Investigation of Physico-chemical and Microbiological Characteristics of Urban Wastewater For Use in Agricultural Production

摘要

Today, scarcity of water is one of the greatest challenges in agriculture. The reasons for this scarcity are population growth, promotion of lifestyle, climate change, continuous droughts, and lack of proper water resource management, under such circumstances, use of unconventional water sources including urban wastewaters in agriculture as the major consumer of water is of special importance. In this paper, quality of raw wastewater of Meshkinshahr, located in Ardabil Province, Iran, was studied, which is directly used in spring and summer in Brazil Village, a village in the southern part of the county, due to shortages of water sources for irrigation of orchards and farms. The present research is a descriptive-cross sectional study carried out bysampling from raw urban wastewaters in spring and summer 2014. The results suggested that average values of pH, DO, COD, BOD5, TSS, Cr, Mg, B, Cd, Pb, Hg, Fe, parasite eggs, oil and fat, turbidity, nitrates, Ca, Mn, Na, CI and phosphates were 7.05 mg/1,2 mg/1, 412.5 mg/I, 235 mg/1, 92.5 mg/1, 0.0265 mg/1, 0.02 mg/1, 0.15 mg/1, 0.015 mg/1, 0.22 mg/1, 0.05 mg/1, 0.275 mg/ 1,4.8 mg/1, 91.5 mg/1, 0.085 mg/1, 53.5 mg/1, 37 mg/1, 39.5 mg/1, 0 mg/1, 12.55mg/l, respectively, which are lower than agricultural standards of Department of the Environment (DOE). Average contents total and fecal coliforms were 3300mg perlOOml and 2300mg perlOOml, respectively, which were inconsistent with this standard. Thus, in order to avoid hygienic and coliform-based impacts, chlorinating the wastewater prior to its consumption for agricultural purposes is recommended to reduce the values to DOE standards.