Investigation on Industrial Pollution of Zarjub River- Rasht City- Guilan Province

In this research, environmental impacts of development plans on the pollution of water resources of Rasht County were studied. Two important rivers passing through Rasht are the major source of water for domestic and agricultural uses. Zarjub River that provides the major portion of water used in this country is the most polluted river in Gilan Province and even in the country. This river plays a crucial role in spreading microbial diseases directly or indirectly. The sources of pollution of the river may be classified into industrial wastewater, urban sewage and agricultural wastewater. All shops and markets introduce their waste materials into this river. This study tried to introduce the factors explaining pollution arising from industrial development in urban and rural areas. In order to measure the degree of pollution, BOD, COD, pH, NO3, TSS, DO and coliform tests were carried out. Samples were collected in 12 points (agricultural, industrial and urban areaz) were collected for analysis every three months and the results were compared to environmental standards. Result shows that pollution of the river is above allowed levels and that the river lacks any self-refining system. Ten TSS tests out of 12 (with concentration 500 mg/L), ten TDS tests, seven BOD tests, eleven COD tests, four FTU tests, three pH tests and all coliform tests revealed the fact that pollution in this river has exceeded allowed levels.