Research On Vertical Circulation Oxidation Ditch In High Concentration Pharmaceutical Wastewater Treatment

China has become a global synthetic pharmaceutical production and export country,with the development of China’s pharmaceutical industry,pharmaceutical wastewater has become one of the major sources of pollution.As a result of the synthesis of pharmaceutical industry using a variety of raw materials,chemical compositions and production processes,the production wastewater is also very complicated.The big change of water quality,water quantity and the variety of the pollutants,the much difficult-degradable and inhibitory substance in the pharmaceutical wastewater,which makes the treatment of pharmaceutical wastewater become a big problem.In this paper,the treatment of pharmaceutical wastewater is studied with the practical project as the object.Firstly,the status of pharmaceutical industry development and the characteristics and sources of production wastewater,and various process technologies for pharmaceutical wastewater treatment are summarized.The origin and process characteristics of vertical circulation oxidation ditch as the key process in this paper are especially introduced.Secondly,the wastewater treatment project of a synthetic pharmaceutical company in North China is studied as the research project.By the analysis of water quality and water quantity,the main process route is determined as preliminary treatment,hydrolytic acidification,vertical circulation oxidation ditch,ozone catalytic oxidation and sand filter.The technical parameters and equipments of each unit are also given.Again,the new aerobic process of vertical circulation oxidation ditch is especially studied.Respectively in commissioning stage,stable operation stage including single-stage-single-feed mode and two-stage-two-feed mode,the removal efficiency of pollutants,mainly COD and ammonia,is analyzed,and the operating effect is evaluated.The results are given as follows: for high concentration pharmaceutical wastewater,compared with the single-stage-single-feed mode,the two-stage-two-feed mode is improved on operation flexibility and stabilization,and has advantages on effluent quality and energy saving.Finally,the investment and operating cost of the research project are analyzed.Due to the high degree of automation and the high level of equipment brand,the investment of the project is in the middle-high level of the same kind of wastewater treatment.Due to the energy saving advantage of the used process and the additional frequency control method,the operation cost is in the medium level.