A method for treating rural domestic sewage in cold and arid regions

Abstract

This invention relates to the field of wastewater treatment technology, specifically a household-based rural domestic wastewater treatment method for cold and arid regions. Each household is treated as an independent unit, operating entirely by gravity flow. The method includes, in sequence, household collection, anaerobic pretreatment, solar-coupled biochemical treatment, sedimentation and clarification, chlorine disinfection, and effluent resource reuse. This method is adapted to the low-temperature climate and dispersed rural layout characteristics of cold and arid regions. By adopting an overall scheme of "sedimentation and clarification for resource recovery, chlorine disinfection, and differentiated effluent reuse," a closed-loop treatment and resource recycling of wastewater is achieved, thereby solving the problems of secondary pollution and water waste in rural wastewater treatment in cold and arid regions. The coordination of sedimentation and clarification with disinfection ensures that the effluent meets safety standards, while resource reuse transforms wastewater into usable water resources, meeting the ecological and production needs of cold and arid regions. Furthermore, the entire scheme operates entirely by gravity flow, requiring no additional power transmission.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically a method for treating rural domestic wastewater in cold and arid regions on a household-by-household basis. Background Technology

[0002] Rural domestic sewage is characterized by large fluctuations in water quality, pollutants mainly consisting of organic matter and nitrogen and phosphorus, dispersed discharge, and small-scale treatment. Its disorderly discharge easily causes pollution of surrounding soil and water bodies, threatening the rural ecological environment and residents' health. In cold and arid regions, rural domestic sewage treatment also faces dual constraints from geography and climate: on the one hand, the long winters and extremely low temperatures in cold and arid regions significantly reduce the activity of microorganisms in conventional sewage treatment processes, resulting in a significant decrease in pollutant degradation efficiency and making it difficult to consistently meet discharge standards; on the other hand, rural areas in cold and arid regions are mostly characterized by scattered residences, with each household generating a small amount of sewage, and lacking municipal pipe networks, making centralized treatment processes impossible. If centralized treatment facilities are forcibly constructed, not only will the construction costs be high and the operation and maintenance difficulties great, but it will also be difficult to adapt to the actual situation of the dispersed rural layout.

[0003] Currently, most existing rural domestic sewage treatment technologies are developed for humid plains and are difficult to apply directly to cold and arid regions. While some decentralized treatment processes can be adapted to single-household or small-scale treatment, they have several drawbacks: First, the anaerobic pretreatment stage often uses conventional single-cell septic tanks, resulting in incomplete solid-liquid separation, poor degradation of primary organic matter, and an overload on subsequent treatment units, affecting overall treatment efficiency. Second, the biological treatment stage generally uses ordinary packing materials, which lack sufficient pro-microbial properties at low temperatures, making it difficult for microorganisms to attach and survive stably. Furthermore, the lack of efficient aeration control methods prevents the creation of an aerobic / anoxic alternating environment suitable for pollutant degradation, leading to weak simultaneous degradation of pollutants such as COD, ammonia nitrogen, total nitrogen, and total phosphorus. Third, some processes fail to incorporate effluent reuse schemes tailored to the water scarcity characteristics of cold and arid regions, resulting in water waste. Additionally, if a household collection method with full-volume collection is adopted, it can easily mix with low-pollution water bodies such as irrigation water from courtyards, increasing ineffective treatment loads.

[0004] Therefore, developing a household-based domestic sewage treatment method that is suitable for the low-temperature climate and dispersed rural layout characteristics of cold and arid regions, while taking into account treatment efficiency, ease of operation and maintenance, and the resource utilization of effluent, has become an urgent technical challenge to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a method for treating rural domestic sewage in cold and arid regions by individual households.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for treating rural domestic sewage in cold and arid regions, with each household as an independent treatment unit, operates entirely by gravity flow. The method sequentially includes household collection, anaerobic pretreatment, solar-coupled biochemical treatment, sedimentation and clarification, chlorine disinfection, and effluent resource reuse. This method is suitable for the low-temperature climate and dispersed rural layout characteristics of cold and arid regions, with a single-household treatment capacity of 0.5 m³. 3 / d.

[0008] As a further technical solution, the household collection adopts a non-household collection method using PVC / PE pipes, which only collects domestic sewage from farmers' kitchens and bathrooms, and does not collect irrigation water from courtyards, thus reducing the treatment load.

[0009] As a further technical solution, the anaerobic pretreatment uses a three-compartment fiberglass septic tank with an effective volume of 2.0 m³. 3 The three tanks have a volume ratio of 2:1:3. They achieve solid-liquid separation and primary organic matter degradation through anaerobic fermentation. The septic tank walls are ≥8mm thick and have acid and alkali resistance and leak-proof properties.

[0010] As a further technical solution, the solar-coupled biochemical treatment adopts a buried carbon steel corrosion-resistant biological purification facility, which is internally divided into a biochemical zone, a sedimentation and clarification zone, and a clear water zone; the biochemical zone is filled with high-efficiency suspended biological packing material.

[0011] The aeration system, powered by solar energy, creates an alternating aerobic / anoxic environment to simultaneously degrade COD, ammonia nitrogen, total nitrogen, and total phosphorus. The filler is composed of the following components by weight percentage: 10-15% chopped basalt fiber, 8-12% multi-stage pore-expanding modified diatomaceous earth porous carrier, 3-5% silane coupling agent, 2-4% sodium bicarbonate pore-forming agent, and the remainder being polypropylene substrate. The filler surface is coated with a chitosan quaternary ammonium salt-nano titanium dioxide-polyglutamic acid low-temperature affinity composite modified layer.

[0012] As a further technical solution, the preparation method of the high-efficiency suspended biological packing includes the following steps:

[0013] S1 substrate blending and melting: Polypropylene, chopped basalt fiber, multi-stage pore-expanding modified diatomaceous earth, silane coupling agent, and sodium bicarbonate pore-forming agent are added to a high-speed mixer in proportion and mixed at 80-100℃ for 20-30 minutes. Then, the mixture is fed into a twin-screw extruder and melt-blended and extruded at 180-200℃ to obtain modified substrate particles.

[0014] S2 feeds the modified substrate particles into a spherical granulator, heats them to 190-200℃ to melt and bind the substrate particles together, and then centrifuges them by high-speed rotation of the granulator. The mixture is then cooled and shaped by 8-12℃ cold air swirl to obtain a porous spherical suspension filler preform.

