Environmental Chemistry

ISSN 0254-6108

CN 11-1844/X

Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
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Influence of iron-mercury coupling on biogeochemical cycle of mercury in aquatic environment: A review of recent studies
ZHU Ailing, CAO Dandan, CHEN Ying, GUO Yingying, YIN Yongguang, LI Yanbin, LIU Jingfu, CAI Yong
2019, 38(7): 1431-1445.   doi: 10.7524/j.issn.0254-6108.2018092402
Abstract PDF 4380KB
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Mercury and its compounds are a class of important global pollutants. Aquatic environment is an important sink for mercury and also crucial sites for its transformation and bioaccumulation. The interaction of iron and mercury in aquatic environment has important impacts on the biogeochemical cycle of mercury. This review focused on the coupling of biogeochemical cycles of iron and mercury in aquatic environment, and discussed and summarized the adsorption of mercury to iron minerals, sulfidation of mercury by iron sulfide, reduction of mercury by dissolved iron and iron minerals, effect of iron on the microbial methylation of mercury, degradation of methylmercury by iron, formation of dimethylmercury induced by iron sulfide, as well as effect of iron plaque on the uptake of mercury. The future trends in iron-mercury coupling on biogeochemical cycle of mercury in aquatic environment was also proposed.
Human health risk assessment for lead contaminated soil after remediation with several phosphate compounds
LI Yan, YIN Naiyi, DU Huili, WANG Pengfei, SUN Guoxin, CUI Yanshan
2019, 38(7): 1446-1452.   doi: 10.7524/j.issn.0254-6108.2018091103
Abstract PDF 1486KB
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The use of phosphate as a stabilizing agent that is widely accepted and capable of lead-contaminated soil remediation. However, there are few studies on the assessment the risk of human health after remediation. In the study, five different phosphorus materials (KH2PO4,NH4 H2PO4,CaHPO4,Phytic acid and Lecithin) were added to lead-contaminated oil, and theirs inactivation of lead was analyzed. In vitro and SHIME models were adopted to evaluate the risk of human health of soil lead after soil remediation. The results showed that, after adding P material for 30 days, the five materials obviously decreases by 62.5%-66.5% DTPA extractable Pb and by 27.8%-49.5% CaCl2 extractable Pb. The Pb inactivation of CaHPO4 and phytic acid was better than the others. Among the five treatments, the Pb bioaccessibility in different phase was quite different, about 8.67%-9.31% in gastric phase, 0.88%-1.55% in small intestinal phase and 2.06%-2.76% in colon phase. The Pb bioaccessibility was highest and no significant difference was observed within the five treatments according to the low pH in gastric phase. In small intestinal, the bioaccessibility of soil lead was lowest after adding KH2PO4, highest after adding lecithin. In colon phase, the bioaccessibility of soil lead was lowest after adding NH4H2PO4, highest after adding lecithin. In addition, the bioaccessibility of lead in colon stage was higher than that in small intestine stage, suggested that the human gut microbiota could induced Pb release from soil and increased bioaccessibility, which may resulted in a high risk to human health. After remediation of lead-contaminated soil with the same amount of the five phosphorous materials, the human health risk was the lowest by KH2PO4 and the highest by lecithin.
Bioaccessibility and health risk assessment of heavy metals in the soil around Huaibei coal mining area
SUN Liqiang, SUN Chongyu, LIU Fei, BAO Xianming
2019, 38(7): 1453-1460.   doi: 10.7524/j.issn.0254-6108.2018092801
Abstract PDF 1282KB
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In order to study heavy metals contamination in the mine soils and evaluate health risks to human, three main coal mines in the Huaibei city were selected as the research areas, and the contents of 6 kinds of heavy metals in the soil were analyzed. The bioaccessibility of heavy metals in soil was calculated by using in vitro gastrointestinal simulation experiment, and the calculation methods of health risk assessment were corrected. The mean concentration (mg·kg-1) of heavy metals in soils were Cd (0.16), Cr (11.82), Cu (12.03), Ni (21.86), Pb (55.09), Zn (41.46), respectively. Compared to other mining area in different style in China, soil heavy metals content around Huaibei coal mining area were relatively low. The bioaccessibility showed Pb (61.69%) > Cu (51.88%) > Cd (43.88%) > Cr (26.48%) > Zn (17.45%) > Ni (14.57%) in stomach, and Cr (58.80%) > Cu (55.71%) > Zn (51.40%) > Ni (39.44%) > Pb (7.59%) > Cd (7.32%) in intestinal phase. Based on bioaccessibility correction, the hazard quotient for both adults and children were below 1, indicating no non-carcinogenic risk. The carcinogenic risk for heavy metals was in a decreasing order:Cr > Cd > Ni. The cancer risk values of Cr for adults and Cr for children stood in the range of acceptable risk (10-6-10-4). Children were in higher carcinogenic risks than adults. The ingestion was the primary pathway to exposure the carcinogenic risk of heavy metals.
Distribution characteristics and risk assessment of heavy metals in overlying water and surface sediments in rivers in typical mining areas of southern Jiangxi Province
CHEN Ming, LI Fengguo, TAO Meixia, HU Lanwen, SHI Yanli, LIU Yan, ZHENG Xiaojun, LIU Youcun
2019, 38(7): 1461-1469.   doi: 10.7524/j.issn.0254-6108.2018120706
Abstract PDF 1823KB
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In order to reveal the heavy metal content, occurrence form and ecological risk of the rivers in the typical mining area of southern Jiangxi province, this paper selects Taojiang as the research object and collects the overlying water and sediments from 10 monitored points.The contents and morphology of heavy metals Cu, Zn, As and W in overlying water and sediment were analyzed by inductively coupled plasma mass spectrometry. The pollution status of four heavy metals in Taojiang sediments was evaluated by Nemero comprehensive pollution index method and risk assessment coding method.The results show that the average contents of Cu, Zn, As and W in the overlying water are 53.12, 38.92, 1.71 and 0.15 μg·L-1, respectively. The average values of Cu, Zn, As and W in sediments are respectively 43.09, 135.55, 16.43 and 17.23 mg·kg-1;The comparison of the proportion of the four heavy metals is residue state > oxidizable state > reducible state > acid soluble state from high to low;the evaluation results of Nemero comprehensive pollution index method show that 50% of the sampling points belong to the middle pollution level, and 40% of the sampling points are at the level of heavy pollution; Only 10% of the sampling points in the risk assessment coding method are at low ecological risk, and 90% of the sampling points are at medium ecological risk.
