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. Includes 21 references, tables, figures.