Textile wastewater treatment by UV/Fenton process

Abstract

The textile wastewater is one of the most complex wastewaters because it contains many persistant organic compounds. In this study, factors effect on UV/Fenton process were investigated including: concentration of H₂O₂, Fe²⁺, initial pH, time reaction and the stirring speed. Raw wastewater was aerated for 24 h and filtered by 20 µm filter paper before conducting reactions. The optimum conditions of the UV/Fenton process were attained at 660 mgH₂O₂/L and 20 mgFe²⁺/L, pH 3, 90 min irradiation time and 100 rpm stirring speed. Decolorisation and COD removal efficiencies were achieved 94.2 % and 75.5 %, respectively. The ratio of BOD₅/COD was increased from 0.1 to 0.45. In addition, the effects of anions Cl^-, SO₄^2- on the efficient treatment were investigated. Both anions could inhibit the mineralization process due to scavenging of hydroxyl radical as well as forming strong complexes with iron ions.