synthesis and application of magnetic metal organic framework nanocomposite as an adsorbent for removal of citalopram from aqueous solutions

Citalopram is an antidepressant belongs to a group of drugs called selective serotonin reuptake inhibitors (ssris). the popularity of citalopram has led to its excessive consumptions consequently. as a pharmaceutical pollutant, citalopram causes contamination when enters into the environment. the development and use of highly efficient methods for its removal from aqueous environments are of great importance for the environmental scientist [1, 2].in the present study, a nanocomposite of meso-metal organic framework (fe3o4@sio2-sba3-mil100-(fe)/so3h, meso-mof) for removal of citalopram hydrobromide was prepared. characterization of the synthesized meso-mof was performed by fesem, ft-ir, xrd, and n2 adsorption-desorption techniques. the results confirmed the synthesis of nanocomposites with particle size less than 30 nm. the obtained bet surface areas and the total pore volume of meso-mof were obtained as 119.69 m2g-1 and 0.09964 cm3g-1, respectively. all of the experimental variables, influencing the citalopram hydrobromide removal efficiency were investigated using central composite design. under the optimum conditions (contact time = 20 min, ph = 10, adsorbent weight = 0.1 g, sample volume = 25 ml and ionic strength = 0), more than 95% of citalopram hydrobromide was removed.the pseudo-first order (r2 = 0.6235), pseudo-second order (r2 = 0.9827), intra particle diffusion (r2 = 0.5354) and elovich kinetic (r2 = 0.7235) models were investigated, and the kinetic data followed the pseudo-second order kinetic model (r2 = 0.9827, qe = 64.23 mg g−1, k2 = 0.012). compared with the langmuir isotherm model (r2 = 0.9366), the freundlich model (r2 = 0.9887), has a higher degree of fitting, which reveals that the adsorption of citalopram hydrobromide by meso-mof is more consistent with the theory of multi-layer adsorption.