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Excessive Fin drinking water due to natural and anthropogenic activities is a serious health hazard affecting humans worldwide. In this study, a comparative assessment was made of eight mineralbased materials with advantageous structural properties for Fuptake: layered-double-hydroxides (LDHs), geopolymers, softening pellets and struvite. These materials are considered low-cost, for being either a waste or by-product, or can be locally-sourced. It can be concluded that Cabased materials showed the strongest affinity for F -(Ca-Al-CO 3 LDHs, slag-based geopolymer, softening pellets). The Langmuir adsorption capacity of Ca-Al-CO 3 LDHs, slag-based geopolymer and softening pellets was observed to be 20.83, 5.23 and 1.20 mg/g, respectively. The main mechanism of Fuptake on Ca-Al-CO 3 LDHs, Mg-Al-Cl LDHs, slag-based geopolymers and softening pellets was found to be sorption at low initial Fconcentrations (<10 mg/L) whereas precipitation as CaF 2 is proposed to play a major role at higher initial Fconcentrations (>20 mg/L). Although the softening pellets had the highest Ca-content (96-97%; XRF), their dense structure and consequent low BET surface area (2-3 m 2 /g), resulted in poorer performance than the Ca-based LDHs and slag-based geopolymers. Nevertheless, geopolymers, as well as struvite, were not considered to be of interest for application in water treatment, as they would need modification due to their poor stability and/or Fleaching.

During drinking water treatment, advanced oxidation process (AOP) with O3 and H2O2 may result in by-products, residual H2O2 and BrO3−. The water containing H2O2 and BrO3− often flows into subsequent granular activated carbon (GAC) filters. A concentrated H2O2 solution can be used as GAC modification reagent at 60 °C to improve its adsorption ability. However, whether low concentrations of H2O2 residuals from AOP can modify GAC, and the impact of H2O2 residuals on BrO3− removal by the subsequent GAC filter at ambient temperature, is unknown. This study evaluated the modification of GAC surface functional groups by residual H2O2 and its effect on BrO3− removal by GAC. Results showed that both H2O2 and BrO3− were effectively removed by virgin GAC, while pre-loaded and regenerated GACs removed H2O2 but not BrO3− anymore. At the ambient temperature 150 µmol/L H2O2 residuals consumed large amounts of functional groups, which resulted in the decrease of BrO3− removal by virgin GAC in the presence of H2O2 residuals. Redox reactions between BrO3− and surface functional groups played a dominant role in BrO3− removal by GAC, and only a small amount of BrO3− was removed by GAC adsorption. The higher the pH, the less BrO3− removal and the more H2O2 removal was observed.