Arsenic removal from water by metal-organic framework MIL-88A microrods

Abstract

Fe-based metal-organic framework MIL-88A microrods were synthesized by hydrothermal method, which were used to adsorb As(V) in water for the first time. The experimental results indicated that MIL-88A has a very fast adsorption rate towards arsenic in water. The kinetic and isothermal data for arsenic removal were better fitted to the pseudo-second-order kinetic model and Langmuir model, respectively, implying a chemical and monolayer adsorption for As(V) on MIL-88A microrods. Two rate-controlling processes during adsorption were revealed by the intraparticle diffusion model. The maximum adsorption capacity of MIL-88A reached 145 mg g, higher than those of Fe-based MIL adsorbents reported previously, which probably originates from its unique microstructure with abundant OH groups and an unusual large swelling towards water. These show that Fe-based MIL-88A is a good candidate for arsenic removal.

Recent Progress in the Removal of Heavy Metal Ions from Water Using Metal‐Organic Frameworks

“…Fe‐based MOF, MIL‐88 A, was selected to remove arsenic pollution in water based on the possibility of making the As‐O‐Fe interactions . The synthesized MIL‐88 A (Fe 3 O(MeOH) 3 (O 2 C‐C 2 H 2 ‐CO 2 ) 3 ⋅(CH 3 CO − 2 )⋅nH 2 O) bears microporous channels and cages, which are beneficial for capture pollutants as shown in Figure a.…”

“… (a) Schematic picture of the MIL‐88 A synthesis and (b) Kinetic information for arsenic removal from aqueous solution with various primary As V concentrations using MIL‐88 A at pH 8 and 25 °C. Adapted with permission from Ref . Copyright 2018, Springer.…”

Highly efficient removal of As(V) using metal–organic framework BUC-17

“…The maximum adsorption capacity of BUC-17 toward AS(V) was 129.2 mg g −1 , which was higher than those of counterpart adsorbents like MIL-53(Al) [18], ZIF-8 [37] and other MOFs as listed in Table 1. For the initial As(V) concentrations of 50 and 100 mg L −1 , 90% equilibrium adsorption capacities were achieved within first 3 h, and the adsorption equilibrium was accomplished for As(V) solution with concentration of 50 and 100 mg L −1 within 12 h. To analyze adsorption kinetics and describe the adsorption behaviors, the pseudo first-order [27] and pseudo second-order kinetic [12,40] models (Eqs. 2and (3)) were fitted to the kinetic data.…”

“…The World Health Organization has regarded arsenic as a human carcinogen in drinking water and set a provisional standard of no more than 10 µg L −1 [11]. In natural waterbody, the arsenic exists in both inorganic arsenic compounds like arsenate, arsenite, and organic arsenic compounds like ASA (Arsanilic, C 6 H 8 AsNO 3 ) and ROX (Roxarsone, C 6 H 6 AsNO 6 ), in which As(V) is the primary arsenic species [12]. The existence of inorganic arsenic in natural water depends on the redox conditions.…”

“…Metal-organic frameworks (MOFs) are unique porous crystalline materials with large surface area, abundant binding site, regular channel, and tunable morphology, which are widely used in the fields of photocatalysis, adsorption, gas storage and separation [28][29][30][31][32]. Adsorptive removal of arsenic using MOFs have attracted extensive attentions due to their outstanding adsorption capacity, high removal efficiency, short reaction time and wide range of suitable pH values [7,12,33,34]. Furthermore, MOFs possess abundant metal sites even unsaturated coordination sites, which can be coordinated with arsenic for enhanced adsorption ability [35,36].…”