Effects of Solute Concentrations on Thermodynamic Properties of Lake Victoria Waters

Abstract

Water help supports life processes and habitats of virtually all organisms. The rivers that flow into Lake Victoria harbor huge amount of solutes which affect its characteristic features and ecological equilibrium. This has affected the distribution of aquatic organisms and led to eutrophication and algal blooms and other invasive species such as water hyacinths. The present study focused on colligative properties (boiling point elevation, freezing point depression and vapour pressure deficit) of waters of Lake Victoria as key parameters in assessment of water quality. Water samples were obtained from five different sites along coastline of the Winam gulf and investigated of their solute properties. As control experiment, the effects of direct addition of selected cations sodium, potassium, calcium, zinc and lead on the samples from the five different sampling sites were also investigated. The samples were refrigerated and later heated for the purpose of determining the effect of salts on freezing point depression and boiling point elevation respectively. Temperature logging carried out using a digital thermometer throughout the experiments.  The resulted obtained and subjected to Analysis of Variance revealed that cation concentrations had insignificant effect on vapor pressure deficit and other colligative properties of the waters. Maximum error barely exceeded 2% for the studied parameters was carried out to determine any significant differences. The results also indicated that cation concentrations were significantly different and direct addition of similar molar solute concentrations could significantly and differentially affect solute properties of the waters.  These finding can support the production of policy formulation on management of waters of the lake.