Study On Degradation Of Refractory Organic Pollutants In The Sewage By Low-Temperature Active Oxygen Species

With the development of global industrialization,more and more various kinds of refractory organics discharged into the water.These refractory organics have big molecular weight and complex structure which cannot be effectively degraded by conventional wastewater treatment method.So it threatened human health and ecological environment.Currently,there are lots of disadvantages existed in deeply degradation technology of the refractory organics in the sewage,such as long treatment time,unsatisfactory pollutants degradation result,chemical reagents and catalysts addition,high investment and running costs and so on which have attracted attention in the academic field.And a lot of work have done for degradation of refractory organic pollutants in the sewage.In this study,a low-temperature active oxygen species was produced by ionization and dissociation of oxygen in a strong ionization discharge electric field.O2+among low-temperature active oxygen species reacted with H2O moleculars to form trace hydroxyl radicals(·OH).A initiator(HO2·)with high reaction rate constant was generated by OH reacting with O3.High concentration of OH were formed by high-concentration of O3 under the action of HO2',whose oxidation potential and reaction rate reach up to 2.80 V,108 L/mol·s,respectively.So it could non-selectively and rapidly mineralize persistent organic pollutants into harmless small molecular organics,CO2 and H2O.It will cause the area of wastewater treatment system,energy consumption,investment and running cost ten times lower than the existing methods.As a result,the study will help to resolve problems of current deeply degradation of the refractory organics in the sewage and wastewater reuse.A low-temperature active oxygen species was produced by strong ionization discharge,and was injected into water to form OH solution.So the concentration of low-temperature active oxygen species will have an effect on OH concentration,and further influence the refractory organics degradation rate in the sewage.The concentration of low-temperature active oxygen species was detected.TA and 4-HBA were used as chemical probe to qualitative and quantitative detection of OH by Fluorescence spectrometer and High performance liquid chromatograph.The refinery sewage after primary treatment which contained large amount of refractory polycyclic organics was treated as experimental wastewater.The experiments of effect of series of experimental parameters such as injection amount of active oxygen species,plasma reactor volume,injection amount of oxygen and mass ratio of active oxygen species to COD and so on on COD and TOC concentration were conducted in the experimental system.The experimental results showed that after active oxygen species treatment,COD concentration of refinery sewage decreased from 174.6 ppm to 19.6 ppm,TOC concentration decreased from 42 ppm to 10.4 ppm,the COD removal rate was 88.7%and the TOC removal rate was 75%.