عنوان مقاله [English]
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 .