METHOD FOR REMOVING AMMONIACAL NITROGEN IN RAW WATER FOR CITY WATER

摘要

PURPOSE:To remove ammoniacal nitrogen in the raw water for city water without need for intricate instrumentation equipment or maintenance by sterilizing the beads of the crushed oyster shell with sodium hypochlorite, packing the sterilized beads in a tower or tank, propagating nitrifying bacteria in the tower or tank and then passing the raw water through the tower or tank. CONSTITUTION:The beads 2 obtained by crushing the oyster shell are sterilized with sodium hypochlorite and closely packed in a tower 3. Air is blown into an aeration tank 1 by a compressor 5 to increase the dissolved oxygen concn. in the raw water, and the propagation of the nitrifying bacteria is promoted. The aerated raw water is introduced into the tower 3 by a transfer pump 6 through flowmeter to oxidize the ammoniacal nitrogen in the raw water to nitrate nitrogen by the nitrifying bacteria, and the ammoniacal nitrogen is removed. The grain size of the beads is controlled to 3-50mm. The raw water is circulated between the aeration tank 1 and the tower 3 packed with the beads 2 until the nitrifying bacteria are sufficiently propagated.