CN213112940U

CN213112940U - Domestic sewage treatment system

Info

Publication number: CN213112940U
Application number: CN202021162249.XU
Authority: CN
Inventors: 徐艳; 郑向群; 王贺程; 贾国委; 邵长弓
Original assignee: Agro Environmental Protection Institute Ministry of Agriculture
Current assignee: Agro Environmental Protection Institute Ministry of Agriculture; Agro Environmental Protection Institute Ministry of Agriculture and Rural Affairs
Priority date: 2020-06-22
Filing date: 2020-06-22
Publication date: 2021-05-04
Anticipated expiration: 2030-06-22

Abstract

The utility model relates to a domestic sewage treatment system, which comprises a pretreatment mechanism, a biochemical treatment mechanism, a membrane separation mechanism and a disinfection mechanism in sequence, wherein the pretreatment mechanism comprises a black water treatment unit, an ash water treatment unit and an adjusting tank, and one end of each of the black water treatment unit and the ash water treatment unit is connected with the adjusting tank; the adjusting tank is sequentially connected with the biochemical treatment mechanism, the membrane separation mechanism and the disinfection mechanism. Thereby this system is through realizing complete sewage treatment to preliminary treatment, biochemical treatment, membrane system processing and the disinfection of sewage, rational in infrastructure, the practicality is strong, impact resistance is strong, and area is few, can greatly reduce volatile substances, harmful gas and the difficult degradation pollutant in the sewage for sewage treatment efficiency improves greatly.

Description

Domestic sewage treatment system

Technical Field

The utility model belongs to the technical field of sewage treatment, a domestic sewage treatment is related to, especially a domestic sewage treatment system.

Background

Domestic sewage is seen everywhere, and contains a large amount of pollutants, and if the domestic sewage is randomly discharged, the domestic sewage pollutes the environment. At present, most cities are provided with domestic sewage treatment points, and domestic sewage is treated and then discharged to the outside so as to protect the ecological environment.

In the prior art, common domestic sewage treatment equipment adopts modes of oxygenation, stirring, fermentation, precipitation and the like to treat domestic sewage, but the water quality of the treated sewage is not up to the standard, still contains more volatile substances, and has higher operation cost.

The following patent documents related to the present application are found by search.

1. The domestic sewage treatment device and the domestic sewage treatment system (CN207775026U) with low mud yield comprise a water collecting tank, an anaerobic tank, an anoxic tank, a reactor, an aerobic tank, a coagulation tank, a sedimentation tank and a disinfection tank which are connected in sequence; the aerobic tank comprises an aeration fan, a plurality of aerators and a plurality of flow surrounding plates, the flow surrounding plates are arranged in the aerobic tank at intervals so as to form a winding channel between a water inlet and a water outlet of the aerobic tank, the aerators are distributed at the bottom of the aerobic tank and on two side faces of the flow surrounding plates, and the aeration fan is used for supplying air to the aerators.

2. A new kind of domestic sewage treatment equipment (CN207908417U), including domestic sewage treatment equipment body and solarenergy water heater body, waterproof water pump, diving pump, there are two baffles at a certain distance in the box of the domestic sewage treatment equipment body, the baffle divides the box inside into the primary sedimentation tank, second grade sedimentation tank, clean water basin, characterized by that the right side end, front side end and rear side end of the primary sedimentation tank position of the box are the double-deck construction, the outer outside rear end lower part and upper portion of the primary sedimentation tank are fitted with a pipeline respectively, the pipeline communicates with space between the two layers inside and outside the primary sedimentation tank, the outer rear outside end upper portion of the primary sedimentation tank is fitted with a back backup pad, the inner layer front inside end middle part of the primary sedimentation tank is fitted with a front backup pad, still have time circuit, water level switch, switching power supply, the domestic sewage treatment equipment body is pre-, the solar water heater body is arranged on the ground near the domestic sewage treatment equipment body, a water outlet pipe of the solar water heater body is connected with a pipeline on the upper part of the outer rear end of the primary sedimentation tank, a waterproof water pump is arranged on the rear supporting plate, a water inlet end of the waterproof water pump is connected with a pipeline on the lower part of the outer rear end of the primary sedimentation tank, a water outlet end of the waterproof water pump is connected with a water inlet pipe of the solar water heater body, the submersible pump is arranged on the upper end of the front supporting plate, the front part of a water outlet end pipeline of the submersible pump is positioned on the upper end of the secondary sedimentation tank, the water level switch is arranged in the middle part of the inner side of the primary sedimentation tank, the time circuit, the water level switch and the switching power supply are arranged on a circuit board, the circuit board, two output ends of the two sets of time circuits are respectively connected with one end of the submersible pump and one end of the waterproof pump power supply input end, and the other end of the 220V alternating current power supply is connected with the submersible pump and the other end of the waterproof pump power supply input end.

