Domestic mini sewage treatment system and sewage treatment method

Abstract

The present application relates to the field of sewage purification, and discloses a household micro sewage treatment system and a sewage treatment method, which comprises the following steps: building a septic tank; preparing a household micro sewage treatment system, an aeration system and suspended filler for microbial attachment; pumping clarified liquid by a lifting pump, and the clarified liquid enters a contact oxidation zone, and microorganisms degrade COD and BOD in the clarified liquid; the clarified liquid at the contact oxidation zone flows into an electrocoagulation zone, and electrocatalytic flocculation is performed; then, pollutants and phosphorus in the clarified liquid are filtered by a filtering zone, and the clarified liquid forms purified water; the purified water is taken from a water outlet zone, and is used for crop irrigation; or, a landscape zone for breeding aquatic plants or plankton is arranged at the water outlet zone. In the present application, the contact oxidation zone, the electrocoagulation zone, the filtering zone and the water outlet zone are sequentially and continuously arranged from bottom to top, and the arrangement structure of the whole household micro sewage treatment system is compact, and it is more convenient to arrange the system in a separate house environment in rural areas.

Description

TECHNICAL FIELD

[0001] The present application relates to the sewage purification technical field, especially to a household micro sewage treatment system and a sewage treatment method. BACKGROUND

[0002] With the rapid development of economy and the acceleration of urbanization, the discharge of domestic sewage in China is increasing year by year. Sewage treatment plants in cities can timely treat sewage, but the discharge of sewage in economically backward rural areas and small settlements is also increasing. The current treatment method in rural areas is to directly discharge most of the sewage by gravity, and there is a lack of supporting sewage treatment means. This is because the population in rural areas is scattered, and it is difficult to lay drainage networks between households. Moreover, laying long-distance drainage networks will directly lead to a rapid increase in sewage treatment costs.

[0003] Therefore, at present, the construction of septic tanks is still used for sewage collection in rural areas, but there is still a lack of facultative or aerobic filter, sewage chemical treatment process, etc. for treating sewage in septic tanks. This sewage can only be used for single crop irrigation and cannot be applied to other living scenarios. At the same time, if facultative or aerobic filters are used to treat sewage, the required land area of the facultative or aerobic filters is large, the construction cost is high, and the professional ability of the sewage treatment personnel is also high, which is not suitable for the use of individual households in rural areas. At the same time, when using the sewage chemical treatment process to treat sewage, PAC / PAM is often used as a phosphorus flocculant in the process. The chemical reagent in the chemical treatment process can easily cause secondary chemical pollution to the environment. At the same time, the requirement for the amount of chemical reagent input during the treatment process is high, which increases the labor cost of operation, and the operation and management are complex, making it difficult to realize remote intelligent control. SUMMARY

[0004] In view of the deficiencies in the prior art, the present application provides a household micro sewage treatment system and a sewage treatment method to solve the problem that the existing urban sewage treatment mode cannot be applied to rural sewage treatment.

[0005] To achieve the above purpose, the basic scheme of the present application is as follows: a sewage treatment method, comprising the following steps:

[0006] constructing a septic tank;

[0007] preparing a household micro sewage treatment system, an aeration system, and suspended filler for microorganism attachment. The household micro sewage treatment system sequentially comprises a lifting pump, a contact oxidation zone, an electric flocculation zone, a filtration zone, and a water outlet zone. The contact oxidation zone, the electric flocculation zone, the filtration zone, and the water outlet zone are sequentially connected from bottom to top. The lifting pump is connected to the contact oxidation zone.

[0008] The sewage of the household is discharged into the septic tank, the septic tank hydrolyzes the sewage, the sediment and sundries in the sewage sink into the bottom of the septic tank to form sediment A, and the sewage in the septic tank forms supernatant which is clear liquid;

[0009] The lifting pump is put into the septic tank, the suspended filler is put into the contact oxidation zone, and the aeration system is communicated with the contact oxidation zone; the lifting pump is started to extract the clear liquid, the clear liquid enters the contact oxidation zone, the COD and BOD in the clear liquid are degraded by microorganisms, the ammonia nitrogen in the clear liquid is converted into nitrate nitrogen by microorganisms, and the pollutants in the contact oxidation zone sink to form sediment B;

[0010] The clear liquid at the contact oxidation zone flows into the electrocoagulation zone to perform electrocoagulation, and the pollutants and phosphorus in the clear liquid sink to form sediment C;

[0011] The clear liquid at the electrocoagulation zone flows into the filtration zone, the pollutants and phosphorus in the clear liquid are filtered by the filtration zone, and the clear liquid forms purified water;

[0012] The purified water is taken from the water outlet zone and used for crop irrigation; or, a landscape zone for breeding aquatic plants or plankton is arranged at the water outlet zone, and the overflow purified water at the landscape zone can be used for crop irrigation.

