Nanoporous Silica Polyamine Composites with Surface-bound Zirconium (IV) and Methods of Use

摘要

Silica polyamine composites (SPC) made from silanized amorphous nano-porous silica gel and poly(allylamine) (BP-1) were functionalized with phosphorus acid using the Mannich reaction, resulting in a phosphonic acid modified composite (BPAP). Zirconium (IV) was immobilized on BPAP. Arsenate anions strongly adsorbed on the ZrBPAP composite in the pH range 2 to 8, while arsenite only adsorbed well at pH 10. Regeneration of the resin was carried out successfully for As(V) and As(III) using 2M-H2SO4. Four adsorption/desorption cycles were performed for As(V) at pH 4 without significant decrease in the uptake performance. ZrBPAP capture capacity and kinetics for arsenate were tested for longevity over 1000 cycles with only a marginal loss of performance.