Catalytic Hydrogen Peroxide By Pyridine Amide-type Iron For The Degradation Of 4-CP In Water

With the development of industry and agricuture, chlorophenols have been widely uesd as preservative, bleach and insecticides. However, because of their toxicity and non-biodegrabable, they cause serious harm to environment. Owing to its merits such as strong oxidation, higher-efficiency, etc. Fenton process can partially solve the above problems, causing the attention of environmental workers. However, the optimum pH value range of Fenton oxidation is in the acidic range, which limits the widespread application of Fenton’s reagent. In order to solve this problem, this study investigates a metal complex catalyst catalyzed hydrogen peroxide to degrade 4-CP under near alkaline conditions. The main research and results are shown as follow:In the process of synthesis and optimization for metal complex catalyst, the synthetic method, solvents, complexing central ion, organic ligands and the molar ratio of the synthesis were investigated. The results showed that the catalyst was synthesised with an organic ligand N,N’-1,2-phenyl-enedipyridine-2-carboxamide and FeCl2 at a molar ratio of 1:1 using solvent method in acetonitrile solution, which has the best catalytic effect on the oxidation of chlorophenol by H2O2.In this paper, the degradation of 4-CP by pyridine amide-type iron catalyzed hydrogen peroxide was studied. Four different treatments were used to compare the degradation efficiency of 4-CP and the degradation order of the methods was catalyst/H2O2>H2O2>Fe2+/H2O2>pyridine amide. The optimum condition for the degradation of 4-CP in pyridine amide-type iron/H2O2 system was that: buffer solution at pH value of 9.9, the initial concentration of 4-CP was 0.7mM, the amount of catalyst was 35μM, the concentration of H2O2 was 3.5mM. The degradation rate of 4-CP under the optimum condition almost reached 99%.The degradation of 4-CP was a second-order reaction, the OH- and pyridine amide-type iron acted as a catalyst. And the catalyst pyridine amide-type iron and pH had a great influence on the degradation reaction. By contrast, the effect of catalyst was greater than that of pH. The kinetic practical equation could be expressed as follows:r=k0[M318(Fe2+)]1.9192[OH-]1.0464[4-CP][H2 O2]...