Biochar assisted thermophilic co-digestion of food waste and waste activated sludge under high feedstock to seed sludge ratio in batch experiment

Qian Li; Manjuan Xu; Gaojun Wang; Rong Chen; Wei Qiao; Xiaochang Wang

doi:10.1016/j.biortech.2017.11.002

Biochar assisted thermophilic co-digestion of food waste and waste activated sludge under high feedstock to seed sludge ratio in batch experiment

Bioresour Technol. 2018 Feb:249:1009-1016. doi: 10.1016/j.biortech.2017.11.002. Epub 2017 Nov 4.

Authors

Qian Li¹, Manjuan Xu¹, Gaojun Wang¹, Rong Chen¹, Wei Qiao², Xiaochang Wang³

Affiliations

¹ International Science and Technology Cooperation Center for Urban Alternative Water Resources Development, Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Engineering Technology Research Center for Wastewater Treatment and Reuse, Shaanxi, Key Laboratory of Environmental Engineering, Shaanxi, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an 710055, China.
² College of Engineering, China Agricultural University, Beijing 100083, China.
³ International Science and Technology Cooperation Center for Urban Alternative Water Resources Development, Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Engineering Technology Research Center for Wastewater Treatment and Reuse, Shaanxi, Key Laboratory of Environmental Engineering, Shaanxi, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an 710055, China. Electronic address: xcwang@xauat.edu.cn.

PMID: 29145112
DOI: 10.1016/j.biortech.2017.11.002

Abstract

Batch experiments were conducted using biochar (BC) to promote stable and efficient methane production from thermophilic co-digestion of food waste (FW) and waste activated sludge (WAS) at feedstock/seed sludge (F/S) ratios of 0.25, 0.75, 1.5, 2.25, and 3. The results showed that the presence of BC dramatically shortened the lag time of methane production and increased the methane production rate with increased organic loading. The higher buffer capacity and large specific surface area of BC promoted microorganism growth and adaption to VFAs accumulation. Additionally, the electron exchange in syntrophic oxidation of butyrate and acetate as intermediate products was significantly facilitated by BC possibly due to the selective succession of bacteria and methanogens which may have participated in direct interspecies electron transfer, in contrast with the control group with low-efficient electron ferried between syntrophic oxidizers and methanogens using hydrogen as the electron carrier.

Keywords: Biochar; Interspecies electron transfer; Organic loading; Organic waste; Thermophilic digestion.

MeSH terms

Anaerobiosis
Bioreactors*
Charcoal*
Food
Methane
Sewage*

Substances

Sewage
biochar
Charcoal
Methane