Adsorption of haloacetonitriles by carbonized metal-organic frameworks

Abstract

This research investigated adsorption efficiency of four including; Chloroacetonitrile (MCAN), Dichloriacetonitrile (DCAN), Bromoacetonitrile (MBAN) and Dibromoacetonitrle (DBAN) on five acid-washed carbonized metal-organic frameworks (MOFs) (WC-ZIF-8, WC-MIL-53, WC-MIL-88B, WC-UiO-66 and WC-HKUST-1) compared with powder activated carbon (PAC S10). The synthesized materials were characterized by XRD, SEM-EDS, nitrogen adsorption isotherms, FTIR and XPS. The screening experiment revealed that WC-MIL-88B, WC-ZIF-8, and PAC had highest adsorption capacities for four HANs, respectively. The HANs molecular size and their hydrophobicity influenced the adsorption rates of HANs in the order of DBAN>DCAN>MBAN>MCAN. The adsorption isotherms showed that Di-halogenic HANs (DBAN and DCAN) can be adsorbed by WC-MOFs much better than mono-halogenic HANs (MBAN and MCAN). From XRD analysis, O-C=O and Fe-O functional groups of WC-MIL-88B might play the important role for adsorption of four HANs., adsorption sites of WC-MIL-88B are expected to be enough for mixed-solute HANs adsorption in low concentration range (0-100ppb), and the order of adsorption capacities does not change from the single-solute adsorption.