3. A domestic sewage treatment system (CN207774842U) comprises a domestic sewage treatment system box body and a connecting convex groove pipeline, wherein a domestic sewage treatment system fixing base is arranged at the bottom end of the domestic sewage treatment system box body, a domestic sewage treatment system fixing base rotating shaft is arranged at two ends of the domestic sewage treatment system fixing base, an extension supporting plate is arranged at the end part of the domestic sewage treatment system fixing base rotating shaft, a domestic sewage treatment system outdoor staircase is arranged at one side of the domestic sewage treatment system box body, a domestic sewage treatment system water outlet is arranged at the other side of the domestic sewage treatment system box body, a hanging ring is arranged at one side of the surface of the domestic sewage treatment system box body, which is opposite to the domestic sewage treatment system water outlet, a connecting port is arranged at the inner side of the domestic sewage treatment system water outlet, an external water pipe is arranged at one side, which is opposite, the surface of domestic sewage treatment system box is provided with the detection mouth, the top of domestic sewage treatment system box is provided with the repair mouth, one side of repair mouth is provided with the handle, the top of repair mouth is provided with the protective cover, the protective cover is provided with the rotation axis with the contained angle department of repair mouth.

Through the contrast of technical characteristics, above-mentioned patent literature of disclosing with the utility model discloses a technical structure is inequality, can not influence the creativity and the novelty of the utility model application.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome prior art's weak point, provide a domestic sewage treatment system, this domestic sewage treatment system is rational in infrastructure, and area is few, and can effectively reduce the volatile substances's in the sewage content to make sewage water stabilization after handling up to standard, and running cost is low, the mud production is few.

The utility model provides a its technical problem take following technical scheme to realize:

the utility model provides a domestic sewage treatment system which characterized in that: the device sequentially comprises a pretreatment mechanism, a biochemical treatment mechanism, a membrane separation mechanism and a disinfection mechanism, wherein the pretreatment mechanism comprises a black water treatment unit, a grey water treatment unit and an adjusting tank, and one ends of the black water treatment unit and the grey water treatment unit are connected with the adjusting tank; the adjusting tank is sequentially connected with the biochemical treatment mechanism, the membrane separation mechanism and the disinfection mechanism.

And, black water processing unit includes black water catch basin and septic tank, be provided with centrifuge in the black water catch basin, black water catch basin one side is provided with the black water import, and the bottom is provided with the black water export, the centrifuge inlet port links to each other with the black water import, the black water export links to each other with the septic tank.

And, the septic tank is three-phase separation septic tank, including cell body, baffle and viewing aperture, import and export are installed respectively to cell body left and right sides upper portion position, import one end is linked together with the black water export of black water catch basin, export one end is linked together with the equalizing basin, the interval is fixed with two baffles in the cell body, falls into one-level anaerobic chamber, second grade anaerobic chamber and clarification chamber with the cell body in proper order, be provided with overflow pipe one on the baffle between one-level anaerobic chamber and the second grade anaerobic chamber, be provided with overflow pipe two on the baffle between stage anaerobic chamber and the clarification chamber, just the position of the overflow mouth of overflow pipe one is less than overflow pipe two's overflow mouth position, all is provided with the viewing aperture on the cell body that corresponds one-level anaerobic chamber, second grade anaerobic chamber and clarification chamber.

