Synthesis of silanized chitosan anchored onto porous composite and its performance in fixed-bed adsorption of Cr(VI)

Chitosan was supported on a porous composite using 3-aminopropyltriethoxysilane (APTES) as silanizing agent through a simple and green method to enhance Cr(VI) uptake performance under batch and continuous-flow systems. Chemical modification was corroborated through ATR-FTIR and SEM/EDX analyses, showing a silane loading of 6.2% onto the surface of the chitosan composite. The silanized composite adsorption capacity was 18 mg/g (155 mg/gchitosan) in batch experiments. The porous nature of the adsorbent had a positive kinetic effect, achieving equilibrium after 30 min. Fixed-bed column adsorption showed an adsorption capacity of 12 mg/g (102 mg/gchitosan). Through an alternative desorbing configuration in column regeneration, the eluted volume was minimized to less than 20% of the treated volume, enhancing the behavior of the adsorbent in multiple adsorption-desorption cycles.

Automated summary

This study demonstrates the enhancement of Cr(VI) uptake performance by supporting chitosan on a porous composite using APTES as a silanizing agent through a simple and green method. Batch and fixed-bed column adsorption experiments show high adsorption capacity and fast equilibrium rate of the silanized composite. In column regeneration, utilizing an alternative desorbing configuration minimizes the eluted volume and improves the behavior of the adsorbent in multiple cycles.