Effect of CaO2 addition on anaerobic digestion of waste activated sludge at different temperatures and the promotion of valuable carbon source production under ambient condition

Qian Ping; Xiao Lu; Ming Zheng; Yongmei Li

doi:10.1016/j.biortech.2018.06.007

Effect of CaO₂ addition on anaerobic digestion of waste activated sludge at different temperatures and the promotion of valuable carbon source production under ambient condition

Bioresour Technol. 2018 Oct:265:247-256. doi: 10.1016/j.biortech.2018.06.007. Epub 2018 Jun 6.

Authors

Qian Ping¹, Xiao Lu¹, Ming Zheng¹, Yongmei Li²

Affiliations

¹ State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
² State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China. Electronic address: liyongmei@tongji.edu.cn.

PMID: 29902657
DOI: 10.1016/j.biortech.2018.06.007

Abstract

The effect of calcium peroxide (CaO₂) addition on anaerobic digestion (AD) of waste activated sludge (WAS) at different temperatures (20 °C, 35 °C, and 55 °C) were investigated. The results show that CaO₂ addition had significant positive effect on short-chain fatty acids (SCFAs) production under ambient and mesophilic conditions. Polysaccharides and proteins embedded in extracellular polymeric substances (EPS) were effectively released from inner fraction to outer fraction, and non-biodegradable humic-like substances were decreased while easily biodegradable tryptophan-like proteins increased. These effects were most remarkable under ambient conditions. However, CaO₂ addition was unfavorable to thermophilic AD because of high free ammonia concentrations and the accumulation of humic-like substances. Temperature showed a stronger effect than CaO₂ on microbial community structure, but CaO₂ addition was more effective than temperature in enhancing hydrolytic and acidifying microorganisms. Predictive functional profiling indicated that microbial hydrolysis, metabolism and acidification were promoted by CaO₂ under ambient conditions.

Keywords: Anaerobic digestion (AD); Calcium peroxide (CaO(2)); Microbial community; Temperature; Waste activated sludge (WAS).

MeSH terms

Anaerobiosis
Carbon*
Fatty Acids, Volatile
Sewage*
Temperature
Waste Disposal, Fluid*

Substances

Fatty Acids, Volatile
Sewage
Carbon