Treated wastewater reuse for green space irrigation in arid and semiarid regions

This research investigated the feasibility of reuse of treated wastewater of the existing treatment facilities in Sistan and Baluchestan province of Iran for green space irrigation as a part of waste management in the form of a pilot study. After investigation of the environmental parameters and wastewater treatment conditions, two pilot plants in zahedan and zabol cities were designed and performed. On the basis of the results of qualitative tests of the soil, before and after establishment of the Zahedan Pilot, we can say that the soil quality has been improved. The values of soil EC, pH, SAR, and ESP prior to establishment of the pilot have been 27.8, 8.05, 44.73 and 38.87 respectively. After irrigation of the pilots for a period of 5 months the said values changed to 8.5, 8.34, 13.62 and 15.61 respectively which show the decrease in EC, SAR and ESP for 30, 30.5 and 40.2 percent respectively. After continuation of the irrigation for 12 months, the said values were decreased to 8.34, 7.89, 13.76 and 15.75 percent respectively. The values of soil EC, pH, SAR, and ESP prior to establishment of the Zabol pilot were 9.55, 8.35, 17.46 and 19.39 respectively. After irrigation of the Zabol pilots for a period of 5 months the said values changed to 5.05, 8.59, 7.35 and 7.81 respectively which shows the promotion of soil properties. After continuation of the irrigation for 12 months, the said values were changed to 3.93, 8.02, 7.91 and 21.82 respectively. The results showed a lack of any adverse effect on the soil quality and growth of the selected plants; the majority of the quality factors were approximately at an optimum level and only soil ESP had been significantly increased in the Zabol pilot. Two solutions are suggested for promotion of the treatment plants operation.