Stabilization of mercury in sediment by using biochars under reducing conditions

JOURNAL OF HAZARDOUS MATERIALS

卷:325

Article

Liu, Peng¹  Ptacek, Carol J.¹  Blowes, David W.¹  Finfrock, Y. Zou^2,3  Gordon, Robert A.^2,3,4 

[1] Univ Waterloo, Dept Earth & Environm Sci, 200 Univ Ave W, Waterloo, ON N2L 3G1, Canada

[2] Argonne Natl Lab, CLS APS Sect 20, PNCSRF, 9700 S Cass Ave, Argonne, IL 60439 USA

[3] Canadian Light Source Inc, Div Sci, 44 Innovat Blvd, Saskatoon, SK S7N 2V3, Canada

[4] Simon Fraser Univ, Dept Phys, 8888 Univ Dr, Burnaby, BC V5A 1S6, Canada

关键词: Biochar;    Mercury;    X-ray absorption spectroscopy;    Confocal x-ray microfluorescence imaging;    Early diagenesis;   

DOI  :  10.1016/j.jhazmat.2016.11.033

来源: Elsevier

【 摘 要 】

Mercury (Hg) is widely distributed in different localities around the world and poses a serious health threat to humans, especially when ingested in the form of methylmercury (MeHg). Efforts have been directed toward decreasing the production of MeHg by converting Hg to stable forms. Activated carbon and biochar have been evaluated as stabilization agents for Hg in contaminated sediments. However, the long-term fate of Hg stabilized by these materials remains unclear. Here, we compare the effectiveness of Hg stabilization using two biochars prepared from switchgrass at 300 degrees C (low T) and 600 degrees C (high T). Experiments were conducted by co-blending biochars and sediment for >600 d under anaerobic conditions. Aqueous concentrations of total Hg and MeHg were greatly reduced in the presence of biochars, with the exception of a spike in MeHg concentration observed at 440 d in the high-T biochar system. Hg co-occurs with S, Fe, Cu, and other elements within the plant structure of low-T biochar particles, but primarily on the outer surfaces of high-T biochar particles. Our results indicate that the stabilization of Hg may be through an early-stage diagenetic process, suggesting that the stabilization of Hg by biochar may be effective over long time frames. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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