Diphonix® Ion Exchange Resin

Part numbers and descriptions
Diphonix® Resin bibliography


Eichrom industries Diphonix® resin is a high performance, gel-type cation resin for the selective separation of metals. Awarded a U.S. patent and the prestigious R&D 100 Award, Diphonix® resin is currently, and successfully, utilized in a growing lineup of applications - including the removal of metals from wastewater, the selective separation of iron from acidic solutions and the purification of acids.

Diphonix® resin is constructed of a polystyrene/divinylbenzene matrix in a spherical bead form. The resin is ployfunctional, containing diphosphonic and sulfonic acid groups bonded to the polymer matrix. The diphosphonic acid ligands contribute to the resin's unique selective capability by preferentially removing selected metals from the solution. The hydrophilic sulfonic acid ligands enhance metal ion accessiblity into the polymer matrix and significantly improve the exchange kinetics.

  • Selectivity: In near neutral pH streams, Diphonix® resin is selective for the multivalent cations of various metals.-including zinc, manganese, chromium, uranium, lead, cobalt, nickel and copper- over alkali cations such as sodium, calcium, and magnesium. The resin also removes ferric iron, chromium, uranium, plutonium, and certain metals other metals from strongly acidic solutions. Coordination of these metal cations to Diphonix® is unaffected by increasing hydrogen ion concentrations.
  • Throughput: By selectively removing only targeted metals, a given volume of Diphonix® resin can provide a much higher throughput than other commercially available resins. (Throughput is defined as the volume of liquid processed - prior to exhaustionof the resin - to a specified metal's effluent concentration.) This advantage increases as the ratio of non-targeted metals to targeted metals increases. Also, for certain metals or highly acidic solutions, Diphonix® resin may be the only viable resin. Diphonix® resin may also drive the targeted metal concentrations lower than other resins, allowing discharge limits and process quality criteria to be met.
  • Kinetics: Eichrom's Diphonix® resin provides exceptional exchange kinetics since the hydrophilic sulfonic acid groups allow quick access to the selective diphosphonic acid groups. This gives the resin the ability to react much faster than commercially available chelating resins. Recommended process flux rates depend on the solution chemistry. For typical wastewater treatment, operating flux rates range from 5 to 15 gallons per minute per square foot of cross-sectional resin bed area. Some applications may require lower flux rates to achieve desired effluent quality.
  • Physical Stability: The plastic matrix used in Diphonix® over a wide range of thermal and chemical conditions. The diphosphonic acid functional group is incorporated into the matrix at the time of polymerization and is thus very stable.
  • Forms Available: Diphonix® resin is available in a variety of bead sizes and cross-linkage percentages to suit a number of laboratory and process applications.