Author(s): Kohsuke Inoue; Kenji Tanaka; Kohji Michioku; Hiroya Tanaka; Masahiro Yagi; Tamihiro Nakamichi
Linked Author(s): Kohji Michioku
Keywords: Landfill leachate; Micro-bubble aeration; Nitrification; Microbe-bound carriers
Abstract: Significant ammonia nitrogen is loaded from a municipal landfill leachate. Since the leachate is deoxidized through infiltration and travelling underground, the first step of water treatment is to oxidize or nitrify the leachate. Although various nitrification techniques have been developed so far, such concentrated treatment systems are feasible only in a case of young landfill with an extremely high level of ammonia load. The landfill in this study is, however, already older than forty years and ammonia-nitrogen load has decreased to a level around several ten mg per liter. In this case, a labor-saving and economic nitrification system is required for making a sustainable water quality management. In a leachate reservoir under investigation, a micro-bubble aeration system was equipped and its nitrification performance was examined by conducting an in-situ experiment in an enclosure. Monitoring time-dependent behaviors of NH4 +-N, NO2 －-N, NO3 －-N and DO, it was discussed how the nitrification rate was influenced by relating limiting factors. It was also confirmed that denitrification took place in addition to nitrification in the experimental system. It is shown that the micro-bubble aeration is a promising technology as an alternative of the present water treatment system.
Year: 2013