Phenols And Quinones Enhanced The Oxidation Of Organic Compounds By Fenton/Fenton-like

With the wanton discharge of industrial wastewater into the environment,refractory organics with high toxicity are brought into the aquatic environment,leading to the water pollution.How to effectively remove the refractory organics in water are also the focus of attention at this stage.Fenton(Fe2+/H2O2)and Fenton-like(Fe2+,3+/persulfate)advanced oxidation technology can effectively remove the refractory organics by using the strong oxidizing free radicals.However,the Fenton reaction has the problem that iron ion cycle is limited and it is difficult to be applied in practical engineering.Therefore,this paper studies the rate of degradation of organics by the addition of electron transfer donor phenol/quinone organics to Fenton/Fenton-like reaction,explores the degradation pathways of organics,extends the application range of pH and evaluates the feasibility of practical engineering application.The kinetics of Fenton/Fenton-like reaction enhanced by phenolic quinones was studied under the condition of pseudo-first order reaction,inspection the effects of solution pH,oxidant concentration,phenol/quinone organic concentration on the reaction and the feasibility of the application in the actual water.The intermediates of phenol,benzoic acid and atrazine were determined by high performance liquid chromatography(HPLC)and liquid chromatography mass spectrometry(HPLC-QToF-MS).Then,the reaction pathway was deduced.The results showed that catechol,resorcinol and hydroquinone could effectively promote the degradation of organics in Fenton and Fenton-like systems at different pHs,among which the enhancement of catechol was the most effective.The main reason for the strengthening of Fenton/Fenton-like reaction of phenolic organics,on the one hand,phenolic organic compounds as complexing agent can be complexed with iron ions in solution to inhibit the hydrolysis of iron ions under high pH conditions and broaden the pH range of Fenton reaction,on the other hand,phenolic organic matter as an electron transfer body can accelerate the conversion of Fe3+to Fe2+.Using the liquid chromatogram,the intermediate o-benzoquinone and p-benzoquinone were generated in catechol and hydroquinone experiments.But quinone was not found in the reaction of resorcinol.Therefore,the addition of benzoquinone can also promote the degradation of organic matter by Fenton and Fenton-like reaction,which is mainly due to the effect of benzoquinone as an electron transfer agent to accelerate the conversion of Fe3+to Fe2+in the reaction.It can be seen that the strengthening effect of catechol and hydroquinone on Fenton and Fenton-like reactions is the result of the interaction of phenol/quinone.Therefore,according to the conversion characteristics of phenol/quinone in the reaction,the oxidative degradation pathways of BA and phenol were deduced.The oxidative degradation products of ATZ in Fenton-like reaction were determined by HPLC-QToF-MS,A total of seven major products were detected,such as DIA,HA,DEA,HDHA,DHA,MEA,nonphytotoxic,and speculate that the degradation path of atz.The effectiveness of phenols and quinone enhanced the oxidation of organic compounds by persulfate in real water is further examined and it was found that the determined rate constants in synthetic buffered waters can predict the oxidation kinetics in natural waters reasonably well.Overall,these technology show a great promise for wastewater treatment.