[0013] The technical principle of the present application is that, in rural sewage treatment, the sewage quantity is much smaller than that in urban sewage treatment, at this time, a separate septic tank is arranged, which is smaller in size and cost compared with the septic tank in the city, and can be used by some surrounding households.

[0014] The lifting pump in the household micro sewage treatment system can extract the clear liquid in the septic tank for water treatment, the contact oxidation zone in the household micro sewage treatment system can cooperate with the aeration system and the suspended filler to oxidize and degrade the clear liquid, degrade the COD, BOD and ammonia nitrogen in the clear liquid, the clear liquid enters the electrocoagulation zone again, the electrocoagulation unit performs electrocoagulation treatment to make the suspended matter in the clear liquid sink, and also performs phosphorus removal treatment, then the clear liquid enters the filtration zone to be filtered to form purified water, the treated purified water can cooperate with the water outlet zone to form landscape zone water or be used for crop irrigation, so that the purified water is fully utilized, and the overflow purified water at the landscape zone can also be connected to farmland for irrigation.

[0015] In the above process, the contact oxidation zone, the electrocoagulation zone, the filtration zone and the water outlet zone are sequentially communicated from bottom to top, so that the arrangement structure of the whole household micro sewage treatment system is compact, and it is more convenient to arrange in the environment of a separate house in the countryside, the contact oxidation zone can perform oxygenation treatment on the clear liquid, so that the final purified water contains a large amount of oxygen, and the contact oxidation unit can supplement oxygen to the purified water in the landscape zone during the starting process, which is more convenient for breeding plankton.

[0016] Further, the microorganism in the suspended filler is facultative bacteria and aerobic bacteria, and the mass ratio of the facultative bacteria and the aerobic bacteria is 0.25-0.4.

[0017] Through the above setting, the ratio of the facultative bacteria and the aerobic bacteria is balanced, and the facultative bacteria and the aerobic bacteria can cooperate with the air filled into the contact oxidation zone by the aeration system to degrade COD, BOD and ammonia nitrogen in the clarified liquid.

[0018] Further, the sediment A, the sediment B and the sediment C can be collected and used as biological fertilizer.

[0019] Through the above setting, the sediment A, the sediment B and the sediment C formed in the sewage treatment process can be fully utilized, and the growth of plants is beneficial.

[0020] Further, the filter zone is a sand filter zone, and the sand filter zone contains quartzite.

[0021] Through the above setting, the quartzite has very good effect on purifying water quality, can adsorb organic matter and heavy metal ions in agricultural wastewater, and makes the clarified liquid more clear and transparent after filtration.

[0022] Further, when the accumulation thickness of the sediment A in the septic tank reaches 0.2-0.5 times the depth of the septic tank, the sediment A in the septic tank is dredged.

[0023] Through the above setting, the septic tank can be cleaned in time, and the sediment A can be used as fertilizer for plants.

[0024] Further, the household micro sewage treatment system implements a sewage treatment method.

[0025] The first treatment shell forms the contact oxidation zone, and the first treatment shell is communicated with the water inlet pipe and the switchable vent pipe, and the first treatment shell is communicated with the aeration system; the lifting pump is communicated with the water inlet pipe;

[0026] The second treatment shell forms the electric flocculation zone, and the second treatment shell is installed with the electric flocculation assembly and the switchable blowdown pipe;

[0027] The third treatment shell forms the filter zone, and the third treatment shell is provided with the filter material;

[0028] The fourth treatment shell forms the water outlet zone; the first treatment shell, the second treatment shell, the third treatment shell and the fourth treatment shell are sequentially communicated and detachably and sealingly connected from bottom to top.

