Design of aeration towers to strip volatile contaminants from drinking water

Chlorohydrocarbon solvents in concentrations up to 1 mg/L are being found with disturbing frequency in ground and surface water supplies across the US. In addition, trihalomethane levels in many water systems exceed the federal standard of 0.1 mg/L. Preliminary analyses suggest that aeration may be a cost‐effective process for removal of these trace organic contaminants. The authors have developed a procedure for the process design of air stripping in packed towers for the removal of volatile organic contaminants, which follow Henry's law at low concentrations. The design methodology incorporates the effects on system design of water and air temperature, volatility of the contaminant, and type and size of packing. It provides an analytical method for estimating the relative cost of air stripping for removal of volatile organic compounds, as well as a quantitative framework for design and evaluation of pilot plant studies.