Degradation Rules Of Organic Compounds By Fenton’s Reagent

The environmental pollution is getting worse with the fast development ofindustry. There are more and more intricate species of organic pollutants in thewaste water, which are a serious hazard to people’s health. Advanced oxidationtechnology is one of the effective ways to deal with these pullutants. Fentonprocess, as one of these advanced oxidation technologies, is widely used in thedegradation of organic pollutants ever since it was discovered. It is an effectiveprocess to degradation those difficult degradable organic wastewater, with greatdevelopment potential and good application prospect. Research on thedegradation rule of organic compounds by Fenton process is helpful to predictthe degradation efficiency of the new or compounds which are lack ofexperimental data.In order to forecast the degradation effeciciency of the new or those organicpollutants which are lack of the experiment data, degradation rule of28organiccompounds by Fenton oxidation process was studied in this research. Aromatichydrocarbon compounds, heterocyclic compounds and halides were included. Atthe early stage of the Fenton reaction process, degradation effect of compoundsfitted the first-order kinetic reaction equation. As time went on, the reactiontended to slow. The first order kinetic rate constants of color degradation rate ofcompounds were bigger than those of their TOC degradation rate. Meanwhile,their average color degradation rate Rcoloris80.8±30.3%, and the TOCdegradation rate RTOCis about0.44times of Rcolor in average, which indicatedthat the color of compounds were easier to be removed by Fenton process thanTOC. In addition, the degradation effect varied with different structures betweencompounds. Low degradation effects happens to the symmetry-structured compounds, such as azobenzene and anthraquinone, due to their poor solubility,while high degradation effects for those asymmetry-structured compounds suchas anline and phenol, which can be well dissolved in water. Obviouslywater-solubility is one of the most important factors which affect thedegradation effect of organic compounds.In order to further explore the degradation rule of organic compounds byFenton process, the degradation mechanism was also studied. Three typicalorganic compounds, which are nitrobenzene, aniline and o-nitroaniline, wereselected to analyse under GC-MS after treated10mins by Fenton process, andthe results showed that the experimental data consistent with the calculated.Other than that, the relationship between the colority degradation efficiencyof compounds and the structures was analyzed.16quantum chemical parameterswere calculated by Gaussian09DFT B3LYP/6-311g(d,p) for each organiccompound, including the Dipole moment, energy, Natural Bond Orbital, surfacearea(grid) and the volume of compounds. Then the relationship between allthese quantum chemical parameters and the colority degradationrate constanthas also been studied. It’s found that the the total energy, the surface area (grid)and most activity point of H atoms of Fukui index are highly correlated to thecolority degradation rate constant of compounds. One quantitativestructure-activity relationship (QSAR) model was then studied based on thisresearch and was proved to be effective.