Assessment Of Selected Physico-Chemical Parameters, Anions, And, Heavy Metals In River Chemosit, Kericho County, Kenya

Abstract

Clean water is fundamental for life. River Chemosit serves as a crucial water source for domestic, agricultural, and industrial purposes, thus sustaining the local livelihoods. The escalating concern regarding river pollutants poses a significant threat to public health. This study aimed to evaluate the water quality of River Chemosit to assess its current pollution status. Both upstream and downstream areas of Chemosit Centre were surveyed from August 2021 to January 2022. Water samples were systematically collected along River Chemosit from Kipkerieny, Chemosit Centre, and Kabitungu sampling points. These samples underwent comprehensive analysis for various physicochemical parameters. pH, temperature, electrical conductivity (EC), dissolved oxygen (DO), and total dissolved solids (TDS) were measured in situ using a calibrated portable professional series (YSI) multiparameter meter model 35 C. Additionally, a UV-VIS spectrophotometer was employed for analysing sulfates, phosphates, and nitrates, while ICP-MS was used for heavy metal analysis. The collected data was statistically analysed using SPSS version 28. Spatially, the mean values for the parameters were as follows: pH 7.0 ± 0.05, temperature 24.15 °C ± 0.18, EC 1187.94 μScm-1 ± 30.84, DO 8.99 mgl-1 ± 0.06, TDS 1460.06 mgl-1 ± 69.14, sulfates 0.08 mgl-1 ± 0.005, phosphates 0.40 mgl-1 ± 0.01, and nitrates 1.6 mgl-1 ± 0.09. Spatially, the mean values for the metals were as follows: Zn 0.07 mgl-1 ± 0.01, Fe 0.43 mgl-1 ± 0.01, Al 0.47 mgl-1 ± 0.03, Cu 0.02 mgl-1 ± 0.001. from the analysis, lead (Pb) was below the detectable limit. Seasonally, significant differences were observed in the mean values of pH, temperature, EC, TDS, sulfates, and phosphates, except for DO and nitrates. The mean values for pH, EC, DO, copper (Cu), zinc (Zn), nitrate (NO3-), and sulfate (SO42-) met WHO guidelines for domestic water use both spatially and seasonally. However, mean values for aluminum (Al), iron (Fe), and phosphate (PO43-) exceeded WHO limits, and TDS mean values surpassed WHO limits during the dry season. Correlation coefficient analysis indicated significant relationships between various physico-chemical parameters. River Chemosit's contamination with pollutants originating from anthropogenic activities and discharge from domestic and industrial sources underscores the imperative for continuous water quality monitoring to ensure compliance with NEMA and WHO standards.