Photocatalytic processes in the presence of titanium dioxide provide an interesting way to destroy hazardous organic contaminants. Part of CIEMAT＇s efforts to commercialize solar photocatalytic detoxification technology has involved the development of photoreactor designs. Although present treatment costs for the solar water detoxification system are higher than for conventional technologies, potentially greater cost reductions are being investigated through the use of one-sun systems. Aspects of these systems that might realize cost reductions include novel collector materials, the manufacturing process and the economics of scale. These issues are being examined extensively in the one-sun photoreactor research effort. A one-sun compound parabolic concentrator designed by CIEMAT and fabricated by the Institute de Maquina Herramienta may be constructed at a cost under $160/m(2) with an annual efficiency of 71.3%. Studies reported in this paper also evaluate the performance of the low cost CPC prototype built at a previous stage using a model compound, and explore the feasibility of this concept as the basis for solar photocatalytic oxidation facilities. Our preliminary findings show that the overall treatment cost can be reduced mainly by reducing the unit catalyst cost instead of the unit reactor cost.