Research On Operation Characteristics Of ANAMMOX-Denitrification Reactor And Treatment Of Landfill Leachates By It

Nitrogen pollution in aquatic bodies, which is considered as one of the main causes to the water quality deterioration and biodiversity shrinkage, has become an increasingly serious environmental issue and has been addressed worldwide. Anaerobic ammonium oxidation (ANAMMOX) is a anaerobic chemoautotroph microbes. Compared to the conventional biological nitrogen removal process, it is more promising due to its advantages of absence of additional carbon source and avoiding secondary pollution as well as saving energy. However, there is some organisms in nitrogenous wastewater,which have a certain effect on ANAMMOX. Meanwhile, in an attempt to put ANAMMOX into practical engineering application, many problems still remain unsolved, i.e, the instability issue caused by influent loading shock and the nitrate production in the ANAMMOX-treated effluent .In part 1 of the test, in order to deal with the problems above effectively,we made sludge with denitrifying bacteria and ANAMMOX sludge mixed and then seeded them into a 3.2L USAB with biofilm. The ANAMMOX-Denitrification reactor was successfully started-up within 35 days in conditions of the influent nitrogen loading rate at 0.25 kg·m³Â·d^-1,an organic (glucose) loading to total nitrogen (TN) ratio of 1 and nitrite loading to ammonia loading of 1.32. Compare with the Start-up of ANAMMOX-Denitrification reactor with methanol , the former had more advantage in treatment effect and start-up time than the latter . The removal efficiencies of ammonia, nitrite, TN and COD in the reactor using glucose as carbon source were found high up to 95.3%, 99.1% , 94.0% and 93.2% respectively, and the nitrate production in effluent was 3.2mg·L^-1. The removal efficiencies of ammonia, nitrite, TN and COD in the reactor using methanol as carbon source were found high up to 94.1%, 97.2% , 92.2% and 89.4% respectively, and the nitrate production in effluent was 4.35mg·L^-1.The average ratio of removed ammonia, removed nitrite and generated nitrate was 1﹕1.36﹕0.02 in ANAMMOX-Denitrification reactor,Compare to the ratio of three kind of nitrogen(1︰1.32︰0.26) in traditional ANAMMOX reactor. The synergism between ANAMMOX and denitrification could enhance nitrogen and phosphorus removal effect, and reduced the nitrogen production, It is of importance to improve the quality of the effluent from the ANAMMOX reactor, and it is also essential for treating the nitrogenous organic wastewater.In part 2 of the test, Effect of hydraulic loading for ANAMMOX-Denitrification reactor was investigated by modulating the hydraulic loading of reactor in four sequential periods. It was found that at low hydraulic loading(0.77～1 L·(L·d)^-1), the reactor worked well, and the amount of nitrate production in effluent is small. Hydraulic loading was further raised to 1.11～1.67L·(L·d)^-1, NH₄⁺-N and NO₂^--N removal efficiencies decreased to 70.4% ,81.7%, and the removal efficiencies of COD was now 89% instead of 81% before. When hydraulic loading was rasied to 2～4L·(L·d)^-1, the average removal rates of ammonia,nitrite and COD showed a marked drop,which were only 54.2%,73.9% and 81% respectively,and the nitrate production in effluent was 9.97mg·L^-1. Through turning down the hydraulic loading again,the effect of ANAMMOX-Denitrification synergistic interaction could be recovered,which demonstrated that the reactor has a certain anti-force capability. Great influence was observed when running the reactor at low temperature,which reduced the treatment effect of reactor. However, the microbes in the reactor have capabilities of cold resisting and faster recovery,which would ensure the success in the second start-up of the reactor.In part 3 of the test, When ammonia and organism in synthetic water were from landfill leachate, practical performance of the synergetic reactor treating nitrogenous wastewater was investigated. The results obtained indicated that during the steady states, the average removal efficiencies of ammonium, nitrite, TN and COD in Reactor were 97.4%,96.4%,87.2%, 74.8%, respectively. The maximum volumetric loading conversion of TN and COD in Reactor were 120.5 and 119.9 g/(m³Â·d), respectively. The synergism in the reactors was inhibited due to overload, and was hard to recover to the previous performance once overload taken place. When the synergism was builded, characteristic changes were presented in the pH value and alkalinity.