The Research Of The Combined Process Of A~2/O-hydrolysis Acidification Treat The Livestock Wasterwater

As the rapid economic development and people’s living standards improvedgradually, people’s demand for livestock and poultry products makes the developmentof livestock and poultry industry, in China, promoted rapidly. Which is workingtowards to intensive and large scale. Although the rapid development of the livestockindustry has brought great benefits to our country and people, the problem oflivestock waste pollutions can not be ignored. At present domestic livestockwastewater treatment technology, according to the processing mode, can be dividedinto three types: returning mode, natural treatment mode, industrial processing mode.Overall, the effect on treatment of livestock wastewater of industrial processing modecan meet the "livestock wastewater discharge standards", but as the scale and numberof farms increasing, even if the above emission standard were meted, The totalamount of COD and NH3-H discharged into the environment is still larger each year,which still will cause great pressure on the environment. Although the research ofdomestic has certain progress in this area, due to seasonal climate, terrain conditions,operation cost and constrain of the technical level of maintenance, the application inpractical engineering is seldom.The main research contents of this paper is the experimental study of effect ontreatment of livestock wastewater by hydrolytic acidification A~2/O process.In this experiment, the hydrolysis acidification pool optimal hydraulic retentiontime was8h. The optimal control parameters of A~2/O: the ratio of return sludge wascontrolled at70%, the ratio of mixed liquor reflux was controlled at300%, thedissolved oxygen concentrations was controlled at3mg/g. The total hydraulicretention time was15h.The experimental research shows that the average removal rate is about4.5%in thehydrolysis acidification pool stability, after the operation, the Ammonia water changes is not toobig. The average remove rate of COD is higher in A~2O of the hydrolysis acidification pretreatmentthan that in the A~2O operating alone. The removal rate of COD is increased from74.5%to82.1%.The removal rate of TP is increased from79.5%to84.2%. The removal rate of NH3-N is reducedfrom76.2%to74.8%.After the operation stable, the combined process of A~2O-hydrolysis acidification could treatthe livestock wastewater of this experiment effectively, in the optimum operation conditions. Thetotal average removal rate of COD in Wastewater was up to88.6%, the average concentration of effluent COD reached to290mg/L. The total average removal rate of TP in Wastewater was up to85.4%, the average concentration of effluent TP reached to5.6mg/L. The total average removalrate of NH3-N in Wastewater was up to75.8%, the average concentration of effluent NH3-Nreached to57.6mg/L. The total average removal rate of SS in Wastewater was up to95.23%, theaverage concentration of effluent SS reached to about62.5mg/L.All kinds of indexes met"livestock wastewater discharge standards"（GB18596-2001）.