[0015] Preparation of S3 composite modified solution: Chitosan quaternary ammonium salt, nano titanium dioxide, and polyglutamic acid were dissolved in 2% acetic acid aqueous solution at a mass ratio of 1:0.2:0.1:100 and ultrasonically dispersed for 30 min to obtain a uniform composite modified solution;

[0016] S4 Dip Coating Gradient Curing: The porous suspended filler blank is completely immersed in the composite modification liquid for 15-20 minutes. After removal, it is first pre-dried at 40-50℃ for 10 minutes, and then cured and dried at 60-70℃ for 20 minutes. The dip coating-curing process is repeated twice.

[0017] S5 UV irradiation activation: Place the cured filler in a UV irradiation chamber and irradiate with UV light for 10-15 minutes to activate the functional groups on the surface of the filler and enhance the adhesion of microbial biofilm and low-temperature biological activity.

[0018] As a further technical solution, the ultraviolet irradiation is: 365nm ultraviolet irradiation.

[0019] As a further technical solution, the method for preparing the multi-stage pore-expanding modified diatomite is as follows:

[0020] ① Acid washing to remove impurities: Soak diatomaceous earth in 5wt%-8wt% hydrochloric acid solution at 80-90℃ for 40-60 minutes, filter, and wash with deionized water until neutral;

[0021] ② Alkaline solution pore enlargement: 3wt%-5wt% sodium hydroxide solution, water bath treatment at 60-70℃ for 20-30 minutes, filtration, etching to open and seal the pores;

[0022] ③ High-temperature calcination and shaping: calcination in a muffle furnace at 450-500℃ for 90-120 minutes to remove organic impurities and stabilize the pore structure;

[0023] ④ Surface hydroxylation activation: Soak in 3wt%-5wt% hydrogen peroxide solution at room temperature for 15-20 min, filter, and dry at 60℃ for 4 hours to obtain the product.

[0024] As a further technical solution, the sludge separated in the sedimentation and clarification zone is periodically removed and utilized as a resource, and the supernatant is temporarily stored in the clear water zone. The clear water zone is disinfected by manually adding chlorine tablets, which does not require electric drive or professional operation and maintenance.

[0025] As a further technical solution, the wastewater in the clear water area is extracted by hand pumps and used for irrigation of dryland crops during the irrigation season, and for dust suppression in courtyards and irrigation of vegetable gardens during the non-irrigation season, so as to realize the full resource utilization of wastewater.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] 1. The household-based rural domestic sewage treatment method of this invention for cold and arid regions adopts a non-household collection method using PVC / PE pipes in the household collection stage: it only collects domestic sewage from farmers' kitchens and bathrooms, excluding irrigation water from courtyards. This controls the concentration and total amount of pollutants in the treated sewage from the source, avoiding redundant treatment load caused by the mixing of low-pollution water bodies. It is also suitable for the scattered residential layout in cold and arid rural areas, reducing the difficulty and cost of constructing the collection network and achieving precise and lightweight sewage collection. The anaerobic pretreatment uses a three-compartment fiberglass septic tank: through staged anaerobic fermentation, it achieves efficient solid-liquid separation and primary organic matter degradation. Compared with conventional single-compartment septic tanks, this improves the pretreatment effect, reduces the organic load on subsequent biochemical treatment units, and lays the foundation for deep degradation of pollutants. Furthermore, the fiberglass material is resistant to low temperatures and corrosion, making it suitable for the low-temperature environment of cold and arid regions and extending the service life of the pretreatment facilities.

[0028] 2. Solar-coupled biochemical treatment utilizes highly efficient suspended biological packing material: The packing material uses polypropylene as the base material, combined with short-cut basalt fibers to enhance structural strength. Multi-level pore-expanding modified diatomaceous earth porous carriers increase specific surface area, silane coupling agents enhance the compatibility of each component, and sodium bicarbonate pore-forming agents construct a porous structure, ensuring the physical properties and adsorption capacity of the packing material itself. The chitosan quaternary ammonium salt-nano titanium dioxide-polyglutamic acid low-temperature affinity composite modified layer coated on the surface of the packing material can enhance the adhesion and metabolic activity of microorganisms in low-temperature environments in cold and arid regions, solving the core problem of microbial activity attenuation at low temperatures. The aerobic / anoxic alternating environment formed by solar-powered aeration provides suitable reaction conditions for microbial degradation of pollutants, simultaneously achieving efficient degradation of COD, ammonia nitrogen, total nitrogen, and total phosphorus.

[0029] 3. Special preparation process of multi-stage pore-expanding modified diatomaceous earth: Through step-by-step treatment of acid washing for impurity removal, alkaline pore expansion, high-temperature calcination for shaping, and surface hydroxylation activation, the closed pores of diatomaceous earth are opened, the pore structure is stabilized, and active hydroxyl sites are introduced, significantly improving the adsorption performance and surface activity of diatomaceous earth. This allows it to effectively adsorb pollutants in wastewater in the packing material, while enhancing the interaction with the composite modified layer and microorganisms, further improving the pollutant degradation efficiency. Synergistic design of sedimentation clarification and chlorine disinfection: The sedimentation clarification zone achieves solid-liquid separation, and the sludge is regularly removed for resource utilization, avoiding secondary pollution caused by sludge accumulation and realizing resource recycling. The clear water zone uses manual addition of chlorine tablets for disinfection, which is simple to operate, low in cost, and suitable for rural operation and maintenance levels. It can effectively kill E. coli in the effluent, ensuring the sanitary safety of effluent discharge and reuse. The differentiated design for wastewater resource reuse: A hand pump is used to extract wastewater, which is used for irrigation of dryland crops during the irrigation season and for dust suppression in courtyards and irrigation of vegetable gardens during the non-irrigation season. Combined with the characteristics of water scarcity in cold and arid areas, the wastewater is utilized for resource recovery, alleviating the regional water shortage problem and reducing the environmental risks caused by wastewater discharge.

