Conductive and hydrophilic polypyrrole modified membrane cathodes and fouling reduction in MBR

For increasing separation efficiency and reducing energy consumption, study about membrane fouling reduction has ever been a hot topic. To prepare fouling-resistant, hydrophilic and conductive membrane, polyester filter cloth was modified with polypyrrole (PPy) in-situ formed by polymerization of pyrrole (concentration 3.868 g/L) and sodium dodecyl benzene sulfonate (SDBS). Increase in SDBS concentration (0.5, 1 or 2 g/L) during polymerization increased the membrane electric conductivity and hydrophilicity, and enhanced the permeate flux and anti-fouling properties of modified membrane. A voltage drop at 0.2 or 0.4 V/cm exhibited better fouling reduction than 0 V/cm. In the long-term filtration tests with the PPy (2 g/L SDBS) modified membrane, both the irreversible and the total resistances were decreased (5 times and ∼2 times, respectively) by applying 0.2 V/cm electric field, indicating the effect of applied electric field towards fouling reduction. The membrane cathode successfully prevented the pore clogging.

► PPy and SDBS made the membrane more hydrophilic, conductive and fouling resistant. ► Electric field and PPy membrane cathode reduced fouling in MBR significantly. ► 0.2 V/cm voltage drop increased flux and lowered membrane resistance effectively.