Spatial distribution of selenium and its influencing factors in soils of oasis zone in Ruoqiang County, Xinjiang
FAN Wei, ZHOU Jinlong, WANG Songtao, DU Jiangyan
2019, 38(7): 1470-1478.   doi: 10.7524/j.issn.0254-6108.2018092902
Abstract PDF 1671KB
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To evaluate selenium content and distribution, and to study its relationship with soil properties, 434 topsoil samples were collected. The results showed that selenium content ranged from 0.06 to 0.47 mg·kg-1 with average of 0.18 mg·kg-1. On the whole, the selenium level belonged to medium, marginal or deficient, with no Se-poisoning. Among soil types, meadow soil had the highest Se content(0.23 mg·kg-1), while saline soil had the lowest Se content(0.13 mg·kg-1). Among soil parent materials, the highest content was recorded in diluvial deposit with an average Se content by 0.25 mg·kg-1, while lake deposit was the lowest with an average by 0.14 mg·kg-1. In terms of land use, paddy soil had the highest Se content(0.32 mg·kg-1). MgO, Corg, clay contents, TN, iron and manganese oxides were the main factors, which affected soil selenium content.
Phosphorus analysis and release risk of sediments in West Lake, Hangzhou, China
YAN Pan, XU Dong, LIU Zisen, HAN Fan, HE Feng, LIU Biyun, ZHANG Yi, WU Zhenbin
2019, 38(7): 1479-1487.   doi: 10.7524/j.issn.0254-6108.2018093002
Abstract PDF 2324KB
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The phosphorus (P) forms of sediments in three sub-lakes of West Lake, Hangzhou, China:Maojiabu, Xiaonanhu and Wuguitan were investigated, and the P release risk of the sediments was evaluated through the P sorption index (PSI) and degree of P saturation (DPS). The results showed that the sediment in West Lake mainly exists in the reduced state. The growth of submerged plants affected the redox potential of sediments, which was raised with the increase of submerged plants coverage, and the sediments oxidizability was increased. The concentration of P in the sediment was mainly related to the content of active iron-aluminum oxides. The adsorption index of P in different areas of West Lake is different, mainly related to the ecological adversity. We concluded that the release of P in sediments of the three sub-lakes in West Lake was at a moderate risk after considering the various related factors.
Effect of straw returning with different lengths on mercury methylation in paddy soil and methylmercury accumulation in rice plants
ZHANG Dingxi, SUN Tao, WANG Yongmin, LI Guangzhi, DONG Yudan, TANG Zhenya, YIN Deliang, WANG Dingyong
2019, 38(7): 1488-1496.   doi: 10.7524/j.issn.0254-6108.2018092501
Abstract PDF 1656KB
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To explore a reasonable straw returning pattern to alleviate the methylmercury (MeHg) exposure risk in paddy ecosystems, pot experiments were conducted in this study by adding rice straw with three different lengths (5 cm, 2 cm and pulverized rice straw) into paddy soil. The methylation of mercury (Hg) in soil and MeHg distribution in rice plants were investigated during the whole growing period of paddy. The results showed that rice straw returning could promote soil Hg methylation and increase the MeHg levels in rice. The length of straw for returning to field could influence the net MeHg production. The longer straw (5 cm) showed a prolonged promotion for Hg methylation in paddy soil, resulting in higher MeHg concentrations in soil at later growth stage and increased MeHg accumulation in rice. The pulverized rice straw could bring about a MeHg increase in soil in a shorter incubation time, however, MeHg concentrations in soil decreased at later growth stage, which further made a lower rice MeHg compared to other treatments with 5 cm and 2 cm straw. Therefore, it is clear from this study that straw smashing before returning to field could alleviate the methylmercury (MeHg) exposure risk of rice induced by straw returning.
Biosurfactants generated from Marine Microbe and Chelator assisted remediation of Cadmium and Copper contaminated Saline-alkaline Soil by Ficus concinna var.Subsessilis
BAO Genlian, DENG Huanhuan, LI Shaojun, MA Binbin, YE Sheng, GE Liyun
2019, 38(7): 1497-1506.   doi: 10.7524/j.issn.0254-6108.2018092705
Abstract PDF 1747KB
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The strengthening effects of surfactants produced by marine bacteria and yeast and chemical chelators on the removal of heavy metals Cd and Cu in saline-alkaline soil by Ficus concinna var.subsessilis were studied in pot experiments. The results showed when adding Cd and Cu, Ficus concinna var.subsessilis was able to grow well, and the heavy metal content in the plants increased with the increasing addition of the biosurfactant, and the heavy metal content in the root was higher than in the shoot. With the enhancement of 300 mg·kg-1 bacterial surfactant, the maximum content of Cd in the root was 313 mg·kg-1, whereas with 1 mmol·kg-1 CA-300 mg·kg-1 yeast surfactant addition, and the maximum content of Cu in the root was 2156 mg·kg-1. The accumulation of Cd and Cu in Ficus concinna var.subsessilis was significantly increased by the addition of the fortifier, and the absorption and enrichment capacity of Ficus concinna var.subsessilis to Cd and Cu in the soil of was remarkably increased. The maximum enrichment coefficient of Cd under the enhancement of 1 mmol·kg-1 CA-300 mg·kg-1 yeast surfactant was (9.76±0.10), which was 8.90 times as many as the control group S1 (1.1±0.02). The maximum enrichment coefficient of Cu under the single enhancement of 300 mg·kg-1 yeast surfactant was (7.42±0.16), which was 9.60 times as many as the control group S1 (0.77±0.03). It was weak for Ficus concinna var.subsessilis to transfer Cu from the shoot to the upper parts, and TF was below to1, which showed a limited extraction and repair potential of Ficus concinna var.subsessilis for Cu. The maximum repair rate of Cd with the combined enhancement of 300 mg·kg-1 bacterial surfactant was 2.56%, which was 4.70 times as many as in the blank reaction system "S1", and the maximum repair rate of Cu with the combined enhancement of 300 mg·kg-1 bacterial surfactant-1 mmol·kg-1 EDTA was 1.80%, which was 3.30 times as many as in the blank reaction system "S1". Then, the Ficus concinna var.subsessilis has a better potential to remove the heavy metal in saline-alkali soil, and the addition of biological surfactant and chemical chelator can effectively improve the absorption and enrichment efficiency of heavy metal Cd and Cu in Ficus concinna var.subsessilis.
