Method for increasing denitrification rate in wastewater treatment through goethite

Abstract

The invention discloses a method for increasing denitrification rate in wastewater treatment through goethite. The method is characterized in that nanometer goethite is fed in a certain ratio according to carbon-nitrogen ratio into an anaerobic tank of a sewage treatment plant to be uniformly mixed; or granular goethite can fill as fillers a reaction column, a film is covered, sewage is poured into the reaction column from bottom to top after startup, and the hydraulic retention time is controlled to be 0.5 to 12h so that the sewage can be fully in contact with goethite; goethite promotes the microorganism to reduce nitrate in sewage into NO or N2O or N2 through organic matters in the sewage, so as to achieve the denitrification effect. With the adoption of the method, the denitrification rate can be increased, and the damage of accumulated nitrite to microorganism can be avoided; in addition, the quantity of fed external carbon sources can be decreased while the denitrification rate is increased, and thus the cost is effectively reduced.

Description

1. Technical field [0001] The invention relates to the treatment and denitrification technology of organic sewage. 2. Background technology [0002] Nitrogen is a major constituent element in nature. It is constantly migrating, transforming and recycling in nature. Nitrogen is the most important form of nitrogen, and nitrogen in water exists in the form of ammonia nitrogen, nitrate nitrogen, nitrite nitrogen and organic nitrogen. The nitrogen cycle in nature can avoid the accumulation of certain forms of nitrogen in the environment, but with the expansion of cities, the growth of population and the rapid development of industry and agriculture, this balance is destroyed, resulting in the accumulation of nitrogen in water bodies, causing water bodies Eutrophication and deterioration of water quality. Nitrogen in environmental water mainly comes from domestic sewage, domestic garbage, industrial wastewater and agricultural production. Except for molecular nitrogen, all the...

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Problems solved by technology

[0004] The shortcomings of traditional biological nitrogen removal technology are mainly as follows: (1) Nitrifying bacteria are autotrophic bacteria that grow slowly, and cannot compete with heterotrophic bacteria in the mixed culture activated sludge system, and it is difficult to gain an advantage; (2) Nitrifying bacteria are easy to Affected by the external environment, it is very sensitive to environmental shocks, especially toxic shocks, and it is quite difficult to restart the system; (3) It is difficult to unify the nitrification and denitrification processes in time and space, and the denitrification effect is poor, resulting in biological denitrification. The multi-step biocatalytic reaction is limited by the substrate transfer rate, substrate and product inhibition; (4) higher oxygen consumption, to completely oxidize ammonia nitrogen into nitrate, 1mg ammonia nitrogen needs to consume 4.57mg O 2 , which means a large amount of energy consumption; (5) Heterotrophic denitrification requires a large amount of carbon sources, and wastewater with a low carbon-to-nitrogen ratio requires additional carbon sources, which will increase operating costs and easily cause secondary pollution; the system Poor impact resistance, high concentration of NH 4 + , NO 2 - inhibits the growth of nitrifying bacteria

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