Ion Exchange Synthesis of Struvite Accompanied by Isothermal Supersaturation: Influence of Polymer Matrix and Functional Groups Type

Abstract

AbstractAn exhaustive study of the functional groups and the structure of the exchangers have been carried out. In this paper we show the result of three different ion exchangers, Lewatit CNP80 macroporous carboxylic resin, Lewatit S100 microporous sulphonic resin, and Amberlite IRC86 macroporous sulphonic resin, which have been used in order to choose the appropriate one for continuous column production of pure struvite (MgNH4PO4•6H2O). The parameters studied were the influence of the functional group and also the matrix of each ion exchanger in the Ion Exchange Isothermal Supersaturation process (IXISS), which allows the recovery of ammonium phosphate from waste waters, together with the magnesium from marine sources previously loaded onto the ion exchanger, as struvite. The sulphonic group of the Lewatit S100 raises the supersaturated solution to a pH value more acid than the carboxylic groups of Lewatit CNP80 and Amberlite IRC86. The obtained precipitate was RX analyzed in order to certify the purity of the precipitate.Keywords: Amberlite IRC86Lewatit CNP80Lewatit S100ion exchangestruvitesupersaturation