The study of Fenton oxidation process efficiency in the simultaneous removal of phenol, cyanide, and chromium (Ⅵ) from synthetic wastewater

摘要

Background and objectives: phenol, cyanide, and chromium (Ⅵ) are toxic pollutants. They can be discharged from different industries simultaneously such as iron and steel industry, coal mining, automobile manufacturing of parts. Presence of these pollutants in water and waste-water is a serious hazard and these substances lead to undesirable effects on both the environment and human. Thus, control of these contaminants is essential for human health and environment. The main objective of this study was to assess the efficiency of Fenton process for simultaneous removal of phenol, cyanide, and chromium (Ⅵ) from synthetic wastewater. Materials and methods: This study is an experimental study in lab scale that was carried out in a batch system. Variations of this study including pH, chemicals concentration (Fe~(2+) and H_2O_2 and molar ratio Fe~(2+)/H_2O_2), and reaction time were investigated. Cyanide, phenol, and total chromium were determined respectively by colorimetric method (spectrophotometer), high-performance liquid chromatography, and atomic absorption spectrophotometer. Results: The results of this research showed that simultaneous removal efficiency of phenol, cyanide, and chromium ((Ⅵ) from synthetic wastewater by Fenton process were 88, 86 and 92%, respectively (conditions: pH = 4, Cr~(6+) and CN~- = 10mg l~(-1), Phenol = 150 mg l~(-1), H_2O_2 = 150mg l~(-1), Fe~(2+) = 140mg l~(-1) (Fe~(2+)/H_2O_2 = 0.58) after 30min reaction time). Conclusion: According to the results, it can be concluded that Fenton process can be considered as a suitable process for cyanide, phenol, and chromium (Ⅵ) removal to achieve environmental standards.