Removal of benzene from industrial wastewater by vapor stripping

Abstract

Four types of vapor stripping processes are designed in an effort to investigate methods to treat industrial wastewater in compliance with the Environmental Protection Agency's recently promulgated Benzene National Emission Standards for Hazardous Air Pollutants (NESHAP) regulations. Each vapor stripping technology involves a unit operation producing a benzene‐enriched vapor stream and a wastewater stream containing less than 10 ppmw benzene, per the applicable regulation. Steam stripping, vacuum stripping, air stripping, and natural gas stripping technologies are designed and evaluated. It is concluded that: (1) steam stripping involves high operating costs due to the need to preheat the feed; (2) vacuum stripping requires high capital investment because of the number of equipment items needed; (3) air stripping provides only a partial solution to the problem, as it converts a water pollution problem into an air pollution problem which must be addressed; and (4) natural gas stripping is the solution with fewest disadvantages of those examined, and therefore is the recommended method.

Notes

Until September 1995, address correspondence to: J.B. Phillips, Engineering Development Institute, 8627 North 106th Street, Milwaukee, WI 53224.