And the grey water treatment unit comprises a grey water collecting tank and an oil separation tank, wherein a funnel-shaped inlet is arranged at the top of one end of the grey water collecting tank, a grey water outlet is also arranged at the bottom of the grey water collecting tank, the grey water outlet is communicated with the oil separation tank through a connecting pipe, a mechanical grid is also arranged in the grey water collecting tank, the mechanical grid is obliquely arranged to separate the grey water inlet and the grey water outlet of the grey water collecting tank, and impurity interception is realized.

The oil separation tank comprises a tank body, oil separation plates and oil separation cotton, a water inlet and a water outlet are respectively arranged at two ends of the tank body, the water inlet is communicated with an ash water outlet through a connecting pipe, the water outlet is connected with the regulating tank, two oil separation plates are arranged in the tank body at intervals, the tank body is divided into a first oil separation chamber, a second sedimentation oil separation chamber and a clear water discharge chamber, a first overflow pipe is arranged on the oil separation plate between the first oil separation chamber and the second sedimentation oil separation chamber, a second overflow pipe is arranged on the oil separation plate between the second sedimentation oil separation chamber and the clear water discharge chamber, the oil separation cotton is arranged at the end parts of overflow ports of the first overflow pipe and the second overflow pipe, and the height of the overflow port of the first overflow pipe is higher than that of the second overflow port; and a precipitation short plate is also arranged in the second precipitation oil separation chamber.

And, the equalizing basin includes cell body and sedimentation baffle, one side of cell body is provided with first water inlet and second water inlet, and the cell body opposite side is provided with the delivery port, first water inlet is linked together through the connecting pipe with the export of septic tank, the second water inlet is linked together through the connecting pipe with the delivery port of oil interceptor, the cell body middle part is provided with sedimentation baffle, still is provided with the water pump in the cell body, the water pump leads to pipe to pass the delivery port and links to each other with biochemical treatment mechanism.

And, biochemical treatment mechanism includes the integrative case of biochemical treatment and divides the boxboard, the integrative incasement interval of biochemical treatment is equipped with two branch boxboards admittedly, once falls into anaerobism pond, good oxygen pond and sedimentation tank with integrative case, divide boxboard upper portion all to install the overflow pipe, the bottom is provided with multirow aeration pipe in the good oxygen pond, the aeration head is installed at the equipartition interval on the aeration pipe, the fan is installed to good oxygen pond top, the fan is linked together through ventilation pipe and aeration pipe one end, it has the filler pipe still to install at the interval in the good oxygen pond, the filler pipe is three-dimensional elastic filler, and the filler is the suspension type, all adopts anticorrosive screw steel support fixed from top to bottom, sets up evenly distributed for adsorb the microorganism in the sewage, still be provided with sealed viewing aperture on the integrative case that corresponds good oxygen pond position.

Moreover, the membrane separation mechanism comprises a membrane pool, a membrane frame and membrane wires, one end of the membrane pool is provided with a water inlet which is communicated with a sedimentation tank of the biochemical treatment mechanism, the membrane frame is installed in the membrane pool, the membrane wires are arranged in the membrane frame, fine membrane holes are uniformly distributed and spaced on the membrane wires, both sides of the top of the membrane frame are respectively provided with an air inlet and a water outlet, the top end of the membrane pool is respectively provided with a fan and a self-priming pump, the fan is communicated with the air inlet through an air inlet pipe, one end of the self-priming pump is provided with a water suction pipe, the water suction pipe is connected with the water outlet, the other end of the self-priming pump is provided with a water discharge long pipe, the water discharge pipe is communicated with the disinfection mechanism, the membrane pool is also provided with a backwash pump, one end of the backwash pump is provided with a, the inlet tube of backwash pump also is connected with the drain pipe intercommunication of self priming pump through the tee bend connector, still be provided with first solenoid valve on the inlet tube of backwash pump and the drain pipe between the self priming pump, be provided with the second solenoid valve on the outlet pipe of backwash pump.

