Biodegradable complexing agents for heavy metals
AssigneeCooperatie Cosun U.A.
InventorsPiet Marc Paul Bogaert, Theodoor Maximiliaan Slaghek, Henricus Wilhelmus Carolina Raaijmakers
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Abstract
Heavy metals can be effectively complexed with a derivative of a fructan, which derivative contains complexing groups chosen from --X--CY--ZM, --X--CY--ZM, --X--CY--S--S--CY--X--Q, --PY'(--Z'M).sub.2, --SO.sub.3 M and --NR--CH.sub.2 --COOM, where M is a metal or hydrogen, Q denotes the residue of an alcohol or polyol, R is hydrogen or carboxymethyl and X, Y, Y', Z and Z', independently of one another, are O, S or NH and at least one of X, Y and Z is S, with a degree of substitution of 0.1-2.5. The complexing groups are in particular xanthate, xanthide or dithiocarbamate groups.
Claims13
A process for separating heavy metals from a mixture, comprising treating said mixture with a complexing derivative of a fructan, which derivative contains 0.1-2.5 complexing groups selected from the group consisting of xanthate groups, xanthide groups, dithiocarbamate groups and combinations thereof per monosaccharide group of the fructan, and separating the heavy metals from the mixture.
A metal-complexing derivative of a fructan, which derivative contains 0.1-2.5 complexing groups selected from the group consisting of xanthate groups, xanthide groups, dithiocarbamate groups and combinations thereof per monosaccharide group of the fructan.
A process for the preparation of a derivative of a fructan, which derivative contains 0.1-2.5 complexing xanthate groups per monosaccharide group of the fructan, comprising treating a fructan or modified fructan with carbon disulfide in the presence of a base to form said derivative.
A process for the preparation of a derivative of a fructan, which derivative contains 0.1-2.5 complexing xanthide groups per monosaccharide group of the fructan, comprising treating a fructan or modified fructan with carbon disulfide in the presence of a base, and oxidizing the carbon disulfide-treated fructan to form said derivative.
A process for the preparation of a derivative of a fructan, which derivative contains 0.1-2.5 complexing groups selected from the group consisting of xanthate groups, xanthide groups, and combinations thereof per monosaccharide group of the fructan, wherein said fructan is modified by a treatment selected from the group consisting of:
- addition to the fructan of one or more alkylenoxy groups, and
- oxidation of the fructan to a dialdehyde-fructan and reduction of dialdehyde-fructan, to produce a polyol, and the polyol is treated with carbon disulfide in the presence of a base.
A process for the preparation of a derivative of a fructan, which derivative contains 0.1-2.5 complexing dithiocarbamate groups per monosaccharide group of the fructan, wherein said fructan is modified by a treatment selected from the group consisting of:
- addition to the fructan of one or more alkylenei-mino or (thio)carbonylamino groups, and
- oxidation of the fructan to a dialdehyde-fructan, reaction of the dialdehyde-fructan with an amine and optional reduction of the amine reaction product, to produce a polyamine, and the polyamine is then treated with carbon disulfide in the presence of a base.
Dependencies are inferred from the claim text.