SOLAR-POWERED PHOTOCATALYTIC FIBEROPTIC CABLE REACTOR FOR WASTE STREAM REMEDIATION

The design and testing of a solar-powered fiber-optic cable reactor pr ototype for the photocatalytic destruction of organic pollutants is pr esented. A concentrating collector directs sunlight into a fiber-optic cable which transmits light to a TiO2 photocatalyst immobilized on th e fibers and immersed in a reaction solution. The performance of the r eactor using solar and artificial UV radiation are compared The system is also compared to another fiber-optic cable reactor having a 50 pei cent higher photocatalytic suface area-to-reactor volume ratio to inv estigate mass transport limitations. Reaction rates Set-the oxidation of 4-chlorophenol of 25 and 12 mu M-min(-1) were measured for solar an d artificial UV sources, respectively. The faster reaction rate using solar radiation is due to a higher UV light flux compared to the artif icial source. Both fiber-optic reactor systems were determined not to be mass transport limited. Relative quantum efficiencies of phi = 0.01 4 and phi = 0.020 were determined for the solar and artificial ii-radi ations, respectively. In agreement with previous findings, enhanced qu antum efficiencies are attributed to a lower absorbed light intensity- to-photocatalytic surface area ratio. The solar reactor prototype was found to degrade effectively 4-chlorophenol and may prove useful for t he in situ passive decontamination of subsurface and other remote envi ronments.