In this work, membrane fouling represented as the time-to-filter (TTF) was investigated in a function of current density (ranging from 0.3 to 1.5 mA/cm2) and temperature (from 8 to 20 °C). Settling characteristics, defined as sludge volume index (SVI), were also assessed. Under low temperatures, activated sludge from electro-bioreactors revealed excellent settling and filtration properties at several combinations of low periodic current density (CD) experiments. For instance, after a 72-h electrokinetic (EK) operation at a CD of 0.3 mA/cm2 and a temperature of 8 °C, TTF, SVI, mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), ζ-potential, mean particle-size distribution (PSD), soluble microbial products (SMPs), and extracellular polymeric substances (EPSs) were 4.2 min, 53 mL g−1, 4000 mg L−1, 3200 mg L−1, 12 to − 20 mV, 57.82 μm, 17.26 mg L−1, and 13.9 mg gVSS−1, respectively. Such improvements in both filterability and settleability of activated sludge and then potential membrane performance could be attributed to a change in the floc size and structure of activated sludge by adequate CD field operation. Nevertheless, a CD of 1.5 mA/cm2 with a shorter resting time (i.e., 60 s ON/60 s OFF) exhibited poor filterability compared to other exposure regimes because of the elevated no growth associated SMP products. Overall, this research provides a chemical-free electrokinetic (EK) approach to improve the physicochemical and biological properties of the sludge and reduce membrane fouling at even low-temperature environments. This study demonstrated that the technological parameters of a membrane electro-bioreactor (MEBR) could be applied to low temperature sewage.
