Investigating the Feasibility of Reuse of Effluent from Wastewater Treatment Plant in Borujen City, Iran, for Agricultural and Irrigation Uses

Due to the expansion of agricultural activities and the occurrence of successive droughts, the utilization of urban effluents for agricultural purposes is a suitable and economical way. However, the safely and responsibly use of these resources is essential. The purpose of this study is to investigate the possibility of using the effluent of the Borujen municipal wastewater treatment plant for agricultural irrigation.

In this descriptively-analytically study, the physical, chemical and microbial properties of the effluent of Borujen municipal wastewater treatment plant were measured according to the standard methods for the examination of water and wastewater, for 6 months and then was compared with the standard of Institute of Standards and Industrial Research of Iran (IRNDOE) and The Food and Agriculture Organization (FAO).

The mean concentrations of Biological Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), and Total dissolved solids (TDS) parameters in the effluent were 10.00 ± 1.17, 39.19 ± 4.10, and 513.0 ± 8.7 mg/L respectively. The average of chemical parameters including Cl-, SO42-, PO43-, NO3-, NO2-, Na, Mg, Sodium adsorption ratio (SAR), HCO3-, CO32-, Ca, and alkalinity was within the standard range of IRNDOE and FAO. The average of turbidity in the effluent was 54.27 ± 16.47 NTU. This effluent, in terms of SAR and EC was in the great and acceptable water group respectively. The average concentration of heavy metals was less than the permissible level for these metals. The mean concentration of total coliform, fecal coliform were higher than the standard set for these parameters. Also, no parasite eggs were detected in the effluent.

The results showed that the average chemical parameters of effluent of Borujen wastewater treatment plant were within the standards of effluent use in agriculture. However, the concentration of biological parameters of the effluent was higher than the standard level; and in case of more microbiological purification, it can be used for irrigation of edible agricultural products.