[0030] 4. By adopting a combination of "non-household individual collection and three-compartment fiberglass septic tank pretreatment," precise collection and efficient pretreatment of sewage at the source are achieved, thus solving the problems of difficult sewage collection and poor pretreatment effects in rural areas of cold and arid regions. This combination reduces the load on subsequent treatment and is suitable for the decentralized layout of rural areas, avoiding the high costs and maintenance difficulties of centralized treatment, and achieving synergistic adaptation between collection and pretreatment stages. The use of a combination of "solar-coupled aeration and high-efficiency suspended biological packing" constructs a highly efficient treatment system of "adsorption-biodegradation-synergistic activation" in the low-temperature environment of cold and arid regions, thus solving the problems of low sewage treatment efficiency and unstable operation at low temperatures. Solar power ensures a clean energy supply for the process, adapting to the unstable power supply in cold and arid regions and reducing operating energy consumption. The synergy between the high-efficiency suspended biological packing and the alternating aerobic / anoxic environment significantly improves the removal rates of COD, ammonia nitrogen, total nitrogen, and total phosphorus, ensuring the stability of treatment effects. At the same time, the porous structure and low-temperature resistance of the packing extend the service life of the biochemical treatment facility and reduce operation and maintenance costs.

[0031] 5. By adopting an overall solution of "sedimentation clarification and resource recovery, chlorine tablet disinfection, and differentiated effluent reuse," the entire process of wastewater treatment and resource recycling is completed, thereby solving the problems of secondary pollution and water waste in rural wastewater treatment in arid and cold regions. The combination of sedimentation clarification and disinfection ensures that the effluent meets safety standards, while resource reuse transforms wastewater into usable water resources, meeting the ecological and production needs of arid and cold regions. At the same time, the entire solution operates under gravity gravity without the need for additional power transmission, making it simple to operate and convenient to maintain, and suitable for the maintenance capabilities of rural residents. It achieves a macro-level virtuous cycle of "treatment-compliance-reuse," combining environmental, social, and economic benefits. Attached Figure Description

[0032] Figure 1 This is a distribution map of equipment for a household-based rural domestic sewage treatment method in cold and arid regions. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] This invention provides a household-based rural domestic sewage treatment method for cold and arid regions. Each household is treated as an independent unit, operating entirely by gravity flow. The method sequentially includes household collection, anaerobic pretreatment, solar-coupled biochemical treatment, sedimentation and clarification, chlorine disinfection, and effluent resource reuse. This method is suitable for the low-temperature climate and dispersed rural layout characteristics of cold and arid regions, with a single-household treatment capacity of 0.5 m³. 3 / d.

[0035] In this invention, the household collection adopts a non-household collection method using PVC / PE pipes. The collection scope is limited to domestic sewage generated by the farmer's kitchen 2 and toilet 1, and does not collect irrigation water in the yard. This collection method is suitable for the layout characteristics of scattered rural residences, while reducing the amount of ineffective sewage collection and lowering the subsequent treatment load.

[0036] Wastewater flowing out of kitchen 2 can be pre-treated by a grease trap 3 before being discharged;

[0037] Domestic sewage from kitchen 2 and bathroom 1 is discharged through sewage pipes, passes through inspection well 4, and then connects to septic tank 5;

[0038] After the collection of wastewater from individual households is completed, the collected domestic sewage undergoes anaerobic pretreatment. This anaerobic pretreatment utilizes a three-compartment fiberglass septic tank 5, with an effective volume of 2.0 m³. 3 The volume ratio of the three tanks is 2:1:3. In septic tank 5, the sewage achieves solid-liquid separation through anaerobic fermentation, and at the same time completes the degradation of primary organic matter in the sewage, reducing the difficulty of subsequent biochemical treatment.

[0039] After anaerobic pretreatment, the wastewater enters the solar-coupled biochemical treatment stage. The solar-coupled biochemical treatment adopts a buried carbon steel anti-corrosion biological purification facility 6. The facility is divided into three functional areas: a biochemical zone 61, a sedimentation and clarification zone 62, and a clear water zone 63. The biochemical zone is filled with high-efficiency suspended biological packing material 7. The facility is aerated by solar power 10 to form an alternating aerobic / anoxic reaction environment in the biochemical zone. The metabolic action of microorganisms is used to simultaneously degrade COD, ammonia nitrogen, total nitrogen, and total phosphorus pollutants in the wastewater.

[0040] An aeration pipe 8 is installed in the biochemical zone 61. The aeration pipe 8 is aerated by an aeration pump 11, which is powered by a solar power supply 10.

[0041] In this invention, the high-efficiency suspended biological filler 7 is composed of multiple components by weight percentage. The weight percentage of chopped basalt fiber is preferably 10%-15%, the weight percentage of multi-stage pore-expanding modified diatomaceous earth porous carrier is preferably 8%-12%, the weight percentage of silane coupling agent is preferably 3%-5%, the weight percentage of sodium bicarbonate pore-forming agent is preferably 2%-4%, and the balance is polypropylene substrate. The surface of the filler is coated with a chitosan quaternary ammonium salt-nano titanium dioxide-polyglutamic acid low-temperature affinity composite modified layer. This composite modified layer can improve the biocompatibility of the filler in low-temperature environments in cold and arid regions, ensuring the attachment and metabolic activity of microorganisms.

[0042] This invention specifies the preparation method of the high-efficiency suspended biological packing material, which specifically includes the following steps:

[0043] S1 Substrate Blending and Melting: Polypropylene, chopped basalt fiber, multi-stage pore-expanding modified diatomaceous earth, silane coupling agent, and sodium bicarbonate pore-forming agent are added to a high-speed mixer in a set ratio. The preferred mixing temperature is 80℃-100℃, and the preferred mixing time is 20min-30min. After mixing, the material is fed into a twin-screw extruder and melt-blended and extruded at a temperature of 180℃-200℃ to obtain modified substrate particles.

[0044] S2 Spherical preform preparation: Modified substrate particles are fed into a spherical granulator, and the temperature inside the granulator is heated to 190℃-200℃ to melt and adhere the modified substrate particles. The granulator is formed by high-speed rotation and centrifugal action. At the same time, a cold air vortex of 8℃-12℃ is used to cool and solidify the formed material to obtain a porous spherical suspension filler preform.

[0045] S3 composite modified solution preparation: Chitosan quaternary ammonium salt, nano titanium dioxide, and polyglutamic acid were dissolved in 2% acetic acid aqueous solution at a mass ratio of 1:0.2:0.1:100. The mixed solution was ultrasonically dispersed for 30 minutes to obtain a uniform composite modified solution.

