Superparamagnetic nanoadsorbents for the removal of trace As(III) in drinking water

Abstract

A series of novel zeolitic imidazolate framework (ZIF) decorated superparamagnetic graphene oxide hybrid nanoadsorbents were synthesized, characterized, and tested for their As(III) adsorbed amount in simulated drinking water. The three composite nanomaterials are based each on three isostructural and water stable ZIFs, (C-1 based on ZIF-8, C-2 based on ZIF-67, and C-3 based on ZIF-Zn/Co). The composite nanomaterials and there parent materials were characterized through pXRD, TEM, FTIR, BET and magnetometry methods (SQUID), and were tested as adsorbents in a representative drinking water matrix containing arsenite (As(III)) at an initial trace concentration (realistic in some natural drinking water sources) of 35 µg/L. The nanoadsorbents were magnetically captured and removed after adsorption in batch conditions. Out of the three composites, C-2 shows the highest As(III) adsorbed amount at an initial concentration of 35 µg/L (q0) of 202 µg/g, followed by C-3 with 102 µg/g and C-1 with 82 µg/g.

Keywords

• Superparamagnetic
• Composite nanoadsorbents
• Zeolitic imidazolate frameworks
• Trace arsenic removal