title: Addressing the role of earthworms in treating domestic wastewater by analyzing biofilm modification through chemical and spectroscopic methods.
abstract: Vermifiltration eco-friendly system is an alternative and low-cost artificial ecosystem for decentralized wastewater treatment and excess sludge reduction. The biofilm characteristics of a vermifilter (VF) with earthworms, Eisenia fetida, for domestic wastewater treatment were studied. A conventional biofilter (BF) without earthworms served as the control. Pore number in VF biofilm was significantly more than BF biofilm, and VF biofilm showed a better level-administrative structure through scanning electron microscope. VF biofilms had lower levels of protein and polysaccharide, but phosphoric acids and humic acid showed the opposite results. Furthermore, in the presence of earthworms, VF biofilms contained higher total organic carbon (TOC) percentage composition in the condition of less volatile suspended substances (VSS) contents. Dehydrogenase activity (DHA) and adenosine triphosphate (ATP) contents along VF showed better results than BF by increment of 12.84 ∼ 16.46 %. Overall findings indicated that the earthworms' presence remarkably decreases biofilm contests but increases enzyme activity and improves the community structure of VF biofilms, which is beneficial for the wastewater disposal.
authors.affiliation: Key Laboratory of Yangtze Water Environment for Ministry of Education, State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Yangtze Water Environment for Ministry of Education, State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China. xingmeiyan@tongji.edu.cn.
authors.forename: Mei-Yan
authors.initials: MY
authors.lastname: Xing
authors.affiliation: Key Laboratory of Yangtze Water Environment for Ministry of Education, State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
authors.affiliation: Key Laboratory of Yangtze Water Environment for Ministry of Education, State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
authors.forename: Biao
authors.initials: B
authors.lastname: Lu
mesh_terms: D000818:Animals; D018441:Biofilms; D017753:Ecosystem; D005374:Filtration / Q000379:methods; D006812:Humic Substances; D009835:Oligochaeta / Q000378:metabolism*; D012722:Sewage / Q000737:chemistry; D013057:Spectrum Analysis; D062065:Wastewater; D018508:Water Purification
chemical_list: D006812:Humic Substances; D012722:Sewage; D062065:Wastewater
keywords: Biofilm morphology characteristics; Biofilm organic matter composition; Microbial biomass; Microbial enzyme activities; Vermi-biofilter system