Study On The Degradation Of Organic Matter In Hypersaline Organic Wastewtr Through Microwave Synergistic Sensitizer+Advanced Oxidation

The problem of water pollution is getting worse and the water resources are seriously deficient.The chlor-alkali chemical,pharmaceutical,food processing and other industries produce a large amount of hypersaline organic wastewater,which has brought great harm to the environment.It is very difficulty to treat the hypersaline organic wastewater for recycle and zero discharge because of the complex composition,high content of toxic substances,and high concentration of inorganic salts.The treatment technologies commonly used mainly include biological method,physical chemical method and advanced oxidation.However,the hypersaline organic wastewater still has not been properly treated because of its high salinity and inclusion of organic matter.In this study,the microwave synergistic sensitizer+advanced oxidation technology was adopted to degrade the organic matter presented in hypersaline organic wastewater.First,the sensitizer that absorbs the most microwave energy was selected through comparison test,and the COD remove characterics of Fenton oxidation,potassium persulfate?KPS?oxidation and NaClO oxidation were studied.Then the microwave-assisted oxidation methods were adopted to remove organic matter.In addition,the removal of COD by microwave synergistic activated carbon sensitizer+Fenton and microwave synergistic activated carbon sensitizer+KPS was studied via varying microwave power,irradiation time,dosage and initial pH of the solution.Finally,the oxidation kinetics of processes of microwave assitanted Fenton and microwave synergistic activated carbon+Fenton were also studied.The results obtained from the experimets are as follows:?1?Microwave irradiation test show that Single microwave irradiation has no obvious effect on the removal of organic matter in hypersaline organic wastewater.In the absence of sensitizer,the organic matter could not directly absorb the energy of the microwave,and the microwave irradiation could only heat the water,and could not degrade the organic matter.In the presence of a sensitizer,microwave irradiation could form a"hot spot"on the surface of the sensitizer,and the organic matter in the wastewater could be degraded by catalytic oxidation.Under the synergistic effect of microwave irradiation and activated carbon sensitized,the COD removal reached to91.3%.?2?Fenton,NaClO,KPS oxidation tests show that oxidation technology could effectively remove the organic matter in hypersaline organic wastewater.The COD removal efficiency of Fenton and KPS oxidation methods was better than NaClO oxidation method.The COD removal of Fenton oxidation was 78.4%after oxidation reaction of 240 min,and the COD removal of KPS oxidation was 84.8%after oxidation reaction of 150 min,and the COD removal of NaClO oxidation was 58.9%after oxidation reaction of 300 min.?3?COD removal of the integrated process was studied via varying the microwave power,irradiation time,and initial pH of solution and dosage of oxidant.The results showed that integrated processes of microwave+Fenton and microwave+KPS could effectively remove organic matter from hypersaline organic wastewater.Microwave+NaClO could not remove organic matter from hypersaline organic wastewater.Compared with the oxidation technique described in?2?,the COD removal of microwave-assisted oxidation using Fenton was 79.0%when reaction time was shortened from 240 min to 10 min.The COD removal of microwave-assisted oxidation using KPS was 75.0%when reaction time was shortened from 150 min to15 min.The COD removals of microwave-assisted oxidation using NaClO was 59.8%when reaction time was shortened from 300 min to 15 min.?4?The removal of organic matter from hypersaline organic wastewater was futher invetigated through the intergated methods of microwave synergistic activated carbon+Fenton and microwave synergistic activated carbon+KPS oxidation.The effects of reaction conditions on COD removal were investigated.The results showed that the COD removals of microwave synergistic activated carbon+KPS and microwave synergistic activated carbon+Fenton oxidation could reach up to 87.1%and 90.6%,respectively.?5?The oxidation kinetics of the processes of microwave-assisted Fenton and microwave synergistic activated carbon+Fenton followed the equations of -r_A=-dcCOD/dt=2.734×10^-4C²_COD and -r_A=-dcCOD/dt=6.89×10^-4C²_COD,respectively.