And, disinfection mechanism is including disinfecting pond, glass pipe and ultraviolet lamp, the horizontal interval is provided with many glass pipes in the disinfection pond, and the interval is provided with a plurality of ultraviolet lamp in every glass pipe, the both ends of glass pipe are sealed, disinfection pond top still is provided with disinfectant and adds the mouth.

And in addition, a first filter screen and a second filter screen are arranged in the funnel-shaped inlet at intervals, and the aperture size of the second filter screen is smaller than that of the first filter screen.

The utility model has the advantages that:

the system has the advantages of reasonable structure, strong practicability, strong impact resistance, small backflow amount, stable water outlet, no need of monitoring, high oxygenation efficiency and good oxygenation effect, and can greatly reduce volatile substances, harmful gases and difficultly-degraded pollutants in sewage.

Thereby this system is through the preliminary treatment to sewage, biochemical treatment, membrane system processing and disinfection treatment realize complete sewage treatment, and the processing of this system makes sewage pertinence handle for sewage treatment is more thorough and high-efficient, and the setting of integration makes area few, and the pool capacity is little moreover, can bury in underground or go out water quality of water standard rate safe and reliable on the ground, and the operation is reliable and stable.

This system realizes preliminary edulcoration of depositing respectively of sewage through pretreatment mechanism, through the preliminary disinfection of biochemical treatment mechanism to sewage, reach the standard that the one-level can normally discharge to sewage treatment plant in, macromolecular organic matter and other small living beings in the sewage are removed through membrane separating mechanism again, what purpose is realized through the disinfection of disinfection mechanism at last, accomplish the last processing of sewage through disinfection mechanism at best, then discharge and reuse in afforestation irrigation and current ordinary domestic water.

Drawings

FIG. 1 is a schematic diagram of the system of the present invention;

FIG. 2 is a schematic view of the structure of the oil separation tank of the present invention;

FIG. 3 is a schematic structural view of the biochemical treatment mechanism of the present invention;

fig. 4 is a schematic structural diagram of the membrane separation mechanism of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments, which are illustrative, not restrictive, and the scope of the invention should not be limited thereto.

A domestic sewage treatment system sequentially comprises a pretreatment mechanism 8, a biochemical treatment mechanism 23, a membrane separation mechanism 32 and a disinfection mechanism 44, wherein the pretreatment mechanism comprises a black water treatment unit, a grey water treatment unit and an adjusting tank 21, and one ends of the black water treatment unit and the grey water treatment unit are connected with the adjusting tank; the black water treatment unit comprises a black water collecting tank 6 and a septic tank 10, wherein the black water collecting tank can be used for being communicated with a toilet sewage pipe network so as to receive black water from the toilet sewage pipe network, the black water collecting tank is provided with a black water inlet which is positioned outside the black water collecting tank and is communicated with the inside of the black water collecting tank, the bottom of the black water collecting tank is provided with a black water outlet which is communicated with the septic tank through a connecting pipe 9, the black water collecting tank is also provided with a centrifugal machine 7, the black water inlet is connected with a centrifugal machine inlet through a connecting pipe, the black water enters the centrifugal machine through the connecting pipe, impurities in excrement, urine and sewage are removed through the centrifugal machine, the excrement, the urine and the sewage are thrown into the collecting tank and enter the septic tank for sedimentation and fermentation, and the septic tank is a three-phase separation septic tank, the device comprises a tank body, partition plates 12 and an observation port 14, wherein an inlet and an outlet 18 are respectively arranged at the upper parts of the left side and the right side of the tank body, one end of the inlet is communicated with a black water outlet of a black water collecting tank, one end of the outlet is communicated with an adjusting tank, two partition plates are fixed in the tank body at intervals, the tank body is sequentially divided into a primary anaerobic chamber 11, a secondary anaerobic chamber 15 and a clarifying chamber 17, an overflow pipe I13 is arranged on the partition plate between the primary anaerobic chamber and the secondary anaerobic chamber, an overflow pipe II 16 is arranged on the partition plate between the primary anaerobic chamber and the clarifying chamber, and the position of an overflow port of the overflow pipe I is lower than that of the overflow port of the overflow pipe II, so that the filtering of; the tank bodies corresponding to the primary anaerobic chamber, the secondary anaerobic chamber and the clarifying chamber are provided with observation ports; the three-phase separation septic tank keeps the advantage of sludge-water mixing in the septic tank on the basis of the traditional septic tank, increases the technology of three-phase separation of 'sewage, sludge and digestion gas', separates the sludge and digestion gas at the water outlet end from the sewage treatment process, avoids the interference of the air floatation phenomenon on the sewage treatment, has the sewage retention time of 4-6 hours in the three-phase separation septic tank, saves the effective volume by shortening the sewage retention time compared with the sewage retention time of 12-24 hours in the sludge-water mixing septic tank, can store more sludge precipitated by the sludge, decomposes the organic matters in the sludge into stable inorganic matters, converts the putrescible raw sludge into stable mature sludge, changes the structure of the sludge and reduces the water content of the sludge through anaerobic fermentation for more than 3 months. The sludge is periodically removed and transported out, buried or used as fertilizer.