Ultrasonic assisted ethylenebis(oxyethylenenitrilo)tetraacetic acid washing of heavy metal contaminated soil and assessment of environmental risk reduction
DAI Zhuqing, XIE Mingyang, WANG Minxing, DU Erdeng, ZHANG Wenyi
2019, 38(7): 1507-1517.   doi: 10.7524/j.issn.0254-6108.2018090601
Abstract PDF 1912KB
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The heavy metal contaminated soil was remediated by ultrasonic-assisted ethylenebis(oxyethylenenitrilo)tetraacetic acid (EGTA) washing. Results showed that ultrasonic-assisted EGTA washing had high reduction efficiency of copper (Cu) and cadmium (Cd), but had weaker washing capacity of zinc (Zn) or lead (Pb) in soil. Increasing liquid-solid ratio significantly improved the reduction rates of heavy metals, while increasing ultrasonic time and power revealed a relatively weak effect. After washing treatment, the leaching concentrations of Cu, Zn and Cd decreased, while that of Pb increased. An environmental risk index covering residual concentrations in soil, leaching concentrations and toxicity of heavy metals was constructed. The method was used to evaluate the effects of EGTA dosage, liquid-solid ratio, ultrasonic time and power on removal of each heavy metal and reduction rate of total environmental risk, and then the simulation and optimization of these effects were also conducted. The predicted value of the environmental risk reduction rate was 79.7%, and the measured value reached 78.0% with the condition of EGTA dosage 1.7 g·L-1, the liquid-solid ratio 10, ultrasonic time 40 min, and ultrasonic power 600 W. Under this condition, the concentration of residual Cu, the weak acid extractable Pb and the Zn in reducing fraction decreased significantly, the weak acid extractable Zn concentration increased significantly, and the residual Cd in all fractions decreased significantly. Overall, ultrasound-assisted EGTA washing can effectively reduce the environmental risks of Cu and Zn, but significantly increase the environmental risk of Pb. On the other hand, excessive EGTA dosage may also increase the environmental risk of Cd. Thus it is not suitable for the remediation of Pb contaminated soil. For Cd contaminated soil, it is also necessary to control the potential secondary pollution risk.
Effects of chemical oxidation remediation on concentration and composition of PAHs in agricultural soils and spinach
JIA Cunzhen, LIU Xiuchu, CHAI Chao, WANG Jifang, GE Wei
2019, 38(7): 1518-1527.   doi: 10.7524/j.issn.0254-6108.2018092803
Abstract PDF 2164KB
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Two oxidants, sodium persulfate and hydrogen peroxide were used to remove polycyclic aromatic hydrocarbons (PAHs) in combination with two activators, ferrous sulfate and nanoparticles of zerovalent iron, in the agricultural soils and spinach with pot experiments. Humic acid (HA) was also added. PAHs bound to endogenetic soil humus in soils and the effects of chemical oxidation remediation on the concentration and composition of solvent extractable PAHs in soils and spinach were investigated. The toxic equivalent concentrations of benzo(a)pyrene (BaPeq) in spinach were analyzed. The results showed that, after 7 weeks, hydrogen peroxide was better than sodium persulfate to remove solvent extractable PAHs in soils when the oxidants in soils was 0.2 g·kg-1; and nanoparticles of zerovalent iron was better than ferrous sulfate when the activators in soils was 0.448 g·kg-1. PAH concentration decreased and removal percentage increased in the presence of 2 g·kg-1 HA. The combined treatment of hydrogen peroxide, nanoparticles of zerovalent iron and HA showed the lowest concentration of the solvent extractable PAHs both soils and spinach, and the highest PAHs removal percentage in soils and reduction percentage in spinach. The removal percentage of solvent extractable PAHs was 36.8% in soils, and the reduction percentage of spinach in shoots and roots reached up to 36.8%, 45.3% and 36.4%, respectively. The relative removal percentage of 2-ring, 3-ring PAHs in soils and the relative reduction percentage of 2-ring, 3-ring PAHs in spinach were higher than that in 4-ring, 5-ring, 6-ring PAHs. The combined treatment of hydrogen peroxide, nanoparticles of zerovalent iron and HA showed the highest average removal percentage (44.5%) of PAHs bound to endogenetic soil humus. Chemical oxidation remediation did not have effect on the spinach biomass. The combined treatment of hydrogen peroxide, nanoparticles of zerovalent iron and HA showed the lowest toxic equivalent concentrations of BaPeq in spinach.
