Assessment of treated wastewater quality in Sanandaj city, Iran, for irrigation purposes

The objective of the present study is to assess treated wastewater quality in Sanadaj city, Iran for agricultural irrigation purposes. The wastewater from the wastewater treatment plant operating in Sanadaj city was tested for pH, electrical conductivity (EC) and selected metals presence (As, Cd, Cr, Fe, Mn, Ni, Pb, Ca, Mg, Na, K and Li). The results of wastewater analyses were compared to relative guidelines regarding wastewater reuse for irrigation. The pH and EC parameters showed that the wastewater had none restriction for irrigation purposes. However, according to the values of EC and SAR, the long-term application of the wastewater may reduce the soil infiltration. Among the heavy metals, the As had the most concentration that it should be removed using advanced treatment technologies. Overall, the wastewater can be used for irrigation purposes if efficient advanced treatment methods are applied prior to reuse or adequate management approaches are employed for irrigation. One of the management approaches is alternative irrigation of agricultural lands using fresh water and wastewater, but only for restricted irrigation.

Keywords:

Treated wastewater reuse , Restricted irrigation , Electrical conductivity , Sodium adsorption ratio , Heavy metals