Ex-situ biofilm mediated approach for bioremediation of selected heavy metals in wastewater of textile industry

Abstract

Industrialization plays a major role in strengthening the economy of any country. However, these industries directly or indirectly affect the environment. Industrial wastewater discharge has been reported with certain heavy metals such as chromium, lead, cobalt, and others which are a potential hazard to the water bodies and humans as well. Biofilm is an applied method in the fields of bioremediation for reliving this emerging problem and in the efficient removal of heavy metals from wastewater. Biofilms of Escherichia coli and petroleum soil isolated microorganisms (PSIM) were developed at the V bottom of 96 well microtiter plate. The contaminated water sample was collected from the textile industry, Solan, Himachal Pradesh, India. The biofilms were incubated with the industrial water tested for heavy metals assuming the microbes have the potential to assimilate the heavy metals up to 5 mg/mL of concentration. After the incubation for 1-2 weeks, the microorganisms were able to reduce the level of heavy metals present in the samples which was conveyed by biomass comparison of microorganisms in the successive intervals of time. 0.74 × 10 10 cells/mL and 0.77 × 10 10 cell/mL of E. coli and PSIM biofilms were able to tolerate the metal toxicity on incubation for 2 weeks at the highest concentration due to the functional group present extracellular polymeric substance which forms complexes with heavy metals. This leads to the fact that these biofilms have assimilated the heavy metals and are potent for the removal of heavy metals from industrial wastewater.