Treatment of textile industry effluents by Fenton processes using galvanising industry residues

Effluents from the textile industry pose a significant environmental threat due to their high concentration of toxic synthetic dyes and recalcitrant compounds. Advanced oxidation processes (AOPs) are a promising treatment option, but their high cost limits their practical application. This study used a liquid residue from the pickling stage of the galvanising industry as the acid and iron source to trigger Fenton's reactions for textile wastewater treatment. A Box-Behnken design with two independent variables (2 to 4 mL L-1 pickling liquid residue and 70 to 210 mg L-1 hydrogen peroxide) was used to conduct the experiments. The treatment resulted in 97% colour and 96% turbidity removal, as well as 60% toxicity reduction verified by the germination rate of Lactuca sativa seeds. The treatment also reduced Cr by 54%, Zn by 7%, and eliminated Fe from the final effluent. This method offers a cost-effective and efficient approach for treating textile wastewater.