Pollution characteristics of PFOA and PFOS in typical wetlands of Shandong Province
SUN Jianshu, WANG Shiliang
2019, 38(7): 1528-1538.   doi: 10.7524/j.issn.0254-6108.2018081703
Abstract PDF 3552KB
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As the most typical persistent organic pollutants, PFOA and PFOS have been found in each environmental medium around the world. In order to investigate the levels and spatial distribution of PFOA and PFOS in the representative wetlands from Nansi Lake and the eastern coastal regions of Shandong province, the concentrations of the two pollutants in this study were measured and systematically analyzed with the ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) combined with the solid phase extraction and enrichment. The results show that both PFOA and PFOS were detected in all water samples and the concentrations of PFOA and PFOS ranged from 10.49 to 84.6 ng·L-1 and 0.49 to 25.4 ng·L-1, respectively. Moreover, the PFOA and PFOS levels in water samples showed an increasing trend from the downstream to upstream of the Nansi Lake, and the levels were higher than those of the coastal regions of Shandong province. The concentrations of PFOA and PFOS in sediment samples ranged from 0.09 to 2.76 ng·g-1 and 0.17 to 5.25 ng·g-1, respectively, and the spatial distribution weas similar to that of the water samples. Compared with the levels of PFOA and PFOS in water and sediments in other areas both in and out side of China, the pollution levels of the two pollutants in typical wetlands in Shandong Province are higher and the pollution of PFOA is more serious. Results of the partition coefficient (Kd) show that PFOS had higher Kd values, and the Kd varied among the different areas. We should pay more attention to PFOA and PFOS contamination because the results of risk assessment suggest certain risk of PFOA and PFOS to the local aquatic and wild birds.
Soil denitrification potential and its influence factors in different riparian zones
HAN Lei, ZHUANG Tao, YANG Xinming, YUAN Xuyin, HAN Nian, LI Jie
2019, 38(7): 1539-1547.   doi: 10.7524/j.issn.0254-6108.2018091704
Abstract PDF 1368KB
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Three medium and small watersheds located in the western part of Taihu River were selected as the research areas, where 3 typical riparian zone surface (0-20 cm) soils were collected between July 15 to 20, 2017 respectively. The soil physicochemical properties and denitrification potentials were mearsured, the differences and variation patterns of soil denitrification potentials in different riparian zones were discussed, and the main factors influencing soil denitrification potentials were determined. The results showed that there were significant differences in soil denitrification potential in each watershed, and the soil denitrification potential was 0.294±0.226 (μg N (N2O)·(g·h)-1), 0.542±0.327 (μg N (N2O)·(g·h)-1) and 0.821±0.494 (μg N (N2O)·(g·h)-1) in the Tianmuhu watershed, the Hexi watershed and the Tiaoxi watershed, respectively. Overall, it was shown that the higher the degree of urbanization, the greater the soil denitrification potential. In the same watershed, the soil denitrification potential of woodland was the highest, followed by the grassland and the bareland. The correlation analysis suggested that the soil denitrification potential was positively correlated with physical and chemical properties of soil (n=54, P<0.01), including soil moisture content, nitrate nitrogen concentration, organic matter content and microbial carbon contents. Meanwhile, combined with regression analysis, it was found that soil moisture, nitrate-nitrogen concentration, and microbial biomass carbon concentration were the dominant factors influencing the riparian soil denitrification potential in the Tiaoxi watershed. The soil denitrification potentials of the Hexi watershed and the Tianmuhu watershed were primarily related to soil organic matter and nitrate-nitrogen concentration, respectively. In conclusion, the potential of soil denitrification in the riparian zone was closely related to intensity of human activities, and the main influencing factors were also different among the three watersheds.
Functional metagenomics: One of the most robust tools for discovering new antibiotics resistance genes
HE Rong, YUAN Ke, LIN Li, YANG Ying, ZOU Shichun, LUAN Tiangang, CHEN Baowei
2019, 38(7): 1548-1556.   doi: 10.7524/j.issn.0254-6108.2018090702
Abstract PDF 3964KB
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Antibiotic resistance is one of the greatest challenges on the public health in the world. Currently, antibiotic resistance genes (ARGs) have been regarded as a group of emerging environmental contaminants. The main analytical approaches of ARGs include isolation and incubation of bacterial strains, PCR, and new generation high-throughput sequencing-based metagenomic methods. However, functional metagenomic approach is a robust tool to find the new ARGs that have never been identified. This approach combines the high throughput of new generation sequencing platforms with function identification of constructing gene libraries, which is able to efficiently seek the novel ARGs without any of prior knowledge about the function of them. In this paper, we reviewed research progress on the application of functional metagenomics in the discovery of novel ARGs and summarized the advantages and flaws of current technologies and methods related to functional metagenomics. In final, we provided the perspectives of the future improvement on functional metagenomics.
Research progress in pollution situation and environmental behavior of Sulfonamides
CHEN Shan, XU Fan, ZHANG Wei, TANG Wenqiao, WANG Liqing
2019, 38(7): 1557-1569.   doi: 10.7524/j.issn.0254-6108.2018091901
Abstract PDF 1489KB
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Antibiotics are widely used in pharmaceuticals industry, animal husbandry and aquaculture. However, excessive use of antibiotics can cause harm to the environment. Sulfonamides are a group of commonly used veterinary antibiotics, which have low cost and broad-spectrum antibacterial activity. And it can prevent animal diseases and promote the growth of animals. However, sulfonamides are poorly absorbed by animal body, and often excreted unchanged in faeces and urine, subsequently suffering a series of environmental behaviors and causing environmental pollution. This review introduced the classification, source and hazard of antibiotics, and elaborated on the pollution situation, environmental behavior and toxic effect of sulfonamides at domestic and foreign, in order to provide basic information for the subsequent treatment of antibiotic pollution.
