Influential Mechanism of Natural Organic Matters with Calcium Ion on the Anion Exchange Membrane Fouling Behavior via xDLVO Theory.

Zhun Ma,Xiaomeng Wang,Qun Wang,Lu Zhang,Xiaosheng Ji,Jianliang Xue,Yuting Xu,Yongchao Sun,Xueli Gao,Jian Wang,Ying Liu

doi:10.3390/membranes11120968

Abstract

The fouling mechanism of the anion exchange membrane (AEM) induced by natural organic matter (NOM) in the absence and presence of calcium ions was systematically investigated via the extended Derjaguin–Landau–Verwey–Overbeek (xDLVO) approach. Sodium alginate (SA), humic acid (HA), and bovine serum albumin (BSA) were utilized as model NOM fractions. The results indicated that the presence of calcium ions tremendously aggravated the NOM fouling on the anion exchange membrane because of Ca-NOM complex formation. Furthermore, analysis of the interaction energy between the membrane surface and foulants via xDLVO revealed that short-range acid–base (AB) interaction energy played a significant role in the compositions of interaction energy during the electrodialysis (ED) process. The influence of NOM fractions in the presence of calcium ions on membrane fouling followed the order: SA > BSA > HA. This study demonstrated that the interaction energy was a dominating indicator for evaluating the tendency of anion exchange membranes fouling by natural organic matter.

Highlights

The Institute of Seawater Desalination and Multipurpose Utilization, Ministry of Natural Resources (MNR), College of Safety and Environmental Engineering, Shandong University of Science and Technology, Academic Editor: Yi-Li Lin
Theory, a positive value for the total interaction energy between membrane and foulants indicated the resistance to membrane fouling, while a negative value means a promotion to membrane fouling [36,37]
In all membrane–Sodium alginate (SA)–calcium ion systems, the negative value of the total interaction energy could be inferred that the foulant of SA tended to exacerbate the membrane fouling

Summary

Introduction

This study demonstrated that the interaction energy was a dominating indicator for evaluating the tendency of anion exchange membranes fouling by natural organic matter. Essentially attributed to interface interactions between the membrane surface and foulants in aqueous solution, is a big obstacle to the ED process for wastewater treatment [27]. Shan et al used HA as a model foulant to study its fouling behavior on super-wetting nanofiltration membranes applying xDLVO approach They testified that the super-hydrophilic membrane had the strongest repulsion force to HA due to the highest positive total interaction energy value [27]. Zhao et al utilized xDLVO theory to quantitatively validate the interfacial interactions in the nanofiltration membrane fouling process under various organic matter and Ca2+ concentration [33]. To the best of our knowledge, there are no reports on the application of xDLVO theory to predict and evaluate anion exchange membrane fouling in the ED process

Methods

Results

Conclusion