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Feng L.,Chongqing University | Li G.,Chongqing University of Technology | Zhang S.,Chongqing Academy of Environmental Science | Zhang Y.X.,Chongqing University
Ceramics International | Year: 2017

Here we describe the production of carbon cloth coated with MnO2 nanosheets or MnOOH nanorods through a normal temperature reaction or a hydrothermal approach, respectively. Of note, the electrochemical performance of MnO2-coated carbon cloth was better (429.2Fg-1) than that of MnOOH-coated carbon cloth. When the MnO2-coated carbon cloth is introduced as the positive electrode and the Fe2O3-coated carbon cloth as the negative electrode, a flexible asymmetric supercapacitor was obtained with an energy density of 22.8Whkg-1 and a power density of 159.4Wkg-1. Therefore, such a hierarchical MnO2-coated carbon cloth nanocomposite is a promising high-performance electrode for flexible supercapacitors. © 2017.

Zhang Q.,Chongqing Municipal Environmental Monitoring Center | Li Q.,Chongqing Academy of Environmental science | Tang J.,Chongqing University
Advanced Materials Research | Year: 2014

The flow field in anaerobic reactor is very complex, but it has been given wide attention because of its important impact to wastewater treatment effect. It is often studied by numerical simulation. The paper explored the research progress of simulation on the flow field in anaerobic reactor by the summary of development of anaerobic reactor and principle and characteristics of computational fluid dynamics simulation and introduction of study and application status on numerical simulation. And then it gave its opinion on the development of simulation on the flow field in anaerobic reactor in future. © (2014) Trans Tech Publications, Switzerland.

Lei B.,Chongqing Academy of Environmental Science | Zhang L.,Lanzhou University | Xia T.-T.,Chongqing Academy of Environmental Science | Xia T.-T.,Southwest University | And 2 more authors.
Beijing Gongye Daxue Xuebao/Journal of Beijing University of Technology | Year: 2011

Concerning around the universal features existed in new village construction of Chongqing, and based on Analytic Hierarchy Process (AHP) and experts' advice method, appropriate evaluation indexes are selected to build a comprehensive evaluation index system of new village environmental quality from the six aspects (criterion layer) which include economic development, pollution control, resource utilization, living environment, ecology protection, social environment. The evaluation system can provide the basis for eco-environmental protection in new village.

Chen L.,South China Institute of Environmental Sciences | Xu Z.,South China Institute of Environmental Sciences | Ding X.,South China Institute of Environmental Sciences | Ding X.,Chongqing Academy of Environmental Science | And 8 more authors.
Chemosphere | Year: 2012

Total mercury (THg) and methylmercury (MeHg) were measured in large number of soil samples collected from areas with different types of land use, different depth in the Pearl River Delta (PRD) of South China. THg and MeHg concentrations ranged from 16.7 to 3320ngg -1 and 0.01 to 1.34ngg -1, respectively. THg levels are highest in the top 0-20cm soil layer, and decrease from the surface to bottom layer soil. Spatial variation was observed with different types of land use. Urban parks had the highest concentrations and the other areas tended to decrease in the order of residential areas, industrial areas, vegetable fields, cereal fields, and woodlands. Temporal variation was also noted, and two relatively high THg contamination zones located in the northwestern part of the PRD have significantly expanded over the last two decades. Both THg and MeHg concentrations were correlated significantly with soil organic matter (OM), but not with soil pH. THg pollution status was evaluated using two assessment methods. © 2012 Elsevier Ltd.

Tang W.,CAS Research Center for Eco Environmental Sciences | Ao L.,Chongqing Academy of Environmental Science | Zhang H.,CAS Research Center for Eco Environmental Sciences | Shan B.,CAS Research Center for Eco Environmental Sciences
Environmental Earth Sciences | Year: 2014

The enrichment characteristics and risk of heavy metals were studied in the sediments of Liucha River in Chao Lake Valley, where agricultural intensification has developed rapidly since the 1980s. The results revealed that Cd, Pb and Zn showed the lowest levels in the upper reaches and peak values in the lower reaches, increasing from 0.064, 7.75 and 59.75 mg/kg to 0.176, 12.33 and 96.82 mg/kg on average, respectively. Enrichment factor (EF) analysis showed that the EF values of Cd, Pb and Zn (maximum 4.76, 2.51 and 2.74, respectively) all increased from the upper reaches to the lower reaches (>1.5), while correlation analysis and cluster analysis showed that they primarily originated from the extensive use of phosphate fertilizer. In addition, the comprehensive potential ecological risk due to Cd, Cr, Cu, Ni, Pb and Zn in the sediments showed low degree, but Cd showed moderate and high risk at some sites. Therefore, heavy metal pollution due to agricultural intensification in the agricultural regions of Chao Lake Valley should be given great attention during management of the water environment. © 2013 Springer-Verlag Berlin Heidelberg.

