Comprehensive analysis of step-feeding strategy to enhance biological nitrogen removal in alum sludge-based tidal flow constructed wetlands
- 作者：Y.S. Hu ; Y.Q. Zhao ; yaqian.zhao@ucd.ie ; X.H. Zhao ; J.L.G. Kumar
- 关键词：Alum sludge ; Partial nitrification ; Simultaneous nitrification and denitrification (SND) ; Step-feeding ; Tidal flow constructed wetlands
- 刊名：Bioresource Technology
- 出版年：2012
- 期刊代码：11_09608524
- 类别：ce
- 出版时间：May, 2012
- 卷：111
- 期：Complete
- 页码：27-35
- 文件大小：1176 K
摘要
Step-feeding strategies have been extensively studied and comprehensively analyzed in this study for a four-stage alum sludge-based tidal flow constructed wetlands (AlS-TFCWs) system. Enhanced total nitrogen removal of 83%is achieved under high nitrogen loading rate of 19.1 g N/m2 d. The key issues towards the success of a significant nitrogen removal in step-feeding TFCWs are the bed resting time (which provides better aeration for nitrification) and up flow stage/delayed input of side stream(s) (which ensure favorable environment for better denitrification). Simultaneous nitrification and denitrification (SND) was found effective in the 1st stage of the system and SND via nitrite is the main nitrogen conversion mechanism. The optimal influent distribution fraction for step-feeding purpose can be estimated from a theoretical basis, which is a function of the influent BCOD/TKN ratio. Therefore the influent distribution fraction should be adjusted according to the variety of influent characteristics, rather than a fixed value.