[0046] S4 Dip Coating Gradient Curing: The porous spherical suspension filler blank is completely immersed in the composite modification liquid. The dipping time is preferably 15 min-20 min. After dipping, the filler blank is taken out and pre-dried at 40℃-50℃ for 10 min, and then cured and dried at 60℃-70℃ for 20 min. The above dipping-curing operation is repeated twice.

[0047] S5 Ultraviolet Irradiation Activation: The cured filler is placed in an ultraviolet irradiation chamber for ultraviolet irradiation treatment. The irradiation time is preferably 10 min-15 min. In this invention, 365 nm ultraviolet light is preferably used for ultraviolet irradiation to ensure the effect of irradiation activation.

[0048] In this invention, the multi-stage pore-expanding modified diatomaceous earth is a self-made modified material, and its preparation method specifically includes the following steps:

[0049] ① Acid washing to remove impurities: Mix diatomaceous earth with 5wt%-8wt% hydrochloric acid solution and soak at 80℃-90℃ for 40min-60min. After soaking, filter the diatomaceous earth and wash it with deionized water until the solution is neutral.

[0050] ② Alkaline solution pore enlargement: Mix the acid-washed and impurity-removed diatomaceous earth with a 3wt%-5wt% sodium hydroxide solution and treat it in a water bath at 60℃-70℃ for 20min-30min. After treatment, filter it and open up the closed pores inside the diatomaceous earth through the alkaline etching action.

[0051] ③ High-temperature calcination and shaping: The diatomaceous earth after pore expansion with alkaline solution is placed in a muffle furnace for high-temperature calcination at a temperature of 450℃-500℃ and a calcination time of 90min-120min. The calcination removes organic impurities from the diatomaceous earth and stabilizes its pore structure.

[0052] ④ Surface hydroxylation activation: The calcined diatomaceous earth is mixed with 3wt%-5wt% hydrogen peroxide solution and soaked at room temperature for 15min-20min. After soaking, it is filtered and dried at 60℃ for 4 hours to obtain multi-stage pore-expanding modified diatomaceous earth.

[0053] Wastewater treated by solar-coupled biochemical processes enters the sedimentation and clarification stage. The sedimentation and clarification are completed in the sedimentation and clarification zone 62 of the biological purification facility. The sludge separated in the sedimentation and clarification zone 62 is regularly removed and treated for resource utilization. The supernatant after sedimentation and clarification is temporarily stored in the clear water zone of the facility. In the clear water zone, the supernatant is disinfected by manually adding chlorine tablets. The effluent after chlorine tablet disinfection enters the resource reuse stage.

[0054] In this invention, the wastewater in the clear water area is recycled by a hand pump 9. Based on the production and living characteristics of cold and arid regions, the disinfected wastewater is used for irrigation of dryland crops during the irrigation season, and for dust suppression in courtyards and irrigation of vegetable gardens during the non-irrigation season, so as to realize the resource utilization of rural domestic sewage and adapt to the water shortage characteristics of cold and arid regions.

[0055] The present invention provides a household-based rural domestic sewage treatment method for cold and arid regions. Each household is an independent treatment unit and operates entirely by gravity flow without the need for additional power transmission, which is suitable for the decentralized layout of rural areas. At the same time, through the design of solar energy coupled with biochemical treatment and low-temperature affinity high-efficiency suspended biological packing, the problem of low sewage treatment efficiency in cold and arid regions under low-temperature conditions is solved, and the effluent is reused as a resource. This is in line with the current situation of water scarcity in cold and arid regions. The overall treatment process is simple to operate and has low operation and maintenance costs, making it suitable for promotion and application in rural areas of cold and arid regions.

[0056] Introduction to main equipment and systems:

[0057] 1. Septic tank:

[0058] A septic tank consists of three interconnected chambers, with a volume ratio of 2:1:3. The two middle chambers are connected by two overflow holes. Fresh feces enter the first chamber through the inlet, where fermentation and decomposition begin. Due to this, the fecal liquid naturally separates into three layers: an upper layer of pasty fecal scum, a lower layer of lumpy or granular fecal sludge, and a middle layer of relatively clear fecal liquid. The upper scum and lower sludge contain the most bacteria and parasite eggs, while the middle layer contains the fewest. The partially fermented middle layer overflows through the drain pipe into the second chamber, while most of the insufficiently fermented scum and sludge remain in the first chamber for further fermentation. The fecal liquid flowing into the second chamber undergoes further fermentation and decomposition. Parasite eggs continue to sink, pathogens gradually die, and the fecal liquid is further rendered harmless, resulting in a significantly reduced scum and sludge thickness compared to the first chamber. The fecal liquid flowing into the third chamber is generally fully decomposed, with most bacteria and parasite eggs killed. The main function of the third chamber is to store the largely harmless fecal liquid.

[0059] Fiberglass septic tanks are formed using specialized fiberglass molds by manually applying reinforcing unsaturated polyester resin and high-strength alkali-free fiber cloth. They feature acid and alkali resistance, leak-proof construction, high strength, and long service life. They are a convenient and economical alternative to cast-in-place reinforced concrete or steel-concrete septic tanks.

[0060] 2. ZKHR Individual Household Biological Purification Treatment Facilities:

[0061] ZKHR household-type biological purification treatment facility (referred to as integrated tank) is a new generation of deep toilet renovation and sewage treatment equipment developed by reflecting on the problems and shortcomings that have emerged in the national toilet renovation and decentralized sewage treatment in the past few years, drawing on the successful experience of decentralized sewage treatment, optimizing the treatment process, and especially targeting the difficulties and pain points of rural toilet renovation in cold regions.

[0062] The integrated tank uses a septic tank for anaerobic fermentation and solid-liquid separation of feces at the front end. The integrated tank is equipped with a biochemical zone, sedimentation and clarification zone, and clear water zone (hand-operated pumping well) and other treatment processes. The effluent stably meets the irrigation standards for dryland crops. The equipment is characterized by simple structure, stable operation, long-term compliance, low energy consumption, small footprint, and easy inspection and maintenance.

[0063] The integrated tank is made of corrosion-resistant carbon steel. The product has a beautiful appearance, is pressure-resistant, corrosion-resistant, and has a service life of up to 20 years.

