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期刊论文 3

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2017 3

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Assessment of leaching behavior and human bioaccessibility of rare earth elements in typical hospital

Chunfeng Wang, Guanfei Chen, Yanchen Zhu, Dan Yao, Wanfeng Wang, Lianjun Wang

《环境科学与工程前沿（英文）》 2017年 第11卷 第6期 doi: 10.1007/s11783-017-0946-2

摘要： Leaching behavior and gastrointestinal bioaccessibility of rare earth elements (REEs) from hospital waste incineration (HWI) fly and bottom ash samples collected from Beijing and Nanjing Cities were assessed. In the same ash sample, the leaching concentrations of individual REEs determined by the Toxicity Characteristic Leaching Procedure (TCLP) were higher than those detected by the European standard protocol (EN-type test), thereby suggesting that the low pH value of leaching solution was an important factor influencing the leachability of REE. The REE bioaccessibility results, which were evaluated using the physiologically based extraction test (PBET), indicated that REEs were highly absorbed during gastric phase by dissolution; and subsequently precipitated and/or re-adsorbed in small intestinal phase. The relative amounts of the total REEs extracted by the TCLP method, EN-type test and PBET test were compared. In addition to the pH value of extraction solutions, the chelating role of REEs with organic ligands used in the PBET method was also an important parameter affecting REE adsorption in human body. Additionally, this study showed that REEs were extracted by these methods as concomitants of heavy metals and anions (NO , F , SO , and Cl ) from HWI ash, which probably caused the remarkably complex toxicity on human body by the exposure pathway.

关键词： Assessment     Rare earth elements     Leaching behavior     Bioaccessibility     Hospital waste    

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Assessing human bioaccessibility of trace contaminants in size-fractionated red mud, derived precipitates

Chunfeng Wang, Yanchen Zhu, Dan Yao, Guanfei Chen, Lianjun Wang

《环境科学与工程前沿（英文）》 2017年 第11卷 第6期 doi: 10.1007/s11783-017-0956-0

摘要： The objective of this study was to provide insight into human exposure to trace contaminants bearing red mud, derived precipitates and geopolymeric blocks due to inhalation contact and/or hand-to-mouth ingestion. The in vitro bioaccessibility behavior of trace contaminants was investigated with the PBET (physiologically based extraction test), ALF (artificial lysosomal fluid) and MGS (modified Gamble’ solution) methods. The results showed that total contents of trace contaminants and operation parameters, such as pH and chelating properties of simulated gastrointestinal phases (PBET), played a joint role in controlling the bioaccessibility efficacy for size-fractionated red mud particles. As for airborne particles (<38 µm size fractions), trace contaminants concentrations extracted by MGS was significantly higher than those by ALF. Additionally, higher bioaccessibility (PBET) values of Cu, Pb, Zn, As, V and U were obtained from red mud derived precipitates compared with those of red mud itself. Even though short-term and long-term leaching values of trace contaminants were relatively lower in the prepared geopolymeric blocks, the health risk could be significantly higher due to the more pronounced bioaccessibility characteristics.

关键词： Bioaccessibility     Trace contaminants     Red mud     Precipitates     Geopolymeric blocks.    

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The speciation, leachability and bioaccessibility of Cu and Zn in animal manure-derived biochar: effect

Qi Lin, Xin Xu, Lihua, Wang, Qian Chen, Jing Fang, Xiaodong Shen, Liping Lou, Guangming Tian

《环境科学与工程前沿（英文）》 2017年 第11卷 第3期 doi: 10.1007/s11783-017-0924-8

摘要： Biochars derived from animal manures may accumulate potentially toxic metals and cause a potential risk to ecosystem. The synchrotron-based X-ray spectroscopy, sequential fractionation schemes, bioaccessibility extraction and leaching procedure were performed on poultry and swine manure-derived biochars (denoted PB and SB, respectively) to evaluate the variance of speciation and activity of Cu and Zn as affected by the feedstock and pyrolysis temperature. The results showed that Cu speciation was dependent on the feedstock with Cu-citrate-like in swine manure and species resembling Cu-glutathione and CuO in poultry manure. Pyrolyzed products, however, had similar Cu speciation mainly with species resembling Cu-citrate, CuO and CuS/Cu S. Organic bound Zn and Zn (PO ) -like species were dominant in both feedstock and biochars. Both Cu and Zn leaching with synthetic precipitation leaching procedure (SPLP) and toxicity characteristic leaching procedure (TCLP) decreased greatly with the rise of pyrolysis temperature, which were consistent with the sequential extraction results that pyrolysis converted Cu and Zn into less labile phases such as organic/sulfide and residual fractions. The potential bioaccessibility of Zn decreased for both the PB and SB, closely depending on the content of non-residual Zn. The bioaccessibility of Cu, however, increased for the SB prepared at 300°C–700°C, probably due to the increased proportion of CuO. Concerning the results of sequential fractionation schemes, bioaccessibility extraction and leaching procedure, pyrolysis at 500°C was suggested as means of reducing Cu/Zn lability and poultry manure was more suitable for pyrolysis treatment.

关键词： Animal manure     Biochar     Metals     Molecular species     Pyrolysis    

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标题 作者 时间 类型 操作

Assessment of leaching behavior and human bioaccessibility of rare earth elements in typical hospital

Chunfeng Wang, Guanfei Chen, Yanchen Zhu, Dan Yao, Wanfeng Wang, Lianjun Wang

期刊论文

Assessing human bioaccessibility of trace contaminants in size-fractionated red mud, derived precipitates

Chunfeng Wang, Yanchen Zhu, Dan Yao, Guanfei Chen, Lianjun Wang

期刊论文

The speciation, leachability and bioaccessibility of Cu and Zn in animal manure-derived biochar: effect

Qi Lin, Xin Xu, Lihua, Wang, Qian Chen, Jing Fang, Xiaodong Shen, Liping Lou, Guangming Tian

期刊论文