Treatment of Textile Waste Water by Heterogenous Photocatalytic Oxidation Processes

Abstract

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 % BOD₅ removal.