The grey water treatment unit comprises a grey water collecting tank 2 and an oil separation tank 56, the grey water collecting tank is used for being communicated with a sewage pipe network of grey water generated in kitchens and washing so as to receive the grey water from the sewage pipe network generated in washing, a funnel-shaped inlet 5 is arranged at the top of one end of the grey water collecting tank, a first filter screen 4 and a second filter screen 3 are further arranged at the funnel-shaped inlet at intervals, the pore size of the second filter screen is smaller than that of the first filter screen, the first filter screen is mainly used for filtering garbage with larger volume, the second filter screen is mainly used for filtering garbage with smaller volume, correspondingly, the second filter screen is closer to the grey water collecting tank than the first filter screen, a grey water outlet is further arranged at the bottom of the grey water collecting tank, the grey water outlet is communicated with the oil separation tank through a connecting pipe 55, and a mechanical grating 1 is further arranged in the grey water collecting, the mechanical grating is obliquely arranged to separate a grey water inlet and a grey water outlet of the grey water collecting tank, so that impurities in the grey water collecting tank are continuously intercepted; the oil separation tank comprises a tank body,

oil separation plates

52 and 49 and oil separation 53, a water inlet and a water outlet are respectively arranged at two ends of the tank body, the water inlet is communicated with a grey water outlet through a connecting pipe, the water outlet is connected with the regulating tank, two oil separation plates are arranged in the tank body at intervals, the tank body is divided into a first oil separation chamber 54, a second sedimentation oil separation chamber 50 and a clear water discharge chamber 48, a first overflow pipe is arranged on the oil separation plate between the first oil separation chamber and the second sedimentation oil separation chamber, a second overflow pipe is arranged on the oil separation plate between the second sedimentation oil separation chamber and the clear water discharge chamber, oil separation cotton is arranged at the end parts of overflow ports of the first overflow pipe and the second overflow pipe, and the height of an overflow port of the first overflow pipe is higher than that of an overflow port of the second overflow pipe, so that oil which is not separated in water cannot enter the next space; a precipitation short plate 51 is further arranged in the second precipitation oil separation chamber to realize precipitation of large-particle impurities; sewage in the grey water collecting tank enters a first oil separating chamber of an oil separating tank through a pipeline, oil-water separation is carried out, then the sewage enters a second precipitation oil separating chamber through a first overflow pipe, the sewage enters a clear water discharging tank through a second overflow pipe after the precipitation of the oil separating chamber is precipitated through the second overflow pipe, the purpose of double-layer oil separation is realized by oil separating cotton arranged on the first overflow pipe and the second overflow pipe, oil stains in the sewage are greatly filtered, and oil separating treatment is achieved.

