Analysis of Escherichia coli Transport through the Soil

Abstract

Escherichia coli is one of the major bacterial contaminant of groundwater that leads to health ailments. In the present study, effect of different height and soil grain size on transportation of E. coli was analyzed by performing column experiments. Experiments were conducted by using 0.25 m long column with internal diameter of 0.06 m. Transportation of bacteria was assessed by comparing relative concentration (C/Co) of bacteria at different time intervals by performing MTT assay and plate count. In this work, the breakthrough curves of E. coli were studied for different grain sizes (1.6, 1 and 0.6 mm) and at different heights of soil (10, 15 and 20 cm) at a flow rate of 2.5 ml per minute. The results indicated that the maximum relative concentration of bacteria decrease with increase in height in all cases of different grain size. On the other hand, the maximum relative concentration of bacteria increased with increase in the grain size of soil particle at all heights. Retention of bacteria was more (increase in the height of soil) and less (increase in grain size of soil particle) in soil which suggests that the ground water gets contaminated fast in less height and large grain size.