Study On Swine Wastewater Treatment With A New Type Matrix Of Constructed Wetland

China’s water environment pollution sources are divided into industrial sewage,domestic sewage and agricultural sewage.Agricultural pollutants account for about 50%of the country’s total water pollution,while livestock and poultry farming waste water accounts for more than 70%of the agricultural water pollution,of which the swine wastewater accounts for the highest proportion.On the basis of mastering the characteristics of pig-raising pollution sources,the method of dry excrement is adopted to realize the control of pollutants from the source and the utilization of pollutants.Through the source separation-ABR anaerobic treatment of swine wastewater is rich in high NH₄⁺-N.,Low COD characteristics,resulting in lower C/N,later denitrification effect worse,how to effectively deal with swine wastewater is a challenge and need to be solved.In order to solve the traditional problems of poor nitrogen removal,complicated operation and high energy consumption,a new type of constructed artificial wetland with PCL as the matrix for strengthening nitrification and denitrification was constructed.Based on this,a new type of filler constructed wetland was used to treat swine wastewater.The effects of NH₄⁺-N and COD removal,as well as the amount of PCL added and the effect of HRT on the treatment efficiency of constructed wetlands1.The release of PCL in the water-solubility experiment was stable and long-lasting.The average daily carbon release per gram was 0.22mg/L.When using PCL（25g）as the carbon source and microbial carrier required for denitrification process,the effect of influent C/N on the removal of NO₃^--N and COD in pig-breeding wastewater was studied,and the appropriate addition of PCL was calculated.the amount.The removal rate of NO₃^--N reached the best when C/N was 4 to 7,which was in the range of 86.27%-99.40%.However,with the increase of C/N,the COD concentration also had a tendency of accumulation by 30.61mg/L is increased to 43.48mg/L.The carbon release performance of PCL filler and the treatment effect of NO₃^--N under different C/N conditions can be obtained.Daily treatment of 1mg/L of NO₃^--N should be suitable to fill the PCL range of 18g to 33g.2.To study the effects of HRT on the removal rates of NO₃^--N and COD under different C/N conditions,the removal rates of NO₃^--N and COD gradually increase with the extension of HRT.Under the same HRT conditions,NO₃^--N The removal rate of N is positively correlated with the size of C/N.3.The performance of a new type of filler constructed wetland to treat swine wastewater was studied:When the reactor hydraulic load was 1.06m³/（m²·d）,the influent COD and NH₄⁺-N concentrations were 300mg/L and 110mg/L,respectively.In the enhanced nitrification area,the COD and NH₄⁺-N removal rates could reach 64.29%and 86.05%,respectively,and the enhanced denitrification zone could remove 83.47%of NO₃^--N.When combined in series,the removal rates of COD and NH₄⁺-N were 70.03%and 89.00%,respectively,and the accumulation of NO₂^--N was in the range of 0.32 mg/L to 2.71 mg/L.The effluent quality reached the"Contamination of Livestock and Poultry Industry"Emission Standards（GB18596-2001）Emission Standards.4.When the reactor hydraulic load is 1.06m³/（m²·d）,the influent COD and NH₄⁺-N concentrations are 300mg/L and 100mg/L respectively,the optimal PCL filling amount in the reactor is 1500g to 2000g.At this time,the removal effects of COD,NH₄⁺-N,and NO₃^--N were the best.The removal rates ranged from 77.34%to 78.68%,55.60%to 58.61%,and69.55%to 70.08%,respectively.5.When the influent COD and NH₄⁺-N concentrations of the reactor are 300mg/L and100mg/L,respectively,when the HRT in the enhanced nitrification zone is 60min,the nitrification intensity is the highest and the NH₄⁺-N is most effectively removed.When the HRT in the denitrification zone is 6h,NO₃^--N can be removed efficiently,and the COD concentration is the lowest value.This is the best dynamic equilibrium point of the carbon source emission and denitrification intensity of PCL.Therefore,the combination of 60 min and 6 h of HRT in the newly constructed artificial wetland in the enhanced nitrification zone and the enhanced denitrification zone has the best removal of pollutants.