Removal of Phosphate from Aqueous Media by Lanthanum Modified Nanochitosan

The biosorbent nanochitosan was synthesized by the ionic gelation and modified with lanthanum to improve efficiency and performance. The features of synthesized adsorbents were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray diffraction (EDX) and nitrogen adsorption–desorption isotherms and after confirming the nanostructure adsorbent, used as a suitable adsorbent for phosphate removal. In order to correct the results of the adsorption process, Langmuir and Freundlich adsorption models were used. The results showed that the adsorption of phosphate on lanthanum-modified nanocitosan adsorbent follows the Langmuir isotherm and the maximum adsorption capacity is 144.92 mg/g. The equilibrium time of adsorption process was also studied on lanthanum modified nanocitosan and experimental data showed that the time required to reach equilibrium was 30 min. The kinetic studies of the adsorption process will also be performed on lanthanum modified nanocitosan and the kinetic information obtained will be evaluated by pseudo-first, -second order and intra-particle diffusion kinetic models. Investigation of three kinetic models showed that the adsorption process with a 0.9967 correlation coefficient is in good agreement with pseudo-first kinetic model.