Rural decentralized sewage unpowered treatment method and system using terrain potential energy

Abstract

The invention provides a rural decentralized sewage unpowered treatment method and system using terrain potential energy, natural height difference is determined through terrain survey to construct a potential energy driving system, and continuous treatment of sewage can be realized without extra power. The method comprises the following steps: calculating potential energy required by fluid flow based on a terrain height difference, arranging a treatment unit, collecting sewage through a collection unit, sequentially carrying out pretreatment, enhanced filtration, gravity type biological reaction and deep purification unit treatment, and finally discharging or recycling after reaching the standard. The system is correspondingly provided with treatment units and potential energy guide structures which are arranged in a stepped manner, unpowered flow of sewage is realized by utilizing a fluid mechanics principle, the pollutant removal efficiency is improved by combining a composite filter material and a high-efficiency biological reaction system, and meanwhile, the operation period is prolonged by virtue of an anti-blocking design. The device does not need to be driven by electric power, is low in investment and operation cost, adapts to rural complex terrains and decentralized sewage characteristics, and realizes efficient removal of pollutants and cyclic utilization of water resources.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rural sewage treatment and non-powered environmental protection, and particularly relates to a non-powered treatment method for rural scattered sewage using terrain potential energy and a system thereof. BACKGROUND

[0002] Rural scattered sewage has the characteristics of scattered pollution sources, large water fluctuation, complex water quality (containing domestic sewage and a small amount of agricultural non-point source pollution), and irregular topographic distribution, and the traditional sewage treatment technology is difficult to adapt to the application scene. At present, the rural sewage treatment mainly has the following technical bottlenecks: The centralized sewage treatment system depends on large-scale pipe network laying, and the rural residential areas are scattered and the topography is complex (hilly and mountainous). The pipe network construction investment is large, the construction difficulty is high, the operation and maintenance cost is high, and it is difficult to popularize in a large area. The existing non-powered treatment technology (such as septic tank and simple oxidation pond) has low treatment efficiency, can only remove part of suspended solids and organic matter, and the nitrogen and phosphorus removal rate is less than 30%. The effluent is difficult to reach the first level B standard of “Urban Sewage Treatment Plant Pollutant Discharge Standard” (GB18918-2002), and is easy to pollute surface water and groundwater. The powered sewage treatment technology (such as MBR and SBR) needs to rely on power-driven water pump and aeration equipment. The power supply in rural areas is unstable, and the operation energy consumption is high (0.3-0.8 kWh per ton of water). The farmers are difficult to bear the long-term operation and maintenance cost. The existing non-powered treatment equipment generally has the problems of easy clogging, frequent filter replacement, and low biological reaction efficiency. Since there is no power stirring and backwashing mechanism, the filter layer is easy to be clogged by suspended solids, which causes the treatment system to be invalid in a short time, and the operation and maintenance workload is large.

[0003] Therefore, in view of the characteristics of rural scattered sewage, a sewage treatment technology without external power, suitable for complex topography, high treatment efficiency, anti-clogging and easy operation and maintenance has become the key to solve the problem of rural water pollution control. SUMMARY

[0004] The present application provides a non-powered treatment method for rural scattered sewage using terrain potential energy and a system thereof, which aims to solve the technical defects of the existing rural sewage treatment technology, such as dependence on power, high investment and operation and maintenance cost, poor treatment effect, and easy clogging, and to realize low-cost, efficient and non-powered treatment of rural scattered sewage.

[0005] In order to achieve the above-mentioned purpose, the present application is realized by the following technical scheme: In a first aspect, the present application provides a non-powered treatment method for rural scattered sewage using terrain potential energy, comprising the following steps: Surveying topographic elevation data of a rural area to be treated, determining natural terrain elevation difference based on the topographic elevation data, calculating minimum potential energy required for unpowered flow of sewage by a fluid mechanics model, and arranging stepped treatment units according to the natural terrain elevation difference and the minimum potential energy; Collecting rural scattered sewage by a sewage collection unit, and driving the sewage to flow into a pretreatment unit by the potential energy formed by the natural terrain elevation difference, so as to remove large suspended solids and sand in the sewage; The pretreated sewage flows into a reinforced filtration unit under the action of the potential energy, and is intercepted and filtered and preliminarily degraded of pollutants by a composite filter layer; The filtered sewage continues to flow into a gravity type biological reaction unit by the potential energy, and is subjected to deep conversion and removal of organic pollutants, nitrogen and phosphorus by a microorganism group on a biological carrier; The sewage after biological reaction flows into a deep purification unit by the potential energy, and is subjected to tail water purification by an adsorption-catalysis composite material; The purified effluent is directly discharged or introduced into a reuse pipe network after reaching a standard, so as to realize unpowered treatment of rural scattered sewage.

[0006] Further as an improvement of the technical scheme of the present application, the calculation of the minimum potential energy required for unpowered flow of sewage by the fluid mechanics model specifically comprises: Based on Darcy's law and water head loss theory, a potential energy calculation model for unpowered flow of sewage is constructed, and the model expression is: wherein H is the minimum elevation difference required by the natural terrain (m); f is a resistance coefficient along the path, and the value is ; L is the total length of sewage flow (m); D is the inner diameter of a flow guide pipe (m); v is a design flow rate of the sewage (m / s), and the value is 0.4-0.8 m / s; g is the acceleration of gravity (m / s' ); is the sum of local resistance coefficients, and the value is 1.5-3.0; is the sum of elevation differences between inlets and outlets of each treatment unit (m); h_f is the sum of water head losses of filter layers and biological carrier layers (m), h_f=h1+h2, h1 is the water head loss of the reinforced filtration unit (0.3-0.8 m), and h2 is the water head loss of the gravity type biological reaction unit (0.5-1.2 m).

[0007] Further as an improvement of the technical scheme of the present application, the pretreatment unit comprises a grid assembly and a sand trap, the grid bar spacing of the grid assembly is , the hydraulic retention time of the sand trap is , and an inclined sand collecting groove is arranged at the bottom of the sand trap, the inclination angle of the sand collecting groove is , and sand is naturally settled and collected by the potential energy.

[0008] As a further improvement to the technical solution of the present invention, the composite filter media layer of the enhanced filtration unit consists of a coarse quartz sand layer, a zeolite layer, and a modified ceramsite layer from top to bottom, with the thickness of each layer satisfying the formula: ; Where h_i is the thickness of the i-th filter layer (m); Q is the designed wastewater treatment capacity (m). ); The influent suspended solids concentration is (mg / L); K_i is the retention coefficient of the i-th filter media, and the coarse quartz sand layer... zeolite layer Modified ceramsite layer ; Let be the porosity of the i-th filter layer, and be the porosity of the coarse quartz sand layer. zeolite layer Modified ceramsite layer p is the density of the wastewater ( v is the hydraulic load on the surface of the filter media layer (); ); n_i is the filtration efficiency (%) of the i-th filter layer.

[0009] As a further improvement to the technical solution of the present invention, the gravity-type bioreactor unit is a stepped biofilter, which is filled with a mixed packing material of porous ceramic carrier and volcanic rock carrier, with a mixing volume ratio of , and the slope of the biofilter is consistent with the slope of the terrain. The hydraulic retention time of the sewage in the tank is , and the sewage is continuously flowed from top to bottom and reacted with microorganisms through potential energy.

