Advanced Treatment Of Pharmaceutical Wastewater By The Method Of Electrocatalytic Oxidation

Pharmaceutical wastewater is a kind of high concentrated organic wastewater which is difficult to biodegrade, because it has a complex composition, high colority and so on. The discharge of pharmaceutical wasterwater not only caused a huge impact to the environment, but also endangered human health. With the rapid development of the pharmaceutical industry, more attention was taken to the discharge of pharmaceutical wastewater. What’s more, the ‘pharmaceutical industrial water pollutant discharge standards’ has been promulgated and implemented by the state. In this study, two depth treatment programs were recommended to treat the pharmaceutical wastewater of a pharmaceutical factorty in Inner Mongolia for meeting the emission requirements.By using the method of two-dimensional electric catalytic oxidation, some experimental researches had been carried on the flotation tank effluent of pharmaceutical factory. The flotation tank effluent was treated by changing the electricity density, electrode arrangement of the program. The optimum parameters of the flotation tank were obtained as follows: the electrode arrangement was cathode-anode-cathode, the electricity density was10mA/cm2, the time of degradation was1h. Under the best conditions, COD value of the floatation tank degraded from the original145mg/L to43mg/L, chroma degraded from the initial389times to28times, pH from the initial4.105increased to6.103.For the sedimentation tank effluent, two-dimensional electro-catalytic oxidation were used. Because of the high COD value, cathode, which had better effects, was selected for further research by increasing the electricity density. In order to improve the treatment effect of the two-dimensional electro-catalytic oxidation, three-dimensional electro-catalytic oxidation was used for further study, the experimental results showed that electrocatalytic oxidation-electro-Fenton was the best way to treat sedimentation tank effluent, the parameters was obtained as follows: choose graphite electrode as cathode, optimal electricity density was15mA/cm2, the best time was2h, the best dosage of FeSO4was1mmol. Under the optimum operating parameters, COD value degraded from413mg/L to44mg/L, COD value degraded from413mg/L to44mg/L, chroma degraded from the initial996times to6times, pH value is always fluctuating around7.The filed experimental results showed that: the instability of pharmaceutical wastewater resulted in the COD value fluctuates greatly. In order to meet the standards, the optimal electricity density was10mA/cm2,15mA/cm2,20mA/cm2when the COD value fluctuated around100mg/L,200mg/L,300mg/L, respectively. For the initial COD was130mg/L of the flotation tank effluent, hydraulic retention time (HRT) was designed by1.5h. The COD and chroma of effluent was degraded to36mg/L,10times, pH was around7, and the waterwater before and after treatment were studied by GC-MS analysis. After a preliminary economic analysis of the engineering, it cost4million yuan to build a two-dimensional electric catalytic oxidation pool, whose HTR and volume were1.5h and200m3, respectively. The operation cost was2.25yuan per ton everyday with the best operating electricity density,10mA/cm2. Using two-dimensional electro-catalytic oxidation system to treat the flotation tank effluent not only solved the problem of pharmaceutical wastewater pharmaceutical industry, but also provided a reference for other pharmaceutical industrial wastewater treatment.