Quality Assessment of Surface Water for Domestic and Agricultural Purposes Using Hydro-chemical and Microbial Studies in Kilifi County, North Coast Region of Kenya
Bridgits Inyangala
Department of Biochemistry, School of Biomedical Sciences, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya.
Lenny Mwagandi Chimbevo *
Department of Pure and Applied Sciences, School of Applied and Health Sciences, Technical University of Mombasa, Mombasa, Kenya.
Paul Sifuna Oshule
Department of Medical Biochemistry, Medical School, Mount Kenya University, Thika, Kenya.
Suliman Essuman
Department of Medical Microbiology, Medical School, Mount Kenya University, Thika, Kenya.
Mwangome Muye Chongomwa
Department of Environmental Sciences, School of Pure and Applied Sciences, Pwani University, Kilifi, Kenya.
Norbert Adum Atego
Department of Pure and Applied Sciences, School of Applied and Health Sciences, Technical University of Mombasa, Mombasa, Kenya.
*Author to whom correspondence should be addressed.
Abstract
Water has economic and ecological significance. However, quality deterioration due to salinity causes significant decrease in agricultural productivity and a public health problem. This study focuses on hydro-chemical and microbial quality of water sources in Kilifi County. Water samples were collected from 25 different locations within Kilifi County and indicators of salinity and microbial load analyzed. Temperature, pH, EC and TDS were determined using portable pH meter. Anions; F-, Br-, Cl-, SO42-, PO43-, NO2-, NO3-, CO32-, HCO3- and NH4+ were determined using Ion Exchange Chromatography. Cations; Na+, K+, Ca2+, Mg2+, Zn2+, Fe2+, Cd2+, Cr3+, Al3+ and Ag+ were determined using flame photometry. Standard methods were used to determine Microbial loads. Results were pH (7.42±0.52), Temperature (24.61±0.21oC), EC (3.44±0.75 dscm-1), TDS (1672.53±122.87 mgL-1) and Turbidity (152.29±41.20 NTU). Anions; F- (2.90±0.24 mg/L), Cl- (1756.68±900.50 mg/L), NO2- (4.47±0.49 mg/L), Br- (11.72±1.20 mg/L), NO3- (4.67±0.38 mg/L), HCO3- (200.54±25.58 mg/L) PO43- (0.94±0.10 mg/L), CO32- (29.94±2.32 mg/L), and SO42- (300.64±42.47 mg/L). Cations; K+ (8751.80±214.04 mgL-1), Na+ (59.43±1.98 mgL-1), Ca2+ (4.00±0.16 mgL-1), Mg2+ (59.43±1.98 mgL-1), Zn2+ (0.76±0.30 mgL-1), Cu2+ (0.18±0.01 mgL-1), Ag+ (0.03±0.01 mg/L), Cd2+ (0.07±0.01 mg/L), Cr3+ (0.35±0.01 mg/L), Al3+ (0.33±0.01 mg/L) and NH4+ (2.01±1.96 mg/L). Microbial load; MPN (20811.00±402.00), Total coliforms (2970.00±60.00 CFU 100 mL-1), E. coli (26.00±3.00 CFU 100mL-1), S. aureus (411.00±12.00 CFU 100mL-1), Shegela (24.00±2.00 CFU 100mL-1) and S. typhi (67.00±2.00 CFU 100mL-1). Temperature, pH, EC, TDS, Turbidity, F-, Cl-, Br-, PO43-, Na+, Zn2+, Fe2+ and microbial load were above WHO limits whereas SO42-, NO2-, NO3-, CO32-, HCO3-, NH4+, K+, Ca2+, Mg2+, Cd2+, Cr3+, Al3+ and Ag+ were below WHO limits. The study concludes that water sources in Kilifi County are unsuitable for domestic and agricultural uses. It’s recommended that a continuous water quality monitoring program be put in place and development of effective management practices for utilization of the surface water resources be instituted.
Keywords: Quality assessment, surface water, salinity indicators, microbial load