[0010] As a further improvement to the technical solution of the present invention, the adsorption-catalysis composite material of the deep purification unit is a mixture of modified bentonite and nano-zero-valent iron / activated carbon composite material, with a mixing mass ratio of [missing information], and its nitrogen and phosphorus adsorption capacity satisfies the pseudo-second-order adsorption kinetic equation: Where q_t is the adsorption capacity at time t (mg / g); q_e is the equilibrium adsorption capacity (mg / g) for ammonia nitrogen. For total phosphorus k is the adsorption rate constant ( ), value t represents the adsorption time (h). Further, as an improvement to the technical solution of this invention, the potential energy guiding structure includes a flow guide channel and an anti-backflow device, wherein the slope of the flow guide channel is... , the backflow prevention device is built-in float ball type check valve, and automatic opening and closing are realized based on the difference between hydrostatic pressure and potential energy. The second aspect of the present application provides a rural decentralized sewage non-powered treatment system using terrain potential energy, comprising: a sewage collection unit for collecting rural decentralized sewage, the collection unit is provided with a potential energy introduction interface; a pretreatment unit connected with the sewage collection unit through a flow guide pipe, for removing large suspended solids and sand, the inlet elevation of the pretreatment unit is higher than the outlet elevation; a reinforced filtration unit arranged below the pretreatment unit, which receives the pretreated sewage through a flow guide structure, and is internally provided with a composite filter material layer; a gravity type biological reaction unit arranged below the reinforced filtration unit and communicating with the reinforced filtration unit, which is internally filled with biological carriers; a deep purification unit arranged below the gravity type biological reaction unit for tail water purification; a potential energy guiding assembly comprising a flow guide groove, a slope adjusting structure and a backflow prevention device, for guiding the sewage to flow between units by terrain potential energy without power. An effluent unit connected with the deep purification unit for discharging or recycling the effluent water.

[0011] Further as the improvement of the technical scheme of the present application, the slope adjusting structure of the potential energy guiding assembly is a telescopic support foot, by adjusting the height of the support foot, the central axis of each treatment unit and the contour line of the terrain form an angle, ensuring the potential energy required for the sewage flow.

[0012] The third aspect of the present application provides a computer device comprising a memory and a processor, the memory stores a computer program, and the processor is configured to implement the potential energy calculation, filter material parameter optimization and treatment effect prediction steps in the rural decentralized sewage non-powered treatment method using terrain potential energy as described above when executing the computer program.

[0013] The fourth aspect of the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the rural decentralized sewage non-powered treatment method using terrain potential energy as described above.

[0014] The technical scheme of the present application has the following beneficial effects compared with the prior art: ​The present application determines the natural terrain height difference by surveying the terrain elevation data of the rural area to be treated, arranges the stepped treatment unit by combining the fluid mechanics model to calculate the minimum potential energy required for the unpowered flow of sewage, and relies on the terrain potential energy to drive the sewage to be sequentially collected, pretreated, enhanced filtered, gravity type biologically reacted to deep purification full-process treatment and achieve discharge or reuse. The present application does not need to rely on external power to drive water pump, aeration equipment and other power devices, fundamentally solves the pain points of unstable power supply in rural areas and high operation cost of traditional powered sewage treatment technology, significantly reduces the operation cost per ton of water; through the layout of the stepped treatment unit to adapt to the complex terrain of rural hilly and mountainous areas, avoids the high investment and construction difficulties of large-scale pipe network laying of centralized treatment system, and is more suitable for the characteristics of scattered sewage pollution sources in rural areas; at the same time, the full-process treatment links cover bulk suspended solids removal, filter material interception filtration, microbial degradation and tail water deep purification, which can effectively remove organic matter, nitrogen, phosphorus and suspended solids and other pollutants in sewage, ensure that the effluent quality meets the standard, and the effluent that meets the standard can be reused to realize water resource recycling, taking into account environmental governance and resource conservation, the overall scheme has strong practicality and wide popularization value, and can effectively solve the technical bottleneck of rural scattered sewage treatment. BRIEF DESCRIPTION OF DRAWINGS

[0015] Other features, objects, and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments, made with reference to the following drawings: Figure 1 FIG. 1 is a schematic diagram of the framework process of a rural scattered sewage unpowered treatment method using terrain potential energy according to an embodiment of the present application; Figure 2 FIG. 2 is a schematic diagram of the module framework of a rural scattered sewage unpowered treatment system using terrain potential energy according to an embodiment of the present application; Figure 3 FIG. 3 is a schematic diagram of the composition of a computing device according to an embodiment of the present application. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0017] The present application will be further described in detail below in combination with the drawings.

[0018] Reference Figure 1 In a first aspect, the present application provides a rural scattered sewage unpowered treatment method using terrain potential energy, comprising the following steps: Surveying topographic elevation data of rural areas to be treated, determining natural terrain elevation difference based on the topographic elevation data, calculating minimum potential energy required for unpowered flow of sewage by a fluid mechanics model, and arranging stepped treatment units according to the natural terrain elevation difference and the minimum potential energy; Collecting rural dispersed sewage by a sewage collection unit, and driving the sewage to flow into a pretreatment unit by potential energy formed by the natural terrain elevation difference to remove large suspended solids and sand in the sewage; The pretreated sewage flows into a reinforced filtration unit under the action of potential energy, and is intercepted and filtered and preliminarily degraded by a composite filter layer; The filtered sewage continues to flow into a gravity type biological reaction unit by potential energy, and organic pollutants and nitrogen and phosphorus are deeply converted and removed by microorganism groups on biological carriers; The sewage after biological reaction flows into a deep purification unit by potential energy, and tail water is purified by adsorption-catalysis composite materials; The purified effluent meets the standards and is directly discharged or introduced into a reuse pipe network, realizing unpowered treatment of rural dispersed sewage.

[0019] In specific implementation, first, elevation data of the area to be treated is obtained by topographic survey, the natural terrain elevation difference is determined, a fluid mechanics model based on Darcy's law and water head loss theory is constructed, the minimum potential energy required for unpowered flow of sewage is calculated, and a top-down stepped treatment unit is arranged according to the calculation result; second, dispersed sewage is collected by a sewage collection unit, and the sewage is driven to flow into a pretreatment unit by potential energy formed by the natural terrain elevation difference to remove large suspended solids and sand; then, the pretreated sewage flows into a reinforced filtration unit (intercepted and filtered and preliminarily degraded by a composite filter layer), a gravity type biological reaction unit (organic pollutants and nitrogen and phosphorus are deeply converted and removed by microorganism groups on biological carriers), and a deep purification unit (tail water is purified by adsorption-catalysis composite materials) under the action of potential energy; finally, the purified effluent meeting the standards is directly discharged or introduced into a reuse pipe network, and the whole process of unpowered sewage treatment is completed.

[0020] The application does not rely on external power to drive the water pump, aeration equipment and other power devices, fundamentally solves the pain points of unstable power supply in rural areas and high operation cost of traditional powered sewage treatment technology, significantly reduces the operation cost per ton of water; through the layout of the stepped treatment unit, it can adapt to complex terrains such as rural hills and mountains, avoid the high investment and construction difficulties of large-scale pipe network laying of centralized treatment system, and perfectly fit the characteristics of scattered sewage pollution sources in rural areas; the whole process treatment link covers the whole cycle removal of pollutants from coarse screening to deep purification, which can effectively reduce the content of organic matter, nitrogen, phosphorus and suspended solids in sewage, and ensure that the effluent quality meets the standard; at the same time, the standard effluent can be reused to realize water resource recycling, taking into account environmental governance and resource conservation, the overall scheme has strong practicality and wide popularization value, effectively solving the technical bottleneck of rural scattered sewage treatment.

[0021] In some embodiments, the minimum potential energy required for unpowered flow of sewage is calculated by a fluid mechanics model, specifically comprising: based on Darcy's law and water head loss theory, a sewage unpowered flow potential energy calculation model is constructed, and the model expression is: ; wherein H is the minimum elevation difference required by natural terrain (m); is the friction resistance coefficient, and the value is ; L is the total length of sewage flow (m); D is the inner diameter of the flow guide pipe (m); v is the design flow rate of sewage (m / s), and the value is ; g is the acceleration of gravity ( ); is the sum of local resistance coefficients, and the value is ; is the sum of the elevation difference between the inlet and outlet of each treatment unit (m); h_f is the sum of the water head loss of the filter layer and the biological carrier layer (m), h_f=h1+h2, h1 is the water head loss of the enhanced filtration unit ( ), and h2 is the water head loss of the gravity type biological reaction unit ( ). It should be noted that based on Darcy's law and water head loss theory, a sewage unpowered flow potential energy calculation model is constructed, and the model expression is .

