Functionalised alumina adsorbent materials for removal of contaminants from water

A composition for removal of a poly- and perfluorinated alkyl substance (PFAS) from an aqueous liquid, the composition comprising:

• a particulate support material comprising a bimodal alumina having pores within a mesoporous range and pores within a macroporous range;
• (i) wherein a majority of the pores within the mesoporous range have an average pore size of between 2 nm and 50 nm;
• and
• (ii) wherein the bimodal alumina has a BET pore volume within the mesoporous range of not less than around 0.20 cm3/g;
• and
• a sorbent molecule that comprises a linear or branched core polymer selected from one or more of:
• poly(ethylenimine);
• poly(allylamine);
• poly(methylmethacrylate);
• poly(vinylalcohol);
• poly(vinylamine);
• poly(vinylchloride);
• poly(2-vinylpyridine);
• poly(3-vinylpyridine);
• or poly(4-vinylpyridine);
• wherein the linear or branched core polymer is covalently linked to the particulate support material;
• and
• wherein the sorbent molecule further comprises one or more covalently linked sorbent groups.