Effects of Effluent Organic Matter on the Ferrate (Fe(VI))-Coated Sand Reactivity in Synthetic Wastewater Effluent

Ferrate (Fe(VI))-coated sand was developed as a heterogeneous Fe(VI) medium with potential for oxidation, coagulation, disinfection, and filtration processes during (waste)water treatment. However, its reactivity under complex aqueous conditions is still unknown. Herein, we investigated the effect of representative effluent organic matter (EfOM) components─octanoic acid (OA), bovine serum albumin (BSA), alginate (ALG), and humic acid (HA)─on Fe(VI)-coated sand treatment of acetaminophen (ACM), phenol (PHE), sulfamethoxazole (SMX), copper (Cu), lead (Pb), and zinc (Zn) in a synthetic wastewater effluent matrix. While EfOM composition influenced the oxidation of SMX and PHE, there was no observed effect on ACM oxidation. In the presence of HA, 80% PHE degradation was observed within 15 min of reaction by the Fe(VI)-coated sand compared to only 60% in the presence of BSA. Additionally, BSA decreased Fe(VI)-coated sand reactivity toward SMX and PHE. Removal of Cu, Pb, and Zn was nearly complete in the presence of OA within 15 min of reaction but varied (between 59–100%) in the presence of BSA, HA, and ALG, indicating that EfOM composition also affects Fe(VI)-coated sand reactivity toward metals. This study expands our knowledge of Fe(VI)-coated sand functionality for more nuanced water treatment applications.