Comparison of air and steam stripping: removal of organic halogen compounds from process wastewaters

In the engineering practice, there are two basic alternatives of physicochemical treatment for the removal of volatile compounds from process wastewaters: stripping with air or stripping with steam. In this work, these alternatives are investigated and compared in the case of a real industrial problem that is typical for the fine chemical industry and general conclusion is drawn. The removal of the organically bound halogens, called adsorbable organically bound halogens, is investigated. The two alternatives, air and steam stripping, are first modeled in the professional software environment of ASPEN Plus(A (R)). The model is validated on the data of an existing air stripper for the removal of organic halogens. Same organic halogens removal is applied for the design of a steam stripper. It is proved that the steam stripping shows better operability and economic performance than the air stripping; moreover, the volatile and/or adsorbable organically bound halogen compounds can be recovered in the distillate and they can be reused improving the sustainability.