[0064] Application scope: Suitable for the treatment of domestic sewage from villas, small homestays, and rural villages, whether it is a separate household or multiple households.

[0065] Process parameter design:

[0066] One integrated tank, with a processing capacity of 0.5m³. 3 / d. Function: Removes COD, ammonia nitrogen, TN, TP, and SS from suspended solids and colloids.

[0067] Main technical parameters:

[0068] Processing capacity: 0.5m 3 / d

[0069] Equipment dimensions: Φ1.0 1.55m;

[0070] Operation mode: Domestic sewage from farmers flows by gravity into the septic tank through a DN100 PVC-U pipe for anaerobic fermentation, and then flows by gravity into the biochemical zone of the integrated tank (the height difference between the inlet of the septic tank and the integrated tank is greater than 10cm) through a DN65 PE pipe. After biochemical reaction and sedimentation, it enters the clear water zone for temporary storage and is periodically discharged for reuse by a hand pump.

[0071] Structural form: underground carbon steel corrosion resistant;

[0072] Supporting equipment:

[0073] Silent air pump: 12V voltage, 8W power, 20L / min air volume, 27kPa pressure, 1 unit;

[0074] Hand pumps, stainless steel well pumps, brackets, piston cups and other accessories, and pipelines;

[0075] Perforated aeration pipe, high-efficiency suspended packing material;

[0076] Chlorine tablets are used for disinfection in the clean water area;

[0077] Table 1 Oil separator configuration list

[0078]

[0079] Table 2 Septic Tank Configuration List

[0080]

[0081] Table 3. Equipment Configuration List for the Integrated Tank

[0082]

[0083] Table 4 Solar System Configuration List

[0084]

[0085] To further illustrate the present invention, the following detailed description is provided through the embodiments. In the embodiments of the present invention, the PVC / PE pipes and the three-compartment fiberglass septic tanks used are commercially available conventional products, the buried carbon steel anti-corrosion biological purification facilities are customized processed products, the polypropylene substrate, chopped basalt fiber, silane coupling agent, sodium bicarbonate pore-forming agent and other raw materials are all commercially available industrial-grade products, the diatomaceous earth is commercially available calcined diatomaceous earth, and the chitosan quaternary ammonium salt, nano titanium dioxide, polyglutamic acid and other materials are commercially available reagent-grade products.

[0086] Example 1

[0087] This embodiment is based on the left endpoint of the parameter range. The specific method for treating household-based rural domestic sewage in arid and cold regions includes the following steps:

[0088] 1. Household-specific collection: Each household is treated as an independent unit. PVC / PE pipes are used for non-household collection of domestic wastewater from kitchens and bathrooms, excluding irrigation water from yards. The wastewater collection and treatment capacity per household is 0.5m³. 3 / d, the entire process is carried out by gravity flow;

[0089] 2. Anaerobic pretreatment: The collected domestic sewage is introduced into a three-compartment fiberglass septic tank with an effective volume of 2.0 m³. 3 The three tanks have a volume ratio of 2:1:3. The wastewater undergoes solid-liquid separation and primary organic matter degradation through anaerobic fermentation within the tanks.

[0090] 3. Solar-coupled biochemical treatment: The anaerobic pretreated wastewater is introduced into an underground carbon steel corrosion-resistant biological purification facility. The facility is divided into a biochemical zone, a sedimentation and clarification zone, and a clear water zone. The biochemical zone is filled with high-efficiency suspended biological packing material.

[0091] 3.1 Preparation of high-efficiency suspended biological packing material:

[0092] 3.1.1 Substrate blending and melting: Take 10% chopped basalt fiber, 8% multi-stage pore-expanding modified diatomaceous earth porous carrier, 3% silane coupling agent, 2% sodium bicarbonate pore-forming agent, and the remainder polypropylene substrate by weight percentage, put them into a high-speed mixer, mix at 80℃ for 20 min, and then put them into a twin-screw extruder for melt blending, extrusion and granulation at 180℃ to obtain modified substrate particles;

[0093] 3.1.2 Preparation of spherical preforms: Modified substrate particles are fed into a spherical granulator and heated to 190°C to melt and bind the substrate particles together. The granulator is then centrifugally shaped by high-speed rotation and cooled and shaped by 8°C cold air cyclone cooling to obtain porous spherical suspended filler preforms.

[0094] 3.1.3 Preparation of composite modified solution: Chitosan quaternary ammonium salt, nano titanium dioxide and polyglutamic acid were dissolved in 2% acetic acid aqueous solution at a mass ratio of 1:0.2:0.1:100 and ultrasonically dispersed for 30 min to obtain a uniform composite modified solution;

[0095] 3.1.4 Dip-coating gradient curing: The porous suspended filler preform is completely immersed in the composite modified liquid for 15 min. After removal, it is pre-dried at 40℃ for 10 min and then cured and dried at 60℃ for 20 min. The dip-coating-curing process is repeated twice.

[0096] 3.1.5 UV irradiation activation: The cured filler was placed in a UV irradiation chamber and irradiated with 365nm UV light for 10 min;

[0097] 3.2 Preparation of multi-stage pore-expanding modified diatomaceous earth:

[0098] 3.2.1 Acid washing to remove impurities: Immerse diatomaceous earth in 5wt% hydrochloric acid solution at 80℃ for 40 min, filter, and wash with deionized water until neutral;

[0099] 3.2.2 Alkaline solution pore enlargement: 3wt% sodium hydroxide solution was used for water bath treatment at 60℃ for 20 min, followed by filtration and etching to open up and seal the pores;

[0100] 3.2.3 High-temperature calcination and shaping: calcination in a muffle furnace at 450℃ for 90 min to remove organic impurities and stabilize the pore structure;

[0101] 3.2.4 Surface hydroxylation activation: Immerse in 3wt% hydrogen peroxide solution at room temperature for 15 min, filter, and dry at 60℃ for 4 hours to obtain multi-stage pore-expanding modified diatomaceous earth;

[0102] 3.3 Biochemical treatment: Aeration powered by solar energy creates an alternating aerobic / anoxic environment in the biochemical zone, where microorganisms attached to highly efficient suspended biological packing simultaneously degrade COD, ammonia nitrogen, total nitrogen, and total phosphorus in the wastewater;

[0103] 4. Sedimentation and Clarification: Wastewater undergoes solid-liquid separation in the sedimentation and clarification zone of the biological purification facility. The separated sludge is periodically removed and utilized as a resource, while the supernatant flows by gravity into the clear water zone.