[0022] wherein H is the minimum elevation difference required by natural terrain, is the friction resistance coefficient related to the material of the flow guide pipe (PVC pipe takes 0.02~0.03, and PE pipe takes 0.03~0.05), L is the sum of the lengths of the flow guide pipes between the treatment units, D is the inner diameter of the flow guide pipe selected according to the treatment capacity (0.1~0.3m), v is the design flow rate of sewage to ensure that the suspended solids do not deposit and avoid excessive water head loss (0.4~0.8m / s), g is the acceleration of gravity ( ), is the sum of the resistance coefficients of local components such as pipe bends and tees Ah is the sum of the elevation differences between the inlet and outlet of each processing unit (for each unit). h_f represents the sum of the head losses of the enhanced filtration unit and the gravity-fed biological reactor unit (h_f = h1 + h2, where h1 is 0.3~0.8m and h2 is 0.5~1.2m). H is calculated by substituting the actual terrain and system parameters to ensure that the natural elevation difference is not less than H, meeting the requirements for non-powered sewage flow. This calculation model can accurately quantify the minimum potential energy required for non-powered sewage flow, avoiding sedimentation problems caused by insufficient natural elevation differences leading to stagnant or slow flow, while also preventing energy waste and pipeline damage due to excessive elevation differences. The parameter values ​​in the model are set according to the actual needs of rural sewage treatment scenarios, possessing strong pertinence and operability. This provides a scientific basis for the stepped layout of treatment units, ensuring the stability and reliability of the system's non-powered operation and reducing the later modification costs caused by unreasonable layout.

[0023] In some embodiments, the pretreatment unit includes a bar grid assembly and a sedimentation tank, wherein the bar spacing of the bar grid assembly is [missing information]. The hydraulic retention time of the sedimentation tank is Furthermore, the bottom of the sedimentation tank is equipped with an inclined sand collection trough, the inclination angle of which is... It utilizes potential energy to achieve the natural settling and collection of sand and gravel.

[0024] It should be noted that the bar spacing of the bar assembly is set to 5~10mm to intercept large suspended solids (such as plastic bags, dead branches, etc.) in sewage. The bar uses... The inclined design utilizes the potential energy of the sewage flow to drive the screenings to slide naturally down the inclined surface of the screenings bars to the screenings collection trough below; the hydraulic retention time of the grit chamber is controlled to be... To ensure that the sand and gravel in the sewage have sufficient time to settle under gravity, the bottom of the pool is equipped with... The inclined grit collection trough allows settled sand and gravel to naturally converge to the bottom under the combined effect of their own gravity and the potential energy of the wastewater flow. Regular manual cleaning is all that's needed for sand removal. The inclined bar screen design achieves self-collection of screenings without additional power, avoiding the tedious manual removal required by traditional bar screens. The grit chamber, through reasonable control of the hydraulic retention time and the inclination angle of the collection trough, achieves efficient sedimentation and natural collection of sand and gravel, eliminating the need for powered sand removal equipment and reducing equipment investment and maintenance costs. The pretreatment unit effectively removes large suspended solids and sand from the wastewater that can easily clog subsequent filtration units and biological carriers, extending the service life of subsequent treatment units, reducing the risk of system blockage, and improving overall treatment efficiency.

[0025] In some embodiments, the composite filter media layer of the enhanced filtration unit consists of a coarse quartz sand layer, a zeolite layer, and a modified ceramsite layer from top to bottom, with the thickness of each layer satisfying the formula: ; Where h_i is the thickness of the i-th filter layer (m); Q is the designed wastewater treatment capacity (m). ); The influent suspended solids concentration is (mg / L); K_i is the retention coefficient of the i-th filter media, and the coarse quartz sand layer... zeolite layer Modified ceramsite layer ; Let be the porosity of the i-th filter layer, and be the porosity of the coarse quartz sand layer. zeolite layer Modified ceramsite layer p is the density of the wastewater ( v is the hydraulic load on the surface of the filter media layer (); ); Let be the filtration efficiency (%) of the i-th filter layer.

[0026] It should be noted that the enhanced filtration unit has three layers of composite filter media inside, from top to bottom: a layer of coarse quartz sand (particle size...). ), zeolite layer (particle size) Modified ceramsite layer (particle size 0.5~1mm), the thickness of each filter layer is determined by the formula. The calculation determines the thickness of the i-th filter layer, and Q is the designed wastewater treatment capacity per household. Multiple households ), The influent suspended solids concentration for decentralized rural sewage is 100~300 mg / L, and K_i is the retention coefficient of each filter layer (coarse quartz sand layer). zeolite layer Modified ceramsite layer ), The porosity of each filter media layer is (coarse quartz sand layer 0.40~0.45, zeolite layer...). Modified ceramsite layer 0.50~0.60), p is the density of wastewater ( v is the hydraulic load on the surface of the filter media layer ( ), The filtration efficiency of each filter media layer (coarse quartz sand layer 85%~90%, zeolite layer) Modified ceramsite layer When wastewater flows through the composite filter media layer, suspended solids are graded and intercepted through the particle size gradient. At the same time, the ion exchange effect of zeolite and the adsorption and catalytic effect of modified ceramic particles initially remove ammonia nitrogen and organic matter.

[0027] The thickness of the filter layer determined by formula calculation can ensure that each layer of filter material meets the filtering efficiency, avoids the penetration of pollutants due to insufficient thickness, or the excessive water head loss due to excessive thickness; the particle size gradient and material optimization design of the composite filter layer realize the graded interception of suspended solids from large to small, improve the filtering precision, and utilize the functional characteristics of different filter materials to realize the preliminary degradation of pollutants, thereby reducing the load of the subsequent biological treatment unit; the filter material with high porosity and reasonable thickness design can reduce the deposition of suspended solids in the filter layer, reduce the risk of blockage, prolong the filter replacement cycle to 1-2 years, and reduce the operation and maintenance workload and cost.

[0028] In some embodiments, the gravity type biological reaction unit is a stepped biological filter, which is internally filled with mixed fillers of porous ceramic carriers and volcanic rock carriers at a volume ratio of 3:2, and the slope of the biological filter is consistent with the slope of the terrain, and the hydraulic retention time of the sewage in the biological filter is 2-4 h, so that the sewage continuously flows from top to bottom and contacts with microorganisms through potential energy.

[0029] It should be noted that the gravity type biological reaction unit is a stepped biological filter, the slope of the pool body is consistent with the slope of the terrain of the treatment area (3-15), and the continuous flow of the sewage from top to bottom is ensured by relying on the potential energy of the terrain. The biological filter is internally filled with porous ceramic carriers (particle size 3-5 mm) and volcanic rock carriers (particle size ), and the volume ratio of the two is 3:2, and the height of the filler layer is controlled to be 1.0-1.5 m; the hydraulic retention time of the sewage in the filter is set to 2-4 h, and when flowing through the filler layer, the aerobic bacteria, facultative bacteria and anaerobic bacteria on the surface of the filler are fully contacted, and the microorganisms degrade COD, , etc. organic pollutants through metabolic action, and at the same time, the stepped pool body structure forms an aerobic-anoxic alternating environment to promote the nitrification-denitrification and biological absorption of phosphorus. The stepped pool body design does not require additional aeration equipment, and oxygen supply is achieved only by the flow of sewage and natural air diffusion, which greatly reduces energy consumption; the pool body slope is consistent with the terrain, which reduces the amount of civil construction and adapts to the complex terrain in rural areas; the high porosity of the mixed fillers provides sufficient space for microorganisms to adhere, improves the number and activity of the bacterial population, and ensures efficient removal of organic pollutants and nitrogen and phosphorus (COD removal rate 85%, ammonia nitrogen removal rate 80%, total nitrogen removal rate 70%, and total phosphorus removal rate 60%); the reasonable control of the hydraulic retention time takes into account the pollutant degradation efficiency and the compactness of the treatment system, and avoids the problem of excessive land occupation caused by the large size of the pool body.

