Research And Application Of Standard-up Technology In Sewagetreatment Plants In Pharmaceutical And Chemical Parks

China is a large country in pharmaceutical production and use.With the development of the pharmaceutical industry,the treatment scale of pharmaceutical wastewater has gradually increased.Pharmaceutical wastewater is more complicated because of its high organic concentration and high toxicity.Therefore,it is often necessary to use various pretreatment schemes in practical engineering.The research object of this paper is a sewage plant in a pharmaceutical park in Jiangxi.Before the bid formulation and transformation,the sewage plant adopts the process of secondary AAO biochemical treatment as the main body to deeply treat the sewage taken over from the park,and discharge it uniformly after meeting the discharge standards of the park.However,in recent years,due to the continuous expansion of the park and the continuous improvement of discharge standards,it is necessary to treat some refractory sewage through increased pretreatment processes.This paper studied the treatment of refractory medical wastewater by iron-carbon microelectrolysis,Fenton advanced oxidation,and iron-carbon + Fenton combined process through small test experiments.According to the results of the small test,the Fenton advanced oxidation method was finally selected as the pretreatment process of the park sewage plant.The specific conclusions are as follows:(1)Iron-carbon microelectrolysis experiment Determine the reaction time,iron-carbon mass ratio,initial p H of the reaction,and the best aeration intensity(suitable)values according to the single-factor experiment are 2h,3:4,3 and 3mg/L respectively.Under the best value of each factor,the experimental water sample COD376mg/L decreased to 244mg/L,the COD removal rate was about 35%,and the B/C ratio increased from 0.16 to 0.30.(2)Fenton advanced oxidation According to single-factor experiments,the amount of hydrogen peroxide,H2O2: Fe2+ molar ratio,the initial p H of the reaction,and the best reaction time(appropriate)values are 2.0mg/L,3:1,3.5 and 2h respectively.Under the best value of each factor,the experimental water sample COD decreased from 392mg/L to 182mg/L,the COD removal rate was about 45%,and the B/C ratio increased from 0.17 to 0.40.(3)Iron-carbon + Fenton joint process experiment The experimental parameters of the iron-carbon stage are consistent with the above.The initial p H,hydrogen peroxide water injection and reaction time optimal values of the Fenton stage are 3,1.6mg/L and 1.5h respectively.Under the best conditions,the experimental water sample COD of the combined process decreased from 376mg/L to 172.5mg/L,and the COD removal rate was about 54% B/C ratio increased from 0.16 to 0.44.(4)According to the comparison of the three processes,the Fenton advanced oxidation method is finally selected as the final pretreatment process.The comprehensive treatment cost per ton of medical wastewater in Fenton pretreatment is 6.8 yuan.