[0029] Through the above setting, the first treatment shell, the second treatment shell, the third treatment shell and the fourth treatment shell are in a sealed state when connected, avoiding water leakage; when the first treatment shell, the second treatment shell and the third treatment shell need to be cleaned, the first treatment shell, the second treatment shell, the third treatment shell and the fourth treatment shell can also be disassembled, which is convenient for cleaning the first treatment shell, the second treatment shell and the structure inside them through the vent pipe and the drain pipe. The maintenance of the household micro sewage treatment system is convenient.

[0030] Further, the aeration system comprises:

[0031] An aeration device;

[0032] An air inlet pipe in communication with the aeration device;

[0033] An aeration stone located in the first treatment shell, and the end of the air inlet pipe away from the aeration device penetrates the first treatment shell and communicates with the aeration stone.

[0034] Through the above setting, the aeration stone located in the first treatment shell can have more variable positions, and sufficient oxygen can be supplied to the microorganisms in the suspended filler. The air inlet pipe can provide reliable connection for the installation of the aeration stone and the air inlet pipe.

[0035] Further, the second treatment shell is connected with a junction box for supplying power to the electric flocculation assembly, and the drain pipe is communicated with the lower side of the second treatment shell.

[0036] Through the above setting, the junction box is connected with the power supply, which can provide continuous and stable power for the electric flocculation assembly, and then the impurities in the clarified liquid are subjected to electric flocculation treatment. The impurities and suspended solids in the second treatment shell also accumulate to form sludge. When the second treatment shell is filled with too much sludge, the drain pipe at the lower side of the second treatment shell is opened, the sludge in the second treatment shell can be collected, and the second treatment shell is emptied, so that the cleaning of the second treatment shell is more convenient.

[0037] Further, the third treatment shell is provided with a plurality of filter water caps in communication with the third treatment shell at the side close to the second treatment shell; and a handle vertically upwardly pulled is installed on the third treatment shell.

[0038] Through the above setting, when the second treatment shell and the third treatment shell are disassembled, the third treatment shell can be taken out more conveniently by applying force at the handle.

[0039] Further, the intelligent control unit is further included, the intelligent control unit includes sludge concentration sensor, dissolved oxygen sensor, first controller for controlling aeration equipment to open or close, sludge discharge prompter and PLC controller, the sludge concentration sensor, dissolved oxygen sensor, first controller and sludge discharge prompter are electrically coupled with PLC controller;The dissolved oxygen sensor is installed in the first processing shell, and the sludge concentration sensor is installed in the second processing shell;When the dissolved oxygen concentration measured by the dissolved oxygen sensor is less than 2.0 mg / L, the aeration equipment is in continuous operation;When the dissolved oxygen concentration measured by the dissolved oxygen sensor is higher than 4.0 mg / L, the aeration equipment stops running;When the sludge concentration measured by the sludge concentration sensor is higher than 8000 mg / L, the sludge discharge prompter responds to prompt that sludge needs to be discharged.

[0040] Through the above setting, the whole intelligent control unit can automatically control the water inlet and outlet of the household micro sewage treatment device and the treatment state of the clarified liquid, realize automatic monitoring, early warning and diagnosis to the sewage treatment process, so that the purification treatment of the clarified liquid can be automated, thereby improving the efficiency and safety of the sewage treatment;During the use of the household micro sewage treatment device, only the sludge in the household micro sewage treatment device can be cleaned in time under the prompt of the sludge discharge prompter, and the use is very convenient. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 For the process flow chart of the sewage treatment method in the embodiment of the application.

[0042] Figure 2 For the water treatment flow chart of the household micro sewage treatment system in the embodiment of the application.

[0043] Figure 3 For Figure 2 The longitudinal section view of the main view direction of the contact oxidation unit, the electrocoagulation unit, the filtration unit and the water outlet unit.

[0044] Figure 4 For the control flow chart of the intelligent control unit in the embodiment of the application.

[0045] In the above drawings: the first processing shell 10, the aeration equipment 101, the suspended filler 102, the aeration stone 103, the air inlet pipe 104, the vent pipe 105, the air inlet 106, the second processing shell 20, the electrocoagulation assembly 201, the sewage discharge pipe 202, the junction box 203, the filter screen 30, the third processing shell 40, the filter material 401, the filter water cap 402, the handle 403, the lifting pump 50, the water inlet pipe 501, the septic tank 502, the display landscape cabinet 60. DETAILED DESCRIPTION

[0046] The technical solutions in the application will be further described below in combination with the drawings and embodiments.

