Pilot-Scale Study of the Solar Detoxification of VOC-Contaminated Groundwater

The Solar Detoxification Field Experiment was designed to investigate the photocatalytic decomposition of organic contaminants in groundwater at a Superfund site at Lawrence Livermore National Laboratory (LLNL). The process uses ultraviolet (UV) energy, available in sunlight, in conjunction with the photocatalyst, titanium dioxide, to decompose organic chemicals into nontoxic compounds. The fieldexperiment was developed by three federal laboratories: the National Renewable Energy Laboratory (NREL), Sandia National Laboratory (SNLA), and LLNL. The U. S. Department of Energy funded the experiment. The objectives of the pilot-scale study included the advancement of the solar technology into a nonlaboratory waste-remediation environment, the compilation of test data to help guide laboratoryresearch and future demonstrations and the development of safe operational procedures. Results of the pilot study are discussed, emphasizing the effect of several process variables on the system performance. These variables include alkalinity, catalyst loading, flow velocity through the reactor, and incident solar UV radiation. The performance of the solar detoxification process are discussed asit relates to concentrating and nonconcentrating collectors.