CN109160702B - Method suitable for comprehensive treatment of excrement in medium and small livestock farms - Google Patents

Abstract

The invention discloses a method suitable for the comprehensive treatment of feces in medium and small-sized livestock farms, wherein the feces are transported outside and returned to the field after aerobic composting fermentation or composting fermentation; the sewage of livestock breeding is treated by a methane tank or a three-grid septic tank, the generated methane slag and excrement are composted together or composted and returned to the field, the generated methane liquid enters a methane liquid storage tank, the methane generated by the methane liquid storage tank and the methane generated by the methane tank or the three-grid septic tank are dehydrated and desulfurized together and then are used for in-field living energy, and part of the methane liquid in the methane liquid storage tank is transported outside and returned to the field; the domestic sewage and the other part of biogas slurry enter an aeration tank for treatment, and the effluent of the aeration tank sequentially enters a plant pond, an ecological ditch and an ecological pond; rainwater and the effluent of the ecological ditch enter the ecological pond together, and the effluent of the ecological pond is partially used as the water for washing the colony houses in the farm and is partially directly discharged. The method takes a biological method and an ecological treatment method as the core, simultaneously solves the problems of treatment and export of the production and living manure in the farm, and has great popularization and utilization values.

Description

Method suitable for comprehensive treatment of excrement in medium and small livestock farms

Technical Field

The invention belongs to the field of environmental protection and renewable resource development and utilization, and particularly relates to a method suitable for comprehensive treatment of feces in medium and small livestock farms.

Background

With the rapid development of the economy of China and the improvement of the living standard of people, the consumption of meat products is increased year by year. When livestock breeding provides meat products for residents, a large amount of breeding manure generated in the breeding process is reasonably treated if the breeding manure is not timely treated, and the breeding manure pollutes the surrounding water, soil and gas environment and becomes an important source of environmental pollution. According to the first national pollution source census data, the agricultural non-point source exceeds the industrial source and becomes the first major pollution source of the environmental pollution in China, and the livestock and poultry breeding pollution is the main source of the agricultural non-point source pollution. Therefore, in recent years, the attention on pollution control of livestock and poultry breeding is continuously increased, and related technologies are continuously emerged, and the method mainly comprises 3 modes of returning to fields after innocent treatment, standard discharge, ecological treatment and the like. Wherein, discharge up to standard is all higher because of its disposable investment and running cost, only uses at partial oversize and large-scale plant, and ecological treatment is applicable to the plant that does not have enough soil in the plant periphery but self possess a small amount of soil, and returning the field after the dirty innocent treatment of excrement is applicable to the plant that has enough farmland in the periphery.

In recent years, with the continuous promotion of agricultural environmental protection work and the annual decline of farmland soil quality, organic fertilizers are promoted to replace fertilizers and are used as important work of agricultural departments. Wherein, returning the feces to the field in the farm belongs to the important content of fertilizer reduction. At present, livestock breeding pollution dominates in livestock breeding in China, particularly, breeding of live pigs and cows and a large amount of breeding sewage generated in the livestock breeding process has the characteristics of high COD (chemical oxygen demand) and high nitrogen and phosphorus content, contains a certain amount of ascarid eggs, heavy metals, antibiotics and other toxic and harmful substances, and generates serious pollution to the surrounding ecological environment when directly discharged. The method has the advantages that the feces produced by the livestock and poultry farm is returned to the field after harmless treatment, the problem of treatment of the feces is solved, the soil can be fertilized, the application amount of chemical fertilizers is reduced, and the organic combination of the breeding industry is realized. However, from the current practical situation, due to long-term planting and breeding separation, the planting industry is not basically cultivated, the breeding industry is not basically provided with matched farmlands, and in recent years, the livestock breeding industry continuously pursues scale, and the scale of a single livestock farm is too large, so that the difficulty is increased for planting and breeding combination.

After the treatment of the recent 20 years, the treatment work of the large and super-large livestock breeding pollution is basically in place, and the corresponding fecal sewage treatment facility and the operation mechanism are basically established, so that the treatment work of the fecal sewage of the medium and small livestock breeding farm mainly comprising farmers just starts, and the treatment difficulty is higher. Due to the fact that the breeding scale is general, the economic benefit is poor, and the risk resistance is low, the standard reaching discharge mode is obviously not suitable after the excrement treatment of a large-scale farm, the mode of returning the whole amount of the excrement to the field does not have enough farmland, and an excrement returning mechanism is not established yet. Therefore, for the farms with the scale, the mode of returning the manure to the field and ecologically purifying is more easily accepted by farmers. The mode solves the problem of returning the excrement to the field and the problem of no place for arranging the redundant excrement, and is suitable for most small and medium-sized farms.

