Laboratory‐scale testing of a continuous CLAS process

No gases were released to the atmosphere when UV photooxidation was incorporated in a continuous closed‐loop air‐stripping process for removing volatile organic chemicals from water. The removal of five volatile organic chemicals (VOCs) was evaluated by passing the contaminated water once through a hollow‐fiber‐membrane module that received a countercurrent flow of air recycled from an ultraviolet (UV) photooxidation chamber. VOC removal was measured experimentally under a variety of operating conditions. The results compared favorably with the behavior predicted by a mathematical model of the process. When operated as a closed‐loop process, the photooxidation of the VOCs in the gas phase has several advantages over conventional air‐stripping with off‐gas treatment: the end products are reabsorbed back into the water flow; no exhaust gases are released to the atmosphere; and no adsorbent regeneration or disposal costs are incurred.