Granulation of Anammox Sludge in Upflow Reactors
Nitrogen pollution has caused severe eutrophication in water bodies and becomes a key environmental problem around the world.The efficient and cost-effective removal of nitrogen from ammonium-rich wastewater has attracted much attention.Anammox (ANerobic AMMonium OXidation) process is a promising biological nitrogen removal technology for treatment of ammonium-rich wastewater,which could directly oxidize ammonium to dinitrogen gas under anoxic condition.It also contains high value in scientific significance as it contributes more than 50% of the global nitrogen cycle.However,a great challenge for Anammox process is that the chemolithoautotrophic Anammox bacteria exhibit a slow initial growth rate,resulting in poor enrichment ofAnammox biomass and poor stability of reactors.Granulation of the Anammox sludge has shown great advantages to effectively enhance the biomass enrichment.In this study,we reviewed the characteristics of Anammox bacteria,the formation,structure and flotation of Anammox granules under high hydraulic loadings.Full-scale applications of granular Anammox process were also presented.The major points are 1) Anammox bacteria secrete a large amount of extracellular polymeric substances (EPS) and contain plentiful hydrophobic functional groups that facilitate the biomass granulation;2) granulation enhances the sludge settling property and retention time,which contributes to the extremely high nitrogen removal rate (NRR) of 77 kg m-3 d-1 of Anammox upflow reactors;3) flotation of Anammox granules frequently occurs under nitrogen removal rate higher than 10 kg m-3 d-1,which raises as a big problem for further improvement of nitrogen removal rate and stable operation of upflow reactors;the over-production of extracellular polymeric substances (EPS) (especially proteins) under high hydraulic conditions has been considered to be a key reason for Anammox granules flotation.This review sheds light on the enhanced nitrogen removal from wastewaters by Anammox granules.
Anammox biological nitrogen removal sludge granulation settling property flotation extracellular polymeric substances
Chong-Jian Tang Cheng-Shan Duan Cheng Yu Yu-Xia Song Li-Yuan Chai
Department of Environmental Engineering, School of Metallurgy and Environment, Central South University,Changsha 410083, China;Chinese National Engineering Research Center for Control and Treatment of Heavy metal Pollution (CNERC CTHP), Changsha 410083, China
国际会议
The 15th IWA World Conference on Anaerobic Digestion( 第15届IWA世界厌氧大会)
北京
英文
228-234
2017-10-17（万方平台首次上网日期，不代表论文的发表时间）