Study On P-tert-butylcatechol Wastewater Treatment Via Supercritical Water Oxidation

Phenol containing wastewater is still a hard concern in the environmental field.The demerits of conventional approaches still exist,especially for dihydric phenol and its derivatives.Supercritical water oxidation(SCWO)is introduced into the field of wastewater management and disposal.SCWO is in development of both the pilot scale and full scale plants in varies countries including China PR.So far,the degradation of phenol and its derivatives via SCWO met the high removal level.However,for the degradation of dihydric phenol species,the application of SCWO was not abundantly reported yet.P-tert-butylcatechol,TBC,a typical species of dihydric phenol,is also included in the non-degradable content of wastewater.As a high-efficient,clean and high-reaction rate approach,SCWO was used in this research for the TBC wastewater treatment.Liquid chromatography,COD test,conductivity test and p H test were applied to analyze the degradation performance.The parameters including temperature,pressure,oxygen excess,detention time and initial concentration were analyzed and optimized.Resultantly,the COD remaining of the samples with initial concentration of 0.15 wt%(approximate 1500 mg/L)can be steadily controlled under 50 mg/L,which is required by the corresponding national standard.Simultaneously,the parameters were optimized as 550 oC of temperature,25 MPa of pressure,n = 3 of oxygen excess,10 min of detention time and 0.15 wt% of initial concentration.ReaxFF force field was introduced to study the TBC degradation processes.Combined the experimental and simulation results,temperature raise and the spread of detention time can both promote the degradation of p-tert-butylcatechol(TBC)because of the actuation caused by OH radical,HO2 radical,H radical and H2O2 etc.Especially,the generation of OH radical affects the ring opening rate.Generally,the simulation results indicate the proof of experimental results and the design of new apparatus.