Research On The Pretreatment And Advanced Treatment Of Pharmaceutical Wastewater By Electrocatalytic Oxidation

As a kind of high density and difficulty degradable indu stry wastewater,discharge of pharmaceutical wastewater caused severe impacts to environment.With the promulgation and implementation of Discharge standards of waterpollutants for pharmaceutical industry, the wastewater discharge standardsbecame more stringent. Many pharmaceutical companies need to modify existingwastewater treatment process. Aimed at the practical problems existing in thewastewater treatment, and based on the analysis of characteristics of thewastewater, the original treatment process was improved by conventionalmethod and the electrocatalytic oxidation system. The pretreatment scheme ofantibiotic wastewater in the pharmaceutical factory workshop and the advancedtreatment scheme of secondary effluent were explored by experiment, in order toprovide important basis and references for the wastewater treatment.Partial acid wastewater in the pharmaceutical factory workshop was studiedby pretreatment of technology with electrocatalytic oxidation, gas flotationcoagulation and combined technology with gas flotation-electrocatalyticoxidation and coagulation-electrocatalytic oxidation,coagulation-electrocatalyticoxidation was determined as the best treatment scheme by comparing thewastewater COD removal rate and the biochemical change s. The parameterswere optimized by single factor experiment, the organic before/after thetreatment were studied by GC-MS analysis. The optimal parameters ofcoagulation-electrocatalytic oxidation were determined, the coagulant was PAC,pH=6, dosing amount was0.2g/L, the current density of electrocatalyticoxidation was10mA/cm~2, time was30min.The advanced treatment of secondary effluent was studied by two-dimensional and three-dimensional electrocatalytic oxidation system respectively.The effects of current density and electrode configuration mode to wastewatertreatment were studied, which determined the best electrode configuration modewas two anodes with three cathodes and the current density was7.5mA/cm~2bycomparing removal efficiency of COD and chromaticity. In the stu dy of three-dimensional electrocatalytic oxidation system, the quartz ceramic ring particle electrodes loaded with Sb doped SnO2were regenerated by dip coating treatmentmethod and were detected by SEM method. Through single factor experimentand three levels of three factors of orthogonal experiment, the optimizationparameters of three-dimensional electrode system listed as follows, slot voltage11V, electrode gap8cm, particles of filling layer filling quantity of volume2/3.The treatment effect, energy consumption and current efficiency were comparedbetween the two-dimensional and three-dimensional electrode system, the resultshowed that three-dimensional electrode system was better than two-dimensionalelectrode system in all aspects.According to the experiment optimization result and the advantages ofbaffle reactor such as simple structure, without stirring, and simulated byFLUENT software, three-dimensional baffle reactor was designed and itoperated continuously and sta bly for30cycles. The treatment efficiency ofdifferent hydraulic retention time was studied, the structure was designed andthe cost of engineering was preliminarily calculated according to the experimentresults. The result showed that the optimal hydraulic retention time was35min,the total investment was5.46million yuan and the operation cost was1.87yuanper ton everyday, which had a certain economic and technical feasibility.