The impact of photocatalytic TiO2 on permeable concrete mix designs and its application for the degradation of organic pollutants in water

摘要

The project examines the influence of the addition of photocatalytic titanium dioxide (TiO2) to permeable concrete with respect to percentage voids, permeability, mix designs, void connectivity and the degradation of organic pollutants within the fluid stream. It was unclear what effect the addition of TiO2 would have on the properties of permeable concrete as little or no research had been reported in this area of study. It was necessary to design and produce “standard” permeable concrete mixes to establish a baseline to measure the impact of adding TiO2. The percentage of voids present in permeable concrete produced was determined and compared by applying two different methods, apparent density (standard test), and an image analysis approach. This allowed determination of any effect that the photocatalytic titanium dioxide had on the hydraulic and mechanical properties of the permeable concrete. The effectiveness of photocatalytic titanium dioxide permeable concrete was analysed under laboratory conditions for the degradation of naphthalene, a poly-aromatic hydrocarbon in a fluid load. The process was to expose permeable concrete samples containing 5, 10 and 15 percentage addition of titanium dioxide to ultra violet light irradiation to compare the relative breakdown of pollutant (as represented by naphthalene). The research has shown, TiO2 significantly reduced the workability of the permeable concrete and helped to ensure increased void space. The increased surface area of permeable concrete, with the addition of TiO2 significantly improved the degradation rate of naphthalene compared to traditional concrete pavement.