Method for purifying contaminated groundwater using steel slag

摘要

A method for purifying contaminated water involves passing contaminated water through a porous bed of steel slag. The steel slag can be used to remove various contaminants or reduce the concentration of such contaminants, such as heavy metals (for example, hexavalent chromium), chlorinated organic compounds, and certain inorganic anions. The method preferably involves placing an underground barrier of a porous bed of steel slag in a flow path of contaminated groundwater then allowing contaminated groundwater to pass through the barrier to purify the contaminated groundwater. The slag particles may be used as produced with no further grinding necessary, although the slag may be passed through a sieve or sieves to obtain a set of slag particles having a median diameter of about ⅛ inch to 1 inch, and preferably between about ¼ inch to ⅜ inch. Due to the inherent permeability of slag, no additive need be mixed with the slag. The method also contemplates periodically replacing the spent slag with fresh slag or placing another wall adjacent the first wall of slag.