An Investigation on the Industrial Wastewater in Tehran Province

During 1994 to 1999 a research program titled “A qualitative and quantitative review of industrial wastewater in Tehran province” was done. This article presents the most important results obtained from this study. The research covered 330 food, textile, chemical, and Materials (Metal and liquid materials) factories. Completing of the questionnaire, sampling from the wastewater and analyzing have been done for 5 years. The results show that completely wastewater treatment in food, textile and metal industries were done in 8%, 18% and 17% of units respectively. In chemical industries for major groups include pharmaceutical, soap and detergent, pulp and paper, and paint industries were studied. In pharmaceutical and pulp and paper industries, there were only one factory in each group which were doing a complete treatment, and in detergent and paint industries there were no complete treatment at all. Maximum discharge of wastewater in food and textile industries were into surface waters. They were 62.4% and 48.8% respectively. But mainly wastwater discharging in metal and liquid materials industries were into ground waters which were 86% and 83% respectively.