Performance of acid mine drainage sludge as an innovative catalytic oxidation source for treating vehicle-washing wastewater

Abstract

This study introduces iron sludge recovered from acid mine drainage (AMD) waste, as advanced oxidation processes, that is, AMD/H₂O₂ (Fenton’s reagent) to treat vehicle-washing wastewater. Vehicle-washing wastewater was collected from car washing facility in West Virginia, USA, and subjected for laboratory-scale batch experiments. Response surface methodological analysis was chosen to optimize the parametric conditions of the Fenton’s system. A 15-level of quadratic Box-Behnken design model was applied via response surface methodology to evaluate the effects and interactions of the system variables. The optimized system variables were attained at pH 4.0 using 92 and 354 mg/L of AMD and H₂O₂ concentrations, respectively, to achieve the maximum predicted organics removals of 91.4%. Analysis of variance, which was applied for statistical data analysis, showed the significant of the quadratic models for treatment. The linear correlation between the total organic carbon (TOC) and chemical oxygen demand (COD), with sufficient accuracy, is providing the possibility of estimating COD from TOC values. Finally, the results showed that the reaction is endothermic, non-spontaneous in nature and follows the second-order reaction kinetics rate. The results of this work signify the importance of using iron from waste effluents for treating wastewater.

Graphical Abstract

KEYWORDS:

• Car wash
• Fenton
• acid mine drainage
• kinetics
• thermodynamics