Research On Degradation Of Phenol By A New Fenton-like System

In order to solve the problems of the low optimal pH, catalysts hard to recover andlarge amount of ferric hydroxide sludge produced by traditional homogeneous Fentonsystem, heterogeneous Fenton-like system and its catalysts have gradually becomeresearch hotspots.In this study, Fe, Cu, C and pore forming agent were used to prepare heterogeneousFenton-like catalyst with high temperature sintering process in N2atmosphere. Theoptimal proportion and the different effect of each materia l on the catalyst were studiedby orthogonal experiment. The influence of catalyst preparation condition on thecatalyst properties and catalytic efficiency were investigated. Possible mechanism of theFenton-like system was proposed. Factors influencing the Fenton-like system were alsobe discussed. Finally the catalyst with good performance had been prepared.After orthogonal experiment, the optimal proportion of materials were Fe: C=7:2,Cu=9%, Na2SiO3=5%; the initial COD and phenol concentration were2500mg/L and1000mg/L, the removal efficiency of COD and phenol were92.61%and98.60%respectively in90min. The effect order on COD and phenol removal efficiency wasFe>Cu>C>Na2SiO3. The effect of the Fe and Cu dosage on catalytic efficiency werevery significant, the dosage of C only has significant effects on phenol removal rate, andthe dosage of Na2SiO3had no significant effect on catalytic efficiency.After the system efficiency and the catalytic properties were discussed, theoptimum sintering temperature and sintering time were850℃and3h were obtained.Under such condition, the surface of catalyst was consist of relatively polyhedronparticles, patical size ranged from1-3m. Main components were Fe, Cu, and someFe2O3, CuFe2O4. Specific surface area, pore volume and average pore diameter were3.646×10-1m2/g,9.06×10-4cm3/g and7.08nm respectively. The maximum compressionload and broken rate were218.18N and0.36%respectively. After catalyst was reused,the removal efficiency of COD and phenol were stabilized around90%and95%. Thecatalytic activity was stable during the reused process. The quantities of dissolved ironion and copper ion only accounting for0.028%and0.05%of the total mass. Only a small amount chemical sluge was produced.The system activity was not only the function of a single material but the outcomeof combined action of all kinds of material in the catalyst. In this Fenton-like system,the catalysts in liquid phase were Fe2+and Cu+, while on the solid phase were Fe2O3,CuFe2O4, HO·could be produced on the surface of the catalyst and in bulk solution. Theoptimal system condition was as below: the catalyst dosge was80g/L, the consumptionof H2O2was45.6mmol/L, initial pH=3.0, reaction temperature was30℃, reaction timewas90min.