Two large pilot scale fixed-bed photocatalytic reactor designs are evaluate
d by assessing the processing rate for 2 mg l(-1) phenol solutions. Taking
into account total volume treated and reactor surface area, processing rate
s for the packed-bed and coated-mesh reactors were 140 mg m(-2) h(-1) and 2
0 mg m(-2) h(-1) respectively. The significantly lower degree of removal fo
r the coated-mesh reactor is attributed to insufficient surface contact tim
es, low levels of available attached TiO2 and a small reactor to tank volum
e ratio. In the absence of any time dependent UV intensity data, irradiatio
n intensity was estimated from daily global irradiation data assuming a Gau
ssian distribution; Photonic efficiencies For removal of 100 mg(-1) dichlor
oacetic acid solutions using the packed-bed reactor are only 40% lower than
ideal suspension systems suggesting that fixed-bed photocatalysis is highl
y suitable for degradation of contaminated water. (C) 2000 Elsevier Science
Ltd. All rights reserved.