Treatment of textile waste water by heterogenous photocatalytic oxidation processes

Waste water (COD=1063 mg l(-1), BOD5=367 mg l(-1)) obtained from an integrated textile manufacturing plant was treated in two stages. In the first stage it was coagulated by 1200 mg l(-1) alum and 2 mg l(-1) polyelectrolyte at pH=8. In the second stage application of photocatalytic advanced oxidation processes to the coagulated waste water was investigated. Treatment efficiency of the photocatalytic reaction was affected by pH, dosages of H2O2 and Fe3+. The experimental results indicated that photocatalytic treatment efficiency was enhanced by the addition of 10 mM H2O2 and 1 mM Fe3+ ion at pH=4. the highest treatment efficiency was obtained by the combination of coagulation and TiO2/Fe3+/H2O2 treatment system resulting in a 75 % COD and 58 % BOD, removal.