Photochemical Remediation of Tetrachloroethylene: Reactor Design, Construction, and Preliminary Results

Abstract

A custom designed pilot-scale photochemical remediation reactor is constructed for remediation of vapor-phase volatile organic halocarbons (VOHs), particularly chlorinated hydrocarbons such as PCE (tetrachloroethylene). Ultraviolet (UV) light, when emitted at an effective absorption frequency, cleaves a VOH’s carbon-chloride bond, transforming harmful contaminants to harmless products. The stainless steel reactor is of tubular-shape with an inner diameter of 32 cm and a length of 105 cm. The net volume of the reactor is approximately 73.7 L. Three stainless steel baffles are welded inside the reactor to create a well-mixed vapor phase and uniform UV contact time. Special low-pressure mercury amalgam UV lamps (Heraeus, Inc., Duluth, Ga.) are used as the photoenergy source. Two independent vapor-phase PCE destruction experiments are conducted using different influent contaminant concentrations. Both experiments show a PCE destruction efficiency of over 99%.