Cumulative effects of bamboo sawdust addition on pyrolysis of sewage sludge: Biochar properties and environmental risk from metals

Junwei Jin; Minyan Wang; Yucheng Cao; Shengchun Wu; Peng Liang; Yanan Li; Jianyun Zhang; Jin Zhang; Ming Hung Wong; Shengdao Shan; Peter Christie

doi:10.1016/j.biortech.2016.12.103

Cumulative effects of bamboo sawdust addition on pyrolysis of sewage sludge: Biochar properties and environmental risk from metals

Bioresour Technol. 2017 Mar:228:218-226. doi: 10.1016/j.biortech.2016.12.103. Epub 2016 Dec 30.

Authors

Junwei Jin¹, Minyan Wang², Yucheng Cao¹, Shengchun Wu¹, Peng Liang¹, Yanan Li¹, Jianyun Zhang¹, Jin Zhang³, Ming Hung Wong⁴, Shengdao Shan⁵, Peter Christie⁶

Affiliations

¹ Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, School of Environmental and Resource Sciences, Zhejiang Agriculture and Forestry University, 88 Huancheng North Road, Lin'an, Hangzhou 311300, China.
² Jiyang College, Zhejiang Agriculture and Forestry University, 77 Puyang Road, Zhuji 311800, China.
³ Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, School of Environmental and Resource Sciences, Zhejiang Agriculture and Forestry University, 88 Huancheng North Road, Lin'an, Hangzhou 311300, China; Consortium on Health, Environment, Education and Research (CHEER), Department of Science and Environmental Studies, The Education University of Hong Kong, 10 Lo Ping Road, Tai Po, Hong Kong Special Administrative Region. Electronic address: jzhang@zafu.edu.cn.
⁴ Consortium on Health, Environment, Education and Research (CHEER), Department of Science and Environmental Studies, The Education University of Hong Kong, 10 Lo Ping Road, Tai Po, Hong Kong Special Administrative Region.
⁵ Institute of Ecology and Environment, Zhejiang University of Science and Technology, 318 Liuhe Road, Hangzhou 310023, China.
⁶ Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, School of Environmental and Resource Sciences, Zhejiang Agriculture and Forestry University, 88 Huancheng North Road, Lin'an, Hangzhou 311300, China; Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China.

PMID: 28064134
DOI: 10.1016/j.biortech.2016.12.103

Abstract

A novel type of biochar was produced by mixing bamboo sawdust with sewage sludge (1:1, w/w) via a co-pyrolysis process at 400-600°C. Changes in physico-chemical properties and the intrinsic speciation of metals were investigated before and after pyrolysis. Co-pyrolysis resulted in a lower biochar yield but a higher C content in the end product compared with use of sludge alone as the raw material. FT-IR analysis indicates that phosphine derivatives containing PH bonds were formed in the co-pyrolyzed biochars. In addition, co-pyrolysis of sludge with bamboo sawdust transformed the potentially toxic metals in the sludge into more stable fractions, leading to a considerable decrease in their direct toxicity and bioavailability in the co-pyrolyzed biochar. In conclusion, the co-pyrolysis technology provides a feasible method for the safe disposal of metal-contaminated sewage sludge in an attempt to minimize the environmental risk from potentially toxic metals after land application.

Keywords: Bamboo sawdust; Potential environmental risk assessment; Pyrolysis; Sewage sludge; Trace metals.

MeSH terms

Charcoal / chemical synthesis*
Charcoal / chemistry
Metals, Heavy / chemistry*
Sewage / chemistry*
Spectroscopy, Fourier Transform Infrared
Waste Disposal, Fluid / methods*
Wood / chemistry*

Substances

Metals, Heavy
Sewage
biochar
Charcoal