Method and device for realizing lasting and stable accumulation of nitrite nitrogen under low-temperature condition

Abstract

The invention relates to a method and device for realizing the lasting and stable accumulation of nitrite nitrogen under a low-temperature condition. The lasting and stable accumulation of the nitrite nitrogen is completed in two stages of biological aerated filter systems. The method comprises the following steps: step a. starting a first-stage biological aerated filter and a secondary-stage biological aerated filter, cleaning a filter material, soaking, forming a biofilm, commissioning and operating; b. preparing testing wastewater, and maintaining water temperature at 6 to 10 DEG C; c. enabling wastewater to flow out from a head tank and enter the first-stage biological aerated filter from below; and d. enabling yielding water of the first-stage biological aerated filter to enter the secondary-stage biological aerated filter from bottom to top in the same way. The nitration types of the two stages of biological aerated filter are nitrous acid-type nitration, the stable accumulation of NO2--N in the yielding water is shown, the accumulation rate is 63.2% to 79.8%, and the accumulation time is up to 30 to 35 days. The method has the advantages that the biofilm process adopting the two stages of biological aerated filters can be used for solving the problems of high energy consumption at a high temperature (30 to 40 DEG C), and sludge bulking under a low DO (Dissolved Oxygen) condition, and the effective removal of organic matters in wastewater with a low C / N ratio (less than 3) and the lasting and stable accumulation of NO2--N are realized.

Description

technical field [0001] The invention relates to the field of environmental engineering waste water treatment, in particular to a method and device for realizing long-lasting and stable accumulation of nitrite nitrogen under low temperature conditions (6-10°C), which lays the foundation for later short-range denitrification and is suitable for coking, petrochemical, and chemical fertilizers Treatment of low C / N ratio (<3) wastewater such as industrial and landfill leachate. Background technique [0002] The traditional biological denitrification method is to remove nitrogen in the water body through the nitrification and denitrification of microorganisms. Traditional nitrification refers to the conversion of NH by nitrous bacteria under aerobic conditions 4 + -N oxidation to NO 2 - -N, and then NO by nitric acid bacteria 2 - -N oxidation to NO 3 - -N; denitrification is mainly NO 3 - -N is an electron acceptor and reduces it to N 2 So as to achieve the purpose o...

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Problems solved by technology

[0006] The purpose of the present invention is to aim at the current stage that NO can only be realized under relatively harsh conditions such as high temperature or low DO. 2 - - Shortcomings of N accumulation, a method and device that can realize long-lasting and stable nitrite nitrogen accumulation under the temperature condition of 6-10°C are proposed; the present invention adopts the biofilm method of two-stage biological aerated filter to solve the problem of high temperature The problem of sludge bulking will occur under high energy consumption (30-40°C) and low DO, and NO can be realized at a water temperature of only 6-10°C 2 - -N accumulation, the accumulation rate is 63.2%~79.8%, stable for 30~35 days, the effluent COD is 33.5~41.9mg / L, NH 4 + -N is 18.3~23.4mg / L, COD and NH in effluent after treatment 4 + -N respectively meet the requirements of GB18918-2002 A standard and two standards

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