title: Earthworm eco-physiological characteristics and quantification of earthworm feeding in vermifiltration system for sewage sludge stabilization using stable isotopic natural abundance.
abstract: Previous studies showed that the presence of earthworm improves treatment performance of vermifilter (VF) for sewage sludge stabilization, but earthworm eco-physiological characteristics and effects in VF were not fully investigated. In this study, earthworm population, enzymatic activity, gut microbial community and stable isotopic abundance were investigated in the VF. Results showed that biomass, average weight, number and alkaline phosphatase activity of the earthworms tended to decrease, while protein content and activities of peroxidase and catalase had an increasing tendency as the VF depth. Earthworm gut microbial communities were dominated by Gammaproteobacteria, and the percentages arrived to 76-92% of the microbial species detected. (15)N and (13)C natural abundance of the earthworms decreased with operation time, and increased as the VF depth. Quantitative analysis using δ(15)N showed that earthworm feeding and earthworm-microorganism interaction were responsible for approximately 21% and 79%, respectively, of the enhanced volatile suspended solid reduction due to the presence of earthworm. The finding provides a quantitative insight into how earthworms influence on sewage sludge stabilization in vermifiltration system.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, The National Engineering Research Center for Urban Pollution Control, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, The National Engineering Research Center for Urban Pollution Control, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China. Electronic address: lixiaowei419@163.com.
authors.forename: Meiyan
authors.initials: M
authors.lastname: Xing
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, The National Engineering Research Center for Urban Pollution Control, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, The National Engineering Research Center for Urban Pollution Control, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
authors.forename: Xiaohu
authors.initials: X
authors.lastname: Dai
mesh_terms: D000818:Animals; D005247:Feeding Behavior; D007554:Isotopes; D009835:Oligochaeta / Q000502:physiology*; D012722:Sewage
chemical_list: D007554:Isotopes; D012722:Sewage
keywords: Earthworm feeding; Earthworm–microorganism interaction; Sewage sludge; Stable isotope; Vermifiltration