Degradation of a cationic textile surfactant formulation with the photo-fenton and H₂O₂/UV-C processes

H₂O₂/UV-C and photo-Fenton oxidation processes were applied to treat a toxic cationic textile surfactant (a quaternary ammonium ethoxylate) frequently used in the textile preparation stage. The effect of pH, effluent COD, H₂O₂ concentration and photochemical treatment time were investigated. Experimental results have indicated that the cationic surfactant could be completely degraded within short UV irradiation times (20-30 min) and low H₂O₂ concentrations (15-20 mM) accompanied with significant COD and TOC removal efficiencies (50-80%). Fe ²⁺ addition (during photo-Fenton oxidation) had a dramatic effect on COD abatement kinetics rather than parent pollutant (surfactant) degradation. Complete elimination of activated sludge inhibition was accomplished in parallel to surfactant degradation emphasizing that partial photochemical treatment under relatively "mild" reaction conditions is sufficient if only detoxification and surfactant degradation rather than full treatment (complete oxidation) is targeted.