New titanium oxide sorbent for As(V) and Cr(VI) removal as well as La(III) and Nd(III) recovery

A new commercial sorbent ADSORBSIA™ As500 was used for As(V) and Cr(VI) removal as well as La(III) and Nd(III) recovery from aqueous solutions. The physicochemical properties were characterized by nitrogen adsorption/desorption analyses, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The adsorption kinetics of ADSORBSIA™ As500 was analysed using the reaction and diffusion base models such as the pseudo-first order, pseudo-second order, intraparticle diffusion, and Dumwald-Wagner. The effect of different pH values, dose, initial concentrations and the type of metal ions on the adsorption capacity was analysed. As for adsorption data, the Langmuir, Freundlich and Temkin models were used. Desorption of adsorbed metal ions from ADSORBSIA™ As500 was not studied. The sorption equilibrium was established within 60 min. The maximum amount of metals (qe) adsorbed at equilibrium was 37.98, 15.91, 24.77 and 22.23 mg/g for As(V), Cr(VI), La(III) and Nd(III), respectively, which can be arranged in the following selectivity order: As(V) > La(III) > Nd(III) > Cr(VI). The sorption capacities were found to be pH, time, concentration and sorbent dose dependent. The equilibrium data were well described by the Langmuir adsorption isotherm, but the kinetic data were fitted by the pseudo-second order model. [Display omitted] •The physicochemical properties of ADSORBSIA™ As500 were tested.•Adsorption isotherm, kinetics and thermodynamics of the process were determined.•ADSORBSIA™ As500 can effectively remove As(V), Cr(VI), La(III) and Nd(III) ions.