hourglass>taper in>straight, and the band gap range can be effectively adjusted by changing the cavity size. For the noise reduction performance of sonic crystal noise barrier, Bragg scattering and cavity resonance effect were coupled and the number of rows can be increased to improve the noise reduction effect in the band gap by 0.9~3.5dB(A). As a discontinuous periodic structure, the noise reduction effect after the barrier was unevenly distributed, especially between the scatters, therefore, when measuring, the number of measuring points should be increased and the influence of the interval should be considered. Compared with the traditional noise barrier and the Bragg-type sonic crystal noise barrier, the noise reduction effect of hourglass type was improved by 0.9~14dB(A) in the 500~1000Hz target frequency band gap.
2022 Vol. 42 (1): 474-482 [Abstract] ( 224 ) [HTML 1KB] [ PDF 1325KB] ( 2190 )
483 Regional water-energy-food green efficiency and heterogeneity and their influencing factors
ZHANG Jing-jing, WANG Wen-sheng, LI Yang
In view of the green development concept, a multi-dimensional input-output index system was established by constructing Meta-SSBM and Meta-Malmquist-Luenberger models. The static and dynamic green efficiencies of water-energy-food across the mainland of China during 2004~2018 were evaluated. The characteristics of temporal and spatial differences at the green development level in terms of the east, central and western areas were correspondingly decomposed by the Theil index. The results show that: (1) there was a great difference in the efficiency under the meta- and group-frontier caused by the inefficiency of the technology gap, being the potential optimized technical level in the eastern area and being a risk of overestimation in both the central and western areas; (2) the inefficient implementation of both management and technology was responsible for the inefficiency in the eastern area, the central area and the western area; (3) the highest growth rate of water-energy-food green TFP in eastern area was due mainly to technological progress, and the decline in green TFP in the central and western areas due to the slow down in technological progress; (4) the Theil index of green TFP growth rate in the western area was the highest and the difference within the group was much greater than that among the groups, especially for the western area; (5) the proportion of the education and the science and technology expenditure in the fiscal expenditure, per capita meat production, and per capita vegetable production, along with the water-energy-grain green TFP, changed in the same direction, but in the opposite direction for urbanization rate, population density, and per capita GDP.
2022 Vol. 42 (1): 483-496 [Abstract] ( 254 ) [HTML 1KB] [ PDF 558KB] ( 1620 )
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