Solar photocatalytic treatment of wastewater with zinc oxide nanoparticles and its ecotoxicological impact on Channa punctatus –a freshwater fish

Azo dye and hexavalent chromium are two carcinogenic and toxic pollutants present in industrial wastewater. Zinc oxide nanoparticles can be used for the treatment of these pollutants with solar energy. However the nanoparticles themselves generally have some inherent toxicity for aquatic life. In this work, we have selected Channa punctatus as the model aquatic animal and examined whether the net toxicity to which it was exposed in wastewater before treatment, decreases after photocatalytic treatment of dye and hexavalent chromium using ZnO nanoparticles as photocatalyst under sunlight. Lipid Peroxidation (TBARS) and Reduced Glutathione (GSH) have been used as measures of toxicity in fish. We have compared these parameters under different experimental conditions comprising organic and heavy metal pollutants with and without nanoparticles.