[0104] 5. Chlorine tablet disinfection: Chlorine tablets are manually added to the clean water area to disinfect the supernatant;

[0105] 6. Wastewater resource reuse: The disinfected wastewater in the clean water area is extracted by hand pump and used for irrigation of dryland crops during the irrigation season, and for dust suppression in courtyards and irrigation of vegetable gardens during the non-irrigation season. The entire process is assisted by gravity flow to realize the resource utilization of wastewater.

[0106] Example 2:

[0107] This embodiment is based on the right endpoint of the parameter range. The specific method for treating household-based rural domestic sewage in arid and cold regions includes the following steps:

[0108] 1. Household-specific collection: Each household is treated as an independent unit. PVC / PE pipes are used for non-household collection of domestic wastewater from kitchens and bathrooms, excluding irrigation water from yards. The wastewater collection and treatment capacity per household is 0.5m³. 3 / d, the entire process is carried out by gravity flow;

[0109] 2. Anaerobic pretreatment: The collected domestic sewage is introduced into a three-compartment fiberglass septic tank with an effective volume of 2.0 m³. 3 The three tanks have a volume ratio of 2:1:3. The wastewater undergoes solid-liquid separation and primary organic matter degradation through anaerobic fermentation within the tanks.

[0110] 3. Solar-coupled biochemical treatment: The anaerobic pretreated wastewater is introduced into an underground carbon steel corrosion-resistant biological purification facility. The facility is divided into a biochemical zone, a sedimentation and clarification zone, and a clear water zone. The biochemical zone is filled with high-efficiency suspended biological packing material.

[0111] 3.1 Preparation of high-efficiency suspended biological packing material:

[0112] 3.1.1 Substrate blending and melting: Take 15% chopped basalt fiber, 12% multi-stage pore-expanding modified diatomaceous earth porous carrier, 5% silane coupling agent, 4% sodium bicarbonate pore-forming agent, and the balance of polypropylene substrate by weight percentage, put them into a high-speed mixer, mix at 100℃ for 30 min, and then put them into a twin-screw extruder, melt blend at 200℃, extrude and granulate to obtain modified substrate particles;

[0113] 3.1.2 Preparation of spherical preforms: Modified substrate particles are fed into a spherical granulator and heated to 200°C to melt and bind the substrate particles together. The granulator is then centrifugally shaped by high-speed rotation and cooled and shaped by 12°C cold air cyclone cooling to obtain porous spherical suspended filler preforms.

[0114] 3.1.3 Preparation of composite modified solution: Chitosan quaternary ammonium salt, nano titanium dioxide and polyglutamic acid were dissolved in 2% acetic acid aqueous solution at a mass ratio of 1:0.2:0.1:100 and ultrasonically dispersed for 30 min to obtain a uniform composite modified solution;

[0115] 3.1.4 Dip-coating gradient curing: The porous suspended filler blank is completely immersed in the composite modified liquid for 20 min. After removal, it is pre-dried at 50℃ for 10 min and then cured and dried at 70℃ for 20 min. The dip-coating-curing process is repeated twice.

[0116] 3.1.5 UV irradiation activation: The cured filler was placed in a UV irradiation chamber and irradiated with 365nm UV light for 15min;

[0117] 3.2 Preparation of multi-stage pore-expanding modified diatomaceous earth:

[0118] 3.2.1 Acid washing to remove impurities: Immerse diatomaceous earth in 8wt% hydrochloric acid solution at 90℃ for 60 min, filter, and wash with deionized water until neutral;

[0119] 3.2.2 Alkaline solution pore enlargement: 5wt% sodium hydroxide solution was used for water bath treatment at 70℃ for 30 min, followed by filtration and etching to open and seal the pores;

[0120] 3.2.3 High-temperature calcination and shaping: calcination in a muffle furnace at 500℃ for 120 min to remove organic impurities and stabilize the pore structure;

[0121] 3.2.4 Surface hydroxylation activation: Immerse in 5wt% hydrogen peroxide solution at room temperature for 20 min, filter, and dry at 60℃ for 4 hours to obtain multi-stage pore-expanding modified diatomaceous earth;

[0122] 3.3 Biochemical treatment: Aeration powered by solar energy creates an alternating aerobic / anoxic environment in the biochemical zone, where microorganisms attached to highly efficient suspended biological packing simultaneously degrade COD, ammonia nitrogen, total nitrogen, and total phosphorus in the wastewater;

[0123] 4. Sedimentation and Clarification: Wastewater undergoes solid-liquid separation in the sedimentation and clarification zone of the biological purification facility. The separated sludge is periodically removed and utilized as a resource, while the supernatant flows by gravity into the clear water zone.

[0124] 5. Chlorine tablet disinfection: Chlorine tablets are manually added to the clean water area to disinfect the supernatant;

[0125] 6. Wastewater resource reuse: The disinfected wastewater in the clean water area is extracted by hand pump and used for irrigation of dryland crops during the irrigation season, and for dust suppression in courtyards and irrigation of vegetable gardens during the non-irrigation season. The entire process is assisted by gravity flow to realize the resource utilization of wastewater.

[0126] Example 3:

[0127] This embodiment describes a household-based rural domestic sewage treatment method in arid and cold regions, with the following steps:

[0128] 1. Household-specific collection: Each household is treated as an independent unit. PVC / PE pipes are used for non-household collection of domestic wastewater from kitchens and bathrooms, excluding irrigation water from yards. The wastewater collection and treatment capacity per household is 0.5m³. 3 / d, the entire process is carried out by gravity flow;

[0129] 2. Anaerobic pretreatment: The collected domestic sewage is introduced into a three-compartment fiberglass septic tank with an effective volume of 2.0 m³. 3 The three tanks have a volume ratio of 2:1:3. The wastewater undergoes solid-liquid separation and primary organic matter degradation through anaerobic fermentation within the tanks.

[0130] 3. Solar-coupled biochemical treatment: The anaerobic pretreated wastewater is introduced into an underground carbon steel corrosion-resistant biological purification facility. The facility is divided into a biochemical zone, a sedimentation and clarification zone, and a clear water zone. The biochemical zone is filled with high-efficiency suspended biological packing material.

