Fenton oxidation treatment of recalcitrant dye in fluidized bed reactor: Role of SiO2 as carrier and its interaction with fenton's reagent

The role of SiO2 and its interaction with Fenton's reagent in fluidized bed Fenton (FBF) process were investigated in this work. Due to the inherent complexity of fluidized bed process, theoretical and experimental approaches were adopted in the study. Quantum computational approach was employed to predict the thermodynamic feasibilities of the possible interactions in the process. Experiments were conducted to study the effect of carrier loading and its contribution to the pollutant removal. FESEM/EDX and FTIR analyses were used to investigate the changes on the surface of the carriers due to interaction with Fenton's reagent. The results of quantum analysis show that with Delta G = -0.3263052 kcal/mol, complex formation between SiO2 and H2O2 is highly feasible. This is attributed to the siloxane bridge (Si-O-Si) of the SiO2 network. The experimental results revealed that carrier loading has a positive effect on the process and more than 23% of the initial COD can be removed through adsorption. The fluidization process resulted in 20% higher COD removal compared to the conventional Fenton oxidation. The results of both experimental and quantum computation indicated that besides iron crystallization on the carriers, other interactions are also possible in the FBF process. (c) 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019