Thermal-alkaline pretreatment of polyacrylamide flocculated waste activated sludge: Process optimization and effects on anaerobic digestion and polyacrylamide degradation
Author(s)
Liu, Xuran
Xu, Qiuxiang
Wang, Dongbo
Yang, Qi
Wu, Yanxin
Li, Yifu
Fu, Qizi
Yang, Fan
Liu, Yiwen
Ni, Bing-Jie
Wang, Qilin
Li, Xiaoming
Griffith University Author(s)
Year published
2019
Metadata
Show full item recordAbstract
Deterioration of anaerobic digestion can occur with the presence of polyacrylamide (PAM) in waste activated sludge, and little information on mitigating this deterioration is currently available. In this study, simultaneous mitigation of PAM negative effects and improvement of methane production was accomplished by thermal-alkaline pretreatment. Under the optimized pretreatment conditions (i.e., 75 °C, pH 11.0 for 17.5 h), the biochemical methane potential of PAM-flocculated sludge increased from 100.5 to 210.8 mL/g VS and the hydrolysis rate increased from 0.122 to 0.187 d−1. Mechanism investigations revealed that the ...
View more >Deterioration of anaerobic digestion can occur with the presence of polyacrylamide (PAM) in waste activated sludge, and little information on mitigating this deterioration is currently available. In this study, simultaneous mitigation of PAM negative effects and improvement of methane production was accomplished by thermal-alkaline pretreatment. Under the optimized pretreatment conditions (i.e., 75 °C, pH 11.0 for 17.5 h), the biochemical methane potential of PAM-flocculated sludge increased from 100.5 to 210.8 mL/g VS and the hydrolysis rate increased from 0.122 to 0.187 d−1. Mechanism investigations revealed that the pretreatment not only broke the large firm floccules, improved the degradation of PAM, but also facilitated the release of biodegradable organics from sludge, which thereby provided better growth environment and enough nutrients to anaerobic microbes for methane production. The activities of key enzymes responsible for methane production and PAM degradation were greatly improved in pretreated reactor, with the accumulation of acrylamide being avoided.
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View more >Deterioration of anaerobic digestion can occur with the presence of polyacrylamide (PAM) in waste activated sludge, and little information on mitigating this deterioration is currently available. In this study, simultaneous mitigation of PAM negative effects and improvement of methane production was accomplished by thermal-alkaline pretreatment. Under the optimized pretreatment conditions (i.e., 75 °C, pH 11.0 for 17.5 h), the biochemical methane potential of PAM-flocculated sludge increased from 100.5 to 210.8 mL/g VS and the hydrolysis rate increased from 0.122 to 0.187 d−1. Mechanism investigations revealed that the pretreatment not only broke the large firm floccules, improved the degradation of PAM, but also facilitated the release of biodegradable organics from sludge, which thereby provided better growth environment and enough nutrients to anaerobic microbes for methane production. The activities of key enzymes responsible for methane production and PAM degradation were greatly improved in pretreated reactor, with the accumulation of acrylamide being avoided.
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Journal Title
BIORESOURCE TECHNOLOGY
Volume
281
Subject
Bioprocessing, bioproduction and bioproducts
Environmental engineering
Environmental sciences
Water treatment processes
Water resources engineering