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Speciation 98: Abstracts
S. D Wilkinson and D. R Williams
Department of Chemistry, Cardiff University, PO Box 912, Cardiff, Wales, CF1 3TB, UK
The chemical industry produces 166,000 t of aminocarboxylates each year, of which about 10,000 t of EDTA and NTA are used in the UK. These ligands are used extensively as metal complexing agents in a range of products from detergents to agrochemicals. Neither of these two ligands is readily biodegradable, and so potentially they accumulate in the environment. There is a need to replace these ligands with readily biodegradable chelates which are capable of achieving the same chelation role.
The JESS computer program has been used to compare the chemical speciation of a new readily biodegradable chelate S,S-Ethylenediaminedisuccinic acid (EDDS) with EDTA for several different metal ions at various pH values. The ability of EDDS to replace EDTA can then be assessed in terms of the prevailing species, and optimum pH and ligand concentration conditions.
