A field study was conducted to determine the behavior and distribution of arsenic during the pyrometallurgy process in a typical SKS(Shuikoushan) lead smelter in Hunan province, China. Environmental influences of arse...A field study was conducted to determine the behavior and distribution of arsenic during the pyrometallurgy process in a typical SKS(Shuikoushan) lead smelter in Hunan province, China. Environmental influences of arsenic in selected samples were evaluated. Arsenic contents in all input and output samples vary from 0.11% in raw lead to 6.66% in collected dust-2. More arsenic is volatilized in blast furnace and fuming furnace(73.02% of arsenic input) than bottom blowing furnace(10.29% of arsenic input).There are 78.97%, 13.69%, 7.31% of total arsenic distributed in intermediate materials, stockpiled materials and unorganized emissions, respectively. Matte slag-2, collected dust-1 and secondary zinc oxide are hazardous based on the arsenic concentrations of toxicity characteristic leaching procedure. According to risk assessment code(RAC) guideline, arsenic in collected dust-1 poses a very serious risk to the surrounding environment, arsenic in speiss, matte slag-2, water-quenched slag and secondary zinc oxide show low risk, while arsenic in matte slag-1, collected dust-2 and post dust has no risk to the environment.展开更多
Plant biosurfactants were used for the first time to remove As and co-existing metals from brownfield soils. Tannic acid （TA）, a polyphenol, and saponin （SAP）, a glycoside were tested. The soil washing experiments...Plant biosurfactants were used for the first time to remove As and co-existing metals from brownfield soils. Tannic acid （TA）, a polyphenol, and saponin （SAP）, a glycoside were tested. The soil washing experiments were performed in batch conditions at constant biosurfactant concentration （3%）. Both biosurfactants differed in natural pH, surface tension, critical micelle concentration and content of functional groups. After a single washing, TA （pH 3.44） more efficiently mobilized As than SAP （pH 5.44）. When both biosurfactants were used at the same pH （SAP adjusted to 3.44）, arsenic mobilization was improved by triple washing. The process efficiency for TA and SAP was similar, and depending on the soil sample, ranged between 50%-64%. Arsenic mobilization by TA and SAP resulted mainly from decomposition of Fe arsenates, followed by Fe3＋ complexation with biosurfactants. Arsenic was efficiently released from reducible and partially from residual fractions. In all soils, As（V） was almost completely removed, whereas content of As（III） was decreased by 37%-73%. SAP and TA might be used potentially to remove As from contaminated soils.展开更多
基金Project(2011AA061001)supported by the National High Technology Research and Development Program of ChinaProject(51304251)supported by the National Natural Science Foundation of China+1 种基金Project(2013M542141)supported by China Postdoctoral FoundationProject(K1201010-61)supported by Planned Program of Science and Technology of Changsha,China
文摘A field study was conducted to determine the behavior and distribution of arsenic during the pyrometallurgy process in a typical SKS(Shuikoushan) lead smelter in Hunan province, China. Environmental influences of arsenic in selected samples were evaluated. Arsenic contents in all input and output samples vary from 0.11% in raw lead to 6.66% in collected dust-2. More arsenic is volatilized in blast furnace and fuming furnace(73.02% of arsenic input) than bottom blowing furnace(10.29% of arsenic input).There are 78.97%, 13.69%, 7.31% of total arsenic distributed in intermediate materials, stockpiled materials and unorganized emissions, respectively. Matte slag-2, collected dust-1 and secondary zinc oxide are hazardous based on the arsenic concentrations of toxicity characteristic leaching procedure. According to risk assessment code(RAC) guideline, arsenic in collected dust-1 poses a very serious risk to the surrounding environment, arsenic in speiss, matte slag-2, water-quenched slag and secondary zinc oxide show low risk, while arsenic in matte slag-1, collected dust-2 and post dust has no risk to the environment.
基金supported by the Faculty of Environmental Sciences,University of Warmia and Mazury in Olsztyn,Poland(No.GW/2013/24)
文摘Plant biosurfactants were used for the first time to remove As and co-existing metals from brownfield soils. Tannic acid （TA）, a polyphenol, and saponin （SAP）, a glycoside were tested. The soil washing experiments were performed in batch conditions at constant biosurfactant concentration （3%）. Both biosurfactants differed in natural pH, surface tension, critical micelle concentration and content of functional groups. After a single washing, TA （pH 3.44） more efficiently mobilized As than SAP （pH 5.44）. When both biosurfactants were used at the same pH （SAP adjusted to 3.44）, arsenic mobilization was improved by triple washing. The process efficiency for TA and SAP was similar, and depending on the soil sample, ranged between 50%-64%. Arsenic mobilization by TA and SAP resulted mainly from decomposition of Fe arsenates, followed by Fe3＋ complexation with biosurfactants. Arsenic was efficiently released from reducible and partially from residual fractions. In all soils, As（V） was almost completely removed, whereas content of As（III） was decreased by 37%-73%. SAP and TA might be used potentially to remove As from contaminated soils.
