Preparation Of Iron-Loaded Graphene Modified Mesoporous MCM-41 Catalyst And Studies On Fenton Catalytic Degradation Of Phenol

Heterogeneous Fenton Oxidation is one technology of advanced oxidation processes (AOPs), which can get rid of refractory organic matter. It is an oxidation process to produce hydroxyl radical, which has strong oxidizing. In this paper, a variety of supported catalysts were synthesized and used to study the effect of catalysts on the phenol degradation by heterogeneous Fenton technology.In this paper, iron oxide and copper oxide loaded catalysts were synthetized,which used MCM-41 and Al2O3 as carriers, then MCM-41 and Fe(NO3)3·9H2O were choosed as carrier and active constituent. Graphene oxide was prepared by improved Hummers method, then the graphene modified mesoporous molecular sieves MCM-41 were synthesized via a high temperature reflow method. Al-MCM-41-Fe, gh-Al-MCM-41-Fe and gh-MCM-41-Fe were compared by their effect on phenol degradation. The chemical valance and morphology of catalysts were characterized by XRD, SEM-EDX, surface analyzer. The results showed gh-Al-MCM-41-Fe possessed mesoporous structure and the doped graphene reduced particle size. When pH was 3.0, the phenol degradation was 100%, the removal rate of COD reached more than 62.16%, the iron solution value was 0.06 mg·L-1 after 90min reaction. The gh-Al-MCM-41-Fe catalyst can broaden the pH range, lower the iron solution value and reduce the secondary pollution.The gh-MCM-41-Fe catalyst was prepared by hydryothermal method. The catalyst was characterized by SEM、TEX、XRD、XPS and material preparation process and reaction conditions were also investigated. The results showed the gh-MCM-41-Fe catalyst had bigger specific surface area and pore volume. The gh-MCM-41-Fe catalyst also possessed mesoporous structure. The material characterization indicated the effective reduction of GO to graphene. The XRD showed the a-Fe2O3 crystal in gh-MCM-41-Fe catalyst. The optimum reaction conditions were that pH=3.0, graphene dosage of 30 mL, iron dosage of 5%, calcination temperature of 550-550℃, the phenol initial concentration of 100 mg·L-1, the H2O2 initial concentration of 9.8 mmol·3L-1, the reaction temperature of 298K. The degradation rate of phenol was nearly 100%, the removal of COD and TOC were 63% and 38.89%, resperctively, dissolved iron concentration was 0.825 mg·L-1, the apparent activation energy was 18.43 kJ·mol-1 after 90 min. The kinetics of phenol degradation in the system of heterogeneous Fenton reaction were well-fitted to a pseudo first-order model. Compared with MCM-41-Fe, the dope of graphene could obviously increase catalyst efficiency, reduce the iron dissolution and secondary pollution. Humic acid and oxalate in water both inhibited the phenol degradation.