Removal of arsenic from ammoniacal etching waste liquor by 3-(2-aminoethylamino)propyltrimethoxysilane functionalized silica gel sorbent

Abstract 3-(2-Aminoethylamino)propyltrimethoxysilane (AAPTS) functionalized silica gel (AAPTS/SiO2) was synthesized by a sol–gel process and was used for the arsenic removal from ammoniacal etching waste liquor which was oxidized by H2O2. The AAPTS/SiO2 sorbent reached absorption saturation at 20 min and had a substantial binding capacity in the range of pH 4.7–10.2. The maximum static adsorption capacity of AAPTS/SiO2 sorbent for arsenic was 16.1 mg g−1. Equilibrium data fitted perfectly with Langmuir isotherm model compared to Freundlich isotherm model. The removal rate of arsenic by AAPTS/SiO2 sorbent was 95.4% at the optimal conditions from ammoniacal etching waste liquor. Results showed that AAPTS/SiO2 sorbent could be used for the arsenic removal from ammoniacal etching waste liquor.