Patent ID: 8652329
Filing Date: 2014-02-18
Classification: C02F,Y02W

Abstract:
1. Apparatus for lowering the concentration of dissolved nitrate in wastewater, wherein: the apparatus includes a de-nitrification station; the de-nitrification station includes a de-nitrification enclosure, which defines a hollow interior chamber; the apparatus is so structured and arranged that oxygen is substantially prevented from entering the chamber; the enclosure includes a water-inlet-port, through which water is conveyed into the chamber; the apparatus includes a volume of biological filter medium, located inside the chamber; the material of the filter medium is substantially inert with respect to water, with respect to contaminants present in the wastewater, and with respect to anaerobic microbiological reactions that break down the contaminants; the material of the filter medium is porous, absorbent, and capable of retaining water by capillary action; the material of the filter medium is permeable to flow of water within and inside the material; the apparatus includes a source of carbon, and includes an operable injector which is effective, when operated, to inject the carbon into the chamber; the apparatus is so arranged that: (a) the water-inlet-port deposits water on top of the volume of filter medium, in such manner that the water trickles down through the volume of medium; and (b) the volume of biological filter medium is characterizable as free-draining.