Abstract |
Much of the recent concern by regulatory agencies about drinking water quality has been directed toward organic contamination in drinking water. Although organic contamination has been thought to primarily affect surface waters, there is a growing awareness and concern over groundwater contamination. What usually occurs is that the groundwaters contain a few organic compounds at high concentrations (microg/L to mg/L levels) while surface water supplies contain many organic compounds at low concentrations microg/L levels). For example, an EPA research project using the GROB Closed Loop Stripping Method, identified approximately 225 organic compounds during sampling of treated surface water prior to granular activated carbon adsorption at the Cincinnati, Ohio Water Works. Except for the four trihalomethanes (chloroform, dichlorobromomethane, dibromochloromethane, bromoform) all concentrations were in the low part per trillion (microg/L) range. The health significance of these concentrations is unknown. However, one may wonder which is more significant; ingesting a few organics at high concentrations or many organics at low concentrations. The goal of any treatment scheme should be to remove as much contamination as feasible, technologically and economically. Various treatment options are available for removing organic contaminants from drinking water. Three of the treatment options are: granular activated carbon, air stripping, and reverse osmosis. |