Study On The Treatment Of Wastewater In Phenol-acetone Production

In this paper,evaporation desalination pretreatment process improvement and the treatment combined anoxic acidification with anoxic acidification are proposed to treat the phenol and acetone production wastewater in Shandong lihuyi weiyua Chemical Co.Ltd.,which contains high concentration of salt.A series of experiments are studied systematically.Originally,a kind of black tar-like substance which can block the pipeline and the evaporator heating pipes seriously appeared during the operation of the evaporation desalination treatment device in this company.In order to ensure the stable operation,the following process equipment improvements have been carried out after a series of experiments:?1?adding a preheater,?2?adding a molecular mill,?3?select a DTB crystallizer.There is no black tar substance appearing with these improvements,thus ensure the follow-up biological treatmentASBR anoxic acidification is offered as the biochemical process for this wastewater treatment.The effect of stirring time,temperature,p H,hydraulic residence time?HRT?and volume loading on the COD,volatile phenol and VFA indicators are studied.The results showed that when HRT is 21 h and the volume loading is about 5.93 kg COD/?m3·d?,the removal efficiency of COD and volatile phenol can reach 91.9% and 96.5% respectively,the growth index of VFA reaches high at 2.68.Orthogonal experiments are designed to investigate the influence of pH,H-2O-2 concentration,FeSO4·7H₂O concentration and reaction temperature on phenol and COD removal.The results indicate the basic operating condition: H₂O₂=7.6m L/L,FeSO₄·7H₂O =2.1g/L,pH=3,t=80min,T=25?.Then three kinds of experiments are studied under these conditions showing that COD content in the wastewater is all under 100mg/L,which is qualified for emission.