[0030] In some embodiments, the adsorption-catalysis composite material of the deep purification unit is a mixed system of modified bentonite and nano zero-valent iron / activated carbon composite material at a mass ratio of 5:1, and the nitrogen and phosphorus adsorption capacity thereof satisfies the pseudo-second-order adsorption kinetics equation: ; wherein q t is the adsorption capacity at time t (mg / g); q e is the equilibrium adsorption capacity (mg / g), 18 mg / g for ammonia nitrogen and 25 mg / g for total phosphorus; k is the adsorption rate constant (h -1) , and the value of k is ; and t is the adsorption time (h).

[0031] It should be noted that the deep purification unit is internally filled with adsorption-catalysis composite material, which is a mixed system of modified bentonite and nano zero-valent iron / activated carbon composite material, and the mass ratio of the two is 5:1; wherein the modified bentonite is activated by aluminum sulfate, and the specific surface area is , and it has strong adsorption capacity for phosphorus; the nano zero-valent iron / activated carbon composite material has a nano zero-valent iron particle size of 50 nm and a loading capacity of 5% to 10%, and has the functions of catalytic reduction and adsorption. The nitrogen and phosphorus adsorption capacity of the composite material satisfies the pseudo-second-order adsorption kinetics equation , wherein q t is the adsorption capacity at time t, q e is the equilibrium adsorption capacity (18 mg / g for ammonia nitrogen and 25 mg / g for total phosphorus), k is the adsorption rate constant (h -1) , and t is the adsorption time (0.5 to 1.0 h of the hydraulic retention time of the deep purification unit); when the sewage flows through the composite material layer, the residual nitrogen and phosphorus, trace organic matter and suspended solids are removed by adsorption and catalysis.

[0032] The synergistic effect of modified bentonite and nano zero-valent iron / activated carbon composite material greatly improves the nitrogen and phosphorus adsorption capacity and adsorption rate, ensures deep removal of tail water pollutants, and makes the effluent water quality meet the first level A standard; the pseudo-second-order adsorption kinetics equation can accurately describe the adsorption process of the composite material, provide a scientific basis for setting the hydraulic retention time, avoid insufficient adsorption due to insufficient retention time or low efficiency due to excessive retention time; the composite material has strong stability and long service life (1 to 1.5 years), does not need to be replaced frequently, reduces operation and maintenance costs, and is widely available and low in price, suitable for large-scale application in rural areas.

[0033] In some embodiments, the potential energy guiding structure includes a flow guide groove and an anti-backflow device, the slope of the flow guide groove is 1% to 3%, and the anti-backflow device is provided with a floating ball type one-way valve, which automatically opens and closes based on the difference between the hydrostatic pressure and the potential energy.

[0034] It should be noted that the diversion groove adopts a U-shaped structure, the width is 0.1-0.2 m, the depth is 0.1-0.3 m, and the slope is 1%-3%, which is used for connecting various treatment units and guiding sewage to flow along the set path by relying on potential energy; the anti-backflow device is provided with a floating ball type one-way valve, which is installed at the inlet end of each treatment unit; when the sewage flows forward under the action of potential energy, the fluid static pressure pushes the floating ball to open the valve, allowing the sewage to enter the unit; when the sewage appears a backflow trend, the floating ball closes the valve under the action of the reverse pressure and its own gravity, preventing the backflow of the sewage.

[0035] The reasonable slope design of the diversion groove ensures the stable flow speed of the sewage, avoids the deposition of suspended solids caused by too slow flow speed or the excessive water head loss caused by too fast flow speed, and the U-shaped structure can reduce the risk of sewage overflow; the floating ball type one-way valve realizes automatic opening and closing based on the difference between the fluid static pressure and the potential energy, without external power control, and has a simple and reliable structure, which can effectively prevent the pollution of the treatment unit or the failure of the treatment effect caused by the backflow of the sewage; the potential energy guiding structure improves the stability of the overall system without power operation, ensures that the sewage flows through each treatment unit in the preset process, and avoids the interruption of treatment caused by abnormal flow path.

[0036] The second aspect of the present application provides a rural decentralized sewage non-powered treatment system utilizing terrain potential energy, comprising: A sewage collection unit is used for collecting rural decentralized sewage, and the collection unit is provided with a potential energy introduction interface; A pretreatment unit is connected with the sewage collection unit through a diversion pipe and is used for removing large suspended solids and sand, and the inlet elevation of the pretreatment unit is higher than the outlet elevation; A reinforced filtration unit is arranged below the pretreatment unit, receives the pretreated sewage through a diversion structure, and is internally provided with a composite filter layer; A gravity type biological reaction unit is arranged below the reinforced filtration unit, communicates with the reinforced filtration unit, and is internally filled with biological carriers; a depth purification unit is arranged below the gravity type biological reaction unit and is used for tail water purification; a potential energy guiding assembly comprises a diversion groove, a slope adjusting structure and an anti-backflow device, and is used for guiding the sewage to flow between units by relying on the terrain potential energy without power; a water outlet unit is connected with the depth purification unit and is used for discharging or recycling the standard effluent.

[0037] It should be noted that the sewage collection unit is connected with the water collection tank and the water collection pipe network to collect dispersed sewage, and the potential energy is introduced into the interface to connect the pretreatment unit; the pretreatment unit (grating + grit chamber) has an inlet elevation higher than an outlet elevation, and removes large suspended solids and sand; the enhanced filtration unit is arranged below the pretreatment unit, receives sewage through a flow guide structure, and realizes staged filtration through an internal composite filter layer; the gravity type biological reaction unit is arranged below the enhanced filtration unit, fills biological carriers to realize microbial degradation; the advanced purification unit is arranged below the biological reaction unit, and purifies tail water through a composite material; the potential energy guiding assembly (flow guide groove, slope adjusting structure, anti-backflow device) guides the unpowered flow of sewage; the effluent unit stores the standard effluent to realize discharge or reuse. The system of the present application adopts modular design, and each unit has independent function and cooperates with each other, can flexibly adjust the unit scale according to the number of rural users (single household or multiple households), and adapts to different treatment requirements; the stepped arrangement fully utilizes the potential energy of the terrain, and the whole process is driven without power, thereby reducing the operation cost and power dependence; the whole process treatment unit covers the complete link from sewage collection to purification, ensures efficient removal of pollutants, and realizes standard effluent; at the same time, the system has the effluent reuse function, improves the water resource utilization rate, meets the rural water saving demand; the system structure is compact, occupies less land, has small amount of civil construction, is suitable for installation in complex rural terrain, and has low popularization and application difficulty. In some embodiments, the slope adjusting structure of the potential energy guiding assembly is a telescopic support foot, the height of the support foot is adjusted to make the central axis of each treatment unit and the terrain contour line form an angle of 3-15, and the potential energy required for the flow of sewage is ensured.

