Physicochemical Analysis of Untreated Municipal Wastewater for Irrigation Purposes in Chiro Town, West Hararghe, Ethiopia

Abstract

Reuse of wastewater for irrigation is certainly an effective substitute, especially in developing countries where there is a scarcity of fresh water, depletion of groundwater, the cost of pumping underground water, and the supply of some valuable plant nutrients. Therefore, the objective of this paper was to assess the suitability of untreated municipal wastewater (UMWW) for irrigation purposes in Chiro town, west Hararghe zone, Ethiopia using relevant standard methods. The results obtained show that the average values of hydrogen ion concentration (pH) and electrical conductivity (EC) in the sample were 7.48 and 2.54 dS/m. The average values obtained for the principal cations (Ca²⁺, Mg²⁺, K⁺, and Na⁺) and anions (Cl^-, CO₃^2-, SO₄^2-, HCO₃^-) were (119.56, 38.10, 13.00, and 58.00) mg/L and (88.75, 0.00, 11.91,705.6) mg/L, respectively.  The experimental results obtained for other miscellaneous factors, such as total suspended solids (TSS), total dissolved solids (TDS), and chemical oxygen demand (COD), are 90.0, 695.0, and 136.0 in mg/L. Throughout this study, the salinity hazard was assessed by analyzing the combination of TDS and EC values. The sodium hazard was evaluated by analyzing crucial factors such as sodium adsorption ratio (SAR), soluble sodium percentage (SSP), and residual sodium carbonate (RSC). Finally, the study findings of all relevant quality parameters for irrigation water revealed that the tested UMWW sample can be used in irrigation with a slight to moderate degree of restriction of use.