Study On The Removal Of Nitrogen By Vacuum Reactor And Biological Technique And The Influence On C/N In Wastewater

With the increase of nitrogen pollution, nitrogen pollution control is one of themost hottest field for the researchers, in all the factors which influence the removal ofnitrogen, C/N is one of the most important factors. This manuscript aims at it, vacuumreactors was developed and studied on the effect of nitrogen removal by it, theexperiment on removal rate of ammonia by algae was made, it is achieved thathigher–efficiency removal rate of nitrogen by SND with low oxygen concentrationsuccessfully at first．by the removal of ammonia, the transportation of organic-nitrogen,the degrading of COD, Different concentration of ammonia–high, intermediate, low arepriliminary tested to analyze the effect on the C/N of wastewater by different techniques.The results are showing as follows:(1) By self-made vacuum reactor to treat high-ammonia waste water, it is found thatthe removal of ammonia occurs in the early30minutes, reacting rate is somewhat fast inthe beginning, and is becoming slower with the time passed, finally, it enters the balancestate; In the experiment, the key factors:vacuum degree, the mixing of air, the differentapparatus of vacuum-produce effect the nitrogen removal and C/N, but the influence ofprimary concentration is not obvious.On the test of medium concentration ammonia, a multifunction vacuum reactor wasused which can remove ammonia, abstract, coagulate. in that process, pH value,vacuum-degree, different flow states (the continuous flow and intermittent flow) canchange the C/N; the add of flocculent can change the C/N largely;When using vacuumreactor to treat low pH value wastewater, the removal rate of ammonia nitrogen is not veryhigh, but compared with the free ammonia concentration at normal temperature, pressureand the same pH value, it can improve the removal rate by5-20%.(2) By three factors three levels orthogonal test design, the results show that theoptimal combination of lower ammonia nitrogen removal is pH=6.5, Oedogonium sp.,reaction time for nine days; Oscillatoria’s efficiency is close to Oedogonium sp.; theoptimal combination of COD removal is pH=8.5, Hydrodictyon reticulatum, nine days.pH value, reaction of time, the type of algae, can influence the ammonia nitrogen removal, COD removal efficiency significantly. The experimental on semicontinuous swinewastewater treatment results show that Oscillatoria and Oedogonium sp can effectivelyuse the ammonia nitrogen in wastewater to purify the water. The algae belong toautotrophic organisms, this characteristic can be used to raising C/N value of industrywastewater or other low C/N waste water.(3) At room temperature, using Pasveer oxidation ditch to treat low ammonia and lowC/N sewage, by controlling DO in aerobic area at0.2-0.4mg/L, DO in anaerobic arealower than0.1mg/L, keeping the volume rate of oxidation zone and anoxic zone at1:1,start the process of removal of nitrogen under low oxygen condition successfully;It can befound that both the two models used to start SND reactor is useful, and model2is faster,results show that the removal rate of COD is40%-62%, of ammonia nitrogen is above99%, of total nitrogen is75%. By monitoring the effluent quality of reactor at differentC/N(C/N=1.943.004.19) after the stabilizing of Pasveer oxidation ditch, we found thatthe removal rate of TN can overpass70%, so it can say that at low C/N, low oxygen,SND can be achieved; By analyzing the inner section of Pasveer oxidation ditch, it can befound that the translation among different nitrogen matters; At low oxygen level, sludgebulking did not happen, settle ability was obviously improved, the mean SVI is60-70mL/g; the C/N of effluent of the oxidation ditch is up to6-10:1, it also can be foundthat heterotroph is responsible for the removal of COD at low oxygen, by analyzising theremoval value of COD/TN, we can make conclusion that short-cut nitrification anddenitrifcation is predominant;during the reacting, those physical parameters are hystereticrelevance with water quality criterion and be stable gradually, in this paper, we count theORP value, it is found that the measured value converge to the counting ORP, so ORPcan indicate the process of ammonia remova of SND, Especially in low oxygenenvironment; Analyzing the reasons why effect of SND is good in Pasveer oxidation ditchunder low oxygen, probably because of the adoption of point source aeration facility andspecial Plug-flow in oxidation ditch, contributing to the form of aerobic-anoxiaenvironment.