[0038] It should be noted that the slope adjusting structure of the potential energy guiding assembly is a telescopic support foot, which is installed at the bottom of each treatment unit, and the height adjusting range of the support foot is 0.1-0.5 m. During the system installation process, according to the actual terrain slope of the treatment area, the height of each treatment unit is adjusted by the telescopic support foot, so that the central axis of each treatment unit and the terrain contour line form an angle of 3-15, and the height difference between the inlet and outlet of each unit is formed to meet the requirement of unpowered flow of sewage, and the flow path of adjacent units is smooth, avoiding the deviation of unit arrangement caused by irregular terrain slope. The height adjusting function of the telescopic support foot enables the treatment unit to adapt to different slope rural terrain (3-15) without relying on complex civil construction to level the site, greatly reducing the site transformation cost and construction difficulty; by adjusting the angle between the central axis of the unit and the contour line, the height difference between the units is accurately ensured to meet the flow requirement of sewage, avoiding flow stagnation or too fast caused by improper slope, and improving the system operation stability; the support foot structure is simple and convenient to install, and can be flexibly adjusted according to the terrain change or system maintenance requirement in the later period, enhancing the adaptability and maintainability of the system.

[0039] The third aspect of the present application provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor is configured to implement the potential energy calculation, filter material parameter optimization and treatment effect prediction steps in the rural decentralized sewage non-powered treatment method using topographic potential energy as described above when executing the computer program.

[0040] It should be noted that the processor is configured to obtain and execute the program, and specifically execute the following steps: first, potential energy calculation, input topographic elevation data, pipe parameters, treatment unit size, etc., automatically calculate the minimum potential energy required for non-powered flow of sewage through the above fluid mechanics model, and output the treatment unit step layout suggestion; second, filter material parameter optimization, according to the influent water quality, treatment capacity and other parameters, through the above filter thickness formula, optimize the thickness and material ratio of each filter layer of the enhanced filtration unit; third, treatment effect prediction, based on the influent water quality parameters and system parameters, through the machine learning model to predict the effluent COD, ammonia nitrogen, total phosphorus and suspended solids concentration, to judge whether it meets the standard, if not, automatically adjust the system parameters (such as filter thickness, hydraulic retention time).

[0041] The computer device realizes the automatic calculation and optimization of the key steps of the treatment method, greatly improves the system design accuracy, reduces the manual calculation error, and reduces the design difficulty; the potential energy calculation and filter material parameter optimization function provide data support for the scientific layout and efficient operation of the treatment system, avoid the later reconstruction caused by unreasonable manual design; the treatment effect prediction function can predict the effluent water quality in advance, adjust the system parameters in time, ensure the stable treatment effect, reduce the debugging cost and time in the trial operation stage, and improve the landing efficiency of the technical scheme.

[0042] In some embodiments, the rural decentralized sewage non-powered treatment method using topographic potential energy in the above embodiments can be implemented by a computer device comprising at least one processor, a communication bus, a memory and at least one communication interface.

[0043] The processor can be a general central processing unit (CPU) or an application-specific integrated circuit (ASIC).

[0044] The communication bus can be used to transmit information between the above components.

[0045] The memory can be read-only memory (ROM) or other type of static storage devices that can store static information and instructions, random access memory (RAM) or other type of dynamic storage device that can store information and instructions, electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disk storage, optical storage (including a compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), magnetic storage device, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and that can be accessed by a computer, but not limited to. The memory can exist independently, and is connected with the processor through a communication bus. The memory can also be integrated with the processor.

[0046] The memory is configured to store program code for implementing the scheme of the present application, and the processor is configured to control the execution. The processor is configured to execute the program code stored in the memory. The program code can include one or more software modules. The above-mentioned rural decentralized sewage non-powered treatment method utilizing topographic potential energy can be implemented by one or more software modules in the program code of the processor and the memory.

[0047] The communication interface is configured to communicate with other devices or communication networks using any transceiver-like device, such as an Ethernet, radio access network (RAN), wireless local area network (WLAN), etc. In specific implementation, as an embodiment, the computer device can include multiple processors, each of which can be a single-CPU processor or a multi-CPU processor. The processor herein can refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions). The above-mentioned computer device can be a general-purpose computer device or a special-purpose computer device. In specific implementation, the computer device can be a desktop computer, a laptop computer, a network server, a personal digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, a communication device, or an embedded device. The embodiments of the present application do not limit the type of computer device.

[0048] A fourth aspect of this invention provides a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the aforementioned method for non-powered treatment of decentralized rural sewage utilizing terrain potential energy. When the computer program is executed by the processor, the processor will sequentially perform steps such as terrain survey data processing, minimum potential energy calculation, treatment unit layout, full-process non-powered sewage treatment control, and treatment effect prediction according to the instructions in the program code, ultimately completing the non-powered treatment process of decentralized rural sewage. The computer-readable storage medium facilitates long-term storage and cross-device portability of the treatment method program, supports loading and execution of the program on different computer devices, and ensures the repeatability and consistency of the treatment method in different application scenarios (such as rural areas in different regions and treatment systems of different scales). The storage medium is highly stable, can preserve the program code for a long time, avoids program loss or damage, provides a technical carrier for the promotion and application of the treatment method, and reduces the difficulty of technology dissemination and implementation.

[0049] To provide a clearer understanding of the invention, the invention is further described below: In a first aspect, this application provides a method for decentralized, non-powered wastewater treatment in rural areas utilizing terrain potential energy, the method comprising the following steps: The topographic survey and processing system layout first involves conducting topographic elevation surveys of the rural areas to be processed to obtain... The natural terrain elevation difference data (Hreal) within the area is based on the height difference between the sewage discharge point and the preset location of the treatment system. The process difference was used to determine the stepped layout scheme of the treatment system. The non-dynamic flow of wastewater was calculated using a fluid dynamics model. The minimum potential energy (H) required for movement, ensuring the natural elevation difference H is real, is expressed by the model expression: The parameters are defined as follows: H: Minimum elevation difference required by natural terrain (m), which needs to be adjusted according to the actual terrain, and is usually taken as 1.5~5.0m; Input: Friction resistance coefficient, which is related to the material of the guide pipe; for PVC pipes, take... For PE pipes, the value should be 0.03~0.05. L: Total length of wastewater flow (m), which is the sum of the lengths of the diversion pipes between each treatment unit; D: Inner diameter of the diversion pipe (m), selected according to the processing capacity, with a value of 0.1~0.3m; v: Wastewater design flow velocity (m / s), with a value of 0.4~0.8m / s, to ensure that suspended solids do not settle, while avoiding excessive head loss due to excessive flow velocity; g: acceleration due to gravity ( ),Pick ; : the sum of local resistance coefficients, including the resistance coefficients of pipe bends, tees, valves and other local components, taking the value of 1.5~3.0; : the sum of elevation differences of inlets and outlets of each treatment unit (m), the elevation difference of each unit being controlled within 0.2~0.5m; h_f: the sum of water head losses of the filter layer and the biological carrier layer (m), h_f=h1+h2, h1 being the water head loss of the enhanced filtration unit (0.3~0.8m), and h2 being the water head loss of the gravity type biological reaction unit (0.5~1.2m).

[0050] According to the calculation results of the above formula, the arrangement positions and elevations of the treatment units are adjusted to ensure that the sewage can realize continuous flow among the units only by relying on the terrain potential energy without external power driving.

[0051] The sewage collection and pretreatment collects the decentralized sewage of rural residential areas through decentralized water collection tanks or small water collection pipe networks, the outlet elevation of the water collection tank is higher than the inlet elevation of the pretreatment unit, and the sewage is guided into the pretreatment unit by using the potential energy difference. The pretreatment unit is composed of a grid assembly and a grit chamber: The grid assembly has a grid spacing of 5~10mm for intercepting large suspended solids (such as plastic bags, branches, peels, etc.) in the sewage, and the grid is designed in an inclined manner (inclination angle 60~75°) to realize natural sliding and collection of the grid residues by using the potential energy of the sewage flow; The grit chamber adopts a rectangular structure, and the hydraulic retention time is 10~20min. An inclined sand collecting groove (inclination angle 60~75°) is arranged at the bottom of the chamber, and the sand and stones in the sewage are naturally settled in the sand collecting groove under the guidance of gravity and potential energy, which can be manually cleaned regularly without the need of power sand discharging equipment.

