The Research About Removal Effects Of Nitrogen And Phosphorus On Treating Tailwater In Sewage Treatment Plants Of Town In A/O Functional Constructed Wetland

A/O functional constructed wetland is adding to activated sludge and carbonsource, which is introduced general A2/O processing of sewage treatment plant inconstructed wetland, common constructed wetland is a constructed wetland withoutthem. The performance and mechanisms of A/O functional constructed wetlandsystem were studied for the application and ecological management dataaccumulation in constructed wetland, by using MATLAB software system for theanalysis of trearment effect. The study includes:(1)the removal effects of nitrogen andphosphorus in A/O functional constructed wetland;(2)the research on ecologicaldynamics model in A/O functional constructed wetland;(3)the removal regressionequation of nitrogen and phosphorus in A/O functional constructed wetland. Themajor research findings are as follows:(1) Under the experimental conditions, through the analysis of common constructedwetland and A/O functional constructed wetland for total nitrogen removal effects, thestudy shows that the range of removal rate for total nitrogen gets0.23~0.30g m-3d-1,the average rate is0.26g m-3d-1in common constructed wetland system while therange of removal rate is0.40~0.51g m-3d-1, the average rate is0.46g m-3d-1in A/Ofunctional constructed wetland. The removal capability of A/O functional constructedwetland for total nitrogen removal effect is1.77times as many as commonconstructed wetland. During the analysis of common constructed wetland and A/Ofunctional constructed wetland for total phosphorus removal effects, it shows: therange of removal rate for total phosphorus is0.012~0.023g m-3d-1, the average rate is0.018g m-3d-1in common constructed wetland system while the range of removalrate gets0.016~0.029g m-3d-1, the average rate is0.022g m-3d-1in A/O functionalconstructed wetland. The removal capability of A/O functional constructed wetlandfor total phosphorus removal effect is1.22times than common constructedwetland.Based on the comparison of comprehensive analysis, it shows that the removal effects of total nitrogen and total phosphorus in A/O functional constructedwetland is vastly superior to common constructed wetland.(2) In this paper, the system contains three processing units and the tailwater insewage treatment plants of town flows them one by one.The total nitrogen removaleffects of processing units shows that the average total nitrogen removal rate ofprocessing unit one is about12%, average removal rate of processing unit two isabout26%, while processing unit three is about12%, the total nitrogen removal rateof unit two is twice as many as others. As a result, the key to remove total nitrogenmore efficiently is optimized for processing unit two; Based on the balance analysis ofdifferent nitrogen forms, the major function of processing one makes organic nitrogenbe converted to ammonia nitrogen: it happens ammonificaton; the major function ofprocessing two makes nitrate nitrogen be converted to nitrogen: it happensdenitrification and the major function of processing three makes ammonia nitrogen beconverted to nitrate nitrogen: it happens nitrification.(3) Carbon resources influence the removal effects of total nitrogen and totalphosphorus in A/O functional constructed wetland. Under the analysis of totalnitrogen removal rate using different kinds of carbon source, it finds that the averageremoval rate of straw in2#, stalk in3#, corn cobs in4#trial groups system are39%,36%,37%.The total nitrogen removal rate with carbon source has no differencebetween them in A/O functional constructed wetland system, but the carbon source ofstraw has a much better total nitrogen removal rate than others；Through the totalphosphorus removal effect analysis of straw in2#, stalk in3#, corn cops in4#trialgroups, the total phosphorus average removal effects are40%,33%,50%, the carbonsource of corn cops has a much better total phosphorus removal effect. The carbonresource of straw is good for removal effects on total nitrogen and total phosphorus bycomprehensive analysis and comparison between them.(4) During the analysis of total nitrogen removal effect in different temperaturein A/O functional constructed wetland, At the temperature of11~15℃, the range oftotal nitrogen removal capacity is0.37~0.52g m-3d-1, the average rate is0.45g m-3d-1while the range of total nitrogen removal rate ges0.42~0.57g m-3d-1,the average rate is0.45g m-3d-1the temperature is21~26℃, there are no significantdifferences in total nitrogen removal capacity between two different seasons; Duringthe analysis of total phosphorus removal effect, the range of total phosphorus removalcapacity is0.018~0.10g m-3d-1, the average rate is0.59g m-3d-1while the range of total phosphorus removal capacity gets0.0022~0.080g m-3d-1, the average rate is0.41g m-3d-1in the temperature of11~15℃and21~26℃, it shows that the effect oftemperature has little influence on total phosphorus in A/O functional constructedwetland system, but the main way for total phosphorus removal effect is high qualityof substrate.(5) Nitrification and denitrification in A/O functional constructed wetland systemare the main methods to transform nitrogen, the rates respectively reach0.15~0.19gN m-3d-1and0~6.97gN m-3d-1; Secondly, it is the other system functionof nitrogen removal, but the last is ammonificaton, the rate reaches3.00×10-5~9.66×10-3gN m-3d-1.The main influencing factors in conversion andremoval of nitrogen in the system in decreasing order are denitrification, nitrification,other system function and ammonificaton. Denitrification and nitrification take up76.28%and15.33%of the total nitrogen removal, other system function accounts for7.66%, and0.73%in ammonificaton.(6) Regardless of the inner complex function of biochemistry in A/O functionalconstructed wetland, in the experiment with the method of contiguous water, regularcollection water samples, the inlet and outlet of160groups of water samples fortesting total nitrogen and total phosphorus concentration are measured by linearregression equation and logistic regression equation, it is concluded that there is noinfluence factors of total nitrogen and total phosphorus limitation of regressionequation are: CNo=0.698CNi-0.891and CPo=0.529CPi+0.121, logistic regressionequation are CNo=16.97ln(CNi)-36.94and CPo=0.673ln(CPi)+0.785; Total nitrogen andtotal phosphorus in winter of regression equation are: CNo=0.702CNi-0.829andCPo=0.502CPi+0.096, logistic regression equation are CNo=16.70ln(CNi)-36.40andCPo=0.907ln(CPi)+0.544; Total nitrogen and total phosphorus in the summer ofregression equation are: CNo=0.755CNi-1.994and CPo=0.759CPi-0.001, logisticregression equation are CNo=18.01ln(CNi)-39.49and CPo=0.832ln(CPi)+0.946, they allhave a better degree of fitting.