The adjusting tank comprises a tank body and a sedimentation baffle 20, wherein a first water inlet and a second water inlet are formed in one side of the tank body; the other side is provided with a water outlet, the first water inlet is communicated with the outlet of the septic tank through a connecting pipe 19, the second water inlet is communicated with the water outlet of the oil separation tank through a connecting pipe 47, the middle part of the tank body is provided with a sedimentation baffle, a water pump 22 is also arranged in the tank body, and the water pump passes through the water outlet through a water pipe and is connected with the biochemical treatment mechanism.

The biochemical treatment mechanism comprises a biochemical treatment integrated box and box dividing plates, two box dividing plates are fixedly arranged in the biochemical treatment integrated box at intervals, the integrated box is divided into an anaerobic tank 24, an aerobic tank 28 and a sedimentation tank 31 at one time,

overflow pipes

46 and 30 are arranged at the upper parts of the box dividing plates, a water outlet of the adjusting tank is connected with an inlet end of the anaerobic tank through a water pipe, an outlet end of the anaerobic tank is connected with an inlet end of the aerobic tank, and an outlet end of the aerobic tank is connected with an inlet end of the sedimentation tank; a plurality of rows of aeration pipes 45 are arranged at the bottom in the aerobic tank, aeration heads are uniformly distributed on the aeration pipes at intervals, a fan 25 is arranged at the top of the aerobic tank, the fan is communicated with one end of an aeration pipe through a vent pipe 27 to supply air to the aerobic tank, so that oxygen is dissolved in the sewage, filler pipes 26 are also arranged in the aerobic tank at intervals, combined fillers for culturing strains are suspended in the filler pipes, the combined filler is the existing chemical filler which can be added in the existing aerobic tank reaction, the system is not illustrated, the filler pipe is a three-dimensional elastic filler, the filler is suspended, the upper part and the lower part of the filler are fixed by adopting anti-corrosion deformed steel bar brackets, the arrangement and the distribution are uniform, and in a static state, the sewage treatment device does not sink or float upwards, water flow can stably pass through the sewage treatment device, microorganisms are easily adsorbed, organic matters are better degraded, and sewage is purified, and a sealed observation port 29 is further arranged on the integrated box corresponding to the position of the aerobic tank.

The membrane separation mechanism comprises a membrane pool, a membrane frame 35 and membrane filaments 36, wherein a water inlet is formed in one end of the membrane pool, the water inlet is communicated with a sedimentation tank of the biochemical treatment mechanism through a drain pipe, the membrane frame is installed in the membrane pool and is a rectangular frame, the membrane filaments are vertically arranged between an upper rod and a lower rod of the membrane frame, fine membrane holes are uniformly distributed and arranged at intervals on the membrane filaments, an air inlet 34 and a water outlet are respectively formed in two sides of the top of the membrane frame, a fan 33 and a self-sucking pump 37 are respectively installed at the top end of the membrane pool, the fan is communicated with the air inlet through an air inlet pipe, a water suction pipe 39 is arranged at one end of the self-sucking pump, the water suction pipe is connected with the water outlet, a drainage long pipe 38 is arranged at the other end of the self-sucking pump, the drainage pipe is inserted into, the other end is provided with the inlet tube, the outlet pipe of backwash pump passes through the tee bend connector and installs with the drinking-water pipe intercommunication of self priming pump, the inlet tube of backwash pump also passes through the tee bend connector and is connected with the drain pipe intercommunication of self priming pump, still be provided with first solenoid valve on the inlet tube of backwash pump and the drain pipe between the self priming pump, be provided with the second solenoid valve on the outlet pipe of backwash pump. In the specific implementation of the utility model, the floating ball is further arranged in the membrane pool, when sewage enters the membrane pool, the water level is detected through the floating ball, then the self-priming pump is started to pump water, the first electromagnetic valve is opened, the sewage is discharged into the disinfection pool of the disinfection mechanism through the membrane holes on the membrane wires, redundant activated sludge and macromolecular organic matters in the sewage are intercepted in the membrane pool, in order to prevent the membrane holes on the membrane wires from being blocked by impurities to influence filtration, the fan is started simultaneously, the impurities attached to the membrane holes are separated by the blowing of the fan to the membrane wires, the smoothness of drainage is realized, when the drainage is not smooth, the self-priming pump and the first electromagnetic valve are closed, the backwashing pump is started, the second electromagnetic valve is opened, so that the water in the disinfection pool of the disinfection mechanism is sucked back into the membrane wires and then flows back to the membrane pool from the membrane holes, the backwashing purpose of the membrane holes is realized, the service life of the membrane wires, making the filtration more efficient.

