Tertiary nitrification in a new dual-medium aerated filter.
In an effort to develop an aerated filter with high nitrification capabilities, we formulated a new filter with 2 layers: the upper layer is filled with a plastic medium, and the lower with anthracite. We tested the filter in a pilot-scale apparatus on secondary-treated sewage, and in a small-scale apparatus on secondary-treated sewage and on artificial sewage. We evaluated the nitrification characteristics under various conditions of water velocity, air velocity, temperature, and pH. We designed a tertiary plant to treat 20,000 m3/day of secondary-treated sewage, using the new filter or a conventional filter. From these comparisons, it appeared that the dual-medium aerated filter had high nitrification capabilities and was an effective device for tertiary sewage treatment.
Ishikawa
S
S
Department of Research and Development, Central Laboratories, Maezawa Industries Inc., 5-11 Naka-cho, Kawaguchi 332-8556, Japan.
Suzuki
T
T
Nikata
T
T
Kakii
K
K
Shirakashi
T
T
D000392:Air Movements; D005374:Filtration; D006863:Hydrogen-Ion Concentration; D009584:Nitrogen / Q000378:metabolism*; D012722:Sewage; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000379:methods*
D012722:Sewage; D009584:Nitrogen