Treatment of Contaminated Groundwaters with Granular Activated Carbon and Air Stripping

Abstract

Over the past several years there have been Increasing reports of cases of contaminated groundwater. Many cases were caused by leaking from surface impoundments or landfills, or leakage from underground storage tanks. Treatment of groundwater use, discharge or recharge into the aquifer is becoming a major concern. Two widely used treatment techniques are adsorption with granular activated carbon and packed tower air stripping. Granular activated carbon is often applied when organic contaminants need to be removed to nondetectable levels, and should be a part of the process if nonvolatile contaminants are present. Air stripping is capable of 95-99 percent reduction of volatile contaminants and can be a cost effective treatment technology if nondetectable contaminant levels are not required and air pollution is not a factor. Should off-gas from an air stripper require treatment for removal of organic contaminants, granular activated carbon adsorption can be effectively applied as it was in the water phase. Selection of a groundwater treatment technology depends on factors such as contaminant type, end use of the water and air pollution concern, and each case requires consideration of these factors to arrive at the most cost effective solution.