Alternative methods for cleaning membranes in water and wastewater treatment

Abstract

Membrane fouling is caused by foulant deposition or adsorption through physical or chemical interactions on the membrane surface, causing the reduction of flux through the membrane. The main drawbacks of chemical agents used for cleaning are cost, damage caused on the membrane, and waste stream making the process unattractive. Alternative, methods such as ultrasound, enzymatic process, and osmotic backwashing were explored for membrane cleaning. Among all mentioned methods, micronanobubbles have been reported as a promising and emergent method for membrane surface cleaning; unfortunately, the information is limited, but preliminary studies have shown it as an efficient, cheap, and environmentally friendly technique. Other methods like electrically and vibratory‐enhanced membrane cleaning also could be interesting but currently are unexplored and information is limited. Practitioner Points Chemical cleaning is an efficient option; however, from an environmental point of view, it is not attractive, and high concentrations could cause damage to the membrane. Micronanobubbles are an emergent and suitable technology for membrane and surface cleaning. Membrane modification and functionalization avoid membrane fast fouling, and the cleaning process is easier, but the manufacture cost could be expensive.

Anaerobic membrane bioreactors

“…NaClO is the most used oxidant for membrane cleaning and removes both organic and biological foulants via oxidation and disinfection (Terán-Hilares et al, 2022), and enhances the detachment of organic molecules from the membrane by increasing their hydrophilicity. With ceramic membranes, Song et al (2016) showed that permeate flux can be restored using NaOH at 70 ± 1°C which hydrolyses colloids into fine particles, and organic matter into small molecules.…”

Biogas Production in AnMBRs via Treatment of Municipal and Domestic Wastewater: Opportunities and Fouling Mitigation Strategies

“…NaClO is the most used oxidant employed for membrane cleaning. It allows for the removal of organic and biological foulants via oxidation and disinfection processes [68,69]. It may degrade functional groups of natural organic matter (NOM) into ketonic, carbonyl, and aldehyde groups, leading to their hydrolysis at high pH levels [144].…”

“…In brief, the methods of membrane cleaning are categorized into three groups: chemical, physical, and physio-chemical. It should be emphasized that physical cleaning is adopted to remove reversible fouling while chemical cleaning to remove irreversible fouling [26,68,69].…”

Chemical Stability and Additive Leach Out in Polyethersulfone Membranes Blended with Dragon Blood Resin: An Investigative Study

“…Membrane fouling can be avoided by regular cleaning with chemicals such as sodium hypochlorite or NaOH. However, the more frequently a membrane is cleaned with chemicals, the shorter its life-span [15,22,34].…”