Safety Promotion & Injury Prevention Research Center AND Department of Environmental Health Engineering School of Public Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
In any type of rubber product manufacturing (including tires), the primary concerns are environmental. The aim of the present study was to survey a treatment combination of ozonation and physicochemical processes in the rubber industry. Wastewater samples were collected from the discharge unit of the rubber processing sewage system in Kerman Barez Tire Factory, Kerman, Iran. The wastewater samples used for chemical oxygen demand (COD), biochemical oxygen demand (BOD), total suspended solids (TSS), and oil and grease determinations were collected directly into bottles. After collection, samples were transferred to the laboratory for examination. The 2 methods of physicochemical process and ozonation process were used to treat wastewater. The study results suggest that the use of a chemical coagulation process with ferric chloride (FeCl3.7H2O) in the first stage of this study reduced COD by 37% of the original amount (0.56 g/l). The optimum dosage and pH range were 0.775 g/l and 6.5, respectively. When using Al2(SO4)3, the COD reduction rate was 42%, and the optimum dosage and pH range were, respectively, 0.45 g/l and 6.5-7. After the ozonation process, COD was reduced by 70.75% and 90.6%. In accordance with these results and with respect to the high contamination load of this industry’s wastewater and its many environmental hazards, the complete treatment of this industry’s wastewater is crucial. One scientific and practical approach to wastewater treatment is the use of a combination of processes.