[0052] The pretreated sewage is self-flowing into the enhanced filtration unit under the action of potential energy. The unit is internally provided with a three-layer composite filter layer, which is composed of a coarse quartz sand layer (particle size 2~4mm), a zeolite layer (particle size 0.5~1mm) from top to bottom. The thickness of each filter layer is determined by the following formula to ensure the filtration efficiency and anti-blocking performance: Wherein, each parameter is defined as follows: h_i: the thickness of the i-th layer of filter material (m), h1=0.3~0.5m for the coarse quartz sand layer, h2=0.4~0.6m for the zeolite layer, and h3=0.2~0.4m for the modified ceramsite layer; Q: the design treatment capacity of sewage (m3 / d), Q= for a single household treatment system, and Q= for a multi-household joint construction system; ​: Influent suspended solids concentration (mg / L), rural decentralized wastewater =100~300mg / L; K_i: interception coefficient of the i-th filter material layer, coarse quartz sand layer (intercept large particle suspended solids), zeolite layer (intercept medium particle suspended solids and adsorb ammonia nitrogen), modified ceramsite layer (intercept fine particle suspended solids and preliminarily degrade organic matter); : porosity of the i-th filter material layer, coarse quartz sand layer , zeolite layer , modified ceramsite layer ; p: wastewater density ( ), take ; v: filter material layer surface hydraulic load ( ), take value ; : filtration efficiency of the i-th filter material layer (%), coarse quartz sand layer , zeolite layer , modified ceramsite layer .

[0053] The composite filter material layer realizes the hierarchical interception of suspended solids through the gradient design of particle size and the optimization of material, and preliminarily removes ammonia nitrogen and part of organic matter in wastewater by using the ion exchange of zeolite and the adsorption catalysis of modified ceramsite. The porosity gradient design of the filter material layer can reduce the risk of blockage and prolong the filter replacement cycle to years.

[0054] The wastewater after enhanced filtration by gravity type biological reaction treatment continues to rely on potential energy to flow into the gravity type biological reaction unit. The unit adopts a ladder type biological filter structure, and the pool slope is consistent with the terrain slope (3~15), which ensures the uniform flow of wastewater in the pool. The biological filter is filled with a mixture of porous ceramic carriers (particle size 3~5mm) and volcanic rock carriers (particle size ), with a mixed volume ratio of 3:2, and the filler layer height is 1.0~1.5m.

[0055] The hydraulic retention time of wastewater in the biological filter is 2~4h, which relies on the potential energy of the terrain to realize continuous flow from top to bottom, and fully contacts with the microorganism flora (aerobic bacteria, facultative bacteria, and anaerobic bacteria) attached to the surface of the filler. The microorganism flora degrades COD, , etc. organic pollutants in wastewater through metabolic action, and realizes nitrification-denitrification denitrification and biological absorption of phosphorus at the same time, among which: the COD removal rate is 85%, 90% removal rate; 80% ammonia nitrogen removal rate, 70% total nitrogen removal rate; 60% total phosphorus removal rate.

[0056] The stepped design of the biofilter can form an aerobic-anoxic alternating environment, without the need for additional aeration equipment, and oxygen supply is achieved only through wastewater flow and natural air diffusion, reducing energy consumption.

[0057] The wastewater after biological reaction in the deep purification treatment is guided by potential energy to flow into the deep purification unit, which is internally filled with adsorption-catalysis composite material. The composite material is a mixed system of modified bentonite and nano zero-valent iron / activated carbon composite material with a mixing mass ratio of 5:1. Among them: The specific surface area of the modified bentonite is 800-1000 m2 / g after aluminum sulfate activation treatment. It has strong adsorption capacity for phosphorus. The nano zero-valent iron / activated carbon composite material has a nano zero-valent iron particle size of 50 nm and a loading capacity of 5%-10%, and has the functions of catalytic reduction and adsorption, which can strengthen nitrogen and phosphorus removal and degradation of trace organic matter.

[0058] The nitrogen and phosphorus adsorption capacity of the composite material satisfies the pseudo-second-order adsorption kinetics equation: Wherein, the parameters are defined as follows: q_t: adsorption capacity at time t (mg / g); q_e: equilibrium adsorption capacity (mg / g), q_e18 mg / g for ammonia nitrogen and q_e25 mg / g for total phosphorus; k: adsorption rate constant (g / (mg·h)) ), the value is ; t: adsorption time (h), the hydraulic retention time of the deep purification unit t=0.5-1.0 h.

[0059] Through deep purification treatment, the remaining nitrogen and phosphorus, trace organic matter and suspended solids in the wastewater are further removed, ensuring that the effluent water quality meets the first level A standard of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002).

[0060] The standard effluent after deep purification is discharged and reused through the self-flowing of the guide pipeline to the effluent unit, which is provided with a discharge port and a reuse interface: The discharge port is connected to a nearby ditch, farmland irrigation channel or underground infiltration system, and the effluent can be directly discharged without causing pollution to the surrounding water body; the reuse interface can be connected to the courtyard greening irrigation, farmland irrigation or toilet flushing system of the farmer to realize water resource recycling and improve the water resource utilization rate. In a second aspect, the application provides a rural decentralized sewage non-powered treatment system utilizing terrain potential energy, which is a matching device for realizing the above method and comprises a sewage collection unit, a pretreatment unit, a reinforced filtration unit, a gravity type biological reaction unit, a deep purification unit, a potential energy guiding assembly and an effluent unit, each unit is arranged in a ladder type from top to bottom along the terrain, and the specific structure is as follows: the sewage collection unit comprises a water collecting tank and a water collecting pipe network, the water collecting tank is made of PE material or concrete structure, and the volume is , the top of the water collecting tank is provided with a sealing cover and an access hole, the side is provided with a water inlet interface and a potential energy inlet interface, the water inlet interface is connected to the drainage pipeline of the farmer, the potential energy inlet interface is connected to the pretreatment unit through a flow guide pipeline, the installation elevation of the water collecting tank is 0.5-1.0 m higher than the inlet elevation of the pretreatment unit, so that the sewage can flow by itself relying on the potential energy. The pretreatment unit comprises a grid assembly and a sand trap, the grid assembly is arranged at the inlet end of the sand trap, the spacing between the grid bars is , the inclination angle is 60-75, and a grid residue collecting groove is arranged below the grid bar; the sand trap is a rectangular structure, , the inclination angle of the sand collecting groove at the bottom is 60-75, a cleaning port is arranged at the bottom of the sand collecting groove, and the inlet elevation of the pretreatment unit is 0.2-0.5 m higher than the outlet elevation, so that the sewage can flow by itself. The reinforced filtration unit is a cylindrical or rectangular pool body, the height of the pool body is 1.0-1.5 m, coarse quartz sand layer, zeolite layer and modified ceramsite layer are sequentially laid from top to bottom in the pool body, a water permeable partition plate (with a pore diameter of 0.1-0.2 mm) is arranged between each filter material layer to prevent the filter materials from mixing; a water inlet (connected to the outlet of the pretreatment unit) is arranged at the top of the pool body, and a water outlet (connected to the inlet of the gravity type biological reaction unit) is arranged at the bottom of the pool body, the water inlet elevation is 0.3-0.8 m higher than the water outlet elevation, so that the water head loss of the filter material layer is formed to ensure the filtration effect.

