用XDLVO理论解析海藻酸钠微滤膜污染中pH的影响机制

In order to study the role of interfacial interactions in the microfiltration (MF) membrane fouling by sodium alginate, the extended Derjaguin-Landau-Verywey-Overbeek (XDLVO) theory was used to quantitatively calculate the interfacial interaction energies of membrane-alginate and alginate-alginate. The influence of different solution pH and the role of each individual interfacial interaction were investigated. The results showed that within the pH range in this study, the acid-base (AB) interaction played a dominate role. The interfacial interaction between the hydrophobic PVDF membrane and alginate was attractive, while the interfacial interaction between the hydrophilic PES membrane and alginate was repulsive, and this caused the higher resistance removal for PES membrane than that for PVDF membrane in physical cleaning. The fouling potential of each membrane under different solution pH in the adhesion stage of filtration experiment is pH 5>pH 7>pH 8>pH 9, and matched the interfacial interaction energies of membrane-alginate. The fouling potential of the cohesion stage also had a correlation with the interaction energies of alginate-alginate.