Disinfection mechanism is including disinfecting pond 41, glass pipe 43 and ultraviolet lamp 42, the horizontal interval is provided with many glass pipes in the disinfection pond, and the intraductal interval of every glass is provided with a plurality of ultraviolet lamp, the both ends of glass pipe are sealed. Depending on the specific size of the disinfection tank, the number of glass tubes and uv lamps, respectively. The glass pipe can be followed the length or the width direction in disinfection pond and extended to divide into the multilayer on the direction of height in disinfection pond, like this, make ultraviolet lamp can carry out the irradiation of large tracts of land to the sewage after handling, the disinfection pond top still is provided with disinfectant inlet port for the joining of disinfectant.

Although the embodiments of the present invention and the accompanying drawings are disclosed for illustrative purposes, those skilled in the art will appreciate that: various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims, and therefore, the scope of the present invention is not limited to the disclosure of the embodiments and the accompanying drawings.

Claims

1. The utility model provides a domestic sewage treatment system which characterized in that: the device sequentially comprises a pretreatment mechanism, a biochemical treatment mechanism, a membrane separation mechanism and a disinfection mechanism, wherein the pretreatment mechanism comprises a black water treatment unit, a grey water treatment unit and an adjusting tank, and one ends of the black water treatment unit and the grey water treatment unit are connected with the adjusting tank; the adjusting tank is sequentially connected with the biochemical treatment mechanism, the membrane separation mechanism and the disinfection mechanism.

2. The domestic sewage treatment system of claim 1, wherein: the black water treatment unit comprises a black water collecting tank and a septic tank, wherein a centrifugal machine is arranged in the black water collecting tank, a black water inlet is formed in one side of the black water collecting tank, a black water outlet is formed in the bottom of the black water collecting tank, a centrifugal machine inlet is connected with the black water inlet, and the black water outlet is connected with the septic tank.

3. The domestic sewage treatment system of claim 2, wherein: the septic tank is three-phase separation septic tank, including cell body, baffle and viewing aperture, import and export are installed respectively to cell body left and right sides upper portion position, import one end is linked together with the black water export of black water catch basin, export one end is linked together with the equalizing basin, the internal interval of cell is fixed with two baffles, falls into one-level anaerobic chamber, second grade anaerobic chamber and clarification chamber with the cell body in proper order, be provided with overflow pipe one on the baffle between one-level anaerobic chamber and the second grade anaerobic chamber, be provided with overflow pipe two on the baffle between stage anaerobic chamber and the clarification chamber, just the position of the overflow mouth of overflow pipe one is less than overflow mouth position of overflow pipe two, all is provided with the viewing aperture on the cell body that corresponds one-level anaerobic chamber, second grade anaerobic chamber and clarification chamber.

4. The domestic sewage treatment system of claim 1, wherein: the grey water treatment unit comprises a grey water collecting tank and an oil separation tank, wherein a funnel-shaped inlet is formed in the top of one end of the grey water collecting tank, a grey water outlet is further formed in the bottom of the grey water collecting tank, the grey water outlet is communicated with the oil separation tank through a connecting pipe, a mechanical grating is further arranged in the grey water collecting tank, the mechanical grating is arranged in an inclined mode, the grey water inlet and the grey water outlet of the grey water collecting tank are separated, and impurity interception is achieved.