In view of the characteristics of the small and medium-sized livestock farms in producing the excrement and the problem of narrow application range of a single excrement treatment mode, the applicant provides a method suitable for comprehensively treating the excrement and the sewage of the small and medium-sized livestock farms by inquiring a large amount of domestic and foreign literature data and on the basis of a large amount of experimental verification. On one hand, returning the manure to the field reduces the treatment amount of the manure, fertilizes the soil, reduces the using amount of chemical fertilizer, and improves the quality of agricultural products and the soil fertility; on the other hand, the redundant sewage adopts the ecological purification mode, and the play water part is used for colony house sparge water in the scene after disinfecting, and partial discharge up to standard. Through a plurality of earlier stage engineering applications, prove that the method of the application can solve the contradiction between the returning of the manure and the ecological purification of the sewage at the same time, and is suitable for most of medium and small-sized livestock farms. The method has the characteristics of wide applicability, one-time investment saving in fecal sewage treatment, low operation cost, good treatment effect, small occupied area and the like, and has a wide application prospect.

Disclosure of Invention

The invention aims to provide a method suitable for comprehensive treatment of excrement in small and medium-sized livestock farms. The method can simultaneously meet the requirements of sewage harmless returning, reclaimed water recycling and standard discharge, and has the advantages of one-time investment saving, low operation cost and convenient operation and management. The treatment system consists of a fecal sewage harmless treatment unit, a sewage storage unit, a sewage ecological purification unit and a fecal sewage farmland utilization unit, wherein the treatment objects comprise livestock manure, breeding sewage, rainwater and domestic sewage generated in a field area, and zero emission of livestock breeding wastes is realized. The method is suitable for the medium and small livestock farms, wherein the farmlands with certain areas around the farms are not enough to absorb all the excrement generated by the farms.

The technical scheme adopted by the invention is as follows:

a method suitable for the comprehensive treatment of excrement and sewage in medium and small-sized livestock farms, wherein the excrement and sewage comprises excrement (A), livestock breeding sewage (B), domestic sewage (C) and rainwater (D), and the excrement (A) is transported outside and returned to the field after aerobic composting fermentation or composting fermentation; the livestock breeding sewage (B) is treated by a methane tank or a three-grid septic tank, the generated methane slag and excrement are composted together or composted and returned to the field (A2), the generated methane liquid enters a methane liquid storage tank (2), the methane generated by the methane liquid storage tank (2) and the methane (1) generated by the methane tank or the three-grid septic tank (B1) are dehydrated and desulfurized together and then are used for in-field living energy, and part of the methane liquid (3) in the methane liquid storage tank (2) is transported outside and returned to the field; the domestic sewage (C) and the other part of biogas slurry (3) enter an aeration tank (C1) for treatment, and the effluent of the aeration tank (C1) sequentially enters a plant pond (4), an ecological ditch (5) and an ecological pond (D1); the rainwater (D) and the effluent of the ecological ditch (5) enter an ecological pond (D1), and part of the effluent of the ecological pond (D1) is used as the water for flushing the colony houses in the farm and part of the effluent is directly discharged.

The medium and small-sized livestock farm refers to a pig farm with live pigs kept at a position above 200 heads and below 2000 heads, and other livestock are converted by a method of converting into equivalent weight of the pigs; the livestock refers to animals such as pigs, cows, sheep, donkeys and the like which are usually raised in China and provide meat and milk products for residents, farmlands with certain areas are arranged around the livestock farms, but the areas of the farmlands are not enough to fully consume all excrement produced by the livestock farms.

The aeration tank (C1), the plant pond (4), the ecological ditch (5) and the ecological pond (D1) are sequentially connected in series, and the effluent flows to the next stage step by step in a self-overflow mode.

Further, the aeration tank (C1), the plant pond (4), the ecological ditch (5) and the ecological pond (D1) are sequentially connected in series through a pipeline or a sewage ditch

The excrement is collected by a dry excrement cleaning process, and if the water content of the excrement is higher than 80%, the excrement needs to be subjected to solid-liquid separation by a solid-liquid separator and then subjected to aerobic composting fermentation or composting fermentation, or the water content of the excrement is regulated to 50% -60% by adding dry materials and then used for composting treatment.

Further, the dry material is one or more of crushed dry straw, sawdust, waste edible fungus base stock, farm padding, dry branches and fallen leaves, charcoal and decomposed compost.

