Title
Sludge age impacted the distribution, occurrence state and structure of organic compounds in activated sludge and affected the anaerobic degradability
Author
Sisi Chen, Dianhai Yang, Bin Dong, Ning Li, Xiaohu Dai
Year
2019
Journal
Chemical Engineering Journal
Abstract
Long sludge age (10 ~ 30 d) is prevalent in the operation of wastewater treatment plants of China, leading to big challenge to subsequent anaerobic digestion of sewage sludge because of low degradability and poor methane production. In order to overcome the low sludge degradability and promote the directional enhancement, the effects of sludge age on anaerobic digestion performance, especially the corresponding influencing mechanism in terms of distribution, occurrence state and structure of organic compounds in sludge driven by different sludge age were investigated. It was found that when the sludge age during wastewater treatment extended from 5 d to 40 d, the VS reduction of sludge showed an “exponential” decrease, and the degradability of protein, polysaccharides and lipids in sludge all declined. Among them, the degradation of protein was the most affected (down-regulated by 35.8%), and the decrease in degradation of protein accounted for 80.4% of the decrease of VS conversion. Sludge age during wastewater treatment impact the distribution, occurrence state and structure of organic compounds in activated sludge. And it was clarified that instead of the changed amount and components of EPS, the increased molecular weight of EPS and more stable secondary structure of protein driven by α-helix and β-turn in EPS were mainly responsible for the declined degradability of protein and sludge.
Instrument
J-715
Keywords
Circular dichroism, Secondary structure, Agriculture and environmental, Biochemistry