Health and Environmental Impact Assessment of Disposal and Reuse of Effluent from Marand Municipal Wastewater Treatment Plant For Agricalture

Abstract

Background and Objectiv: The water crisis is one of the most important challenges for human societies. Reuse of treated wastewater, especially for irrigation of agricultural products, is one of the solutions to the problem of water shortage. However, due to the nature of wastewater, the environmental and health consequences associated with the use of wastewater in agriculture should not be ignored. Considering the importance of the issue of wastewater reuse for irrigation, the purpose of this study was investigating the quality of effluent of Marand treatment plant and to investigate the environmental and health effects of using wastewater for agricultural irrigation. Materials and Methods: In order to determine the health and environmental impact of reuse and disposal wastewater of Marand wastewater treatment plant, first, information about the performance of treatment plant was prepared by referring to Marand Water and Wastewater Department and then the physicochemical and microbial quality of its effluent was measured by sampling and compared with Environmental standards. Also, through local surveys, the route of the effluent from the treatment plant to the final route was investigated and the health and environmental effects of wastewater disposal and reuse on physical, biological, economic-social and health parameters was evaluated using wooten and rau method. Results: The results showed that the values of physicochemical parameters including BOD, COD, TSS and turbidity were higher than the values recommended in the standards and guidelines for the use of wastewater in agriculture. The values of pH, EC, TDS, SAR, hardness, sulfate, magnesium and chloride parameters were less than the values recommended in the standards.Also, the quality of Marand treatment plant effluent, in terms of salinity parameter, is classified in the category of water with low to medium constraints. The experimental results also showed that total coliforms and fecal coliforms in the effluent were higher than the standard, so the biological quality of the effluent is considered unfavorable for irrigation. Also, the evaluation of environmental and health effects of effluent based on Wooten and Rau matrix was evaluated for the first option (using the existing effluent for irrigation) with a total score of effects equal to (-140) undesirable, for the second option (no use of effluent and discharge to the environment( with a total score of effects equal to (-44) undesirable and for the third option (advanced treatment and planned use of wastewater for irrigation) with a total score of effects equal to (+ 175) desirable. Concusion: The final result of the evaluation suggests the implementation of irrigation project with effluent of Marand city treatment plant for the third option. Keywords: Effluent, Reuse, Environmental Impact Assessment, Marand City, wooten and Rau Matrix