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BACKGROUND The incorporation of Fe( III) was performed in a natural clinoptilolite (Z-N) for simultaneous phosphate and ammonium removal. RESULTS The existence of hydroxyl groups (≅Fe- OH) in the iron zeolite (Z-Fe) enhances the phosphate uptake from 0.6 ± 0.1 mg-P g−1 in Z-N to 3.4 ± 0.2 mg-P g−1 in Z-Fe. However, the ammonium sorption capacity slightly decreases from 33 ± 2 mg-N g−1 in Z-N to 27 ± 2 mg-N g−1 in Z-Fe. The equilibrium and kinetics sorption were well explained by the Langmuir isotherm and the intraparticle diffusion model, respectively. CONCLUSIONS Both the phosphate and ammonium uptake were slightly affected by the coexistence of competing ions. The phosphate sorption capacity of iron zeolite was decreased in the regeneration cycles. Desorption using a 1 mol L−1 NaOH solution under dynamic conditions provided higher enrichment factors for ammonium than phosphate. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND: This study evaluated a polymeric ion exchanger impregnated with nanoparticles of hydrated ferric oxide as a selective sorbent for anionic P(V) species. The hybrid impregnated anion exchanger (HAIX) employed as sorbent combines the durability and mechanical strength of a polymeric weak base anion exchange resin with the high sorption affinity of hydrated ferric oxide towards P(V) species. RESULTS: The P(V) loading capacity of the sorbent at a pH simulating the expected conditions in treated wastewaters was 92±3mg P-PO4 g-1 in single component solutions. The sorption of P(V) is affected slightly by the common ions typically present in these effluents such as Cl-, SO4 2- and NO3-, and a reduction of only 5% was observed (89±2mg P-PO4 g-1) in multicomponent solutions. The sorbent can be regenerated (95±3%) using 4% (w/w) sodium hydroxide solution. CONCLUSIONS: HAIX displays high selectivity for phosphate and small affinity for SO4 2-, NO3- and Cl- ions, which provides excellent conditions for its application at pH values typical of secondary wastewater effluents. HAIX exhibits higher and competitive phosphate removal capacity compared with data reported in the literature for materials based on HFO and for adsorbents prepared by impregnation of HFO onto polymeric supports. [ABSTRACT FROM AUTHOR]