Assessment of physico-chemical parameters and their impacts on the water quality at igombe reservoir, Tabora, Western Tanzania

Assessment of physico-chemical parameters and their impacts on water quality at lgombe reservoir was done by investigating the influence of anthropogenic activities on water quality during wet and dry seasons. Standard methods were used to determine the levels of physico-chemical parameters from the water samples. Physical parameters including temperature, turbidity, alkalinity, dissolved oxygen (DO), electrical conductivity (EC), and pH, were determined in situ. Chemical parameters such as NO3', SiC>2, PO43', Fe2+, SO42', Cl', and major cations were determined in the laboratory. Data show higher concentration of physico-chemical parameters during the wet season than during the dry season at various sampling sites. This has been attributed to reservoir-increased input of the physico- chemical parameters by surface runoff. The mean variation of NO3', SiC>2, PO4 \ Fe , SO4 ", and Cl" concentrations ranged from 0.7 to 2.9 mg/1, 11.38 to 34.9 mg/1, 0.02 to 0.27 mg/1, 0.04 to 0.86 mg/1, 6.3 to 7.8 mg/1, and from 5.2 to 6.5 mg/1 respectively. Data have shown that processes including dissolution, diffusion, adsorption, absorption, nitrification, denitrification, mixing and reduction along with anthropogenic activities explain the variation of physico-chemical parameters in the reservoir. It has been concluded that human activities impacts significantly on the water quality of the reservoir. It is recommended that continuous monitoring and surveillance of anthropogenic activities taking place around the lgombe reservoir should be conducted in order to control pollution from both point and non-point sources to ensure sustainable water resource at the reservoir.