Enhancement of excess sludge hydrolysis and decomposition by combined lysozyme and rhamnolipid pretreatment. (October 2019)

• Record Type: Journal Article
• Authors: Liu, Gaige; Li, Xiangkun; Ma, Linli; Ma, Xiaochen; Chen, Hongying
• Is Part Of: Bioresource technology. Volume 289(2019)
• Publication Date: 2019-10
• Subjects: Excess sludge -- Combination treatment -- Sludge hydrolysis -- Decomposition degree -- Microbial community composition; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2019.121703
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: RL dosage could greatly promote the ES dispersed state. Combined lysozyme and RL treatment had remarkable sludge hydrolysis efficiency. 45.3% bacteria and 84.5% archaea were decomposed under optimal combination system. Combined treated ES benefited VFAs and acetic acid dependent methane generating. Abstract: Feasibility of combined lysozyme and rhamolipid (RL) pretreatment on the enhancement of excess sludge (ES) hydrolysis and decomposition was assessed in this study. Results showed lysozyme and RL combined treatment could significantly promote ES hydrolysis and decomposition, an additional 1196.9 mg/L soluble chemical oxygen demand (SCOD), 792.5 mg/L protein and 133.5 mg/L polysaccharide were released compared with the sum of sole RL and sole lysozyme treatment at the optimal RL dosage of 0.3 g/gSS and lysozyme dosage of 0.15 g/gSS after 8 h co-digestion. 45.3% bacteria and 84.5% archaea decomposition degree were gained under the combined treatment at the optimal RL dosage. Class Gammaproteobacteria and genus Methanothrix were the predominant bacteria and archaea with the relative abundance of 72.4% and 60.8%, respectively. After the combined pretreatment, ES was beneficial for volatile fatty acids accumulation and acetic acid dependent methane generating inferred from the results of microbial community composition.