Evaluation of Urban Wastewater with CWQI Model for agriculture and aquaculture reuse (case study in Zabol, Sistan and Baloochestan, Iran)

The aim of the study was to evaluate the quality of wastewater treatment plant of Zabol in Sistan and Balouchestan province according to related standards. Also, the possibility of agricultural and fisheries usage was investigated with CWQI model. A total 10 physicochemical parameters including pH, EC, COD, BOD5, TSS, TDS, TKN, NO2-, NO3-, PO43- and some heavy metals concentration were measured in effluent and influent of wastewater of treatment plant in middle of June, August and November of 2019. In order to achieve better wastewater application, the results were entered into CWQI (Canadian water quality index) calculator model. Due to effects of accumulation of heavy metals, this determined in agricultural areas that irrigated with treated and untreated wastewater flows. The data shows the wastewater effluent physicochemical parameters were appropriate for irrigation, except BOD5, COD and PO4-3 according to available standards. The heavy metals concentrations were within the range of available standards. The organic matters pattern was obtained in NO2-< NO3-<PO4-3. Conclusions the CWQI results showed that the quality of Zabol wastewater effluent is suitable for irrigation (71), livestock (85) and recreational (100) usage, but not suitable for fisheries (14) and drinking (45).