Highly efficient removal of trace heavy metals by high surface area ordered dithiocarbamate-functionalized magnetic mesoporous silica.

Abstract

The study describes synthesizing and characterizing a novel dithiocarbamate-functionalized magnetic nanocomposite. This nanocomposite exhibits several desirable properties, including a large pore diameter of 2.55 nm, a high surface area of 1149 m2/g, and excellent capturing capabilities. The synthesis process involves the preparation of highly porous magnetic nanocomposites, followed by functionalization with dithiocarbamate functional groups through a reaction with carbon disulfide and amine. The synthesized nanocomposite was thoroughly characterized using various techniques, including X-ray diffraction analysis, transmission electron microscopy, scanning electron microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. The performance of the mesoporous nanocomposite as an adsorbent for removing Pb(II), Cd(II), and Cu(II) cations from contaminated water was evaluated. The study finds that the maximum removal efficiency for Pb(II), Cd(II), and Cu(II) cations is achieved at pH values above 4. The optimal contact time for achieving 100% removal efficiency of the mentioned cations ranged between 60 and 120 min. Within this time range, the adsorbent exhibited efficient capture of the heavy metal cations from contaminated water. Additionally, the appropriate amount of adsorbent required for complete elimination of the heavy metal cations is determined. For Cd(II), the optimal dosage was found to be 50 mg of the adsorbent. For Cu(II), the optimal dosage was determined to be 40 mg. Finally, for Pb(II), the optimal dosage was 30 mg. The adsorbent's regeneration capability was demonstrated, showing that it could be reused for five consecutive runs.