Effect of TiO₂, Al₂O₃, and Fe₃O₄ nanoparticles on phosphorus removal from aqueous solution

Abstract

Phosphorus (P) removal from aqueous solutions was investigated using TiO2, Al2O3, and Fe3O4 nanoparticles (NPs). Adsorption study was performed to determine the optimum operation conditions such as adsorption time, temperature, pH, and adsorbent dosage. Sorption isotherms were well described by linear, Freundlich and Langmuir models. The maximum adsorption capacity of P was 28.3, 24.4, and 21.5 mg g−1 for TiO2, Fe3O4 and Al2O3, respectively. Desorption analysis showed that the desorption capacities were in an order of Al2O3 > Fe3O4 > TiO2. Kinetic data were best fitted with pseudo‐second‐order and intra‐particle diffusion kinetic models. Scanning electron microscopy (SEM), energy dispersive X‐ray (XRD), and NPs solution saturation indices (SI) before and after P sorption showed that the main mechanism of P sorption by TiO2 was adsorption, whereas P sorption by Al2O3 and Fe3O4 were due to adsorption and precipitation. Results showed that double layer model (DLM) could be modeled P adsorption onto adsorbents over a wide range of pH. Thermodynamic parameters confirmed the endothermic and not spontaneity nature of the P adsorption. These NPs have potential for use as efficient sorbents for the removal of P from aqueous solutions and TiO2 NPs were identified as the most promising sorbent due to their high metal uptake. © 2014 American Institute of Chemical Engineers Environ Prog, 33: 1209–1219, 2014

Adsorptive removal of phosphate by magnetic Fe3O4@C@ZrO2

“…Moharami et al [33] investigated phosphorus removal from aqueous solutions using TiO 2 , Al 2 O 3 , and Fe 3 O 4 nanoparticles, and the sorption capacities of nanoparticles for P were found to be 28.3 mg g −1 for TiO 2 , 24.4 mg g −1 for Fe 3 O 4 , and 21.5 mg g −1 for Al 2 O 3 at equilibrium concentration of about 200 mg l −1 , respectively. The best results of phosphate sorption on mixed hydrous oxides Fe 2 O 3 ·Al 2 O 3 ·xH 2 O were observed at pH 3 with maximum sorption capacity of 22.9 mg g −1 at equilibrium concentration higher than 300 mg l −1 [32].…”

Phosphate adsorption on metal oxides and metal hydroxides: A comparative review

“…Fitting the kinetic data can be performed using the intraparticle diffusion model, which indicates that the phosphate adsorption process of the sorbents undergoes three successive steps: (i) mass transfer (boundary-layer diffusion), (ii) adsorption of ions onto sites, and (iii) intraparticle diffusion (Jiang et al 2013;Moharami and Jalali 2014). In many cases, there is a possibility that intraparticle diffusion will be the rate-limiting step, which is normally determined using the intra-particle diffusion model.…”

Mechanisms that control the adsorption–desorption behavior of phosphate on magnetite nanoparticles: the role of particle size and surface chemistry characteristics

“…Among these approaches, sorption stands out owing to its effectiveness, low-cost, ease of handling and the environmentally friendly method. Plenty of materials including natural minerals, 7,8 waste products, [9][10][11] metal oxide compounds, [12][13][14][15][16] synthesized nanomaterials [17][18][19][20][21][22] and so forth have been tested for phosphate adsorption. It has been proven that iron oxide-based materials are quite effective at adsorbing phosphate and that the magnetic iron oxide-based materials, such as magnetite are favored owing to their superiority in separation.…”

“…5 The adsorption of phosphate on iron oxide-based materials including ferrihydrite, goethite, hematite, magnetite, and other iron containing compound has been widely studied. 6,8,16,23 Wang et al revealed that the particle size of the ferrihydrite could control the adsorption kinetic behavior for phosphate, and further demonstrated the formation of a deprotonated bidentate complex between the phosphate and the surface of ferrihydrite could be the dominant adsorption mechanism. 6 Yoon et al also discussed the adsorption mechanism of phosphate to magnetite nanoparticles and indicated that phosphate could form the inner-sphere complexes with the surface of iron oxide through ligand exchange, which is affected by the amount of surface functional groups on the magnetite.…”