Low-carbon nitrate wastewater efficient purification device system based on mixed matrix and purification treatment method

Abstract

The invention provides a low-carbon nitrate wastewater efficient purification device system based on a mixed matrix and a purification treatment method. The device system comprises a water supply unit, a purification device and an effluent collection unit which are connected in sequence, a water distribution layer, an efficient mixed matrix layer and a supporting layer are sequentially arranged in the purification device in the upward direction perpendicular to the ground; a filling medium of the efficient mixed matrix layer comprises a low-valence sulfur mixture and oyster shells. According to the sulfur-pyrite autotrophic denitrification device system disclosed by the invention, efficient denitrification can be realized; the oyster shells can replace carbonate minerals to participate in the sulfur-pyrite autotrophic denitrification process, a large number of attachment sites, trace elements and inorganic carbon sources are provided for microorganisms, and the acid-base environment of the system is kept stable. The device provided by the invention is simple and feasible in system, good in economical efficiency, free of additional addition of an organic carbon source, excellent in denitrification effect and less in by-product, and has good application potential for a water body with low organic carbon content.

Description

technical field [0001] The invention belongs to the technical field of sewage treatment, and in particular relates to a high-efficiency purification device system and purification treatment method for low-carbon nitrate wastewater based on mixed substrates. Background technique [0002] Intensive agriculture and urbanization lead to excessive input of nitrogen (N) in the soil, further increasing nitrate nitrogen (NO 3 - ) to the amount of leaching into groundwater, and groundwater nitrate pollution has become an environmental problem of widespread concern. At present, the concentration of nitrate in groundwater exceeds the standard in many areas, and groundwater is used as a source of drinking water. Excessive nitrate in groundwater will threaten the safety of drinking water sources. [0003] Biological denitrification is widely used in the remediation of nitrate-contaminated sites or the removal of nitrate in wastewater and contaminated drinking water. The mainstream hete...

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Problems solved by technology

CN 112694169A discloses an autotrophic-heterotrophic denitrification integrated denitrification device and method, the method couples autotrophic denitrifying bacteria and heterotrophic denitrifying bacteria in different parts of the same reactor, and promotes denitrification through circulation The autotrophic denitrification reaction zone and the heterotrophic denitrification reaction zone have good mass transfer effects, realizing the coordinated operation of the autotrophic-heterotrophic denitrification process, but the autotrophic denitrification bacteria still use sulfur or sulfide as electrons. donor

[0005] Sulfur autotrophic denitrification technology uses sulfur as the electron donor and has a stable and rapid denitrification ability. However, the high sulfate production affects its value in engineering applications.

The autotrophic denitrification process using pyrite as the electron donor, although the sulfate yield is low, the denitrification rate is slow and the denitrification performance is poor

Moreover, the hydrophobic properties of sulfur particles and the smooth surface of pyrite particles make it difficult for denitrifying bacteria to attach to the surface of the two materials, which reduces the bioavailability of sulfur and pyrite particles as electron donors for denitrification, and limits the Denitrification rate

Aiming at the problem that the autotrophic denitrification process will produce hydrogen ions and the microorganisms are in an unfavorable acidic environment, many studies have focused on using carbonate minerals such as marble, limestone, and eggshells as acid-base buffer materials, such as the one disclosed in CN 112340845A The deep nitrogen and phosphorus removal process of urban sewage, which proposes that the filler used in the sulfur autotrophic denitrification denitrification process is a mixture of egg shells or shellfish shells and elemental sulfur

However, Ca released from common solid carbon sources such as marble, limestone, and eggshells during dissolution 2+ with SO 4 2- CaSO produced by the reaction 4 Slightly soluble in water, adsorbed on the surface of solid carbon source to form a layer of dense CaSO 4 Thin film, inhibits Ca 2+ with SO 4 2- of the continued reaction, thereby affecting the SO 4 2- effective removal of

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