Disinfection of drinking water via algae mediated green synthesized copper oxide nanoparticles and its toxicity evaluation

Industrial and domestic discharges are contaminating surface water via bacterial infestations. Therefore, the present study focused on application of biogenically derived nanoparticles for elimination of such contaminants from water. Green synthesis of copper oxide nanoparticles (CuO NPs) by algal extract resulted in formation of nanoparticles with particle size of 3.6 nm. Effect of pH, concentration of algal extract, stirring speed and initial Cu2+ concentration, was studied and optimized. The synthesized particles showed antimicrobial activity against gram negative bacteria, Escherichia coll. Optimized dose of 50 mu g/mL of NPs were found to be effective against Escherichia coll. in surface water samples. Toxicity assay on fish model was conducted to analyze the probable toxic effect of CuO NPs on living system by observing formation of micronuclei in fish blood. No micronuclei were observed in fish blood after exposure to CuO NPs for 30 days. Cell death assay was conducted on mammalian cell lines, including human gastric epithelium (AGS) and Chinese hamster ovarian (CHO) by MTT (3-(4, 5-dimethylthiazol 2 yl) 2, 5 diphenyl-tetrazolium bromide) assay which showed that cells had toxic effect of CuO NPs above 2.5% concentration indicating the potential use of the green synthesized CuO NPs in drinking water applications.