[0061] The gravity type biological reaction unit is a ladder type pool body, the length of the pool body is 3-8 m, the width is 1-3 m, and the height is 1.2-2.0 m, the slope of the pool body is consistent with the slope of the terrain (3-15), the pool is filled with mixed fillers of porous ceramic carriers and volcanic rock carriers, the height of the filler layer is 1.0-1.5 m, and a 0.2-0.5 m clear water area is reserved above the filler layer; a water distribution device (a porous water distribution pipe) is arranged at the inlet end of the pool body to ensure that the sewage is uniformly distributed, a water baffle is arranged at the outlet end to control the hydraulic retention time, and the inlet elevation of the pool body is 0.5-1.2 m higher than the outlet elevation, so that the sewage flows by relying on the potential energy.

[0062] The deep purification unit is a cylindrical pool with a diameter of 1-2m and a height of 0.8-1.2m. It is filled with an adsorption-catalysis composite material to a height of 0.6-1.0m. A permeable cover is installed above the material, and a support layer (quartz sand, particle size...) is installed below. (Thickness 0.1~0.2m); the inlet elevation of the pool is 0.1~0.3m higher than the outlet elevation to ensure that the sewage and composite material are in full contact and react, with a hydraulic retention time of 0.5~1.0h.

[0063] The potential energy guiding components include a flow guiding pipe, a flow guiding channel, a slope adjustment structure, and an anti-backflow device. The diversion pipe is made of PVC or PE material, with an inner diameter of 0.1~0.3m and a pipe slope of 1%~3% to ensure smooth sewage flow and no sedimentation. The flow guide channel is located at the connection of each unit, adopts a U-shaped structure, has a width of 0.1~0.2m, a depth of 0.1~0.3m, and a slope consistent with the pipeline slope; The slope adjustment structure consists of retractable support legs located at the bottom of each processing unit. The height adjustment range of the support legs is [not specified]. By adjusting the height of the support legs, the central axis of each unit is made to form an angle of 3 to 15 degrees with the terrain contour line, ensuring that the potential energy required for sewage flow is met; The backflow prevention device has a built-in float-type check valve located at the inlet of each unit. It automatically opens and closes based on the difference in fluid static pressure and potential energy to prevent sewage backflow.

[0064] The water outlet unit includes an outlet tank and a reuse pipeline interface; the outlet tank volume is... It is used for temporary storage of qualified effluent. The effluent tank is equipped with a discharge outlet and a reuse interface. The discharge outlet is equipped with a water quality monitoring probe (which can monitor COD, ammonia nitrogen, and suspended solids concentration). The reuse interface is connected to the farmer's irrigation system or toilet flushing system through a pipeline to realize the recycling of water resources.

[0065] To better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments.

[0066] Example 1: Decentralized rural sewage treatment system for a single household Topographical survey: The terrain around a rural household's house is a gentle slope. The elevation difference Hactual between the sewage discharge point and the low-lying area of ​​the courtyard is 2.5m, which meets the minimum potential energy requirement (calculated as H = 1.8m). System layout: Wastewater collection units (collection tanks, volume) are arranged sequentially from top to bottom along the terrain. The system consists of: a pretreatment unit (grit + grit chamber, elevation 99.5m), an enhanced filtration unit (elevation 99.0m), a gravity biological reactor unit (elevation 98.2m), a deep purification unit (elevation 98.0m), and an effluent unit (elevation 97.9m). Process parameters: Design treatment capacity , Influent water quality: COD = 250 mg / L, = 120 mg / L, ammonia nitrogen = 30 mg / L, total phosphorus = 5 mg / L, suspended solids = 200 mg / L; Pretreatment unit: grid bar spacing 8 mm, grit chamber hydraulic retention time 15 min; Enhanced filtration unit: coarse quartz sand layer h1 = 0.4 m, zeolite layer h2 = 0.5 m, modified ceramsite layer h3 = 0.3 m, determined by formula calculation; Gravity type biological reaction unit: length 4 m, width 1.5 m, height 1.5 m, slope 5, mixed filler layer height 1.2 m, hydraulic retention time 3 h; Deep purification unit: diameter 1.2 m, height 1.0 m, composite material filling height 0.8 m, hydraulic retention time 0.8 h; Treatment effect: effluent water quality COD = 42 mg / L, = 8 mg / L, ammonia nitrogen = 4.5 mg / L, total phosphorus = 0.4 mg / L, suspended solids = 8 mg / L, reaching the first level A standard, effluent water used for courtyard greening irrigation.

[0067] Example 2: Multi-family joint rural decentralized sewage treatment system Topographic survey: The topography of a rural village is hilly and sloping land, 10 farmers live together, the elevation difference Hreal = 4.0 m between the sewage collection point and the village ditch, the minimum potential energy H = 2.8 m is calculated, which meets the requirements; System layout: arrange the water collection pipe network from top to bottom along the terrain Sewage collection unit (water collection tank, volume , elevation 120.0 m) Pretreatment unit (elevation 119.5 m) Enhanced filtration unit (elevation 118.8 m) Gravity type biological reaction unit (elevation 117.6 m) Deep purification unit (elevation 117.4 m) Effluent unit (elevation 117.3 m), effluent discharged into the ditch or used for farmland irrigation; Process parameters: design treatment capacity , Influent water quality: COD = 280 mg / L, = 130 mg / L, ammonia nitrogen = 35 mg / L, total phosphorus = 6 mg / L, suspended solids = 250 mg / L; enhanced filtration unit: coarse quartz sand layer h1 = 0.5 m, zeolite layer h2 = 0.6 m, modified ceramsite layer h3 = 0.4 m; gravity type biological reaction unit: length 6 m, width 2.5 m, height 1.8 m, slope 8, mixed filler layer height 1.5 m, hydraulic retention time 3.5 h; treatment effect: effluent water quality COD = 45 mg / L, = 9 mg / L, ammonia nitrogen = 4.8 mg / L, total phosphorus = 0.45 mg / L, suspended solids = 9 mg / L, reaching the first level A standard, ton of water operation cost 0.04 yuan, operation and maintenance cycle is to clean the grid residue and sand once every quarter, and the filter material and composite material are replaced once every 1.5 years. The above examples prove that the treatment method and system of the present application can stably and efficiently treat rural dispersed sewage, and is operated without power and is easy to operate and maintain, and is suitable for rural scene popularization and application. The technical scheme provided by the embodiments disclosed in the present application has the following beneficial effects: power-free operation, suitable for rural scenes: making full use of the natural terrain difference in rural areas, accurately calculating the potential energy demand through a fluid mechanics model, realizing the power-free self-flow of sewage between the various treatment units, without the need for power devices such as water pumps and aeration equipment, solving the problems of unstable power supply and high operation cost in rural areas, with a ton of water operation cost of less than 0.05 yuan, which is much lower than the existing powered treatment technology (0.3-1.0 yuan / ton of water); high treatment efficiency, excellent effluent water quality: adopting a composite treatment process of pretreatment + enhanced filtration + gravity type biological reaction + advanced purification, targetedly removing suspended solids, organic matter, nitrogen and phosphorus and other pollutants in rural dispersed sewage, with the effluent water quality reaching the first level A standard of the “Urban Wastewater Treatment Plant Pollutant Discharge Standard” (GB 18918-2002), COD 50 mg / L, 10 mg / L, ammonia nitrogen 5 mg / L, total phosphorus 0.5 mg / L, suspended solids 10 mg / L, which can be directly discharged or reused; Anti-clogging design, easy to operate and maintain: the composite filter material layer adopts a particle size gradient design and a high porosity material, combined with the self-cleaning effect of potential energy guidance, which greatly reduces the risk of clogging, and the filter material replacement cycle is extended to 1-2 years; the pretreatment unit and the biological reaction unit do not require power equipment, and only need to be manually cleaned of grid residue and sand at regular intervals, with small operation and maintenance workload, which is suitable for scenes in rural areas lacking professional operation and maintenance personnel; Modular layout, suitable for complex terrain: the treatment system adopts a modular design, and each unit can be flexibly adjusted in position and elevation according to the terrain difference, and is adapted to different rural terrains (3-15) through slope adjustment structures, which is suitable for single-family dispersed treatment, and can also be built together with multiple families to form a small treatment station, without the need for large-scale pipe network laying, with low investment cost (single-family system investment 0.5-1.5 thousand yuan, multiple-family joint construction system ton of water investment 1.0-2.0 thousand yuan); Water resource recycling: the standard effluent can be used for courtyard greening irrigation, farmland irrigation, toilet flushing, etc., realizing the recycling of rural water resources, alleviating the problem of rural water resource shortage, and meeting the demand of water-saving society construction.