[0047] The embodiment is basically as shown in Figure 1 , Figure 2 and Figure 3 , the embodiment of the present application proposes a household micro sewage treatment system, which sequentially comprises a communicating lifting pump 50, a contact oxidation zone, an electric flocculation zone, a filtration zone and a water outlet zone; the contact oxidation zone, the electric flocculation zone, the filtration zone and the water outlet zone are sequentially and communicatively arranged from bottom to top; the household micro sewage treatment system further comprises a first treatment shell 10 forming the contact oxidation zone, a second treatment shell 20 forming the electric flocculation zone, a third treatment shell 40 forming the filtration zone and a fourth treatment shell forming the water outlet zone.

[0048] As shown in Figure 3 , the left side of the first treatment shell 10 is communicated with a water inlet pipe 501, and the lifting pump 50 is communicated with the water inlet pipe 501; the right side of the first treatment shell 10 is communicated with a switchable vent pipe 105, the vent pipe 105 is located at the lower side of the first treatment shell 10, the first treatment shell 10 is communicated with an aeration system; the aeration assembly comprises an aeration device 101, an air inlet pipe 104 and aeration stones 103 connected with the air inlet pipe 104, the aeration device 101 is a fan, the right side of the first treatment shell 10 is provided with an air inlet, the aeration stones 103 are fixedly installed on the left end of the air inlet pipe 104 and located in the air inlet, and the right end of the air inlet pipe 104 is fixedly installed at the air inlet and detachably connected with the aeration device 101.

[0049] As shown in Figure 3 , the second treatment shell 20 is installed with an electric flocculation assembly 201 and a switchable blowdown pipe 202, the blowdown pipe 202 is communicated with the lower side of the second treatment shell 20, the right side outer wall of the second treatment shell 20 is fixedly provided with a junction box 203 for supplying power to the electric flocculation assembly 201, the lower side of the second treatment shell 20 and the upper end of the first treatment shell 10 are provided with buckles and sealing rings to realize detachable and sealing connection, a filter communication hole is vertically provided between the second treatment shell 20 and the first treatment shell 10, and a filter screen 30 is provided at the filter communication hole; the electric flocculation assembly 201 is opposite to the filter communication hole.

[0050] As shown in Figure 3 , the third treatment shell 40 is provided with a filter material 401, the filter material 401 is quartz stone, the lower side of the third treatment shell 40 and the upper side of the second treatment shell 20 are also provided with buckles and sealing rings to realize detachable and sealing connection, the lower side of the third treatment shell 40 is provided with a plurality of filters communicated with the second treatment shell 20, the filters are filter water caps 402, the lower ends of the filter water caps 402 pass through the second treatment shell 20 and are located in the second treatment shell 20; at the same time, the upper side of the third treatment shell 40 is integrally formed with a vertically upward pulling handle 403.

[0051] As shown in Figure 2 and3 As shown, the water pumping unit comprises a lifting pump 50 for pumping supernatant in the septic tank 502 and a water inlet pipe 501 in communication with the lifting pump 50, and the right end of the water inlet pipe 501 is in communication with the lower side of the first treatment shell 10; and isolation valves are arranged on the water inlet pipe 501, the vent pipe 105 and the sewage pipe 202.

[0052] As shown in Figure 2 and Figure 3 , the fourth treatment shell is a landscape area for breeding aquatic plants or plankton, and the water outlet area and the landscape area can be integrated to form a display landscape cabinet 60 which is arranged on the second treatment shell 20 or the third treatment shell 40; the first treatment shell 10 and the second treatment shell 20 are both sandblasted with carbon steel and painted according to the environment of the placement area, and the third treatment shell 40 and the display landscape cabinet 60 are both made of transparent organic glass, so that the entire set of equipment has a certain ornamental value.

