Study On Treatment Of Phenol Wastewater And Rubber Industrial Wastewater By Fenton Reagent Oxidation

Fenton oxidation process is an advanced oxidation process,by which the poisonous substances in wastewater can be degraded.In this paper,Fenton oxidative process was studied with phenol wastewater.The common influence factors, operation conditions and reaction mechanism in the Fenton oxidation were researched extensively in it with ultraviolet spectroscopy(UV),High Performance Liquid Chromatography Liquid(HPLC)and Ion Chromatography(IC).Orthogonal experiments were designed to optimize four selected influence factors which were pH,H₂O₂ dosage,Fe²⁺dosage and reaction temperature. According to their influence importance on the oxidation process,we designed the basic operating condition in the single factor experiments:H₂O₂=1.5mL, FeSO₄·7H₂O=0.3g,pH=3,t=30min,T=25℃.The mechanism of Fenton oxidation process was that H₂O₂ was decomposed into hydroxyl radical rapidly in the presence of Fe²⁺as the catalysts.The hydroxyl radical could decompose phenol in a short time and the remove ratio of phenol and COD were above 90%and 80%separately.The phenol degradation mechanism was expected as:phenol→benzoquinone→maleate→oxalic acid,Malonate→propanoic acid,acetic acid,formic acid→CO₂ and H₂O. The correlativity of the reaction time and the relative degrading rate of the phenol were analyzed and a simplified mechanistic model for the organic wastewater of the phenol was derived.The kinetic reaction equation was fitted as follows: d[COD]/dt=18.3496exp(-14616/RT)[H₂O₂]^0.5393[FeSO₄]^0.348In addition,with rubber waste water as the object of study,H₂O₂ dosage, coagulation solution pH value,coagulation dosage and reaction time which had notable effect on the coagulation process with Fenton preoxidation water were investigated in this paper.According to L₉(3³)Orthogonal experiments with H₂O₂ dosage,FeSOa.7HzO dosage and Fe2(SO4)3 dosage;the optimal dosage were 2mL, 0.3g and 0.3g respectively,which provided important theoretical foundation to Fenton preoxidation-coagulation process treatment high concentration organic wastewater.The united process had better COD treatment result compared with Fenton oxidation or direct coagulation.Consequently,the Fenton preoxidation-coagulation united treatment process could reduce H₂O₂ dosage and running cost,overcome the problem of high running cost and low treatment efficiency when treated with Fenton oxidation or direct coagulation individually.