Influencing factors and simulation of adsorption of two different antibiotics in sediments
HU Yuyu, SHEN Danlei, LUO Shuai, ZONG Chenlu, CHEN Jianqiu, CHENG Guanghuan, YU Ying
2019, 38(7): 1570-1581.   doi: 10.7524/j.issn.0254-6108.2018091603
Abstract PDF 14594KB
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Antibiotics are widely presented in the environment. Their migration and distribution in the aquatic environment are mainly affected by the adsorption behavior of sediments. In this paper, the effects of kaolin, black carbon, humic acid, pH and Ca2+ on the adsorption strength of two different antibiotics on sediments were investigated. Then the central composite design was used to investigate the composite effect. According to the experimental data, multi linear equations and BP neural network were used to fit and validate two antibiotic adsorption models. The adsorption models for two antibiotics were obtained by comparison fitting and verification results. The results showed that the effect of pH and Ca2+ on the adsorption capacity of the two antibiotics on the sediment were significant, while the effect of kaolin, black carbon and humic acid on the adsorption capacity of the two antibiotics on the sediment were less. The model simulation results showed that the degree and accuracy of the neural network model were better than the multi linear equation, and the cross validation results also indicate that the neural network model stimulate was better than the multi linear equation. Therefore, the neural network model was able to predict the adsorption behavior of antibiotics in sediments within the factors and concentrations examined reasonably.
Reduction of PCDD/Fs in TSP and PM10 during traffic restriction
SUN Junling, WANG Pengyan, ZHANG Qinghua
2019, 38(7): 1582-1589.   doi: 10.7524/j.issn.0254-6108.2018092701
Abstract PDF 4490KB
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Atmospheric particles (PM10, TSP) with different traffic conditions sampling were carried out simultaneously in Beijing with middle-volume active sampler at the east gate of China University of Geosciences (CUGB) to investigate the concentrations, congener profiles and estimate the effect of traffic restriction on variation trends of Polychlorinated dibenzo-p-dioxins (PCDDs) and Polychlorinated dibenzofurans (PCDFs), seventeen 2, 3, 7, 8-substitituted congeners of PCDD/Fs were determined using high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) based on US EPA 1613B method. The concentrations and I-TEQs of PCDD/Fs were respectively 2045 fg·m-3 (112.87 fg I-TEQ·m-3) (before traffic restriction), 484 fg·m-3 (19.67 fg I-TEQ·m-3) (during traffic restriction) and 1572pg·m-3 (81.06 fg I-TEQ·m-3) (after traffic restriction) for PM10, the concentrations and I-TEQs were 2117 fg·m-3 (120.85 fg I-TEQ·m-3) (before traffic restriction) and 550 fg·m-3 (25.26 fg I-TEQ·m-3) (during traffic restriction) for PCDD/Fs in TSP. The homologue profiles for PCDDs concentrations presented were obviously lower than those of PCDFs, which was classified as thermal source pollution profiles, both the PCDD and PCDF concentrations increased with the increasing levels of chlorination with the exception of OCDF, by contrasting the PM10 and TSP results, an apparent trend was found with higher PCDD/F concentrations in PM10, which accounted for 87%-97% of the total PCDD/F concentrations in TSP, with an average contribution of 92%. The levels of PCDD/Fs during traffic resteriction were significantly lower than that in normal traffic situation, which was attributed to the reduction of traffic flow as well as the increase of fleet speed during the Beijing Olympics. The results from present study provides further aid in evaluating the impact of vehicle as PCDD/Fs emission sources to ambient air, and further to assess the effectiveness of vehicle restriction measures in reducing atmospheric PCDD/Fs.
The temporal variation and photochemical characters of VOCs in summer and winter of Beijing based on PTR-TOF-MS
SHENG Jiujiang, WANG Fei, LI Xia, MA Zhiqiang, LIU Quan, ZHAO Delong, HUANG Mengyu, DING Deping
2019, 38(7): 1590-1599.   doi: 10.7524/j.issn.0254-6108.2018092601
Abstract PDF 11450KB
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To better learn the characters of the VOC variations in Beijing in different seasons, the high time resolution proton transfer reaction-time of flight-mass spectrometer (PTR-TOF-MS) was used to measure continuously the VOCs in Beijing during summer (June 8-20) and winter (from November 22 to December 10) of 2016. The mean values of the mixing ratios (concentration) of VOCs were (summer/winter,×10-9):formaldehyde (8.56/24.58), acetaldehyde (3.95/7.57), acetone (5.06/3.50), isoprene (0.66/0.52), benzene (0.53/1.78), toluene (1.03/2.54), C8-aromatics (1.34/3.42). Being impacted by the atmospheric dilution, the concentrations of the VOCs in summer and winter had similar variation trends. Only the time series of isoprene concentration had higher values in daytime than nighttime in summer, and this was related to the daytime higher vegetation emission. From the diurnal variation, the concentrations of all VOCs were at low level in the daytime, and increased evidently during the morning rush-hour in winter. In summer, the three oxygenated volatile organic compounds, formaldehyde, acetaldehyde and acetone had short time concentration peaks in the morning. This was due to the acceleration of the photochemical secondary formation. What can be known from the concentration ratios of VOC versus benzene are:the winter and summer were similar that the photochemical formation of three OVOCs (formaldehyde, acetaldehyde and acetone) and the photochemical consumption of toluene and C8-aromatics both increased around noon hours, although the extent of the increase in winter was obviously weaker than summer. In both summer and winter, the production rate of formaldehyde at noon was larger than acetaldehyde and acetone. The photochemical consumption rate of C8-aromatics was higher than toluene only shown in summer. In the daytime of winter, the vegetation emission enhance of isoprene did not appear, but the photochemical consumption increase was visible. In summer the VOCs were predominantly impacted by the vehicular emission, however the VOCs could also be emitted from the coal burning in winter.
