Chelating agents - Biodegradable alternatives to EDTA and DTPA

EDTA and DTPA are widely used in the pulp and paper industry for chelating metal ions, especially in the bleaching of chemical or recycled fibres with peroxide where many metal ions increase the decomposition of peroxide.

Initially in Germany and later in a number of other countries, the poor biodegradability (persistence) of EDTA and DTPA in the environment raised questions about the efficacy of using these chemicals.  Not surprisingly, there has been considerable research into finding alternatives, especially by the peroxide producers and suppliers.

Recently Kemira R&D has developed some alternative chemistries which are starting to show promise.  As is often the case with greener alternatives, there is a price to pay as the cost/perfomance of the new products is inferior.  Nevertheless, there is now a good environmentally-friendly option.  The products marketed by Kemira under the Fennobio trademark are based on aspartic acid diethoxysuccinate (AES).

There is a more detailed article by Kemira on this topic.