Recovery of phosphate from wastewater represents a sustainable alternative to phosphate rock, a limited resource. Magnesium aluminum layered double hydroxides (MgAl-LDH), are promising sorbents due to their high phosphate removal capacity by ion-exchange (26-124 mgP/g). Furthermore, an increased sorption capacity has been reported by the addition of zirconium (Zr(IV)) into the LDH lattice. However, ambiguity exists especially in relation to the incorporation of Zr and the stability of the MgAl-LDH. To understand how Zr(IV)-addition affects the phosphate sorption properties (both capacity and mechanism) on the atomic level, solid state multi-nuclear NMR spectroscopy was combined with complimentary characterization techniques to study a series of MgAl-LDH with Zr to Al ratios of 1:9 and 1:1, which had the Mg to (Al+Zr) ratio fixed at 2:1. The LDH were synthesized by coprecipitation and subsequently aged or hydrothermally treated to improve the crystallinity (particle size). No evidence of Zr(IV) incorporation in the LDH was observed, instead Zr was present as Zr(IV)-hydroxide (X-ray amorphous) and crystalline Zr(IV) oxide after aging and hydrothermal treatment, respectively. The segregation of Zr(IV)and resulting lower Al content in the MgAl-LDH decreased the phosphate sorption capacity from 45-54 to 16-20 mgP/g. Zr (hydr)oxide impurities contributed with less than 5 mgP/g. Moreover, 31 P MAS NMR spectroscopy quantified showed that the MgAl-LDH contribute to less than 60% of the total P removal capacity.