Research On The Degradation Of Ppcps In Water By Advanced Oxidation Technologies(Aots)

Phamarceutical and personal care productsas an new micro pollutant is diffulut to be degradated by conventional wastewater treatment technique, this sort pollutant is harmful to water environment and human being. The AOPs is an valid method to treat nodegradable organic pollutants which has an huge develop potential and benign apply prospect. The degradational characteristic, operational parameters and kinetics of specified PPCPs (OFL and MNZ ) by Fenton, Oxone/Co²⁺process and UV/Oxone/Co²⁺,UV/Fenton process have been dicussed systematically, the kinetics process, degradation efficiency and possible degradation pathways have been discussed, which provide theoretical evidence to the decomposition of PPCPs by AOPs. The experiment results show:1. The degradation of OFL in aqueous solution by Fenton process and Oxone/Co²⁺ process: the removal efficiency of OFL was defines as the standard to investigate the experimental parameters, the optimal conditions are following: Fenton process: [OFL]=9mgL^-1, [H2O2]=1.5mmolL^-1,[Fe²⁺]=0.03mmol L^-1, pH=4.0, temperature=25℃, time=120min, removal efficiency=99.5%,TOC removal efficiency=56.2%. Oxone/Co²⁺process:[OFL]=9mgL^-1,[Oxone]=1.2mmolL^-1,[Co²⁺]=0.003mmolL^-1,pH=6.0,temperature=25℃,time=30min, removal efficiency=100%,TOC removal=65.8%. The intermediates and possible degradation pathways were speculated in terms of the MS spectrum. The Fenton process is eco-friendly than Oxone/Co²⁺ process, but is less economic and effective than Oxone/Co²⁺ process.2. The degradation of OFL in aqueous solution by UV/Oxone/Co²⁺ process: in the condition of pH=5.0,[Oxone]/[Co²⁺]=1000, [Oxone]=0.6mmolL^-1, [OFL]=9.0mgL^-1, temperature=25℃, time=60min, the OFL was completed removal, the TOC removal is 87.0%, the kinetic in the optimal condition is pseudo-first-order, the rate constant is 0.0767 min^-1. The degradation of OFL strongly depend on the initial pH of reaction solution, the removal efficiency is going up then dropping with increasing of pH; the dosage of Oxone and Co²⁺ are not the more the better; temperature can slightly affect the experimental results.3. The degradation of OFL in aqueous solution by UV/Fenton process: the influence of various parameters on the OFL removal were investigated in terms of OFL removal efficiency and reaction constant rate, such as the initial pH, temperature, molar ratio of [H2O2]/[Fe²⁺], H2O2concentration.The optimal conditions are following: [H2O2]=1.5mmolL^-1, [Fe2+]=0.03mmolL^-1, [OFL]=9mgL^-1, pH=3.5, temperature=25℃, reaction time=60min, In this process, the degradation of OFL fit the pseudo-first-order reaction, the rate constant is 0.0496 min^-1, the TOC removal efficiency is 67% and OFL could be better degraded than Fenton process.4. The degradation of MNZ in aqueous solution by Oxone/Co2+ process: the MNZ was completely degraded in the process, the pH of solution significantly affect the removal efficiency, the degradation efficiency of MNZ increasing with the rising of [Co2+], [Oxone], temperature. The optimal codition: pH=5.0, [Oxone]/[ Co2+]=100, [Oxone]=1.5mmolL^-1, temperature=25℃, time=30min.