[0131] 3.1 Preparation of high-efficiency suspended biological packing material:

[0132] 3.1.1 Substrate blending and melting: 12% by weight of short-cut basalt fiber, 10% by weight of multi-stage pore-expanding modified diatomaceous earth porous carrier, 4% by weight of silane coupling agent, 3% by weight of sodium bicarbonate pore-forming agent, and the balance of polypropylene substrate are fed into a high-speed mixer and mixed at 90°C for 25 min. Then, the mixture is fed into a twin-screw extruder and melt-blended and extruded and granulated at 190°C to obtain modified substrate particles.

[0133] 3.1.2 Preparation of spherical preforms: Modified substrate particles are fed into a spherical granulator and heated to 195°C to melt and bind the substrate particles together. The granulator is then centrifugally shaped by high-speed rotation and cooled and shaped by 10°C cold air cyclone cooling to obtain porous spherical suspended filler preforms.

[0134] 3.1.3 Preparation of composite modified solution: Chitosan quaternary ammonium salt, nano titanium dioxide and polyglutamic acid were dissolved in 2% acetic acid aqueous solution at a mass ratio of 1:0.2:0.1:100 and ultrasonically dispersed for 30 min to obtain a uniform composite modified solution;

[0135] 3.1.4 Dip-coating gradient curing: The porous suspended filler blank is completely immersed in the composite modified liquid for 18 min. After removal, it is pre-dried at 45℃ for 10 min and then cured and dried at 65℃ for 20 min. The dip-coating-curing process is repeated twice.

[0136] 3.1.5 UV irradiation activation: The cured filler was placed in a UV irradiation chamber and irradiated with 365nm UV light for 12min;

[0137] 3.2 Preparation of multi-stage pore-expanding modified diatomaceous earth:

[0138] 3.2.1 Acid washing to remove impurities: Immerse diatomaceous earth in 6wt% hydrochloric acid solution at 85℃ for 50 min, filter, and wash with deionized water until neutral;

[0139] 3.2.2 Alkaline solution pore enlargement: 4wt% sodium hydroxide solution was used for water bath treatment at 65℃ for 25 min, followed by filtration and etching to open and seal the pores;

[0140] 3.2.3 High-temperature calcination and shaping: calcination in a muffle furnace at 480℃ for 105 min to remove organic impurities and stabilize the pore structure;

[0141] 3.2.4 Surface hydroxylation activation: Immerse in 4wt% hydrogen peroxide solution at room temperature for 18 min, filter, and dry at 60℃ for 4 hours to obtain multi-stage pore-expanding modified diatomaceous earth;

[0142] 3.3 Biochemical treatment: Aeration powered by solar energy creates an alternating aerobic / anoxic environment in the biochemical zone, where microorganisms attached to highly efficient suspended biological packing simultaneously degrade COD, ammonia nitrogen, total nitrogen, and total phosphorus in the wastewater;

[0143] 4. Sedimentation and Clarification: Wastewater undergoes solid-liquid separation in the sedimentation and clarification zone of the biological purification facility. The separated sludge is periodically removed and utilized as a resource, while the supernatant flows by gravity into the clear water zone.

[0144] 5. Chlorine tablet disinfection: Chlorine tablets are manually added to the clean water area to disinfect the supernatant;

[0145] 6. Wastewater resource reuse: The disinfected wastewater in the clean water area is extracted by hand pump and used for irrigation of dryland crops during the irrigation season, and for dust suppression in courtyards and irrigation of vegetable gardens during the non-irrigation season. The entire process is assisted by gravity flow to realize the resource utilization of wastewater.

[0146] Comparative Example 1:

[0147] The method for treating rural domestic sewage in cold and arid regions according to Embodiment 3 of the present invention differs in that: the biochemical zone of the solar-coupled biochemical treatment is not filled with high-efficiency suspended biological packing material, but with conventional polypropylene suspended packing material, and the surface of the packing material does not have a low-temperature affinity composite modification layer. The remaining treatment steps and parameters are completely consistent with Embodiment 3.

[0148] This comparative example is used to verify the impact of high-efficiency suspended biological packing material on wastewater treatment efficiency in cold and arid regions under low-temperature conditions. Compared with conventional packing material, it verifies the low-temperature adaptability and pollutant degradation advantages of the high-efficiency suspended biological packing material of this invention.

[0149] Comparative Example 2:

[0150] The method for treating rural domestic sewage in cold and arid regions according to Embodiment 3 of the present invention differs in that: the solar-coupled biochemical treatment does not use solar-powered aeration, but uses mains power for aeration, and does not form an alternating aerobic / anoxic environment, but only maintains an aerobic environment. The remaining treatment steps and parameters are completely consistent with Embodiment 3.

[0151] This comparative example is used to verify the effect of alternating aerobic / anoxic environments formed by solar-coupled aeration on the nitrogen and phosphorus removal efficiency in wastewater, and to verify the adaptability and energy efficiency of solar power supply for rural wastewater treatment in cold and arid regions.

[0152] Comparative Example 3:

[0153] The method for treating rural domestic sewage in cold and arid regions according to Embodiment 3 of this invention differs in that: the anaerobic pretreatment does not use a three-compartment fiberglass septic tank, but instead uses a conventional single-compartment septic tank with an effective volume of 2.0 m³. 3 The remaining processing steps and parameters are completely consistent with those in Example 3.

[0154] This comparative example is used to verify the anaerobic pretreatment effect of the three-compartment fiberglass septic tank. Compared with a single-compartment septic tank, it verifies the advantages of the three-compartment septic tank with a volume ratio of 2:1:3 in solid-liquid separation and primary organic matter degradation.

