Iron Coated-Sand from Acid Mine Drainage Waste for Being a Catalytic Oxidant Towards Municipal Wastewater Remediation

The accessibility of clean water and green environment are the major requirements for survival and sustainable development. In this study, iron-coated sand, derived from acid mine drainage effluent, has been applied as a heterogeneous catalyst. Treatment with H 2 O 2 , iron-coated sand, and iron-coated sand-Fenton processes is compared for the COD removals from municipal wastewater effluent. The results showed that the iron-coated sand catalyzed Fenton process could generate hydroxyl radicals (•OH) and oxidize the organic pollutants. Fenton process based on the iron-coated sand catalyst proved to be the most efficient process. The effect of operating conditions such as initial pH and Fenton’s reagent doses, i.e. initial H 2 O 2 and iron on the organics oxidation from such wastewater was investigated. The results showed that 70% removal efficiency of COD was obtained within 30 min under optimized conditions (pH 3.0, H 2 O 2 400 mg/L and iron 40 mg/L). The rate equation of iron-coated sand-Fenton system was simply expressed by the second-order equation and the model was found to fit well the data. Thermodynamic analysis of the results indicated that the iron-coated sand-Fenton oxidation is non-spontaneous and endothermic in nature. Regeneration of iron-coated sand was attempted and the catalyst had a good stability and reusability for successive treatments and reducing the quantity of sludge produced in Fenton reactions. Thus, expanding the sustainability scope of iron-coated sand based Fenton catalyst and offer new sustainable and inexpensive alternatives for the classical Fenton process. Article Highlights Iron recovered from acid mine drainage to prepare iron coated-sand as a Fenton source. Novel Fenton reaction is proposed for treating polymer industry wastewater. The system avoids iron sludge by-product by providing catalyst reusability. The approach points the competitive novel iron waste source to applied as a Fenton technology.