Feasibility of anaerobic digestion for contaminated rice straw inoculated with waste activated sludge

Liqing Xin; Zhaohui Guo; Xiyuan Xiao; Wenxuan Xu; Ran Geng; Wenwen Wang

doi:10.1016/j.biortech.2018.06.048

Feasibility of anaerobic digestion for contaminated rice straw inoculated with waste activated sludge

Bioresour Technol. 2018 Oct:266:45-50. doi: 10.1016/j.biortech.2018.06.048. Epub 2018 Jun 19.

Authors

Liqing Xin¹, Zhaohui Guo², Xiyuan Xiao¹, Wenxuan Xu¹, Ran Geng¹, Wenwen Wang¹

Affiliations

¹ Institute of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China.
² Institute of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China. Electronic address: zhguo@csu.edu.cn.

PMID: 29944977
DOI: 10.1016/j.biortech.2018.06.048

Abstract

Anaerobic digestion of the heavy metal-contaminated rice straw inoculated with waste activated sludge was carried out through an orthogonal array. The results indicated that the digestion process was optimized with an inoculum to substrate ratio (I/S) of 0.25, a total solid (TS) content of 5%, and an initial pH of 7.0, with corresponding total biogas and methane yields of 745.4 and 285.2 mL/g VS, respectively. Under the optimized conditions, the bioleaching percentages of Cd and As in the biomass were 13.13% and 42.90%, respectively. According to range analysis, the biogas yield, methane yield, and bioleaching percentages of Cd and As in the biomass significantly decreased with an increase in TS content from 5% to 15%. The results suggested that anaerobic digestion with waste activated sludge was feasible for achieving both biogas production and bioleaching of heavy metals from contaminated rice straw.

Keywords: Anaerobic digestion; Arsenic; Bioleaching; Cadmium; Contaminated rice straw.

MeSH terms

Anaerobiosis
Biofuels
Bioreactors*
Methane / biosynthesis*
Oryza*
Sewage

Substances

Biofuels
Sewage
Methane