Size distribution of PCDD/Fs, PCNs and PCBs and risk assessment of respiratory exposure in atmospheric particulate matter during a heavy pollution episode in Beijing
YANG Xinrui, HU Jicheng, WANG Ran, WU Jing, XU Chenyang, ZHANG Yu, WANG Ying, JIN Jun
2019, 38(7): 1600-1608.   doi: 10.7524/j.issn.0254-6108.2018092401
Abstract PDF 3982KB
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From May 4th to 7th, 2017, atmospheric particulate matter of 4 different sizes (>10 μm, 5-10 μm, 2.5-5 μm, <2.5 μm) were collected in Beijing during a heavy pollution episode and the clear episode sample was collected as contral. The concentrations of 17 species, 2,3,7,8-PCDD/Fs, tri-to octa-chlorinated naphthalene, and 12 dl-PCBs congeners in different particle size fractions were determined, and then size distribution and exposure risk of these compounds were analyzed and evaluated. The results showed that the concentrations of PCDD/Fs, PCNs and dl-PCBs in atmospheric particulate matter were 8.03, 6.68 and 1.18 pg·m-3 during the heavy pollution episode in urban area of Beijing, respectively, which were significantly higher than those in the clear episode. PCDD/Fs, PCNs and dl-PCBs were mainly found in fine particles with particle size <2.5 μm, accounting for 86.5%, 47.9% and 39.8% of the total concentrations, respectively. The proportion of high chlorinated PCNs and PCBs homologues in a fraction increased as the particle size decreased. According to the results of the risk assessment, the cancer risks of PCDD/Fs, PCNs and dl-PCBs in atmospheric particulate matter by inhalation were 1.1×10-5, 1.4×10-7 and 2.2×10-7, respectively. They were 33 times higher than that of the clear episode. The contribution rate of PCDD/Fs to total cancer risk was 96.7%, so PCDD/Fs should be controlled as a priority persistent organic pollutant.
Characteristics and health risk assessment of heavy metals in PM2.5 fraction of road dust in Nanchang City
LIU Xianrong, ZHENG Quan, HU Gongren, YU Ruilian
2019, 38(7): 1609-1618.   doi: 10.7524/j.issn.0254-6108.2018090505
Abstract PDF 6097KB
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In order to understand the characteristics and health risk of heavy metals in PM2.5 fraction of road dust in Nanchang city, PM2.5 samples were collected by a resuspension sampler, then concentrations of 11 heavy metals were detected by an inductively coupled plasma mass spectrometer and an atomic fluorescence spectrometer. The results showed that the average concentrations of Mn, Zn, Cr, Cu, Pb, V, As, Ni, Co, Cd and Hg in PM2.5 fraction of road dust were 1014, 208.17, 106.47, 102.40, 62.12, 39.59, 28.93, 24.07, 7.86, 0.58 and 0.53 mg·kg-1, respectively, which were higher than the background values of Nanchang soil except V and Co. The concentrations of heavy metals in secondary roads and branch roads were higher than those of the main road, and were lower than those of other cities. The results of geoaccumulation index revealed that Cd, Hg, Cu, Mn, and Zn were at moderate pollution level, As and Pb showed mild pollution, while the other elements presented no pollution. The average daily exposure dosage showed that Mn in children was the highest (ingestion:2.83×10-3 mg·(kg·d)-1, inhalation:2.50×10-7 mg·(kg·d)-1, dermal contact:6.87×10-6 mg·(kg·d)-1). Ingestion was the major exposure pathway for human health risk. The lifetime exposure dose of Cr was the highest (children:8.63×10-9 mg·(kg·d)-1, adults males:9.12×10-9 mg·(kg·d)-1, adult females:8.12×10-9 mg·(kg·d)-1). The studied heavy metals showed the highest non-carcinogenic risk to children with the non-carcinogenic risk value of 0.58, followed by adult females (0.19) and adult males (0.17), which were all less than the threshold value 1.0, and the major contribution elements were Mn, As and Cr. The five carcinogenic metals Cr, As, Co, Ni and Cd had no carcinogenic risk to human health via inhalable pathway with the risk values of less than the threshold value 10-6. The total carcinogenic risk of heavy metals to adult males (4.29×10-7) was slight higher than that to children (4.06×10-7) and adult females (3.82×10-7), and the major contribution elements were Cr and As.
Spatial distribution of total mercury in timberline forest of tibetan plateau regions and its implications of atmospheric mercury pollution
WU Fei, WANG Xun, LUO Ji, LI Qiuhua
2019, 38(7): 1619-1627.   doi: 10.7524/j.issn.0254-6108.2018092302
Abstract PDF 3677KB
Abstract:
Mercury (Hg) is a global atmospheric pollutant, and its source-sink relationships in remote regions is the hotpot currently. Due to the specific environment and inconvenience of on-line measurements, the characteristics of atmospheric Hg pollution in Tibetan Plateau (TP) still remains unclear. In this study, two series of sampling sets (Yunnan-Southeast TP, Sichuan-Southeast TP) were set to explore such atmospheric Hg pollution by using Hg concentration in litterfall and in surface soils. The results showed that Hg concentration in litterfall, foliage, bark and surface soils decreased with the monsoon direction into TP. Specifically, Hg concentration in litterfall ranged 60-70 ng·g-1 in the boundary regions of Yunnan-Tibet and Sichuan-Tibet, while ranged 20-30 ng·g-1 in Changdu. Based on the Hg emission inventory and the meteorological data, we suggested that further in back-land of TP, the local anthropogenic emission dramatically decreased, and Hg transportation by general atmospheric circulation also intensively decreased, leading to reduce of Hg concentration in vegetation and surface soil. Our study suggested that the litterfall Hg concentration from Abies at timberline of TP can be as the index to predict the atmospheric Hg concentration in remote regions, and verified that South Asia, Southeast Asia, Sichuan Basin and Yunnan-Guizhou Plateau were the potential regions for Hg pollution sources in TP.
