قابليت بازچرخش و استفاده مجدد از فاضلاب صنايع فلزي و كاني غيرفلزي تهران بزرگ

Recycling and reuse potential for effluents of metal and non-metal industries of Tehran metropolitan area

The increasing number of population in Tehran, resulted from high rate of immigration, has caused a significant increase in water use and wastewater production. Also, regarding the development of industrial activities to provide the needs of Tehran population, high rule of industrial wastewater is annually produced in the region. On the other hand, considering the problem of water shortage in Tehran, wastewater reuse and recycling has become an important and considerable issue. This research, with the major objective of studying the possibility of wastewater reuse for Tehran metropolitan area in the group of metal and non-metal industries, was conducted in 2 stages. At first stage, industrial effluents of this group were studied, both quantitatively and qualitatively. Then, possibilities of wastewater recycling in industrial processes and reuse in irrigation were studied. The total amount of annual water which was used in this group of industries in the region was 44160 mʹ/d (85% supplied from groundwater resources and 15% from Kara] dam). Car manufacturing and glass manufacturing.factories presented the highest and lowest water use rates, with 37% and 3% respectively. The total amount of wastewater production in the region reached to 38995 mʹ/d. This study also showed that tile and ceramic and also asbestos industries have a good potential to recycle the final effluent and to reuse it in other processes.Furthermore, results of the study on different soil classes and effluent qualities, showed that industrial wastewater may easily be reused in the west of Tehran for irrigation purposes and groundwater recharge, provided that the acceptable health-related regulations are completely considered.