Interaction energy evaluation of soluble microbial products (SMP) on different membrane surfaces: Role of the reconstructed membrane topology

• Published in: Water research (Oxford) Vol. 46; no. 8; pp. 2693 - 2704
• Main Authors: Chen, Lin, Tian, Yu, Cao, Chu-qing, Zhang, Jun, Li, Zhi-neng
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.05.2012; Elsevier
• Subjects: Applied sciences; atomic force microscopy; Bacteria - chemistry; Biofouling; cellulose acetate; Computer Simulation; effluents; Exact sciences and technology; Extended DLVO theory; filtration; fouling; Interaction energy; Membrane fouling; Membrane surface properties; Membranes, Artificial; Models, Chemical; Organic Chemicals - chemistry; organic matter; physicochemical properties; Pollution; primary energy; probability; Solubility; Soluble microbial products; Surface reconstruction; Surface Tension; Thermodynamics; topology; Water treatment and pollution; Extended DLVO theory; Surface reconstruction; Soluble microbial products; Membrane fouling; Membrane surface properties; Interaction energy; Cartography; Polymeric membrane; Atomic force microscopy; Organic matter; Fouling; Filtration; Roughness; Rough surface; Topology; Morphology; Surface properties; Chemical properties; Effluent
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2012.02.030

Soluble microbial products (SMP), a majority of organic matter in effluents, play a key role in membrane fouling. A series of filtration experiments were conducted, and demonstrated that the flux decrement rate was in order of cellulose acetate membrane (CA, 65.4%), polyvinylidene fluoride (PVDF, 47.9%) and polyether sulfones (PES, 29.2%). Results showed that the fouling behavior of membrane should be predicted from the combined knowledge of solution chemistry, surface chemical properties and surface morphology. To better understand the interactions between the SMP and different membranes, a technique for reconstructing the membrane surface topology was developed on the basis of statistical parameters obtained from atomic force microscopy. The interaction energy, represented by extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) potential, was calculated by surface element integration, allowing exploring the interaction energy profiles for different surfaces and providing considerable insights into the role of such interactions on the macroscopic fouling behavior. The resulting interaction energy differed considerably from the corresponding interaction between perfectly smooth surfaces. The great influence of protrusion on the membrane surface was to reduce the primary energy barrier height, thus rendering rough surface more favorable for deposition. An attractive energy region was immediately surrounded by each positive asperity as demonstrated in the roughness-engendered interaction energy maps. As the SMP approached closer to the membrane, they had a high probability of getting trapped in the attractive energy region, leading to a more rapid loss of flux than smooth membrane. [Display omitted] ► SMP filtration was performed to study the fouling behavior of different membranes. ► A mathematical methodology was developed to reconstruct the membrane surface. ► The primary energy barrier was significantly changed by membrane surface topology. ► Attractive energy contours were immediately surrounded by each positive asperity.