| In this paper, using peanut shells as a carrier for the preparation of catalysts of heterogeneous Fenton system. By comparing the different Fenton catalysts(iron oxide, ferric chloride, ferrous chloride etc.) under the same reaction conditions on the treatment of methylene blue, finally it is concluded that preparation of peanut shell catalyst and ferrous chloride on the treatment effect of methylene blue solution is very significant, because ferrous chloride ions in solution state, iron sludge generated after reaction is not easy to recycle, cause secondary pollution to the solution. Therefore this study selected with peanut shells as the carrier of the preparation of catalysts for degradation of methylene blue. Through the static experiment method to study the effect of degradation of methylene blue under different reaction conditions. The optimum reaction conditions are as follows: the concentration of H2O2 was 22.5mmo L/L 1m L, the initial concentration of methylene blue solution 20 mL is 40 mmo L/L 20 mL, the catalyst dosage of 40 mg, p H is 6.2, reaction time is 30 min. The best conditions for the degradation reaction of methylene blue solution at room temperature was as high as 99.6%, and the removal rate of COD is higher. The kinetics of the heterogeneous Fenton system static degradation of methylene blue solution, the influence of different reaction conditions on the reaction rate, and determine the kinetic reaction rate constant KB =0.12951min-1(activation energy), the Ea value of 5051J/mo L.Based on the study of the optimum reaction conditions for the degradation of methylene blue solution of static heterogeneous Fenton system, to study the dynamic degradation of methylene blue solution. Through the single factor experiment method was used to investigate the effect of degradation of methylene blue solution under the condition of different initial concentration of solution, solution pH, catalyst dosage, flow rate etc. When the reaction conditions are as follows: Methylene blue solution 1L 60mg/L、Peanut shell magnetic carbon 1.3g、H2O2 75 mL 22.5mmo L/L, when the treated solution comes out color and start timing until 255min(Taking a sample to test its concentration each 5min under normal temperature). When the initial solution pH, concentration of hydrogen peroxide, flow velocity, initial concentration of solution single factor changes respectively. The degradation rate of methylene blue solution will be affected. After the treated solution comes out color, and start timing(Taking a sample to test its concentration each 5min) until 250 min. When the degradation of methylene blue concentration tends to balance:(1) When the pH solution concentration is about 1.72, 3.18, 4.93, 6.8 and 9, when it is 1.72, the degradation rate of the solution is about 38.5%. And when the pH is 3.18, the degradation rate of the solution is about 40.8%. When the pH increased to 9, the degradation rate of the solution is about 25.5%;(2)When the concentration of H2O2 is respectively about 15 mmo L/L 、 22.5mmoL/L 、 30mmoL/L 、 37.5mmoL/L and 45 mmo L/L, and the concentration of hydrogen peroxide is 15 mmo L/L, the degradation rate of about 32.97%, and when the hydrogen peroxide concentration increased to 45mmoL/L, the degradation rate of methylene blue solution is about 24.03%;(3) When the catalyst dosage is respectively about 0.6g, 0.8g, 1.0g, 1.3g and 1.6g, and the catalyst dosage is 0.6g, the degradation rate of methylene blue solution is about 13.32%. When the dosage increased to 0.8g, the degradation rate increased to 15.33% too. Increasing the catalyst dosage continually until 1.6g, the degradation rate reached 31.5%;(4)When the flow rate is 3.8cm3/min, the degradation rate of about 43.2%.While it increases to 4.9cm3/min, The degradation rate diminished by about 36.2%,and when it increases to 8.4cm3/min, the degradation rate of only about 12.8%;(5) When the initial concentration of solution is respectively about 20mg/L、40mg/L and 60mg/L, the degradation rate is respectively about 42.8%、35.4% and 27.7%, while the initial concentration of solution is respectively about 80mg/Land 100mg/L, the degradation rate is respectively about 18.25% and 12.8%. The conclusion is different single factor has a significant effect on the degradation effect. |
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