[0068] In summary, the application solves the technical bottleneck of rural decentralized sewage treatment by precise utilization of topographic potential energy and optimization of composite treatment process, has the advantages of no power, high efficiency, low cost, simple operation and maintenance, strong adaptability, etc., and can be widely applied to rural water pollution control.

[0069] The technical solutions provided by the embodiments of the application are described in detail above, specific examples are applied in this paper to describe the principles and implementation modes of the embodiments of the application, and the above embodiment descriptions are only applicable to help understand the principles of the embodiments of the application; meanwhile, for those skilled in the art, the specific implementation modes and application ranges of the embodiments of the application will be changed, and the content of the specification should not be understood as a limitation of the application.

Claims

1. A method for non-powered treatment of rural decentralized wastewater using topographic potential energy, characterized by, The method comprises the following steps: Surveying topographic elevation data of a rural area to be treated, determining natural terrain elevation difference based on the topographic elevation data, calculating minimum potential energy required for unpowered flow of sewage by a fluid mechanics model, and arranging stepped treatment units according to the natural terrain elevation difference and the minimum potential energy; Collecting rural scattered sewage by a sewage collection unit, and driving the sewage to flow into a pretreatment unit by potential energy formed by the natural terrain elevation difference to remove large suspended solids and sand in the sewage; The pretreated sewage flows into an enhanced filtration unit under the action of the potential energy, and is intercepted and filtered and preliminarily degraded of pollutants by a composite filter layer; The filtered sewage continues to flow into a gravity type biological reaction unit under the action of the potential energy, and is subjected to deep conversion and removal of organic pollutants and nitrogen and phosphorus by microorganism groups on biological carriers; The sewage after biological reaction is guided to flow into a deep purification unit by the potential energy, and is subjected to tail water purification by adsorption-catalysis composite materials; The purified effluent is directly discharged or introduced into a reuse pipe network to achieve unpowered treatment of rural scattered sewage.

2. The method for non-powered treatment of rural decentralized wastewater using topographic potential energy according to claim 1, characterized in that: The calculation of the minimum potential energy required for unpowered flow of sewage by the fluid mechanics model specifically comprises: Based on Darcy's law and water head loss theory, a potential energy calculation model for unpowered flow of sewage is constructed, and the model expression is: H is the minimum height difference required by natural terrain; is the along-path resistance coefficient, with a value of ; L is the total length of the sewage flow; D is the inner diameter of the diversion pipe; v is the design flow rate of the sewage; g is the gravitational acceleration; is the sum of the local resistance coefficients, with a value of ; is the sum of the elevation differences of the inlets and outlets of the respective treatment units; h_f is the sum of the water head losses of the filter layer and the biological carrier layer, h_f = h1 + h2, h1 is the water head loss of the enhanced filtration unit, and h2 is the water head loss of the gravity-type biological reaction unit.

3. The method for non-powered treatment of rural decentralized wastewater using topographic potential energy according to claim 1, characterized in that: The pre-treatment unit comprises a grid assembly and a grit chamber, the grid assembly has a grid spacing of , the grit chamber has a hydraulic retention time of , and the bottom of the grit chamber is provided with an inclined sand collecting groove, the inclined angle of the sand collecting groove is , and the sand is naturally settled and collected by using potential energy.

4. The method for non-powered treatment of rural decentralized wastewater using topographic potential energy according to claim 1, characterized in that: The composite filter material layer of the reinforced filter unit is sequentially composed of a coarse quartz sand layer, a zeolite layer and a modified ceramic layer from top to bottom, and the thickness of each layer satisfies the formula: ; Wherein, h_i is the i-th layer filter material thickness; Q is the design sewage treatment capacity; is the influent suspended solids concentration; K_i is the i-th layer filter material interception coefficient, coarse quartz sand layer , zeolite layer , modified ceramsite layer ; is the i-th layer filter material porosity, coarse quartz sand layer , zeolite layer , modified ceramsite layer ; p is the sewage density; v is the filter material layer surface hydraulic load; is the i-th layer filter material filtration efficiency.

5. The method for non-powered treatment of rural decentralized wastewater using topographical potential energy according to claim 1, characterized in that: The gravity type biological reaction unit is a stepped biological filter tank, which is internally filled with mixed fillers of porous ceramic carriers and volcanic rock carriers at a volume ratio of 3:2, and the slope of the tank body is consistent with the terrain slope, the hydraulic retention time of the sewage in the tank is 2-4 h, and the sewage is subjected to continuous flow and microorganism contact reaction from top to bottom by the potential energy.

6. The method for non-powered treatment of rural decentralized wastewater using topographical potential energy according to claim 1, characterized in that: The adsorption-catalysis composite materials of the deep purification unit are a mixed system of modified bentonite and nano zero-valent iron / activated carbon composite materials at a mass ratio of 5:1, and the nitrogen and phosphorus adsorption capacity thereof satisfies a pseudo-second-order adsorption kinetics equation: wherein q_t is the adsorption capacity at t time, q_e is the equilibrium adsorption capacity, q_e is 18 mg / g for ammonia nitrogen and q_e is 25 mg / g for total phosphorus, k is the adsorption rate constant, and t is the adsorption time.

7. The method for non-powered treatment of rural decentralized wastewater using topographical potential energy according to claim 1, characterized in that: The potential energy guiding structure comprises a flow guide groove and an anti-backflow device, the slope of the flow guide groove is 1%-3%, the anti-backflow device is internally provided with a floating ball type one-way valve, and automatic opening and closing are realized based on the difference between the fluid static pressure and the potential energy.

8. A non-powered treatment system for rural decentralized wastewater using topographic potential energy, characterized by, The method comprises the following steps: A sewage collection unit is used to collect rural scattered sewage, and the collection unit is provided with a potential energy introduction interface; A pretreatment unit is connected to the sewage collection unit by a flow guide pipeline, and is used to remove large suspended solids and sand, and the inlet elevation of the pretreatment unit is higher than the outlet elevation; An enhanced filtration unit is arranged below the pretreatment unit, and receives the pretreated sewage by a flow guide structure, and is internally provided with a composite filter layer; A gravity type biological reaction unit is arranged below the enhanced filtration unit, and is in communication with the enhanced filtration unit, and is internally filled with biological carriers; A deep purification unit is arranged below the gravity type biological reaction unit, and is used for tail water purification; A potential energy guiding assembly comprises a flow guide groove, a slope adjusting structure and an anti-backflow device, and is used to guide the unpowered flow of the sewage between the units by terrain potential energy; An effluent unit is connected to the deep purification unit, and is used for discharge or reuse of the effluent meeting the standard.

9. A computer device, comprising: The computer device comprises a memory and a processor, the memory stores a computer program, and the processor is configured to execute the computer program to realize the potential energy calculation, filter material parameter optimization and treatment effect prediction steps in the rural decentralized sewage non-powered treatment method using terrain potential energy according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program is executed by the processor to realize the rural decentralized sewage non-powered treatment method using terrain potential energy according to any one of claims 1 to 7.

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