METHOD FOR PURIFYING CONTAMINATED GROUNDWATER WITH BACTERIA AND PERMEABLE REACTIVE BARRIER USED FOR PURIFYING

摘要

An object of the present invention is to provide a method for purifying contaminated groundwater through a chlorine-based organic compound by using co-metabolism of microorganisms and provide a water-permeable reactive wall used therefor. The method for purifying contaminated groundwater by using microorganisms according to the present invention in order to achieve the object comprises the steps of: measuring the flow velocity in an area contaminated by trichloroethylene (TCE) and the contamination density of the TCE; determining an injection concentration of toluene, which is a first substrate, so as to make the TCE and the toluene have a concentration ratio of 1:50-1:70; installing a water-permeable reactive wall filled with pellets immobilized with microorganisms performing aerobic co-metabolism in a flow path of the groundwater; injecting the toluene, which is the first substrate, along with hydrogen peroxide according to the determined injection concentration through a substrate injecting pipe installed at one side of the water-permeable reactive wall, wherein the injection concentration of the hydrogen peroxide is determined to have a concentration ratio with the toluene, which is the first substrate, of 1:2-1:3 within a range which does not exceed 70mg/L; and suctioning the toluene through a substrate collecting pipe installed at the opposite side of the water-permeable reactive wall so as to enable the circulation of the first substrate in the water-permeable reactive wall. [Reference numerals] (AA) Start; (BB) End; (S10) Measure flow velocity and TCE concentration of contaminated groundwater; (S20) Determined injection concentration of a first substrate (concentration ratio of TCE to toluene = 1:50 to 1:70); (S30) Determine injection concentration of hydrogen peroxide (concentration ratio of TCE to hydrogen peroxide = 1:2 to 1:3, 70mg/L or less); (S40) Determine the width of a water-permeable reactive wall (residence time per toluene concentration = 0.5-7 hr/ppm); (S50) Install the water-permeable reactive wall on a flow path of the contaminated groundwater; (S60) Supply the first substrate and peroxide into the water-permeable reactive wall; (S70) Collect the first substrate in the water-permeable reactive wall and re-supply; (S80) Control the temperature inside the water-permeable reactive wall