Zhang H.,CAS Research Center for Eco Environmental Sciences | Shan B.,CAS Research Center for Eco Environmental Sciences | Ao L.,Chongqing Academy of Environmental science | Tang W.,CAS Research Center for Eco Environmental Sciences | Wen S.,CAS Research Center for Eco Environmental Sciences
Environmental Earth Sciences | Year: 2014

A complete record derived from a core dated both by 210Pb and 137Cs chronologies from Lake Ngoring at the headwater areas of the Yellow River provides new insight into the changing atmospheric deposition of trace metals including Cd, Cr, Cu, Ni, Pb, and Zn. This study showed that there was an inflection in the early 1960s, before which both fluxes and contents of Cd, Ni, Pb, and Zn remained relatively steady or slowly increased, and thereafter continued increases both in fluxes and contents were found. Taking Pb as an example, the flux increased from 0.13 (before 1960) to 0.25 mg m-2 a-1 (averaged 1963-2006). According to atmospheric flux calculations using Al as a reference element, atmospheric fluxes of trace metals generally showed a rapid increase and peaked in recent years, closely following the historical economic development of the neighboring region, mainly for Qinghai and Gansu provinces. The atmospheric inventory for Zn was the highest, reaching 1.068 g m-2, while the lowest was for Cd, at only 0.079 gm-2. The percentage proportions of atmospheric deposition for Cd, Ni, and Zn were 37, 12, and 8.7 %, respectively. Hence, the atmospheric contribution to the trace metal content via long range transport is not negligible when considering input of materials to lake ecosystems. © 2013 Springer-Verlag Berlin Heidelberg.

Deng H.,Chongqing University | Chen G.,Chongqing Academy of Environmental science
Chinese Journal of Geochemistry | Year: 2014

Chromium pollution were investigated by sampling the abandoned chromium contaminated sites in Chongqing. Its health risk was assessed following the procedures made by USEPA. The results showed that the most seriously polluted land was found at the former production area (G4) with average Cr(VI) concentration of 3369.2 mg°kg−1 on the surface soil. The assessment indicated that there was high risk of non-carcinogens for children. The assessed risk of the first layer of office area (G1) for children, chromium slag transition (G2), drainage pipeline chromium slag transition (G3) and production area (G4) for both children and adults were not acceptable (>1.00×10−6). It was strongly suggested that the accessible measures of remediation should be taken for a portion of contaminated sites before the reuse of abandoned lands. © 2014, Science Press, Institute of Geochemistry, CAS and Springer-Verlag Berlin Heidelberg.

PubMed | Chongqing Environmental Monitoring Center and Chongqing Academy of Environmental Science
Type: Journal Article | Journal: Environmental science and pollution research international | Year: 2015

To assess the heavy metal pollution in Changshou Lake, sediments were collected from nine sites at three periods (dry, normal, and wet) in 2013. The Hg, As, Cr, Cd, Pb, Cu, and Zn levels were then determined. The index of geoaccumulation (I geo) and the sediment pollution index (SPI) were applied to the sediment assessment, and Pearsons correlation analysis and factor analysis (FA) were performed to identify common pollution sources in the basin. The results showed that heavy metals presented significant spatial variations with Cr, Cd, Pb, Cu, Zn, Hg, and As concentrations of 29.66~42.58, 0.62~0.91, 24.91~37.96, 21.18~74.91, 41.65~86.86, 0.079~0.152, and 20.17~36.88 mg kg(-1), respectively, and no obvious variations were found among the different periods. The average contents of the metals followed the order Zn>Cu>Cr>Pb>As>Cd>Hg, which showed a high pollution in the sediments collected from open water and at the river mouth. The assessment results indicated that toxic heavy metals presented obvious pollution with I Hg of 0.64~1.36 (moderately polluted), I Cd of 1.66~2.22 (moderately to heavily polluted), and I As of 1.21~2.07 (moderately to heavily polluted). The heavy metal pollution states followed the order Cd>As>Hg>Cu>Pb>Zn>Cr, and the SPI showed that the sediment collected from open water area was more polluted than those obtained from the tributaries and the river mouth. Cr, Cd, Hg, Pb, Cu, As, and Zn were mainly attributed to sediment weathering with Hg, Pb, and Cu and partially due to domestic sewage from the upper reaches. These results indicate that the more attention should be paid to the inner loads of sediment in order to achieve improvements in reservoir water quality after the control of external pollution.

