Evaluation of two solar pilot scale fixed-bed photocatalytic reactors

Two large pilot scale fixed-bed photocatalytic reactor designs are evaluated by assessing the processing rate for 2 mg l−1 phenol solutions. Taking into account total volume treated and reactor surface area, processing rates for the packed-bed and coated-mesh reactors were 140 mg m−2 h−1 and 20 mg m−2 h−1, respectively. The significantly lower degree of removal for the coated-mesh reactor is attributed to insufficient surface contact times, low levels of available attached TiO2 and a small reactor to tank volume ratio. In the absence of any time dependent UV intensity data, irradiation intensity was estimated from daily global irradiation data assuming a Gaussian distribution. Photonic efficiencies for removal of 100 mg−1 dichloroacetic acid solutions using the packed-bed reactor are only 40% lower than ideal suspension systems suggesting that fixed-bed photocatalysis is highly suitable for degradation of contaminated water.