Interactions between activated sludge extracellular polymeric substances and model carrier surfaces in WWTPs: A combination of QCM-D, AFM and XDLVO prediction.

Interactions between activated sludge extracellular polymeric substances and model carrier surfaces in WWTPs: A combination of QCM-D, AFM and XDLVO prediction. Chemosphere. 2020 Aug;253:126720 Authors: Ou Q, Xu Y, Li X, He Q, Liu C, Zhou X, Wu Z, Huang R, Song J, Huangfu X Abstract To understand the biofilm formation of biofilm-based processes in wastewater treatment plants (WWTPs), the interaction mechanisms between extracted extracellular polymeric substances (EPS) and three model carrier surfaces (i.e., negatively charged hydrophilic silica, positively charged hydrophilic alumina, and neutral charged hydrophobic polystyrene) were investigated employing a laboratory quartz crystal microbalance with dissipation monitoring equipment (QCM-D) and an atomic force microscope (AFM). The data suggested that surface charge and hydrophobicity of both EPS and carriers played significant roles in the interaction behaviors. Moreover, increases in ionic strength could lead to the increasing zeta potential and hydrophobicity of EPS. It is worth noting that long-range DLVO forces dominated the EPS deposition on carriers in lower ionic strength while short-range Lewis acid-base (AB) interaction controlled the adhesion behaviors in higher ionic strength. Besides, the presence of calcium ions contributed to the adhesion behaviors because of strong charge neutralization and hydrophobic effect. Bound EPS (BEPS) showed higher affinity to model carriers ...
Source: Chemosphere - Category: Chemistry Authors: Tags: Chemosphere Source Type: research