Microwave pretreatment of polyacrylamide flocculated waste activated sludge: Effect on anaerobic digestion and polyacrylamide degradation

Xuran Liu; Qiuxiang Xu; Dongbo Wang; Yanxin Wu; Qizi Fu; Yifu Li; Qi Yang; Yiwen Liu; Bing-Jie Ni; Qilin Wang; Guojing Yang; Hailong Li; Xiaoming Li

doi:10.1016/j.biortech.2019.121776

Microwave pretreatment of polyacrylamide flocculated waste activated sludge: Effect on anaerobic digestion and polyacrylamide degradation

Bioresour Technol. 2019 Oct:290:121776. doi: 10.1016/j.biortech.2019.121776. Epub 2019 Jul 8.

Authors

Xuran Liu¹, Qiuxiang Xu², Dongbo Wang³, Yanxin Wu², Qizi Fu², Yifu Li², Qi Yang², Yiwen Liu⁴, Bing-Jie Ni⁴, Qilin Wang⁴, Guojing Yang⁵, Hailong Li⁶, Xiaoming Li²

Affiliations

¹ College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China. Electronic address: [email protected].
² College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
³ College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China. Electronic address: [email protected].
⁴ Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia.
⁵ College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, PR China.
⁶ School of Energy Science and Engineering, Central South University, Changsha 410083, PR China.

PMID: 31302462
DOI: 10.1016/j.biortech.2019.121776

Abstract

Deterioration of anaerobic digestion can occur with the presence of polyacrylamide (PAM) in waste activated sludge, but the information on alleviating this deterioration is still limited. In this study, the simultaneous alleviation of negative effect of PAM and improvement of methane production during anaerobic digestion was accomplished by microwave pretreatment. Experimental results showed that with the microwave pretreatment times increased from 0 to 12 min, the biochemical methane potential of PAM-flocculated sludge (12 g PAM/kg total solids) asymptotically increased from 123.1 to 242.5 mL/g volatile solids, hydrolysis rate increased from 0.06 to 0.13 d^-1. Mechanism analysis indicated that the microwave pretreatment accelerated the release and hydrolysis of organic substrates from PAM-flocculated sludge, facilitated the breaking of large firm "PAM-sludge" floccules, and benefited the degradation of PAM, which alleviated the PAM inhibitory impacts on digestion and meanwhile provided better contact between the released organic substrates and anaerobic bacteria for methane production.

Keywords: Anaerobic digestion; Methane; Microwave; Polyacrylamide; Waste activated sludge.

MeSH terms

Acrylic Resins
Anaerobiosis
Methane
Microwaves*
Sewage*
Waste Disposal, Fluid

Substances

Acrylic Resins
Sewage
polyacrylamide
Methane