Application of microporous materials for the recovery of nutrients from wastewaters

The RIM-NUT(R) process is based on ion-exchange precipitation operations for the abatement of the eutrophication potential present in biologically oxidised municipal, zootechnical and industrial wastewaters. A natural zeolite (clinoptilolite) and a commercial macroporous strong-base anion exchanger selectively remove nutrient species (i.e., NH4+; H2PO4=/HPO4-), which are quantitatively precipitated and recovered in the form of a premium-quality, slow-release fertiliser (MgNH4PO4. 6H(2)O) from the exchangers spent regeneration eluates. Demonstration campaigns carried out in Italy and the United States on a 240 m(3)/d mobile plant proved the technical feasibility of the process whose economical proficiency must still be assessed.