Evaluation of the efficacy of membrane bioreactor in removing hexavalent chromium

Abstract Chromium is a hazardous metallic element with poisonous, mutagenic, and cancer‐causing properties. The negative impacts also affect microorganisms, plants, animals, and humans. The primary focus of this research is to examine how hexavalent chromium can be eliminated using a semi‐industrial scale membrane bioreactor (SIS‐MBR). A system consisting of flat sheet and hollow fibre polyethersulphone membranes, with a capacity of 120 L, was utilized to evaluate the effectiveness of eliminating carbonaceous pollutants at different concentrations of Cr(VI). The research demonstrated that a flat sheet membrane bioreactor efficiently eliminated an average of 99.1% of chromium from wastewater within 24 h. The removal rate was notably higher than the 95.9% average removal achieved by a hollow fibre membrane when treating a concentration of 10 mg/L of Cr(VI). The presence of hexavalent chromium at concentrations ranging from 1 to 10 mg/L does not impact the elimination of carbonaceous pollutants. However, there is a slight decrease in COD removal efficiency when the Cr(VI) concentration reaches 50 mg/L. The study validated the feasibility of chromium removal using the SIS‐MBR equipment.