Purification Method of Industrial Waste Water with Hexavalent Chromium Removal

Abstract

Background and Objective: Common sources of chromium in wastewater are electroplating and leather industries. Thus, the aim of this study is synthesis activated carbon fiber/zinc oxide composite to remove of Cr (VI) from polluted water.Materials and Methods: The immobilization of zinc oxide (ZNO) on activated carbon fiber (ACF) was accomplished by Sol-gel method and synthesized activated carbon fiber composite (ACF/ZNO),was used to reduction of chromium under ultraviolet light from aqueous solution. And characterized by BET, SEM, XRD. After the design of the reactor, hexavalent chromium stock solution, using a solution of potassium dichromate (K2Cr2O7) in distilled water, were prepared. The residual concentration of chromium was analyzed by the 1,5-diphenylcar-bazide method using a spectrophotometer at a wave length of 540 nm.Results: The XRD results showed that a typical hexagonal phase for ZnO. The SEM results showed that zinc oxide were distributed on the ACF surface. It showed that the BET surface area was related to adsorption capacity for composite. Parameters effect, including concentration of pollutants, composite dose and pH were studied.Conclusion: In optimal conditions, initial chromium concentration of 5 mg/l, composite dose 2.5 g/l and a pH of 3, after 120 minutes, system removal efficiency was 85%.</p