摘要 |
<p>A composition is contacted with an aqueous solution having a pH greater than 2 containing a suitable Th<4><+> chelating agent and a carboxylic acid. The composition comprises either (A) one or more organic chelating compounds comprising microbial siderophores, covalently fixed to the surface of a suitable insoluble carrier and possessing one or more co-ordinating sites, or (B) one or more catechol compounds covalently fixed to the surface of a suitable insoluble carrier at the benzene ring thereof, the catechol compounds comprising unsubstituted catechol or catechol substituted on the benzene ring by one or two electrophilic substituents.</p> |