Continuous liquid fermentation of pretreated waste activated sludge for high rate volatile fatty acids production and online nutrients recovery

Lihui Zhang; He Liu; Zhiyong Zheng; Huijun Ma; Meng Yang; Hongbo Liu

doi:10.1016/j.biortech.2017.10.103

Continuous liquid fermentation of pretreated waste activated sludge for high rate volatile fatty acids production and online nutrients recovery

Bioresour Technol. 2018 Feb:249:962-968. doi: 10.1016/j.biortech.2017.10.103. Epub 2017 Nov 4.

Authors

Lihui Zhang¹, He Liu², Zhiyong Zheng³, Huijun Ma¹, Meng Yang¹, Hongbo Liu⁴

Affiliations

¹ Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environmental and Civil Engineering, Jiangnan University, 214122 Wuxi, PR China.
² Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environmental and Civil Engineering, Jiangnan University, 214122 Wuxi, PR China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou 215011, PR China. Electronic address: liuhe@jiangnan.edu.cn.
³ School of Biotechnology, Jiangnan University, 214122 Wuxi, PR China.
⁴ Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environmental and Civil Engineering, Jiangnan University, 214122 Wuxi, PR China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou 215011, PR China.

PMID: 29145123
DOI: 10.1016/j.biortech.2017.10.103

Abstract

Raw sludge was pretreated, and the separated sludge liquid was used as substrate in a continuous operated up-flow anaerobic sludge blanket reactor to produce volatile fatty acids (VFAs). The highest VFA productivity of continuous fermentation with sludge liquid at an organic loading rate (OLR) of 10.0 kg COD/m³/d was about 5.0-fold and 4.0-fold higher than batch and semi-continuous fermentation with pretreated sludge slurry, respectively. Moreover, the liquid fermentation with an OLR of 10.0 kg COD/m³/d consumed the least energy, which was about 10.57% and 12.12% of batch and semi-continuous sludge fermentation, respectively. When combined with online nitrogen and phosphorus recovery, VFA production further increased by 20.67% and struvite recovery efficiency reached 1.98 ± 0.28 g/g PO₄^3-. The process showed high VFA production, low energy consumption and good nutrients recovery by continuous liquid anaerobic fermentation, significantly increasing the economic potential of VFA production from waste activated sludge.

Keywords: Continuous liquid fermentation; High rate; Nutrients recovery; VFA production; Waste activated sludge.

MeSH terms

Fatty Acids, Volatile*
Fermentation
Hydrogen-Ion Concentration
Phosphorus
Sewage*
Struvite

Substances

Fatty Acids, Volatile
Sewage
Phosphorus
Struvite