Study of the Efficiency of Isfahan East Wastewater Treatment Plant, Iran, in Achieving Engelberg Index

Today، treated wastewater recycling and reuse has been considered for agricultural irrigation. This can potentially cause health and environmental hazards. Since accessing the engelberg index for sewage is a necessity، this study was undertaken on integrated stabilization ponds (ISP) of Isfahan east wastewater Treatment plant، Isfahan، Iran. This cross-section study was conducted during winter and spring of 2011. Samples of raw and effluent wastewater were taken instantly and every two weeks. Nematode eggs، and total and fecal coliform were counted according to standard methods (APHA،2005). Data were analyzed using statistical tests and SPSS software. Although، no nematode eggs were observed in the discharge of treated wastewater during winter and spring، fecal coliform value and its removal amount during winter was 3. 84 × 104 and 5. 1 log Unit and during spring was 2. 09 × 104 and 4. 5 log Unit. The six-month mean of fecal coliform in treated wastewater was 2. 9 × 104 in 100 ml. There were no significant differences in removal mean in the two seasons (P = 0. 25). The results showed a lack of compliance with the W. H. O standard، and that the fecal coliform number is more than the guideline value for unrestricted Irrigation (< 1000 per 100 ml). Therefore، reuse of this wastewater plant effluent is not suitable for agriculture irrigation without further treatment.