[0155] Influent water quality:

[0156] The domestic sewage involved in this experiment mainly originated from the wastewater discharged by residents from bathing, kitchens, and toilets. It is typical domestic sewage with good biodegradability, but its composition and quantity vary considerably. Based on the results of on-site survey and sampling analysis, the details of the domestic sewage quality in this project are as follows:

[0157] Table 5 Reference Table for Water Quality Range of Domestic Sewage Unit: mg / L

[0158]

[0159] The wastewater treatment methods of Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests. The test environment was a cold and arid winter environment with an ambient temperature of -5℃ to 5℃. The monitoring was carried out continuously for 30 days. The treated domestic wastewater was collected daily, and the removal rates of COD, ammonia nitrogen, total nitrogen, and total phosphorus in the treated water samples were tested. The average value of each indicator was taken over 30 days. The test results are shown in the table below:

[0160] Table 6

[0161]

[0162] As can be seen from the above test results, the household-based rural domestic sewage treatment method of the present invention used in Examples 1-3 maintains a removal rate of over 88% for COD, ammonia nitrogen, total nitrogen, and total phosphorus under low temperature conditions.

[0163] Comparative Example 1, due to the use of conventional packing material and the absence of a low-temperature modification layer, exhibited poor microbial attachment and activity at low temperatures, resulting in a significant decrease in the removal rate of various pollutants. This verifies that the adaptability of the high-efficiency suspended biological packing material of this invention to low-temperature environments is a key feature for improving wastewater treatment efficiency. Comparative Example 2, due to the lack of solar-coupled aeration to create an alternating aerobic / anoxic environment, experienced a significant decrease in denitrification efficiency, verifying the importance of an alternating aerobic / anoxic environment for simultaneous denitrification and phosphorus removal. Comparative Example 3, due to the use of a single-compartment septic tank, had poor anaerobic pretreatment, leading to an increased load on subsequent biochemical treatment and a decrease in pollutant removal rate. This verifies the pretreatment advantages of the three-compartment fiberglass septic tank.

[0164] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0165] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for treating rural domestic sewage in cold and arid regions on a household-by-household basis, characterized in that, The system operates on a gravity-fed, self-flowing basis, with each household as an independent treatment unit. The process sequentially includes household collection, anaerobic pretreatment, solar-coupled biochemical treatment, sedimentation and clarification, chlorine disinfection, and effluent recycling. This method is suitable for the low-temperature climate and dispersed rural layout characteristics of cold and arid regions, with a single-household treatment capacity of 0.5 m³. 3 / d; The solar-coupled biochemical treatment adopts a buried carbon steel corrosion-resistant biological purification facility, which is internally divided into a biochemical zone, a sedimentation and clarification zone, and a clear water zone; the biochemical zone is filled with high-efficiency suspended biological packing material. The aeration system, powered by solar energy, creates an alternating aerobic / anoxic environment to simultaneously degrade COD, ammonia nitrogen, total nitrogen, and total phosphorus. The filler is composed of the following components by weight percentage: 10-15% chopped basalt fiber, 8-12% multi-stage pore-expanding modified diatomaceous earth porous carrier, 3-5% silane coupling agent, 2-4% sodium bicarbonate pore-forming agent, and the remainder being polypropylene substrate. The filler surface is coated with a chitosan quaternary ammonium salt-nano titanium dioxide-polyglutamic acid low-temperature affinity composite modified layer. The preparation method of the high-efficiency suspended biological packing includes the following steps: S1 substrate blending and melting: Polypropylene, chopped basalt fiber, multi-stage pore-expanding modified diatomaceous earth, silane coupling agent, and sodium bicarbonate pore-forming agent are added to a high-speed mixer in proportion and mixed at 80-100℃ for 20-30 minutes. Then, the mixture is fed into a twin-screw extruder and melt-blended and extruded at 180-200℃ to obtain modified substrate particles. S2 feeds the modified substrate particles into a spherical granulator, heats them to 190-200℃ to melt and bind the substrate particles together, and then centrifuges them by high-speed rotation of the granulator. The mixture is then cooled and shaped by 8-12℃ cold air swirl to obtain a porous spherical suspension filler preform. S3 composite modified solution preparation: Chitosan quaternary ammonium salt, nano titanium dioxide, and polyglutamic acid were dissolved in 2% acetic acid aqueous solution at a mass ratio of 1:0.2:0.1:100 and ultrasonically dispersed for 30 min to obtain a uniform composite modified solution; S4 Dip Coating Gradient Curing: The porous suspended filler blank is completely immersed in the composite modification liquid for 15-20 minutes. After removal, it is first pre-dried at 40-50℃ for 10 minutes, and then cured and dried at 60-70℃ for 20 minutes. The dip coating-curing process is repeated twice. S5 UV irradiation activation: Place the cured filler in a UV irradiation chamber and irradiate with UV light for 10-15 minutes.

2. The method according to claim 1, characterized in that, The separate collection system uses PVC / PE pipes for non-household collection, collecting only domestic sewage from farmers' kitchens and bathrooms, and not collecting irrigation water from courtyards.

3. The method according to claim 1, characterized in that, The anaerobic pretreatment uses a three-compartment fiberglass septic tank with an effective volume of 2.0 m³. 3 The three pools have a volume ratio of 2:1:3, and solid-liquid separation and primary organic matter degradation are achieved through anaerobic fermentation.

4. The method according to claim 1, characterized in that, The ultraviolet irradiation is 365nm ultraviolet irradiation.

5. The method according to claim 1, characterized in that, The method for preparing the multi-stage pore-expanding modified diatomite is as follows: ① Acid washing to remove impurities: Soak diatomaceous earth in 5wt%-8wt% hydrochloric acid solution at 80-90℃ for 40-60 minutes, filter, and wash with deionized water until neutral; ② Alkaline solution pore enlargement: 3wt%-5wt% sodium hydroxide solution, water bath treatment at 60-70℃ for 20-30 minutes, filtration, etching to open and seal the pores; ③ High-temperature calcination and shaping: calcination in a muffle furnace at 450-500℃ for 90-120 minutes to remove organic impurities and stabilize the pore structure; ④ Surface hydroxylation activation: Soak in 3wt%-5wt% hydrogen peroxide solution at room temperature for 15-20 min, filter, and dry at 60℃ for 4 hours to obtain the product.

6. The method according to claim 1, characterized in that, The sludge separated in the sedimentation and clarification zone is periodically removed for resource utilization, and the supernatant is temporarily stored in the clear water zone, where chlorine tablets are added manually for disinfection.

7. The method according to claim 1, characterized in that, The wastewater in the clear water area is extracted by hand pumps and used for irrigation of dryland crops during the irrigation season, and for dust suppression in courtyards and irrigation of vegetable gardens during the non-irrigation season.

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