A device and method for recovering nitrogen and phosphorus from septic tank wastewater

Abstract

The invention relates to a device and a method for recycling nitrogen and phosphorus from waste water of a digestion tank, and belongs to the technical field of waste water disposal. An integrated device consists of an overflow pond, a pretreatment pond, a multifunctional inspection well and a crystalizing reaction pond. The method includes steps that sewage enters a digestion tank processing system through a discharge pipe, wherein the sewage firstly enters the pretreatment pond through a grid, and sludge is sunken, gas generated from reaction and fermentation is discharged or recycled from the gas outlet, and liquid supernatant of sewage reaches the lowest water line of the water outlet and enters the crystalizing reaction pond through the pipeline. Sewage entered the crystalizing reaction pond enters the crystalizing reaction pond firstly through interception of a light filter layer and the degrading function of attached microorganisms, magnesium chloride and alkaline solution are added as assistance, thus sewage overflow forms magnesium ammonium phosphate crystal greatly and then recycled; the treated sewage is flowed to a municipal sewage pipe network. If water amount is suddenly increased or the pretreatment pond has sudden fault, sewage directly enters the overflow pond and flows into the municipal sewage pipe network. The sewerage treatment ability of the digestion tank is strong, nitrogen and phosphorus nutrients can be recycled; besides, sewage treatment and resource utilization of sewage and sludge at the same time can be realized; thus the nitrogen and phosphorus load of sewage plant can be effectively reduced; the novel resource processing technology can meet the sustainable development requirement.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to a device and a method for recovering nitrogen and phosphorus from septic tank wastewater. Background technique [0002] The water body problems caused by nitrogen and phosphorus pollution are very serious in our country. Although septic tanks, as the primary treatment structures of urban sewage, have played an active role in the process of urbanization, their disadvantages have gradually become prominent. The conclusion that cities with sewage treatment facilities do not have septic tanks shows that the role of septic tanks has gradually weakened, so it is imminent to expand the functions of septic tanks and find new types of septic tanks. [0003] The removal rate of nitrogen and phosphorus in septic tanks is not high and consumes a certain amount of organic matter. Nutrients will be treated together with the sewage into the municipal drainage pipe netwo...

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Problems solved by technology

[0006] Aiming at the disadvantages of traditional septic tanks, such as single function, excessive nitrogen and phosphorus load in effluent after treatment, and difficulty in realizing simultaneous recycling of sewage sludge, the present invention provides a method for recovering nitrogen and phosphorus resources from septic tank wastewater that can improve the above problems. device and method

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