Heterogeneous wet‐decomposition of COD components in ash filtrate samples by Fenton's reagent, titanium dioxide, and granite porphyry powders

Abstract

Chemical oxygen demand (COD) interferes with the removal of heavy metals from fly ash leachates and wastewater using ferric chemistry. The oxidation of species contributes to COD by treating with heterogeneous suspensions of Fenton's reagent, TiO₂, and granite porphyry with H₂SO₄ prior to heavy metal removal improves subsequent ferric treatment efficiency. Using leachates from fly ash produced by municipal solid waste incinerators in Akita city and wastewaters that resulted from research and clinical studies at Akita University, actual COD was reduced up to 78% in ash filtrate samples and 12–34% in wastewater samples. In some cases treatment with these heterogeneous suspensions to reduce COD prior to Fe treatment for heavy metals removal may be useful.