Constructed wetland denitrification sewage treatment device and sewage treatment method

Abstract

The invention discloses a denitrified sewage treatment device for an artificial wetland. The device comprises a sewage treatment pond. The sewage treatment pond comprises a denitrification layer (3) and a soil layer (4), wherein the soil layer (4) is arranged above or below the denitrification layer (3); the length of the sewage treatment pond is greater than or equal to 1m and the length-width ratio is greater than or equal to 3; the sewage treatment pond is provided with a water inlet and a water outlet; plants are planted on the soil layer (4); and the denitrification layer (3) consists of sulfur particles, plant stem and leaf fragments and gravels. The invention further discloses a denitrified sewage treatment method. The denitrified sewage treatment device disclosed by the invention has the advantages of low cost and good denitrification effect of sewage.

Description

technical field [0001] The invention relates to a sewage treatment experimental device and a sewage treatment method, in particular to a constructed wetland denitrification sewage treatment device and a sewage treatment method. Background technique [0002] Nitrogen pollution is one of the main problems of surface water pollution. Wastewater with high proportion of NOx and low C / N ratio, such as tail water from urban sewage plants and farmland receding water, is one of the main sources of nitrogen pollution in surface and groundwater bodies, which needs to be treated urgently. , in order to prevent water pollution and eutrophication, but also conducive to the reuse of the above types of sewage. [0003] High proportion of NO such as tail water from urban sewage treatment plants and farmland receding water x Low C / N ratio sewage has the characteristics of large fluctuation in water quality and water quantity, and high proportion of nitrite nitrogen and nitrate nitrogen. Due ...

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Problems solved by technology

Heterotrophic denitrification is the use of organic matter such as methanol and acetic acid as carbon sources by heterotrophic denitrifying bacteria to convert NO x Reduction to nitrogen, while generating alkalinity, requires the consumption of H + , but it has the problems of high cost of carbon source addition and residual carbon source in the effluent water quality; the sulfur limestone denitrification system in autotrophic denitrification is a good choice for removing NO due to its economy and good effluent water quality. x A common method in which sulfur denitrifying bacteria use elemental sulfur to convert NO x Reduction to nitrogen gas, while producing H + , needs to consume alkalinity (limestone), but there are problems of effluent hardness and sulfate radical increase; therefore, combining the two, the researchers developed a heterotrophic-sulfoautotrophic polytrophic denitrification process to remove nitrate in sewage , between the two can play a role in mutual adjustment of pH value, can avoid the addition of alkalinity (limestone) and reduce the generation of sulfate radicals, and at the same time, the proportion of heterotrophic and sulfur autotrophic denitrification can be adjusted according to the supply of carbon sources. Fluctuates within the range, favoring NO x effective removal of

[0005] In order to strengthen the denitrification of sewage with low C / N ratio, external carbon sources are mostly adopted. There are three types of carbon sources. One is traditional liquid carbon sources such as methanol and acetic acid, but there is a disadvantage of high cost of addition; the other is that it can be biodegradable. The polymer carbon source also has the disadvantage of high cost; the third is the natural plant carbon source containing cellulose, which is gradually used as a carbon source for strengthening denitrification because of its cheapness, easy availability, and simple operation, but its carbon source release cannot Effective control requires a long hydraulic retention time (HRT), and the effluent water quality is easily affected by the external temperature. When the plant carbon source is released more, the effluent water quality is easily affected by the carbon source released by the residual plant

[0006] In the heterotrophic-sulfoautotrophic polytrophic denitrification process, the carbon sources supplied by heterotrophic denitrification are mostly traditional liquid carbon sources such as methanol and acetic acid, and there is no plant carbon source heterotrophic-sulfoautotrophic polytrophic denitrification process Ratio NO x Report on Low C / N Ratio Sewage

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