Enhanced high-quality biomethane production from anaerobic digestion of primary sludge by corn stover biochar

Wei Wei; Wenshan Guo; Huu Hao Ngo; Giorgio Mannina; Dongbo Wang; Xueming Chen; Yiwen Liu; Lai Peng; Bing-Jie Ni

doi:10.1016/j.biortech.2020.123159

Enhanced high-quality biomethane production from anaerobic digestion of primary sludge by corn stover biochar

Bioresour Technol. 2020 Jun:306:123159. doi: 10.1016/j.biortech.2020.123159. Epub 2020 Mar 7.

Authors

Wei Wei¹, Wenshan Guo¹, Huu Hao Ngo¹, Giorgio Mannina², Dongbo Wang³, Xueming Chen⁴, Yiwen Liu¹, Lai Peng⁵, Bing-Jie Ni⁶

Affiliations

¹ Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, New South Wales 2007, Australia.
² Dipartimento di Ingegneria, Viale delle Scienze, Ed.8, 90128 Palermo, Italy.
³ College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082, China.
⁴ Process and Systems Engineering Center (PROSYS), Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
⁵ School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei 430070, China.
⁶ Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, New South Wales 2007, Australia. Electronic address: bingjieni@gmail.com.

PMID: 32182472
DOI: 10.1016/j.biortech.2020.123159

Abstract

This study conducted batch and continuous tests to reveal the feasibility of corn stover biochar on improving anaerobic digestion of primary sludge (PS). Dosing biochar (1.82, 2.55 and 3.06 g/g Total Solids (TS)) in digester improved methane content increasing from 67.5% to 81.3-87.3% and enhanced methane production by 8.6-17.8%. Model analysis indicated that biochar accelerated PS hydrolysis and enhanced methane potential of PS. The mechanistic studies showed that biochar enhanced process stability provided by strong buffering capacity and alleviated NH₃ inhibition. In continuous test over 116 days, the volatile solids (VS) destruction in the biochar-dosed digester increased by 14.9%, resulting in a 14% reduction in the volume of digestate for disposal. Biochar changed microbial community in an expected direction for anaerobic digestion. This work suggests that biochar technology would apply to co-digestion of WAS and PS to maximize the energy recovery and sludge reduction from the two sludge streams.

Keywords: Anaerobic digestion; Biochar; Methane; Primary sludge; Volatile solids destruction.