Fig. 5: An alternative material for simultaneous NOM and turbidity removal.

a Schematic of negatively charged NOM adsorption and colloid aggregation on positively charged flakes. Conventional flocs aggregate with flakes via hydrogen bonding while contaminant-loaded flakes are trapped on a 2000 µm screen. No settling tank is required. b Schematic of NOM diffusion into the flake’s filamentous/porous structure followed by adsorption on positively charged iron (hydr)oxides (in red). The flake size can be adjusted to prioritize adsorption or separation. c Impact of Fe concentration during grafting (0.6 mM–42 mM Fe) on atomic Fe content (via XPS, in black), on ungrafted Fe (via ICP, in red) and on mass of grafted iron (hydr)oxide (via TGA, in blue) (single measurement per condition). d NOM removal as a function of flake concentration. e Preliminary measurements of phosphorus removal as a function of flake concentration (single jar test per condition). Adsorption tests (d, e) were performed during 30 min and at 21 °C. In panel (d), dashed lines are included as eye guides connecting average values obtained from duplicate experiments. Conditions for (d), (e): no coagulant or flocculant added.