Synthesis of ethylene glycol polymerized MIL-125 and their application in arsenic adsorption
Abstract
[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Arsenic in drinking water poses a great threat to human health. While many methods have been examined for arsenic treatment such as coagulation/filtration, reverse osmosis, ion exchange and adsorption, the efficiency of these are relatively low. In this study, water stable titanium metal-organic framework (MIL-125) with and without polymerized ethylene glycol was synthesized and applied to remove arsenic from aqueous solutions. Several methods of characterization had been used to characterize MIL-125 particle and MIL-125 granule including scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and Fourier-transform infrared spectroscopy (FTIR). Both of MIL-125 particles and granule were evaluated in batch experimental systems for their adsorption isotherm, adsorption kinetics, and pH effect. A remarkable arsenic capacity of 189 mg/g for MIL-125 particle and 213 mg/g for MIL-125 granule were achieved at pH=4.7, which were much higher than the capacities of many other adsorbents reported in the literature, generally less than 100 mg/g. At a high arsenic concentration, i.e., 50 parts per million, 60% arsenic could be removed within 5 h at a solid loading of 1.00g/L, and at a concentration of 100 parts per billion, only 10 min was required to reach the EPA standard of 10 ppb maximum contaminant level at the same solid loading. MIL-125 particle and MIL-125 granule were effective for arsenate sorption within a wide pH range of 2 to 10 and the experiment revealed that the adsorption capacity was the highest at pH=2. MIL-125 was first applied as absorbents to remove aquatic arsenic contamination and the result showed that they have tremendous potential in arsenic treatment.
Degree
M.S.
Thesis Department
Rights
Access is limited to the University of Missouri--Columbia