Development and performance evaluation of native microbial consortium for multi metal removal in lab scale aerobic and anaerobic bioreactor

Shortage of freshwater force farmers to use untreated wastewater for irrigation which leads to the accumulation of contaminants like heavy metals in the food chain and deteriorate the quality of produce and soil. Present study focused on bioremediation of multiple heavy metals (Cd, Cu, Cr, Zn. Pb and Ni) from wastewater used for irrigation of food crops using four continuous Stirred Tank Reactor (CSTR), two aerobic and two anaerobic. One set of bioreactor (aerobic and anaerobic) was fed with actual wastewater, showed heavy metal removal up to 30%-100%. Whereas other set fed with spiked with metal ion concentration showed removal up to 70%-100%, indicating the improvement in removal efficiency due to acclimatization of microbial consortia at higher metal concentration. Present study clearly shows the ability of native microbial consortia in removing even higher concentrations of heavy metals from actual wastewater under ambient conditions. The present bioreactors configuration can be scale up for the onsite wastewater treatment with further optimization of the removal process. It was recommended that after using the present treatment process, treated water is safe for irrational purposes. (C) 2020 Elsevier B.V. All rights reserved.