Application of waste iron in wet flue gas desulfurization (WFGD) wastewater treatment

The wet flue gas desulfurization (WFGD) procedure results in wastewater containing a complex mixture of pollutants, including heavy metals and organic compounds, which are hardly degradable and pose significant environmental challenges. Addressing this issue, the proposed approach, incorporating waste iron shavings as a heterocatalyst within a modified Fenton process, represents a sustainable and effective solution for contaminants degrading in WFGD wastewater. Furthermore, this study aligns with the Best Available Techniques (BAT) regulations by meeting the requirement for compound oxidation-replacing the chlorine utilization with the generation of highly reactive radicals-and coagulation, which completes the treatment process. This method introduces an innovative use of waste-derived iron shavings in a BAT-compliant technology, providing a sustainable and cost-effective alternative to conventional treatments. The study focuses on process kinetics and optimization parameters, achieving approximately 48% total organic carbon (TOC) removal in 90 min at an optimal pH 3, using 1998 mgL^-1 H₂O₂ under UV light. Analysis of variance revealed that the process efficiency depended more significantly on pH than time duration or the H₂O₂ dose. Catalyst's characterization, including the use of microscopic techniques, including electron microscopy, laser diffraction, X-ray fluorescence, Raman spectroscopy, and UV spectroscopy, indicates its stability and great reusability with consistent TOC decrease across three process cycles. This research demonstrates a cost-effective, environmentally friendly approach to wastewater treatment, advancing sustainable methodologies through the repurposing of waste materials and underscoring the catalyst's reuse potential.