A PROCESS FOR THE TREATMENT OF ARSENIC CONTAMINATED GROUNDWATER

摘要

A process for removing arsenic from groundwater comprising the steps of: (a) filling a glass or PVC column having height to width ratio of 3:1 - 4:1 with rigid porous elements in sizes ranging between 2-3 cm, pouring the log phase culture of an arsenic oxidizing bacteria having 108- 109 cells per ml in the column so as to submerge all the said elements, aerating the said column for 24 h, and draining the culture off the column (b) repeating the steps in (a) so as to obtain a visible film of the culture on elements to achieve immobilization of the culture on the said elements; (c) adding at least 0.025 g % of a carbon nutrient in the water contaminated with As (III) in the range of 25 - 1500 ppb and adjusting the pH in the range of 6.0 - 8.0, passing the said water through the column having immobilized bacteria; (d) regulating the flow rate of arsenic contaminated water in step (c) so as to provide adequate contact time of at least 10 minutes for complete oxidation of As(III) to As(V); (e)emoving As(V) from the water by a knwon process such as adsorption and precipitation.