Efficient removal of arsenic from wastewater using aminated Fe-BTC-based Metal-Organic frameworks

DETA-Fe-BTC MOFs with an irregular porous structure is fabricated by a hydrothermal method combining with Diethylenetriamine (DETA) modification and investigated in batch adsorption experiments for arsenic removal from wastewater. DETA-Fe-BTC show high adsorption ability in wide pHs ranged from 2 to 12 and a wide arsenic concentration range from 1 mg/L to 1000 mg/L. The maximal arsenic adsorption capacity reaches 1748.50 mg/g at a pH of 10. Besides, the MOFs reveal a super-fast arsenic-removal rate. 90.58 % of arsenic was removed from wastewater with an initial arsenic concentration of 40 mg/L in 5 s. Arsenic adsorption kinetics and isotherms follow a chemical adsorption mode and a single-molecule adsorption mode that the MOFs offer abundant Fe 3+ active cites forming Fe-O-As coordination with arsenate or arsenite. Considering its strong recyclability and high efficiency, DETA-Fe-BTC will be used as a potential arsenic scavenger for the disposal of arsenic contaminated groundwater or industrial wastewater.