Odour exposure-response relationship evaluation based on field measurement
YANG Weihua, LI Weifang, HAN Meng, ZHANG Yan, LI Jiayin, ZHAI Zengxiu
2019, 38(7): 1628-1635.   doi: 10.7524/j.issn.0254-6108.2018121003
Abstract PDF 5142KB
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In order to study the exposure-response relationship between community annoyance and odour exposure, cigarette factory was selected as the research object, using field measurement to assess odour exposure factor such as frequency, intensity and hedonic tone with trained observers. Additionally, the degree of annoyance, and the frequency of general health complaints were collected from the exposed residents through sociological questionnaire. Multiple logistic regression analysis was used to establish exposure-response associations with odour frequency as independent variables and annoyance as the dependent variable. The epidemiological research method was used to study the effects of odor hedonic tone (offensiveness of the odour perception) and odour intensity on population interference. The results showed that during the monitoring period, the frequency of odour emitted from the cigarette factory spreading to the surrounding residential areas was 2%-37% calculated by "odour hour", the odour intensity was in range of 2-2.8 using 6-level intensity scale, and the hedonic tone level was -1 (slightly unpleasant) to -2.1 (moderately unpleasant) according to 9-point hedonic scale. The percentage of highly annoyed population (HA,%) was found to have a quadratic polynomial relationship with the odour exposure frequency (frequency,%). If the HA is less than 10%,the odour frequency cannot exceed 7%. The exposure-response association was affected by odour intensity and hedonic tone, but the impact of hedonic tone is more significant (OR=3.3, 95%-CI=1.8-6.2). The HA is found to be higher when the odour is less pleasant. The results showed that the establishment of exposure-response association can determine a reasonable acceptable level of odour exposure and provide scientific basis for the development of odour impact assessment standards.
Biodegradation of chlorinated anthracene by Phanerochaete chrysosporium and its degradation pathway
MA Tao, YUAN Wenting, PENG Ying, GAO Zhanqi, SUN Cheng, HE Huan, YANG Shaogui, ZHANG Limin
2019, 38(7): 1636-1644.   doi: 10.7524/j.issn.0254-6108.2018091204
Abstract PDF 3954KB
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Chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs) are chlorinated derivatives of PAHs, but the toxicity of them is equivalent or even higher than that of parent PAHs, Cl-PAHs are widely present in the environments and difficult to be degraded, posing a potential threat to the ecological environment and human health. Microbial degradation has been suggested as one of the best ways to remove organic pollutants from polluted environments. In this study, the optimized degradation conditions, biodegradation ability, the degradation kinetics of chlorinated anthracene(Cl-Ant) as well as the possible degradation pathway were investigated by the model species-Phanerochaete chrysosporium, The results showed a good effect of degrading Cl-Ant under the initial liquid medium at pH 4.5, 1×105 cells·mL-1 Phanerochaete chrysosporium at 35℃, 120 r·min-1 incubation for 6 days,after then 100 mg·L-1 substrate inoculated. After 16 days' experiments, the degradation efficiency of 9-ClAnt and 9,10-Cl2Ant reached to 96.45% and 92.83%, respectively. The kinetic analysis of Cl-Ant degradation follows the rule of the first-order kinetic equation. Five types of intermediate products were detected from the degradation system. Combining with the characteristics of biocatalytic reaction, the possible degradation pathways of Cl-Ant were proposed in this research.
Effects of pre-deposition on removal of humic acid in the coagulation-ultrafiltration process
GAO Qian, ZHANG Chongmiao, XU Hui, WANG Dongsheng, MEN Bin, ZHANG Dawei, LUO Ke
2019, 38(7): 1645-1655.   doi: 10.7524/j.issn.0254-6108.2018091403
Abstract PDF 13629KB
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It is important to investigate effects of pre-deposition on removal of humic acid(HA) in the coagulation-ultrafiltration process. The flocs formed by AlCl3 and Al13 were pre-deposited on the surface of ultrafiltration membrane by natural sedimentation, and the removal of HA and the water purification process were investigated. The results showed that the flocs deposited on the surface of the membrane using Al13 coagulant could remove HA more efficiently and the membrane fouling could be alleviated, while the use of AlCl3 would enhance membrane fouling. As the Al13 coagulant dosage was increased from 0.08 mmol·L-1 to 0.18 mmol·L-1, the removal rate of HA was also increased from 26% to 34%. At a higher dosage of 0.18 mmol·L-1, the fractal dimension (2.45) of flocs formed by Al13 coagulant was larger than that of AlCl3 (2.29), but the floc size (300 nm) formed by Al13 was smaller than that of AlCl3(600 nm). Results of zeta potential showed that Al13 had larger amount of positive charges than AlCl3, and the flocs would adsorb HA molecules more easily.
Effect of oxidation degree of graphene oxide on photocatalytic activity of bismuth phosphate/graphene composite aerogel
TANG Shihui, YAO Wenqing, TAN Ruiqin
2019, 38(7): 1656-1665.   doi: 10.7524/j.issn.0254-6108.2019020205
Abstract PDF 21517KB
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Three-dimensional network bismuth phosphate/graphene aerogel (BiPO4/GA) could be used to achieve adsorption enrichment and in situ photocatalytic synergistic purification. The effects of graphene oxide on the morphology, structure, optical absorption and photocatalytic properties of the composites were investigated using SEM, FTIR, XRD and DRS characterizations. The graphene oxide with higher oxidation degree turned to brown and could easily form aerogel with BiPO4, while the color of graphene oxide with lower oxidation degree was dark and could hardly keep an aerogel shape. The degradation rate of phenol and methylene blue (MB) by BiPO4/GA composite material with high oxidation degree was about 1.88 and 2.34 times of that with low oxidation degree BiPO4/GA, respectively. The results demonstrated that the photocatalytic activity of BiPO4/GA aerogel could greatly be enhanced by increasing the oxidation degree of graphene oxide. The photocatalytic mechanism was due to the adsorption of organic pollutants on the surface of BiPO4/GA aerogel. The photogenic electrons were transferred from BiPO4 to the graphene layer, and effective oxidative degradation of organic compounds was carried out through the holes and superoxide radical (·O2-) generated on the catalyst.
