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.    全文下载

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

School of Biotechnology, Jiangnan University, 214122 Wuxi, PR China

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 PO₄³⁻ . 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; Nutrients recovery; High rate; Waste activated sludge; VFA production;

GRAPHIC ALABSTRACT：

JOURNAL:Bioresource Technology

SOURCE:Elsevierjournal

DOI: 10.1016/j.biortech.2017.10.103

YEAR:2018

PAGES:962-968

PUBLISHER:Elsevier Ltd