title: Mechanism and kinetics of biofilm growth process influenced by shear stress in sewers.
abstract: Sewer biofilms play an important role in the biotransformation of substances for methane and sulfide emission in sewer networks. The dynamic flows and the particular shear stress in sewers are the key factors determining the growth of the sewer biofilm. In this work, the development of sewer biofilm with varying shear stress is specifically investigated to gain a comprehensive understanding of the sewer biofilm dynamics. Sewer biofilms were cultivated in laboratory-scale gravity sewers under different hydraulic conditions with the corresponding shell stresses are 1.12 Pa, 1.29 Pa and 1.45 Pa, respectively. The evolution of the biofilm thickness were monitored using microelectrodes, and the variation in total solids (TS) and extracellular polymer substance (EPS) levels in the biofilm were also measured. The results showed that the steady-state biofilm thickness were highly related to the corresponding shear stresses with the biofilm thickness of 2.4 ± 0.1 mm, 2.7 ± 0.1 mm and 2.2 ± 0.1 mm at shear stresses of 1.12 Pa, 1.29 Pa and 1.45 Pa, respectively, which the chemical oxygen demand concentration is 400 mg/L approximately. Based on these observations, a kinetic model for describing the development of sewer biofilms was developed and demonstrated to be capable of reproducing all the experimental data.
authors.affiliation: Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China E-mail: aihainan@126.com.
authors.forename: Hainan
authors.initials: H
authors.lastname: Ai
authors.affiliation: Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China E-mail: aihainan@126.com.
authors.forename: Jingwei
authors.initials: J
authors.lastname: Xu
authors.affiliation: Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China E-mail: aihainan@126.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.affiliation: Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China E-mail: aihainan@126.com.
authors.forename: Qiang
authors.initials: Q
authors.lastname: He
authors.affiliation: Advanced Water Management Centre, The University of Queensland, St Lucia, Brisbane, Queensland 4067, Australia.
authors.forename: Bingjie
authors.initials: B
authors.lastname: Ni
authors.affiliation: Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China E-mail: aihainan@126.com.
authors.forename: Yinliang
authors.initials: Y
authors.lastname: Wang
mesh_terms: D001419:Bacteria; D018441:Biofilms; D019149:Bioreactors; D007700:Kinetics; D008962:Models, Theoretical; D012498:Sanitary Engineering; D013314:Stress, Mechanical; D013997:Time Factors