5. The domestic sewage treatment system of claim 4, wherein: the oil separation tank comprises a tank body, oil separation plates and oil separation cotton, a water inlet and a water outlet are respectively arranged at two ends of the tank body, the water inlet is communicated with an ash water outlet through a connecting pipe, the water outlet is connected with an adjusting tank, two oil separation plates are arranged in the tank body at intervals, the tank body is divided into a first oil separation chamber, a second sedimentation oil separation chamber and a clear water discharge chamber, a first overflow pipe is arranged on the oil separation plate between the first oil separation chamber and the second sedimentation oil separation chamber, a second overflow pipe is arranged on the oil separation plate between the second sedimentation oil separation chamber and the clear water discharge chamber, the oil separation cotton is arranged at the end parts of overflow ports of the first overflow pipe and the second overflow pipe, and the height of an overflow port of the first overflow pipe is higher than that of an overflow port of the second overflow pipe; and a precipitation short plate is also arranged in the second precipitation oil separation chamber.

6. The domestic sewage treatment system of claim 1, wherein: the equalizing basin includes cell body and sedimentation baffle, one side of cell body is provided with first water inlet and second water inlet, and the cell body opposite side is provided with the delivery port, first water inlet is linked together through the connecting pipe with the export of septic tank, the second water inlet is linked together through the connecting pipe with the delivery port of oil interceptor, the cell body middle part is provided with sedimentation baffle, still is provided with the water pump in the cell body, the water pump leads to pipe to pass the delivery port and links to each other with biochemical treatment mechanism.

7. The domestic sewage treatment system of claim 1, wherein: biochemical treatment mechanism includes the integrative case of biochemical treatment and divides the boxboard, the integrative incasement interval of biochemical treatment is equipped with two branch boxboards admittedly, once falls into anaerobism pond, good oxygen pond and sedimentation tank with integrative case, divide boxboard upper portion all to install the overflow pipe, the bottom is provided with multirow aeration pipe in the good oxygen pond, the aeration head is installed at the equipartition interval on the aeration pipe, the fan is installed to good oxygen pond top, the fan is linked together through ventilation pipe and aeration pipe one end, it has the filled tube still to install at the interval in the good oxygen pond, the filled tube is three-dimensional elastic filler, and the filler is the suspension type, all adopts anticorrosive screw steel support fixed from top to bottom, sets up evenly distributed for adsorb the microorganism in the sewage, still be provided with sealed viewing aperture on the integrative case of biochemical treatment.

8. The domestic sewage treatment system of claim 1, wherein: the membrane separation mechanism comprises a membrane pool, a membrane frame and membrane wires, wherein a water inlet is formed in one end of the membrane pool and is communicated with a sedimentation tank of the biochemical treatment mechanism, the membrane frame is installed in the membrane pool, the membrane wires are arranged in the membrane frame, fine membrane holes are uniformly distributed on the membrane wires at intervals, an air inlet and a water outlet are respectively formed in two sides of the top of the membrane frame, a fan and a self-priming pump are respectively installed at the top end of the membrane pool, the fan is communicated with the air inlet through an air inlet pipe, a water suction pipe is arranged at one end of the self-priming pump and is connected with the water outlet, a water discharge long pipe is arranged at the other end of the self-priming pump and is communicated with the disinfection mechanism, a backwash pump is further installed on the membrane pool, a water outlet pipe is arranged at one end of the backwash pump, a water inlet pipe, the inlet tube of backwash pump also is connected with the drainage long tube intercommunication of self priming pump through the tee bend connector, still be provided with first solenoid valve on the inlet tube of backwash pump and the drainage long tube between the self priming pump, be provided with the second solenoid valve on the outlet pipe of backwash pump.

9. The domestic sewage treatment system of claim 1, wherein: disinfection mechanism is including disinfecting pond, glass pipe and ultraviolet lamp, the horizontal interval is provided with many glass pipes in the disinfection pond, and the interval is provided with a plurality of ultraviolet lamp in every glass pipe, the both ends of glass pipe are sealed, disinfection pond top still is provided with disinfectant and adds the mouth.

10. The domestic sewage treatment system of claim 4, wherein: still be provided with first filter screen and second filter screen in the funnel type inlet at interval, the aperture size of second filter screen is less than the aperture size of first filter screen.