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Optimal Sample Preservation and Analysis of Cr(VI) in Drinking Water Samples by High Resolution Ion Chromatography Followed by Post Column Reaction and UV/Vis Detection

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Journal of Analytical Sciences, Methods and Instrumentation 2012年第2期2卷 74-80页

作者： Prince Ezebuiro Jay Gandhi Chunlong Zhang Johnson Mathew Melvin Ritter Marvelyn Humphrey Metrohm usA Inc. Riverview Florida USA 3U.S. epa region 6 laboratory Houston USA U.S. epa region 6 laboratory Houston USA University of houston-Clear Lake Houston USA 2Metrohm usA Inc. Riverview Florida USA University of houston-Clear Lake Houston USA 2Metrohm usA Inc. Riverview Florida USA 3U.S. epa region 6 laboratory Houston USA

A recent study by the Environmental Working Group reported the detection of hexavalent chromium (Cr(VI)) in tap water at 31 out of 35 states investigated in the United States. Even though Cr(III) is an essential element for human diet, Cr(VI) is a potential carcinogen. Previous work has clearly identified a linear trend of increasing risk of lung cancer mortality with increasing cumulative exposure to water soluble Cr(VI). Regardless, Cr(VI) is still not regulated or monitored in drinking water in the U.S. There is an existing method (epa 218.6) for the analysis of Cr(VI), however, this analytical method does not addresses detailed sample preservation techniques and optimization process to achieve lowest detection limit possible. In this study, five buffer solutions with pH of 9 and above were compared to determine the most suitable buffer to preserve Cr(VI) in drinking water samples for an extended period of time. Results showed that the five buffers responded very differently to Cr(VI)-fortified drinking water. The best preserving reagent was found to be Ammonium Hydroxide + Ammonium Sulfate (pH 9.2) and Sodium Carbonate + Sodium Bicarbonate+ Ammonium Sulfate (pH 9.7), whereas a buffer solution with Sodium Hydroxide + Sodium Carbonate (pH 11.5+) resulted in a poor chromatographic resolution. A controlled study with a fortified Cr(III) at 1 ppb was also conducted to ensure no false positive detection of Cr(VI) due to the potential oxidation of Cr(III) during sample storage. The optimal preserving reagent identified from this study was compatible with the existing epa method 218.6 using ion chroma-tography followed by post column reaction, with a method quantitation limit of 0.020 ppb and matrix spike recovery of ± 10%.

关键词： Hexavalent Chromium Ion Chromatography usepa Method Sample Preservation

Source attribution for mercury deposition with an updated atmospheric mercury emission inventory in the Pearl River Delta region, China

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Frontiers of Environmental Science & Engineering 2019年第1期13卷 39-52页

作者： Jiajun Liu Long Wang Yun Zhu Che-Jen Lin Carey Jang Shuxiao Wang Jia Xing Bin Yu Hui Xu Yuzhou Pan Guangdong Provincial Key laboratory of Atmospheric Environment and Pollution Control College of Environment and Energy South ChinaUniversity of Technology Guangzhou Higher Education Mega Center Guangzhou 510006 China Department of Civil and Environmental Engineering Lamar University Beaumont TX 77710 USA us epa Office of Air Quality Planning & Standards Res Triangle Park NC 27711 USA State Key Joint laboratory of Environment Simulation and Pollution Control School of Environment. Tsinghua University Beijing 100084 China Guangzhou Environmental Monitoring Centre Guangzhou 510030 China

We used CMAQ-Hg to simulate mercury pollution and identify main sources in the Pearl River Delta (PR.D) with updated local emission inventory and latest regional and global emissions. The total anthropogenic mercury emissions in the PRD for 2014 were 11,939.6 kg. Power plants and industrial boilers were dominant sectors, responsible for 29.4 and 22.7%. We first compared model predictions and observations and the results showed a good performance. Then five scenarios with power plants (PP), municipal solid waste incineration (MSWI), industrial point sources (IP), natural sources (NAT), and boundary conditions (BCs) zeroed out separately were simulated and compared with the base case. BCs was responsible for over 30% of annual average mercury concentration and total deposition while NAT contributed around 15%. Among the anthropogenic sources, IP (22.9%) was dominant with a contribution over 20.0% and PP (18.9%) and MSWI (11.2%) ranked second and third. Results also showed that power plants were the most important emission sources in the central PRD, where the ultra-low emission for thermal power units need to be strengthened. In the northern and western PRD, cement and metal productions were priorities for mercury control. The fast growth of municipal solid waste incineration were also a key factor in the core areas. In addition, a coordinated regional mercury emission control was important for effectively controlling pollution. In the future, mercury emissions will decrease as control measures are strengthened, more attention should be paid to mercury deposition around the large point sources as high levels of pollution are observed.