Wang Y.-C.,Chongqing Academy of Environmental Science | Lei B.,Chongqing Academy of Environmental Science | Yang S.-M.,Chongqing Academy of Environmental Science | Zhang S.,Chongqing Academy of Environmental Science
Huanjing Kexue/Environmental Science | Year: 2012

To investigate the effect of 175 m trial impounding (2008 and 2009) of the Three Gorges Reservoir on soil heavy metals, three draw-down areas with similar geological environment and history of land-use in Zhongxian County were chosen. Altogether 36 surface soil samples (including 0-10 cm and 10-20 cm soil layer) from water-level altitude of 160 m and 170 m were obtained, and their heavy metals concentrations (As, Cd, Cr, Cu, Ni, Pb and Zn) were measured by the X-ray fluorescence spectrometric method. Geoaccumulation index (Igeo) and Håkanson potential ecological risk index were applied to assess the heavy metals pollution status and potential ecological risk, respectively. Results indicated that although the inundation period of 160 m was 224 d longer than that of 170 m, significant difference in concentrations of heavy metals were not found between the two water-level altitudes. Except for Cd, most of the heavy metals highly related with each other positively. According to the geoaccumulation index, the pollution extent of the heavy metals followed the order: As>Cd>Cu>Ni>Zn=Pb>Cr. The Igeo value of As, Cd and Cu were 0.45, 0.39 and 0.06, respectively, indicating that the soil was only lightly polluted by these heavy metals. Håkanson single potential ecological risk index followed the order: Cd>As>Cu>Pb>Ni>Cr>Zn. Cd with Ei values of 59.10, had a medium potential for ecological risk, while As, Cr, Cu, Pb, Ni and Zn only had a light potential. Consequently, although As, Cd and Cu were the major heavy metals with potential ecological risk for surface soil pollution in the draw-down areas in Zhongxian County, the Three Gorges Reservoir.

Ao L.,Chongqing Academy of Environmental Science | Lei B.,Chongqing Academy of Environmental Science | Wang Y.-C.,Chongqing Academy of Environmental Science | Zhou X.,Chongqing Academy of Environmental Science | Zhang S.,Chongqing Academy of Environmental Science
Huanjing Kexue/Environmental Science | Year: 2014

Typical country WLFZ in Zhongxian located in the core region of the Three Gorges Reservoir was chosen as research subject in this study. In July 2012, sediment samples of WLFZ were collected after dam water level dropped. Heavy metals were analyzed for sediment potential risk assessment and then applied for sources analysis in this area, which supplied basic data for non-point pollutants control. The results showed that As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn ranged in 155-160 m: 5.17-14.81, 0.06-0.57, 8.55-20.56, 62.79-93.04, 15.38-60.97, 425.72-782.32, 21.34-48.5, 23.03-43.39 and 57.78-130.10 mg·kg-1, and 170-175 m: 7.05-12.57, 0.17-0.33, 10.71-18.89, 65.22-92.89, 18.89-42.91, 74.06-774.41, 22.47-42.49, 24.17-29.23, 55.67-103.18 mg·kg-1, respectively. Index of geo-accumulation (Igeo) suggested the accumulation orders were Cd>Co>Mn>As>Cu>Pb>Zn in 155-160m WLFZ and Co>Mn>Cd>As in 170-175 m WLFZ. Sediment pollution index (SPI) showed that sediments in 155-160 m WLFZ had higher potential risk than that of 170-175 m with the highest risk appeared in 155-166 m WLFZ site located downstream of Zhongxian. In 155-160 m WLFZ, Cr, Cu, Pb and Zn were mainly originated from natural resources, while As, Ni, Cd, Co and Mn were possibly sourced from upland water. In contrast, in 170-175 m WLFZ, Cr, Ni, Pb and Zn in the sediment came from natural resources, while Cd, As, Co, Mn and Cu were probably rooted from both agricultural non-point source and upland water.

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