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Magnetic core–shell Fe3O4@La–Ce composites were prepared through a rapid coprecipitation method for adsorption of phosphate and fluoride anions from aqueous solution in a single system. Fe3O4@La–Ce...

A highly effective zirconium-modified carbon nanotube (Zr-CNTs) adsorbent was prepared to remove phosphate (PO43–) from solution in batch mode. Characterizations of Zr-CNTs were analyzed using FTIR...

An effective adsorbent, a zirconium hydroxide coating on the surface of magnetic materials (Zr–Fe3O4), was successfully synthesized by a precipitation method to selectively adsorb Alizarin red (AR)...

The adsorption of two basic dyes, namely, methylene blue (MB) and malachite green (MG), onto natural rice husk (NRH) and oxalic acid modified rice husk (MRH) was studied in a batch adsorption system. Factors influencing dyes adsorption such as the concentration of the adsorbate, the pH, the salt concentration, the temperature, and the contact time were investigated. The Langmuir and Freundich isotherms were used to fit the equilibrium data, and the results showed that the Langmuir isotherm exhibited a little better fit to the MG adsorption data by both adsorbents, while the Freundlich isotherm seemed to agree better with the MB adsorption. The kinetic experimental data were analyzed using three kinetic equations, via the pseudo-first-order equation, the pseudo-second-order equation, and the intraparticle diffusion model, to examine the mechanism of adsorption and the potential rate-controlling step. The mechanism of the process was found to be complex, consisting of both surface adsorption and pore diffus...

A natural wheat straw was used as adsorbent for removal of copper and methylene blue (MB) from aqueous solution. A batch system was applied to study the behavior of Cu2+ and MB adsorption in single and binary systems on wheat straw. In the single systems, there was no significant difference in the quantity of MB adsorbed onto wheat straw within a pH range of 4.0 to 10.0. But for Cu2+, the optimal pH is about 5. Kinetic studies indicate that Cu2+ and MB adsorption on the wheat straw follows the Elovich equation. The Cu2+ adsorption isotherm follows the Langmuir and Redlich−Peterson models, while MB adsorption follows the Redlich−Peterson isotherm. The adsorption capacities of Cu2+ and MB at 273 K and pH 5 are (7.05 and 60.66) mg·g−1, respectively. In the binary system, Cu2+ and MB exhibited competitive adsorption. The adsorption of Cu2+ or MB is considerably reduced with an increasing concentration of the other. The quantity of Cu2+ adsorbed is more strongly influenced by MB due to the higher affinity of w...

A new adsorbent, manganese oxide coated zeolite (MOCZ), was characterized and employed for the removal of Cu(II) and Pb(II) from aqueous solution using batch equilibrium experiments. Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and BET analyses were used to observe the surface properties of the coated layer. Binding of Cu(II) and Pb(II) ions by MOCZ was clearly pH-dependent, and the loading capacities increased with increasing pH. Adsorption behavior of Cu(II) and Pb(II) ions can be approximately described with the Langmuir and Redlich−Peterson equation. The thermodynamic parameters (ΔG°, ΔH°, and ΔS°) were also determined, and the adsorption process is more favored at higher temperatures.