关键词： Emission inventory Mercury deposition Pearl River Delta (PRD) Source attribution Control strategy

Heavy metals pollution in water,suspended matter and surface sediment in typical mountainous urban river:A case study in Qingshui Stream in Chongqing,China

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Journal of Central South University 2009年第S1期16卷 286-291页

作者：何太蓉李百战李贤良刘存东 Key laboratory of Three Gorges Reservoir region's Eco-Environment Ministry of EducationChongqing University School of Geography Science Chongqing Normal University Physical-chemical Lab Chongqing Entry-Exit Inspection and Quarantine Bureau

Based on a detailed environmental investigation of the whole Qingshui Stream catchments,samples of water and surface sediments were collected at 15 different places from the upper to the lower reaches of Qingshui Stream,and samples of suspended matter were obtained by filtrating the water samples. The concentrations of heavy metals (Cd,Cu and Zn) were measured in filtered water,suspended matter,and surface sediment by ICP-AES. The results show that the concentrations of the three heavy metals in filtered water are 0.18,6.6 and 17.67 μg/L,lower than that of the Fresh Water Quality Criteria (us epa) and those of the plain urban rivers,but the contents of Cd,Cu and Zn are much higher than the mean values of rivers in the world and the background value in Jialing River basin. The heavy metals concentrations in the suspended matter from Qingshui Stream are 2.08,438.14 and 1 348.05 mg/kg,much higher than the corresponding background values of soils in Chongqing city. The heavy metals concentrations in the surface sediment from Qingshui Stream are 0.84,189.75 and 838.23 mg/kg,and the values of index of geoaccumulation Igeo of Cd,Cu and Zn show that their pollution degrees are moderate. The heavy metals exist in three transferable forms such as water,suspended matter and surface sediment in Qingshui Stream. The heavy metals concentrations in water are the lowest,and those in the suspended matter are the highest,so the ecological risk in suspended matter is the highest. The distribution tendencies of three metals in water,suspended matter and surface sediment in main riverbed are different.

关键词： heavy metal water suspended matter surface sediment pollution Qingshui Stream

Distribution of fluoride in surface water and a health risk assessment in the upper reaches of the Yongding River

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Journal of Geographical Sciences 2020年第6期30卷 908-920页

作者： WANG Tao SHAO Zhijiang YU Hui BAH Hamidou Key laboratory of Mountain Surface Processes and Ecological Regulation CAS:Institute of Mountain Hazards and EnvironmentCASChengdu 610041China Institute of Superior Agronomy and Veterinary of Faranah(ISAV/F) Faranah 131Guinea

The excessive exposure to high concentrations of fluoride in drinking water can lead to a serious disease called *** upstream region of the Yongding River is an ecological protection area for *** studies have reported that there is a high concentration of fluoride in the groundwater in this ***,there are few data on the distribution of fluoride in surface water and health risk assessments in this *** this study,the fluoride concentrations were determined by using the spectrophotometric method using data from 2013 to 2017 from 9 surface water quality monitoring stations in the upper reaches of the Yongding *** health risks of fluoride were assessed using the approach developed by the United States Environmental Protection Agency(us epa).The results indicated that the fluoride content in the drinking water ranged from 0.30 to 1.50 mg L 1,with an average of 0.86 mg L"*** total,22.7%of the analyzed samples exceeded the Chinese limit of 1.0 mg L"1 for fluoride,and 5.5%of samples had less than the permissible limit of 0.5 mg L"*** fluoride concentrations and fluorosis hotspots were found to be predominately located downstream of the Yanghe River close to the Guanting Reservoir,where 71.4%of samples exceeded the limit of 1.0 mg/L'*** spatial distribution of high fluoride concentrations was found to be primarily determined by *** hazard quotient(HQ)index for children,teenagers and adults indicated that 19.6%,15.6%,and 5.1%of the samples in the upper reaches of the Yongding River,respectively,posed health hazards to the associated ***,the HQ index more than 1 for children,teenagers and adults had values of 64.3%,56.1%,and 19.4%,respectively,in samples from the downstream region of the Yanghe ***,there are potential risks of dental and skeletal fluorosis in the upper river reaches of the Yongding *** is imperative to take measures to reduce the fluoride pollution in surface water and contro

关键词： fluoride hazard quotient index surface water health risk Yongding River

Heavy metals and their source identification in particulate matter(PM_(2.5)) in Isfahan City, Iran

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Journal of Environmental Sciences 2018年第10期30卷 166-175页

作者： Mohsen Soleimani Nasibeh Amini Babak Sadeghian Dongsheng Wang Liping Fang Department of Natural Resources Isfahan University of Technology Isfahan's Department of Environment Division of Environmental Monitoring State Key laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Faculty of Material Science and Chemistry China University of Geosciences

The presence of heavy metals（HMs） in particulate matters（PMs） particularly fine particles such as PM2.5 poses potential risk to the health of human being. The purpose of this study was to analyze the contents of HMs in PM2.5 in the atmospheric monitoring stations in Isfahan city,Iran, in different seasons between March 2014 and March 2015 and their source identification using principle component analysis（PCA）. The samples of PM2.5 were taken using a high volume sampler in 7 monitoring stations located throughout the city and industrial zones since March 2014 to March 2015. The HMs content of the samples was measured using *** results showed that the concentrations of As, Cd and Ni were in a range of 23–36, 1–12,and 5–76 ng/m3 at all the stations which exceeded the us-epa standards. Furthermore,the concentrations of Cr and Cu reached to 153 and 167 ng/m3 in some stations which were also higher than the standard levels. Depending on the potential sources of HMs, their concentration in PM2.5 through the various seasons was different. PCA illustrated that the different potential sources of HMs in the atmosphere, showing that the most important sources of HMs originated from fossil fuel combustion, abrasion of vehicle tires, industrial activities（e.g., iron and steel industries） and dust storms. Management and control of air pollution of industrial plants and vehicles are suggested for decreasing the risk of the HMs in the region.

关键词： Air pollution Heavy metals Particulate matters Principle component analysis

Historical Record and Flux of DDTs and PCBs to the Palos Verdes Shelf Superfund Site,California

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Historical Record and Flux of DDTs and PCBs to the Palos Ver...