Microbial electrolysis cell (MEC): A new platform for CO2 bioelectromethanogenesis assisted by bioelectrocatalysis
ZHENG Shaojuan, LU Xueqin, ZHANG Zhongyi, ZHEN Guangyin, ZHAO Youcai
2019, 38(7): 1666-1674.   doi: 10.7524/j.issn.0254-6108.2018091502
Abstract PDF 5210KB
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Microbial electrolysis cell (MEC) has great potential in the removal of pollutants, CO2 capture and carbon conversion and the biosynthesis of renewable energy, which can simultaneously alleviate energy crisis and the greenhouse effect. Although significant progress has been made in the working principles, process design/optimization and electron transfer mechanism exploration, the development of MEC from the proof of concept to real applications still faces many technical issues and challenges. This paper introduced the basic theory and latest research progress of MEC in CO2 electromethanogenesis, and specifically the behavior of electroactive bacteria colonizing on the biocathode, extracellular electron transport mechanisms, and membrane fouling were reviewed. Finally, future needs and perspectives of MEC technology in practical engineering applications were described as well.
Degradation of residual medicament of mineral processing wastewater by VUV/O3
ZHANG Dachao, WU Meng, CHEN Min, DENG Xiaoyu, WANG Chunying
2019, 38(7): 1675-1681.   doi: 10.7524/j.issn.0254-6108.2018091305
Abstract PDF 1497KB
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In this paper, the degradation of pine oil by VUV/O3 (vacuum ultraviolet, VUV, vacuum ultraviolet) was studied. The influence of the initial pH value, O3 concentration, initial concentration of pollutants, reaction time and coexisting ions on VUV/O3 degradation of pine oil was investigated, and the optimum experimental conditions were obtained.The experiments showed that VUV/O3 has the best degradation effect on pine oil with the degradation rate of 99.99% under the conditions of VUV light source was 15W, O3 concentration was 6 g·h-1, initial pH 8, and the reaction time was 15 min. Six kinds of coexisting ions, such as SiO32-, CO32-, Cl-, SO42-, Na+ and Ca2+, inhibited the effect of VUV/O3 on the removal of pine oil. The order of effect was CO32- > Ca2+ > SiO32- > SO42- > Cl-(Na+). In the process of VUV/O3 degradation of pine oil, the degradation rate of TOC reached a balance of 70.88% in the solution and of the pine oil was 99.14% after the reaction time of 20 min. The activity mechanism of the degradation process was analyzed by adding t-BuOH inhibitors. It was considered that ·OH played a major role in the process of VUV/O3 degradation of pine oil.
Preparation of ZIF-8@PS hollow microspheres by Pickering emulsion and adsorption performance on amoxicillin
YU Peilin, OU Hongxiang, ZHENG Xudong, ZHANG Jialu, DING Jianning, PAN Jianming
2019, 38(7): 1682-1690.   doi: 10.7524/j.issn.0254-6108.2018090603
Abstract PDF 9674KB
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In this paper, The ZIF-8@polystyrene (ZIF-8@PS) hollow microspheres were prepared by Pickering emulsion polymerization with zeolitic imidazolate framework-8 (ZIF-8) as stabilizer for oil-in-water emulsion, and were used for the adsorption removal of amoxicillin (AMOX) from aqueous solution. The physicochemical properties of ZIF-8@PS hollow microspheres were investigated by methods such as Fourier transform infrared spectroscopy, X-ray diffraction analysis, scanning electron microscopy, and Nitrogen adsorption-desorption. A series of static adsorption experiments and different adsorption isotherm models and kinetic models were used to analyze the AMOX adsorption performance on ZIF-8@PS. The results indicated that ZIF-8@PS possessed a good hollow porous structure, with a specific surface area of 380.4 m2·g-1. The best adsorption performance was obtained at pH 7.0 and 308 K. The AMOX adsorption on ZIF-8@PS could be better described by Langmuir model and the presudo-first-order kinetic model. The adsorption process tended to be monolayer adsorption. At 308 K, the maximum adsorption capacity calculated by Langmuir model reached 0.6232 mmol·g-1. ZIF-8@PS also exhibited excellent regeneration capacity with approximately 11.15% loss after three adsorption-desorption cycles.
Analysis of false positive results of HT-2 toxin in Pu-erhTea
LI Wenting, LI Jie, SHEN Ying, FAN Zhongji, MEI Jindan, OU Lihua
2019, 38(7): 1691-1693.  
Abstract PDF 1363KB
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Samples were extracted by organic solvent (methanol-water-formic acid 70:29:1 solution), purified by PriboFast RMulti-Toxin IAC immunoaffinity purification column, determined and analyzed by multi-reaction monitoring of ultra-high performance liquid chromatography tandem mass spectrometry, and quantified by internal standard method, through standard addition recovery experiment, quality control of known samples to verify the comparison. The regression equation of HT-2 toxin has a good linear relationship with a correlation coefficient of 0.9995. The recovery rates at three different levels are 85.3%-92.6%, and the relative standard deviations are 4.24% -5.61%. Among the 174 Yunnan Pu-erh teas, the detection results by the immunoaffinity column purification treatment were not detected, and 52 samples were confirmed as false positive samples by the multi-function purification and purification treatment, with a false positive rate of 29.8%, with the content ranged of 0.52-14.27 μg·kg-1.
Screening and analysis of odorous substances in drinking water by odor analysis system
TIAN Feifei, SUN Huizhong, YU Shuang, TANG Bochong, ZHANG Xi
2019, 38(7): 1694-1697.  
Abstract PDF 7158KB
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In this paper, the method for analysis of 150 odor substances in drinking water were established by using the Shimadzu GCMS-TQ8040 gas chromatography-tandem triple quadrupole mass spectrometry and AOC-6000 multifunctional automatic sampling device combined with odor substances database of Off-flavor Smart Database. Normal and abnormal water samples were analyzed separately and the results were compared. Eight candidate components causing odor were identified. Semi-quantitative analysis was carried out using standard curve generated in the database. The estimated concentration was compared with odor threshold. Finally, six odor components were found. The method is simple, convenient, fast and suitable for the screening of odorous substances in drinking water.