| dc.description.abstract | Synthetic dyes are commonly found in industrial wastewater due to their wide application as colorants in the textile, paper, food, leather and plastic industries. Among the various treatment methods, adsorption is generally considered to be the most efficient method for quickly lowering the concentration of dissolved dyes in an effluent. In recent years, there has been great interest in the use of Metal Organic Frameworks (MOFs) to remove dyes from contaminated water because of their diverse porous structures, high surface areas, and chemical tunability. In this thesis, the removal of methyl orange (MO) from aqueous solutions was investigated in batch and continuous setups using three MOFs, namely, Fe-BTC, Cu-BTC, and ZIF-8. The experimental results showed that at the same MO initial concentration (15 mg/L) and the same dosage (100 mg), Fe-BTC had the highest removal efficiency of 91%, followed by ZIF-8 (63%), and finally Cu-BTC (35%). Furthermore, pH effect experiments showed that Fe-BTC maintained consistent adsorption capacity over a wide range of pH suggesting that it could be a good candidate for dye removal from wastewater. The equilibrium study revealed that the experimental data could be best described by the Langmuir isotherm. The calculated maximum monolayer adsorption capacities were 100.3, 105, and 114 mg/g for Fe-BTC compared to 7.56, 5.62, and 4.65 mg/g for ZIF-8 at 298, 303 and 313 K, respectively. The calculated thermodynamic parameters indicated that the adsorption process was endothermic in the case of Fe-BTC (ΔH° was 16.86 kJ/mol) and exothermic in the case of ZIF-8 (ΔH° was -9.94 kJ/mol). In the continuous setup, a fixed-bed column was packed with Fe-BTC to study the performance of MO adsorption. The influent MO solution concentration was 15 mg/L, and the influent flow rate was 4.5 mL/hr. The adsorption performance was investigated at two different bed heights (0.75 and 1.5 cm). The results showed that as bed height increased the breakthrough time increased (20.0 hr at 0.75 cm to 46.2 hr at 1.5 cm). The bed maximum adsorption capacity also increased from 20.2 to 21.6 mg/g. The experimental data were found to best fit the modified dose response model (R2>0.99). | en_US |
