treatment of tannery wastewater by various oxidation and combined processes

a general overview on the prospective of various oxidation and combined processes in the treatment of tannery industry effluent are reported. various oxidation and combined processes such as uv/h2o2/hypochlorites, fenton and electro-oxidation, photo-chemical, photo-catalytic, electro-catalytic oxidation, wet air oxidation, ozonation, biological followed by ozone/uv/ h2o2, coagulation or electro-coagulation and catalytic treatments have been considered. the tannery wastewater with sulphide as main sources of pollutant, electro-coagulation is the best removal efficiency process among the other oxidation processes, whereas for chromium, photo catalytic oxidation process using nano-tio2 and wet air oxidation in the presence of manganese sulphate and activated carbon as a catalyst are more efficiency processes. the integrated combined processes described permit to meet disposal limits, health quality standards and the recovery of several chemicals utilized in the tanneries.