The livestock breeding sewage and sewage (B) is urine discharged by livestock, flushing colony house water and water leakage of drinking water, COD and nitrogen and phosphorus concentration in the sewage are relatively high, after anaerobic treatment by a methane tank or a three-grid septic tank (specifically determined according to the scale of a farm), solid parts are composted together with dry manure after solid-liquid separation and returned to the field, the produced methane is used for domestic energy such as cooking in the farm, and the produced methane liquid enters a methane liquid storage tank for storage.

Three manure pits of cutting into squares comprise the sealed manure pit of three check rooms of two excrement pipe intercommunications, the first pond of the sealed manure pit of three check rooms: a second pool: the volume ratio of the third pool is 2: 1: 3, the sewage depth of the first pool and the second pool is not less than 1.0 m.

The shape of crossing excrement pipe is lute shape, and the bore is 150 millimeters, advances excrement pipe lower extreme and sinks under the excrement liquid level, and its degree of depth is 1/2 departments of excrement liquid level height, three manure pits of check are the brick structure, need make waterproof measure, and the top is sealed with the apron, and the third check can not be sealed, but need do rain-proofly, and the pool wall highest point needs to be higher than the earth's surface 20cm, avoids peripheral rainwater to merge into.

The methane Tank can adopt an Upflow Solid anaerobic Reactor (USR), a fully mixed anaerobic Reactor (CSTR), a Plug Flow Reactor (PFR) or a mode of connecting a plurality of household methane tanks in series, so as to reduce the construction cost of the methane Tank.

The biogas slurry in the biogas slurry storage tank (2) can enter the next treatment process after being stored for at least 3 months, and a large amount of pathogenic microorganisms in the biogas slurry can die through long-time biogas slurry storage so as to achieve the aim of harmless treatment; the highest position of the wall of the biogas slurry storage tank (2) needs to be higher than the ground surface by more than 20cm so as to avoid the inflow of peripheral rainwater; the biogas slurry storage tank can be built by adopting a steel-concrete structure, a brick-concrete structure or a mode of covering an impermeable membrane after digging a pit by using a digging machine.

The domestic sewage (C) is rice and vegetable washing water, domestic water and toilet water which are generated in daily life of workers in the livestock breeding field, has the characteristics of high Suspended Solids (SS), high nitrogen and phosphorus, low COD and the like, and has low COD, TN and TP concentrations, so the domestic sewage (C) and the biogas slurry in the biogas slurry storage tank are treated by a subsequent biological-ecological purification system and then reach the standard to be discharged.

The biological-ecological purification system consists of an aeration tank (C1), a plant pond (4), an ecological ditch (5) and an ecological pond (D1), wherein the treatment units are connected through pipelines or ditches, and sewage sequentially passes through the aeration tank, the plant pond, the ecological ditch and the ecological pond to realize biological purification. The aeration tank mainly plays the purpose of removing COD and a small amount of nitrogen phosphorus in the sewage, and plant pond, ecological ditch and ecological pond mainly play the effect of getting rid of nitrogen phosphorus and suspended solid in the sewage, and ecological pond effluent discharge to reach standard, and some effluent is used for the colony house after the disinfection and washes the water.

The aeration tank (C1) adopts a sequencing batch activated sludge process, namely a batch water feeding and discharging mode, and is particularly suitable for discharging the sewage in medium and small livestock farms. The aeration tank is of a steel-concrete or brick-concrete structure, waterproof measures need to be taken, two jet flow aeration machines are arranged at the bottom of the aeration tank (C1) in an oblique diagonal manner to realize the aeration and mixing of sewage in the aeration tank, and the aeration of a conventional submersible centrifugal pump can also be adopted.

The plant pond (4) is used for removing pollutants such as suspended solids, partial Chemical Oxygen Demand (COD) and nitrogen and phosphorus in sewage. The plant pond can be reformed and derived based on the original pond or the bricked sewage pond in the field, the appearance is the optimum rectangle, is divided into 3 ~5 grids along the pond length direction, and the division wall height between every two grids from the water inlet direction reduces 20cm ~ 30cm gradually, all plants aquatic plant in every cell.

The plant pond (4) is preferably rectangular.

Furthermore, from the water inlet direction, duckweed, water peanuts and water hyacinth are planted in each cell in sequence.

The side surface of the ecological ditch (5) is trapezoidal, brick layers are laid on the bottom and the side surface of the whole ecological ditch (5), impermeable films are covered on the brick layers, and soil layers of 30-50 cm are backfilled on the impermeable films.

