title: Preconditioning of model biocarriers by soluble pollutants: a QCM-D study.
abstract: Preconditioning of a biocarrier surface is the first step in triggering biofilm formation in attached-growth bioreactors. However, the quantification and control of this step as influenced by solution conditions and biocarrier properties have been rarely explored. In this paper, deposition behaviors of soluble pollutants on the model biocarriers polystyrene (PS) and polyamide (PA) were performed using a quartz crystal microbalance with dissipation monitoring (QCM-D). Three types of wastewater from municipal and industrial wastewater treatment plants and 12 synthetic wastewaters with different configurations of model macromolecules (bovine serum albumin and sodium alginate) and ionic compositions (Na(+) and Ca(2+)) were prepared. Results showed that high organic contents (protein and humic acid) in real wastewater increased deposition compared to the impact of ions on the two types of carriers. For synthetic wastewater, an interesting phenomenon was observed in that the presence of Ca(2+) can transform a thin and rigid adlayer into a denser and viscoelastic one on the surface of PS with low organic contents, yet a viscoelastic adlayer can directly form on PS and an increase in the ionic strength hinders deposition in the presence of high organic contents. The deposition of solutes on PA produces a thicker and viscoelastic adlayer that is strengthened an elevated concentration of organic materials. Additionally, a weakening effect of Ca(2+) on deposition was revealed under high ionic strength. This is the first demonstration of control strategies for preconditioning hydrophilic and hydrophobic biocarriers under different water quality conditions and has important implications for the design of a start-up process for biofilm formation in attached-growth bioreactors.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
authors.forename: Li-li
authors.initials: LL
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
authors.forename: Hong-qiang
authors.initials: HQ
authors.lastname: Ren
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
authors.forename: Jin-ju
authors.initials: JJ
authors.lastname: Geng
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
authors.forename: Ke
authors.initials: K
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D008422:Materials Testing / Q000379:methods; D055617:Micro-Electrical-Mechanical Systems / Q000379:methods*; D011108:Polymers / Q000737:chemistry*; D012995:Solubility; D013499:Surface Properties; D062065:Wastewater / Q000737:chemistry* / Q000382:microbiology*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D011108:Polymers; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: QCM-D; biocarrier; deposition; preconditioning; soluble pollutants