Review of New Approaches for Fouling Mitigation in Membrane Separation Processes in Water Treatment Applications

Abstract

This review investigates antifouling agents used in the process of membrane separation (MS), in reverse osmosis (RO), ultrafiltration (UF), nanofiltration (NF), microfiltration (MF), membrane distillation (MD), and membrane bioreactors (MBR), and clarifies the fouling mechanism. Membrane fouling is an incomplete substance formed on the membrane surface, which will quickly reduce the permeation flux and damage the membrane. Foulant is colloidal matter: organic matter (humic acid, protein, carbohydrate, nano/microplastics), inorganic matter (clay such as potassium montmorillonite, silica salt, metal oxide, etc.), and biological matter (viruses, bacteria and microorganisms adhering to the surface of the membrane in the case of nutrients) The stability and performance of the tested nanometric membranes, as well as the mitigation of pollution assisted by electricity and the cleaning and repair of membranes, are reported. Physical, chemical, physico-chemical, and biological methods for cleaning membranes. Biologically induced biofilm dispersion effectively controls fouling. Dynamic changes in membrane foulants during long-term operation are critical to the development and implementation of fouling control methods. Membrane fouling control strategies show that improving membrane performance is not only the end goal, but new ideas and new technologies for membrane cleaning and repair need to be explored and developed in order to develop future applications.

Influence of the Zeolite ZSM-22 Precursor on a UF-PES Selective Substrate Layer for Salts Rejection

“…The enhanced surface hydrophilicity of the fumed silica zeolite NF membranes attract more water molecules close to the membrane than those of colloidal silica zeolite NF membranes, and facilitated the transport of water molecules in the membrane, which is an observed phenomenon here in line with most reported work [51,97,98]. Also, the diffusion affinity seems to be of great interest probably due to the nature of both zeolites resulting from different silica sources used.…”

Bio-Stimulated Adsorption of Cr(VI) from Aqueous Solution by Groundnut Shell Activated Carbon@Al Embedded Material

“…Various strategies have been addressed for the expulsion of Cr(VI) from contaminated water and procedures, such as precipitation, electro-dialysis, electro de-fluoridation, membrane, filtration, ion-exchange, oxidation, coagulation and reverse osmosis, etc., are utilized [9][10][11]. These techniques have a few disadvantages, such as a particularly high amount of sludge disposal, the development of large-sized particles, blockage of membranes by metal hydroxide formation, and high operation costs.…”

Biogas Production from Concentrated Municipal Sewage by Forward Osmosis, Micro and Ultrafiltration

“…Other authors have proposed the combination of coagulation with membrane filtration, with positive results [28][29][30]. Several fouling mitigation alternatives have been tested when using membranes for water treatment applications [31]. For example, fouling during the operation of membrane bioreactors has been extensively studied [32,33].…”