[0053] At the same time, as shown in Figure 4 , the household miniature sewage treatment system further comprises an intelligent control unit, which comprises a sludge concentration sensor, a dissolved oxygen sensor, a first controller for controlling the opening and closing of the aeration device 101, a second controller for controlling the opening and closing of the lifting pump 50, a third controller for controlling the opening and closing of the electric flocculation assembly 201, a sludge discharge indicator, and a PLC controller, the sludge concentration sensor, the dissolved oxygen sensor, the first controller, the second controller, the third controller and the sludge discharge indicator are electrically connected with the PLC controller, the sludge discharge indicator is a prompt light or a buzzer, and the sludge discharge indicator is fixedly installed on the sewage pipe 202 by adhesion or bolts, the dissolved oxygen sensor is installed in the first treatment shell 10, and the sludge concentration sensor is installed in the second treatment shell 20.

[0054] In addition, as shown in Figure 3 , the first treatment shell 10, the second treatment shell 20, the third treatment shell 40 and the fourth treatment shell have a total length and width of 500-1200 mm after being installed as a whole, and the overall size height can reach 1000-1800 mm; at the same time, the volume ratio of the first treatment shell 10 can reach 1 / 3 of the overall size, the volume ratio of the second treatment shell 20 can reach 1 / 3 of the overall size, the volume ratio of the third treatment shell 40 can reach 1 / 6 of the overall size, and the volume ratio of the fourth treatment shell can reach 1 / 6 of the overall size.

[0055] When the household miniature sewage treatment system is used to treat rural sewage, a sewage treatment method is formed, which specifically comprises the following steps:

[0056] Constructing a septic tank 502;

[0057] The micro sewage treatment system for household, the aeration system and the suspended filler 102 for microorganism attachment are prepared, the microorganism in the suspended filler 102 is facultative bacteria and aerobic bacteria, and the mass ratio of the facultative bacteria and the aerobic bacteria is 0.3;

[0058] The sewage of the household is discharged into the septic tank 502, the septic tank 502 hydrolyzes the sewage, the sediment and sundries in the sewage sink into the bottom of the septic tank 502 to form the sediment A, the sewage in the septic tank 502 forms the supernatant, and the supernatant is clear liquid; when the accumulation thickness of the sediment A in the septic tank 502 reaches 0.2-0.5 times of the depth of the septic tank 502, the sediment A in the septic tank 502 is dredged;

[0059] The lifting pump 50 is put into the septic tank 502, the suspended filler 102 is put into the contact oxidation area, and the aeration equipment 101 is communicated with the first treatment shell 10; the lifting pump 50 is started by the second controller of the PLC controller, the lifting pump 50 extracts the clear liquid, the clear liquid enters into the first treatment shell 10 through the water inlet pipe 501, the aeration equipment 101 is started by the first controller of the PLC controller, the air enters into the aeration stone 103 through the air inlet pipe 104, and the clear liquid is subjected to aeration treatment; at this time, the clear liquid is degraded in COD, BOD and ammonia nitrogen under the action of the facultative bacteria and the aerobic bacteria in the suspended filler 102, the microorganism converts the ammonia nitrogen in the clear liquid into nitrate nitrogen, and the pollutants in the first treatment shell 10 sink to form the sediment B;

[0060] The clear liquid treated by the contact oxidation unit enters into the second treatment shell 20 through the filter communication hole, the electric flocculation assembly 201 is electrified by the second controller of the PLC controller, the electric flocculation assembly 201 after electrification can perform electric flocculation on the clear liquid, removes the suspended matter and phosphorus in the clear liquid, and the pollutants and phosphorus in the clear liquid sink to form the sediment C;

[0061] After the clear liquid is subjected to electric flocculation, the clear liquid enters into the third treatment shell 40 through the filter water cap 402, the filter water cap 402 performs preliminary filtration on the treated clear liquid, the quartz stone in the third treatment shell 40 further filters the clear liquid to form purified water, and the purified water enters into the water outlet unit and the display landscape cabinet 60; the purified water can be used for the cultivation of aquatic plants or plankton, the overflow of the purified water in the display landscape cabinet 60 can also be used for the irrigation of a small amount of crops; under the action of the aeration equipment 101, the purified water contains a large amount of oxygen, and the oxygen content of the purified water in the display landscape cabinet 60 can be supplemented, which is convenient for the cultivation of plankton, and a landscape fish tank can be formed;

