Speciation evolution of zinc and copper during pyrolysis and hydrothermal carbonization treatments of sewage sludges

WATER RESEARCH

卷:132

Article

Huang, Rixiang¹  Zhang, Bei¹  Saad, Emily M.¹  Ingall, Ellery D.¹  Tang, Yuanzhi¹ 

[1] Georgia Inst Technol, Sch Earth & Atmospher Sci, 311Ferst Dr, Atlanta, GA 30324 USA

关键词: Sewage sludge;    Pyrolysis;    Hydrothermal carbonization;    Heavy metals;    Speciation;   

DOI  :  10.1016/j.watres.2018.01.009

来源: Elsevier

【 摘 要 】

Thermal and hydrothermal treatments are promising techniques for sewage sludge management that can potentially facilitate safe waste disposal, energy recovery, and nutrient recovery/recycling. Content and speciation of heavy metals in the treatment products affect the potential environmental risks upon sludge disposal and/or application of the treatment products. Therefore, it is important to study the speciation transformation of heavy metals and the effects of treatment conditions. By combining synchrotron X-ray spectroscopy/microscopy analysis and sequential chemical extraction, this study systematically characterized the speciation of Zn and Cu in municipal sewage sludges and their chars derived from pyrolysis (a representative thermal treatment technique) and hydrothermal carbonization (HTC; a representative hydrothermal treatment technique). Spectroscopy analysis revealed enhanced sulfidation of Zn and Cu by anaerobic digestion and HTC treatments, as compared to desulfidation by pyrolysis. Overall, changes in the chemical speciation and matrix properties led to reduced mobility of Zn and Cu in the treatment products. These results provide insights into the reaction mechanisms during pyrolysis and HTC treatments of sludges and can help evaluate the environmental/health risks associated with the metals in the treatment products. (C) 2018 Elsevier Ltd. All rights reserved.

【 授权许可】

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