Start-up And Operation Of Anaerobic Ammonia Oxidation Reaction At Normal Temperature

Anaerobic ammonia oxidation is a new method for biological nitrogen removal.Compared with the traditional biological nitrogen removal technology, the removalefficiency of anaerobic ammonia oxidation is higher. It doesn’t need to provideoxygen and organic carbon sources, so it is an efficient and an economic newbiological nitrogen removal technology. Anaerobic ammonia oxidation has become ahot research in recent years. The studies showed that anaerobic ammonia oxidationbacteria can only show high anaerobic ammonia oxidation activity at about32℃. Itwill increase the cost to heating sewage for the majority of domestic sewage.In this paper, by using UASB reactor, fed with artificial wastewater composedwith ammonium and nitrite and seed with activated sludge from an wastewatertreatment plant, the experiments were carried out to study whether the anaerobicammonia oxidation bacteria can show high activity of anaerobic ammonia oxidation atnormal temperature. The main results are as follows:(1) Seeded with activated sludge from an oxidith process municipal wastewatertreatment plant in winter and fed with artificial wastewater composed withammonium and nitrite concentration of50mg/L and70mg/L respectively at (321)℃, the UASB-biofilm anaerobic ammonia oxidation reactor was start up quicklyafter26days. And then close the heating water bath, the reactor continued to run atnormal temperature (20℃~24℃). When the ratio of ammonia and nitrite is1:1.4ofthe influent, the average removal rates of ammonia, nitrite and total nitrogen can reach99.7%,98%and97.7%respectively. The results showed that the anaerobic ammoniaoxidation activity is still very high in the UASB-biofilm reactor at normaltemperature (20℃~24℃).(2) Seeded with activated sludge in winter and fed with artificial wastewater，at the high temperature UASB-biofilm anaerobic ammonia oxidation reactor was startup and the reactor ran at normal temperature, and experienced deferent substrate concentration, but it can maintain the high nitrogen removal efficiency steady. Itshowed that the temperature and the substrate concentration have little effect on thenitrogen removal efficiency after the actor was started up successfully.(3) Seeded with the activated sludge in spring,the anaerobic ammonia oxidationstart-up experiment were did twice with low concentrations of the UASB-reactor attemperature (20℃~24℃). The concentrations of ammonia and nitrite were50mg/Land70mg/L respectively in the artificial water. The first time, the average removalrates of ammonia, nitrite and total nitrogen can reach33%,81%and61.7%respectively after62days. The second time, the average removal rates of ammonia,nitrite and total nitrogen can reach49.1%,44.8%and27.8%respectively after71days. Two start processes showed that there some anaerobic ammonia oxidationactivity in the reactor at normal temperature, but it doesn’t reach the high anaerobicammonia oxidation activity stage.(4) Seeded with the activated sludge in winter,the anaerobic ammonia oxidationstart-up experiment were did twice with high concentrations of the UASB–biofilmreactor at temperature (20℃~24℃). The concentrations of ammonia and nitrite were100mg/L and140mg/L respectively in the artificial water. The results showed thatthe average removal rates of ammonia, nitrite and total nitrogen can reach7.1%、5.2%�'�5.9%respectively after27days. There is almost no anaerobic ammonia oxidationactivity in the reactor.(5) The Anammox reactor start-up process speed is likely to be related with thethe seeding sludge and sludge in different seasons. Sludge taken from the samesewage treatment plant, but in different season, when the reactor started under thesame temperature conditions, anaerobic ammonia oxidation activity in reactor is notthe same.