[0062] When the dissolved oxygen concentration measured by the dissolved oxygen sensor is lower than 2.0 mg / L, the PLC controller receives the data of the dissolved oxygen sensor and judges, and then the PLC controller controls the aeration equipment 101 to be continuously opened through the first controller, and the aeration equipment 101 is in a continuous running state; when the dissolved oxygen concentration measured by the dissolved oxygen sensor is higher than 4.0 mg / L, the PLC controller receives the data of the dissolved oxygen sensor and judges, and then the PLC controller controls the aeration equipment 101 to be closed through the first controller, and the aeration equipment 101 stops running;

[0063] When the sludge concentration measured by the sludge concentration sensor is higher than 8000 mg / L, the PLC controller receives the data of the sludge concentration sensor and judges, and then controls the sludge discharge prompter to respond to the prompt of needing to discharge sludge. The sludge concentration sensor and the sludge discharge prompter can timely remind the management personnel, and the management personnel only need to timely open the isolation valves on the sewage pipe 202 and the vent pipe 105 to clean the sludge in the first shell and the second shell. When cleaning, the first treatment shell 10, the second treatment shell 20, the third treatment shell 40 and the fourth treatment shell can be disassembled, the handle 403 on the third treatment shell 40 is held, and the filter unit is taken out. Then, the buckle between the first treatment shell 10 and the second treatment shell 20 is disassembled, and the first treatment shell 10 and the second treatment shell 20 can be separated. The contact oxidation unit, the electric flocculation unit and the filter unit can be disassembled and independently cleaned. The first treatment shell 10, the second treatment shell 20 and the third treatment shell 40 can also be replaced individually, which is convenient to use.

[0064] When the sludge concentration measured by the sludge concentration sensor is 3000-5000 mg / L, and the dissolved oxygen concentration measured by the dissolved oxygen sensor is 0.2-0.4 mg / L, the PLC controller controls the lifting pump 50 to be in a closed state through the second controller, and the clarified liquid in the first treatment shell 10 and the second treatment shell 20 is backflowed internally, thereby improving the contact oxidation treatment and electric flocculation treatment capacity of the corresponding batch of clarified liquid. Otherwise, the PLC controller controls the lifting pump 50 to be in an open state through the second controller, and the first treatment shell 10 continuously feeds water to continuously purify the clarified liquid.

[0065] The sediments A, B and C are collected and used as biological fertilizer for large plants.

[0066] The whole household micro sewage treatment system is an integrated sewage treatment system with high efficiency and energy saving function, which has small size structure, low use cost, is very convenient for the use of rural individual house, can quickly and efficiently treat rural sewage, and the sewage treatment process also requires less operation of the treatment personnel, is convenient and fast to use, and effectively utilizes the rural sewage for secondary use, reduces the rural sewage discharge; In the whole sewage process, no chemical agent is used, which can avoid secondary chemical pollution to the rural environment; The intelligent control unit can automatically control the water inlet and outlet of the household micro sewage treatment system and the treatment state of the clarified liquid, realize the automatic monitoring, early warning and diagnosis of the sewage treatment process, make the purification treatment of the clarified liquid automatic, thereby improve the efficiency and safety of the sewage treatment; In the use process of the household micro sewage treatment system, only need to clean the sludge in the household micro sewage treatment device in time under the prompt of the sludge prompter, so in the sewage treatment process, the manual participation steps are very few, and the use mode is very convenient.

