Effect Of Sulfate On Anaerobic Denitrification

The A~2/O process was proposed by Marais and Rabinowitz and took the lead in Europe,with good denitrification and subsequent introduction into the country.But the process in the domestic operation is difficult to achieve the same operating results in Europe.Investigation of the content of each substance in Europe and domestic wastewater found that the content of sulfuric acid in the domestic sewage was generally high.While the domestic sewage quality of sulfuric acid in water is generally low.Due to geographical and seasonal effects,the content of sulfate is very different.The poor performance of domestic A~2/O process may also be related to the low content of influent sulfate.In the laboratory to establish A~2/O experimental device,continuous operation of all-round simulation of sewage treatment plant open water treatment environment,and strive to achieve the same treatment with the sewage treatment plant effect.Preparation of different concentrations of sulfate wastewater to study the concentration of sulfate and total nitrogen removal rate between the existence of relevance.The effect of sulfate on the removal rate of total nitrogen in A~2/O process was verified.Through the study of this subject,the effect of sulfate in the A~2/O process on the removal of total nitrogen was enriched,and the influencing factors of denitrification in A~2/O were enriched and deepened,that is,the high concentration of sulfate resulted in the total nitrogen The removal rate is improved.Indirectly demonstrate why the A~2 / O process works better in Europe than in China.In this study,the possible mechanism of the process of denitrification in the A~2/O process aerobic tank under low oxygen condition was explored,including the possible microbial synthesis,sulfate anaerobic ammonium oxidation and so on.Through a large number of experimental studies,we confirmed that the anaerobic tank exists SO42-and NH4 +reaction,that is,sulfate in anaerobic conditions oxidized ammonia nitrogen,itself is reduced to low-cost sulfide,while low-grade sulfide is accompanied Sludge into the back of the denitrification unit,as an electron donor,the completion of the late denitrification.Sulfuric acid per 1 kg of ammonia nitrogen can produce a net yield of 1.71 kg of COD,which means that sulfate-participating ammonia-nitrogen reactions can provide excess carbon sources for subsequent denitrification units that help solve the common carbon Lack of source.China and the vast majority of the world are faced with the lack of carbon sources and lead to excessive nitrogen and then the emergence of eutrophication of lake reservoirs,the discovery of this reaction is undoubtedly of great significance.In summary,this study focused on the effect of sulfate concentration on the denitrification treatment of A~2/O process,and studied the mechanism of denitrification of A~2/O process in the presence of sulfate.It was confirmed that the sulphate anaerobic Ammonia oxidation,the results show that the appropriate concentration of sulfate ions can improve the A~2/O process to remove the total nitrogen capacity for the further development and utilization of the latter laid the foundation.