A Pilot Study of Novel Hexavalent Chromium Removal from Chemical Film Rinse Water at General Dynamics - Fort Worth Division

Hexavalent chromium is a common constituent of solutions used in the aerospace industry for corrosion protection. One such solution, Chemical Film solution, composed primarily of chromic acid, is used extensively throughout the fabrication and finishing of aircraft, from touch up work to spray-on applications.

At General Dynamics - Fort Worth Division (GD/FW), Chemical Film solution is applied to aircraft prior to painting. It is sprayed on and then rinsed off using deionized water. This process generates 900-1100 liters of wastewater containing 520 mg/l of hexavalent chromium, per aircraft. It was determined that a point source treatment system for this stream would be most applicable. Several technologies were assessed and Alcoa's SORBPLUS® adsorbent was chosen for further study. This paper summarizes the results of pilot tests performed using SORBPLUS and presents a series of comparisons between SORBPLUS adsorbent and the Best Available Technologies (BATs) for hexavalent chromium removal.