QUANTIFYING ADSORPTION OF AN INDICATOR BACTERIA IN A SOILWATER SYSTEM

Abstract

Two experiments were conducted to investigate and quantify the weak and strong adsorption of an indicatorbacterium (Escherichia coli) in soilwater systems composed of Tangi silt loam (14% clay) or Commerce clay loam (35%clay). Percent adsorption of E. coli was significantly higher in Commerce clay loam than in Tangi silt loam for both weakand strong adsorption. The distribution coefficient of weak adsorption of E. coli in the Commerce soilwater system was foundto be significantly higher than that of strong adsorption. However, the distribution coefficient of weak adsorption of E. coliin the Tangi soilwater system was found to be significantly lower than that of strong adsorption. For strong adsorption,together with literature data, a high correlation (R 2 = 0.89) was found between percent adsorption and clay content.Significant correlation (R 2 = 0.67) was found between distribution coefficient and clay content. The relationships developedmay be used for modeling purposes.