[0067] Finally, it is pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and are not limited, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the purpose and scope of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A method of sewage treatment, characterised in that, The method comprises the following steps: building a septic tank; preparing a household micro sewage treatment system, an aeration system and suspended filler for microorganism adhesion, the household micro sewage treatment system comprises a lifting pump, a contact oxidation zone, an electric flocculation zone, a filtering zone and a water outlet zone in sequence; the contact oxidation zone, the electric flocculation zone, the filtering zone and the water outlet zone are sequentially and communicatively arranged from bottom to top, and the lifting pump is in communication with the contact oxidation zone; the household micro sewage treatment system further comprises a first treatment shell forming the contact oxidation zone, a second treatment shell forming the electric flocculation zone, a third treatment shell forming the filtering zone and a fourth treatment shell forming the water outlet zone; a landscape zone for breeding aquatic plants or plankton is arranged at the water outlet zone, and the water outlet zone and the landscape zone are integrally arranged as a display landscape cabinet which is fixedly and sealingly sleeved on the second treatment shell or the third treatment shell; The household sewage is discharged into the septic tank, and the septic tank hydrolyzes the sewage; the sediment and sundries in the sewage sink to the bottom of the septic tank to form sediment A, and the sewage in the septic tank forms supernatant which is clear liquid; The lifting pump is put into the septic tank, the suspended filler is put into the contact oxidation zone, and the aeration system is in communication with the contact oxidation zone; the lifting pump is started to draw the clear liquid, the clear liquid enters the contact oxidation zone, microorganisms degrade COD and BOD in the clear liquid, and the microorganisms convert ammonia nitrogen in the clear liquid into nitrate nitrogen, and the pollutants in the contact oxidation zone sink to form sediment B; The clear liquid at the contact oxidation zone flows into the electric flocculation zone to perform electric flocculation, and the pollutants and phosphorus in the clear liquid sink to form sediment C; The clear liquid at the electric flocculation zone flows into the filtering zone, the pollutants and phosphorus in the clear liquid are filtered by the filtering zone, and the clear liquid forms purified water; The overflowed purified water at the landscape zone is used for crop irrigation.

2. A method of sewage treatment according to claim 1, characterised in that, The microorganisms in the suspended filler are facultative bacteria and aerobic bacteria, and the mass ratio of the facultative bacteria to the aerobic bacteria is 0.25-0.

4.

3. A method of sewage treatment as claimed in claim 2, characterised in that, The sediment A, the sediment B and the sediment C are all collected for use as biofertilizer.

4. A method of sewage treatment as claimed in claim 3 wherein, The filtering zone is a sand filtering zone, and the sand filtering zone contains quartz stone.

5. A method of sewage treatment as claimed in claim 4 wherein, When the accumulation thickness of the sediment A in the septic tank reaches 0.2-0.5 times of the depth of the septic tank, the sediment A in the septic tank is dredged.

6. A domestic mini sewage treatment system, said system implementing the sewage treatment method as claimed in claim 1, characterized in that, The first treatment shell is in communication with a water inlet pipe and a switchable vent pipe, and the first treatment shell is in communication with the aeration system; the lifting pump is in communication with the water inlet pipe; An electric flocculation assembly and a switchable blowdown pipe are installed in the second treatment shell; A filtering material is arranged in the third treatment shell; The first treatment shell, the second treatment shell, the third treatment shell and the fourth treatment shell are sequentially and detachably and sealingly connected from bottom to top.

7. The domestic mini sewage treatment system as claimed in claim 6, wherein, The aeration system comprises: an aeration device; an air inlet pipe in communication with the aeration device; aeration stones in the first treatment shell, and the air inlet pipe is in communication with the aeration stones through the first treatment shell away from the aeration device.

8. The domestic mini sewage treatment system as claimed in claim 7, wherein, An interface box for supplying power to the electric flocculation assembly is connected to the second treatment shell, and the blowdown pipe is in communication with the lower side of the second treatment shell.

9. The domestic mini sewage treatment system as claimed in claim 8, wherein, A plurality of filtering water caps in communication with the third treatment shell are arranged at the side of the third treatment shell close to the second treatment shell; and a vertically upwardly pulling handle is arranged on the third treatment shell.

10. The domestic mini sewage treatment system as claimed in claim 9, wherein, The intelligent control unit comprises a sludge concentration sensor, a dissolved oxygen sensor, a first controller for controlling the opening or closing of the aeration equipment, a sludge discharge prompter and a PLC controller, and the sludge concentration sensor, the dissolved oxygen sensor, the first controller and the sludge discharge prompter are electrically connected with the PLC controller; the dissolved oxygen sensor is installed in the first treatment shell, and the sludge concentration sensor is installed in the second treatment shell; when the dissolved oxygen concentration measured by the dissolved oxygen sensor is lower than 2.0 mg / L, the aeration equipment is in a continuous running state; when the dissolved oxygen concentration measured by the dissolved oxygen sensor is higher than 4.0 mg / L, the aeration equipment stops running; when the sludge concentration measured by the sludge concentration sensor is higher than 8000 mg / L, the sludge discharge prompter responds to prompt that sludge needs to be discharged.

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