Understanding Membrane Fouling in Electrically Driven Energy Conversion Devices

Positively charged (cetylpyridinium chloride), negatively charged (sodium dodecyl sulfate), and non-charged (polyethylene glycol) surfactants are used as potential foulant in reverse electrodialysis systems supplying seawater and river freshwater. Fouling tendency of the foulants to ion-exchange membranes is investigated in terms of the adsorption by electromigration, electrostatic attraction, and macromolecule interaction in reverse electrodialysis systems. According to theoretical prediction of fouling tendency, charged foulants in seawater streams could foul ion-exchange membranes significantly. However, the worst fouling behavior is observed when the charged foulants are present in river streams. As a result of zeta potential measurement, it is found that the Debye length of the charged foulants decreases due to the higher ionic strength of seawater streams and causes to lower net electrostatic effect. It finally results in less fouling tendency in reverse electrodialysis.

Automated summary

The study investigates the fouling tendency of positively charged, negatively charged, and non-charged surfactants on ion-exchange membranes. It is found that charged foulants in seawater could significantly foul the membranes, while the worst fouling behavior is observed when charged foulants are present in river streams. Through zeta potential measurement, it is demonstrated that the Debye length of charged foulants decreases in seawater streams due to higher ionic strength, leading to lower net electrostatic effect and less fouling tendency in reverse electrodialysis.