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Cao L.,Sun Yat Sen University | Cao L.,South China Sea Marine Engineering and Environment Institute | Wang J.,Sun Yat Sen University | Huang C.,South China Sea Marine Environment Monitoring Center | And 4 more authors.
Jilin Daxue Xuebao (Diqiu Kexue Ban)/Journal of Jilin University (Earth Science Edition) | Year: 2014

The ecological risk assessment of trace heavy metals in Daya Bay is investigated based on the surficial sediments collected in 2011. The analyzed trace heavy metals include Cr, Ni, Cu, Pb, Zn, Cd, and As. The modified BCR method was used to identify the chemical forms and the potential sources. Results show that the content of trace heavy metals is distributed as bends, with high content in Dapeng, Yaling and Fanhe Bay, descend from the shore to bay by varying degrees. The BCR sequential extraction identifies the speciation of the main trace metals. Cr, Ni, Cu, Zn, As are present in the residual form, Pb is present in reducible form and Cd is present in acid-soluble form. The ratio of heavy metals in non-residual form with descending order is Pb(78.83%), Cd(78.65%), Cu(48.54%), Zn(48.10%), Ni(38.31%), Cr(28.43%), and As(27.76%). The ratio of Pb content is the highest, meaning the highest mobility of Pb. The source analysis shows the pollutants are mainly from natural weathering and secondly from industrial wastewater and aquaculture wastewater. The risk assessment of the seven trace heavy metals shows Cr, Ni, Cu, Pb, Zn, As are at low pollution level, but the Cd is at the highest pollution level. ©, 2014, Jilin University Press. All right reserved.

Yang J.,South China Sea Marine Environment Monitoring Center | Yang J.,Sun Yat Sen University | Zhang B.,South China Sea Marine Environment Monitoring Center | Peng X.,South China Sea Marine Environment Monitoring Center | And 4 more authors.
Open Chemical Engineering Journal | Year: 2014

This study concerns the distribution and potential sources of elevated heavy metal concentrations (Cu, Zn, Pb, Cd, As) in surface sediments of the Dongzhai Harbor, Hainan Island, a national important mangrove ecosystem protection area.It was found that the pollution of As may occur occasional biological effect by numerical Sediment Quality Guidelines. Further, Geoaccumulation indices (Igeo) suggest there are serious pollution levels of As at all five stations. Spatial distribution of ecotoxicological index and pollution load index suggested that most of the surface sediments have a 9% probability of being toxic and the potential ecological risk zone appear in northern and southern of Dongzhai Harbor. Correlation analysis, principal component analysis, and cluster analysis showed that these metals primarily originate from natural sources. As and Pb resulted primarily from aquaculture, and combustion of gasoline and diesel fuel by ships. The present study provides a baseline record of heavy metals in mangrove surface sediments on the Dongzhai Harbor, and provide a useful aid for sustainable marine management in this region. © Lu et al.; Licensee Bentham Open.

Cao L.L.,South China Sea Marine Engineering and Environment Institute | Yang J.,South China Sea Marine Environment Monitoring Center | Wang P.,South China Sea Marine Engineering and Environment Institute | Wang L.,South China Sea Marine Environment Monitoring Center | And 3 more authors.
Kemija u industriji/Journal of Chemists and Chemical Engineers | Year: 2015

The metal profiles in sediments of the Daya Bay (DYB) in China were established using sequential extraction protocols proposed by the European Community Bureau of Reference (BCR). The surface sediment samples from 23 representative stations were collected in 2011 and were analysed to evaluate the mobility and bioavailability of a suite of potentially toxic metals (Cr, Cu, Ni, Zn, Pb and Cd) and metalloid (As). The obtained ranking order of migration and transformation, and the degree of pollution was Pb > Cd > Cu > Zn > Ni > Cr > As. Among these elements, Pb is considered to pose a serious threat to human health and ecological environment due to its significant percentage in non-residual form. The ratios of secondary and primary phases showed that studied sediments are moderately to heavily polluted with Cu and Zn, and Cd and Pb respectively. The levels of association between the variables (metal-metalloid) at each step of sequential extractions were evaluated with multivariate statistical analysis, including correlation analysis and principal components analysis. With these analyses, the possible sources of potential pollution were deduced. The correlation analysis revealed that Total Organic Carbon content is the most important influencing factor affecting the distribution of potentially toxic elements in Daya Bay. The principal components analysis (PCA) suggested that the studied elements in DYB area originate primarily from natural weathering and secondly from industrial wastewater and aquaculture waste water. © 2015, Croatian Society of Chemical Engineers. All rights reserved.

Cao L.,Guangzhou University | Cao L.,South China Sea Marine Engineering and Environment Institute | Huang C.,South China Sea Marine Environment Monitoring Center | Wang J.,Guangzhou University | And 5 more authors.
Journal of Residuals Science and Technology | Year: 2014

Selected metals (Cr, Ni, Cu, Pb, Zn, Cd and As) in surface sediments from the Pearl River Estuary (PRE) and Daya Bay (DYB) were analyzed to observe their total concentrations and chemical phase portioning. It was shown that the amounts of all contents, except Pb, have decreased over the past decade. The mean concentrations in PRE, excluding Pb, were significantly higher than those in DYB. Based on the PLI and mERM-Q, it was revealed that the highest potential ecological risk zones were in the northwest of PRE and sub-basins of DYB. An overwhelming majority of sediments had a 21% probability of toxicity in PRE and 9% probability of toxicity in DYB. The speciation analyzed by the optimized BCR sequential extraction method showed that, in both areas, Cr, As and Ni were present dominantly in the residual fraction and thus of low bioavailability, while Cd and Pb were found to be abundant in the non-residual fraction and thus of high potential availability, indicating significant anthropogenic sources. The partitioning of Cu and Zn showed a significant difference between the two areas. The source analysis shows that the pollutants resulted primarily from anthropogenic material, and secondly from the input of natural weathering products in PRE, while being mainly attributed to natural geological sources of metals, followed by industrial wastewater and aquaculture activity in DYB. © 2014 DEStech Publications, Inc.

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