Simultaneous solid-liquid separation and wastewater disinfection using an electrochemical dynamic membrane filtration system

An electrochemical dynamic membrane filtration (EDMF) system for simultaneous solid-liquid separation (also protecting electrodes against fouling) and sewage disinfection was developed. At a low voltage of 2.5 V, efficient disinfection performance was achieved in the EDMF, with similar to 100% log removal efficiency (no detectable bacteria in the effluent). Results also demonstrated that the EDMF system, operated at membrane flux of 100 L/(m(2) h), could maintain long-lasting bacterial disinfection efficiency of real wastewater (similar to 100% log removal) in continuous flow tests. Transmembrane pressure (TMP) increased from 0.8 kPa to 22 kPa within 80 d (one operation cycle), and cleaning of EDMF could effectively restore TMP and biocidal behaviors for subsequent filtration cycles. In contrast, without dynamic membrane, the disinfection efficiency was decreased from initial similar to 100% log removal (with no detectable live bacteria) to similar to 44.4% log removal within 7 d. Reactive oxygen species (ROS)-mediated oxidation was responsible for bacteria disinfection in the EDMF, and HO center dot and H2O2 generated in this system played a dominant role, causing damage to cell membranes and K+ leakage from cytosol. Moreover, catalase and superoxide dismutase for intracellular ROS attenuation were inhibited, resulting in the increase of intracellular oxidative stress and thus high-efficient disinfection. These results highlight the potential of EDMF system to be used for wastewater treatment and disinfection.