FUNCTIONALISED ALUMINA ADSORBENT MATERIALS FOR REMOVAL OF CONTAMINANTS FROM WATER
A composition is provided for removal of a target substance from a fluid stream. The composition may be used to remove polyfluorinated alkyl substances (PFAS) from water. The composition comprises a support material comprising an alumina; and a sorbent molecule that comprises a core polymer; wherein the core polymer is covalently linked to the support material; and wherein the sorbent molecule further comprises one or more covalently linked sorbent groups. Processes for removal of target substances such as PFAS are also provided.
1 . A composition for removal of a contaminant from an aqueous fluid stream, wherein the composition comprises:
a) a particulate support material comprising porous alumina; and
b) a sorbent molecule comprising:
i) a linear polymer or branched polymer covalently linked to the particulate support material; and
ii) one or more covalently linked sorbent groups.
2 . The composition of claim 1 , wherein the porous alumina comprises a bimodal alumina having pores within a mesoporous range and pores within a macroporous range.
3 . The composition of claim 2 , wherein:
(i) a majority of the pores within the mesoporous range have an average pore size of between 2 nm and 50 nm; and
(ii) the bimodal alumina has a BET pore volume within the pores within a mesoporous range of not less than around 0.20 cm 3 /g.
4 . The composition of claim 2 , wherein the pores within a mesoporous range have an average pore size of between 2 nm and 20 nm.
5 . The composition of claim 2 , wherein a majority of the pores within the macroporous range have an average pore size of between 1 μm and 10 μm.
6 . The composition of claim 1 , wherein the sorbent molecule comprises a linear polyamine or branched polyamine.
7 . The composition of claim 1 wherein the linear polymer or branched polymer is 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).
8 . The composition of claim 7 , wherein the linear polymer or branched polymer is a poly(ethylenimine) that has a weight average molecular weight of not less than around 25 kDa.
9 . The composition of claim 1 , wherein the covalently linked sorbent group is a substituted or unsubstituted C 1 -C 12 alkyl group.
10 . The composition of claim 9 , wherein the covalently linked sorbent group comprises a C 2 -C 8 group selected from the group consisting of:
butyl; hexyl; octyl; isobutyl; isohexyl; and isooctyl.
11 . The composition of claim 6 , wherein the linear polyamine or branched polyamine comprises at least one tertiary amino group and wherein the at least one tertiary amino group is converted to a quaternary nitrogen.
12 . The composition of claim 6 , wherein the linear polyamine comprises a C 1 -C 10 alkyl substituted linear poly(ethylenimine).
13 . The composition of claim 6 , wherein the branched polyamine comprises a C 1 -C 6 alkyl substituted branched poly(ethylenimine).
14 . The composition of claim 1 , wherein the particulate support material is in a form selected from: granular; powder; and spheroidal particles.
15 . The composition of claim 1 , wherein the contaminant comprises one or more poly- and perfluorinated alkyl substance (PFAS).
16 . The composition of claim 15 , wherein the PFAS is a perfluorinated anionic surfactant compound.
17 . The composition of claim 15 , wherein the PFAS is selected from the group consisting of:
perfluorobutanesulfonic acid (PFBS); perfluorobutanoic acid (PFBA);
perfluorohexanesulfonic acid (PFHS); perfluorohexanoic acid (PFHA); perfluorooctanoic acid (PFOA); perfluorooctanesulfonic acid (PFOS); perfluorononanoic acid (PFNA); and perfluorodecanoic acid (PFDA); and 6:2 fluorotelomer sulfonic acid (6:2 FTSA).
18 . A method of removing a contaminant from an aqueous fluid stream, the method comprising contacting the aqueous fluid stream with the composition of claim 1 .
19 . The method of claim 18 , wherein the contaminant comprises one or more poly- and perfluorinated alkyl substance (PFAS).
20 . The method of claim 18 , wherein the PFAS is a perfluorinated anionic surfactant compound.
21 . The method of claim 19 , wherein the PFAS is selected from the group consisting of:
perfluorobutanesulfonic acid (PFBS); perfluorobutanoic acid (PFBA);
perfluorohexanesulfonic acid (PFHS); perfluorohexanoic acid (PFHA);
perfluorooctanoic acid (PFOA); perfluorooctanesulfonic acid (PFOS);
perfluorononanoic acid (PFNA); and perfluorodecanoic acid (PFDA); and 6:2 fluorotelomer sulfonic acid (6:2 FTSA).
22 . The method of claim 21 , wherein the method further comprises regenerating the composition after the contacting step.
21 . The method of claim 22 , wherein regenerating the composition comprises applying one or more aqueous washes to the composition.
22 . The method of claim 21 , wherein the one or more of the aqueous washes is selected from the group consisting of: a salt wash, and acid wash, and a basic wash
23 . The process of claim 22 , wherein regenerating the composition comprises applying one or more solvent liquid salt washes to the composition, wherein the solvent liquid comprises one or more non-aqueous polar solvent(s).
24 . The process of claim 23 , wherein the one or more non-aqueous polar solvent(s) is selected from the group consisting of:
acetone, methanol, ethanol, and isopropanol.