The specifications of the ecological ditch (5) are that the upper width is 3m, the lower width is 1m, the depth is 1.5m, and the water depth is about 0.8 m. In order to save land, the ditch can be built into a bow shape, and the distance between ditches is not less than 1 m.

The ecological ditch (5) is divided into 3-5 grids, the height difference between the division of the former grid and the division of the latter grid is 10-20 cm, natural falling is formed, and emergent aquatic plants and submerged plants are planted in each grid; aquaculture can also be carried out in the last two compartments.

Slope protection is arranged on two sides of the ecological ditch (5), and plants which grow fast, have strong adaptability, are few in plant diseases and insect pests, and are resistant to barren soil and deep root are planted and comprise one or more of zoysia japonica, wild cattle grass, bermuda grass, carpet grass, blumea, eremochloa ophiuroides, ryegrass, poa pratensis and glume-cutting.

Furthermore, the aquatic plant planting categories from the water inlet direction to the water outlet direction are as follows in sequence: in the first case, canna, thalictrum ramosissimum and calamus are planted in emergent aquatic plants, and watery plants are planted with watery green foxtail algae and tape grass; planting iris hemsleyana, thalictrum ramosissimum and saxifrage in emergent aquatic plants, and planting watermifera and gynura bicolor in submerged plants; thirdly, planting rush, reed and cattail on the emergent aquatic plants, and planting ulva pulchroides and potamogeton crispus on the submerged plants; and fourthly, planting arrowhead, water dropwort, water bamboo and giant reed on emergent water plants and planting waterweed and water caltrop on submerged plants.

Further, the two compartments are separated by pebbles or broken stones.

The ecological pond (D1) is an outlet for sewage ecological purification and is also a place for rainwater treatment, a water inlet of the ecological pond is in a fan shape, emergent aquatic plants and floating plants are planted around the water inlet, emergent aquatic plants are planted around the ecological pond (D1) to form an emergent aquatic plant zone, and shrubs are planted on river banks to protect the slope; submerged plants are planted at the bottom of the pond, perennial herbaceous plants are planted on the side slope, and aquaculture can be carried out in the pond.

Further, the emergent aquatic plant is one or more of reed, calamus, cattail, thalictrum ramosissimum and arundo donax; the floating plant is one or more of medulla Junci, herba Picrasmae, curly pondweed, and Focus vesiculosus; the width of the emergent aquatic plant belt is 2 m; the shrub is bamboo willow and/or shrub willow; the submerged plant is one or more of waterweed, watermifoil and gynura bicolor; the perennial herb is one or more of bermuda grass, clover and ryegrass.

Furthermore, the land and aquatic plant coverage area of the slope protection accounts for more than 50% of the engineering construction area of the ecological pond (D1), wherein the cold-resistant aquatic plants account for more than 75% of the total area of the aquatic plants. In addition, a small amount of spotted silver carps, silver carps and other fishes which eat plankton, snails, freshwater mussels and the like can be put in the pond, so that the aquatic ecosystem is enriched, and the purification capacity of the system is enhanced.

The rainwater (D) is collected by rainwater pipelines in the field, the COD, TN and TP contents of the rainwater are lower, but the direct discharge still has the risk of environmental pollution, so the rainwater (D) is collected and then enters the ecological pond to be purified and then is discharged.

Compared with the prior art, the invention has the following beneficial effects:

1. the method has wide application range, is suitable for most of medium and small livestock farms, and has low requirement on hardware conditions of the farms;

2. the method has the advantages of low one-time investment, low operation cost, simple process, strong operability, convenient operation management, low energy consumption in the operation process and little economic benefit.

3. The excrement is returned to the field after harmless treatment, part of the sewage is returned to the field after the harmless treatment, and part of the sewage is used as water for washing the colony house after advanced treatment, so that the demand of the livestock breeding process on clean water is reduced, and part of aquatic plants obtained by the advanced treatment of the sewage can be used as livestock feed, so that the feeding cost is reduced; aquatic vegetables such as water bamboo cress planted in the ecological ditch and the ecological pond and aquatic animals such as silver carp and loach bred have certain economic value, and the sewage treatment cost is reduced.

4. The sewage treatment process is clean and pollution-free, has no potential secondary pollution problem, and the ecological and sanitary environment in the farm area is improved by planting a large number of plants.

Drawings

FIG. 1 is a flow chart of a comprehensive treatment process of feces in a medium and small livestock farm.

Fig. 2 is a schematic cross-sectional view of an ecological trench.

Fig. 3 is an ecological pond plant map.

Detailed Description

The comprehensive treatment method of the excrement and sewage in the medium and small-sized livestock farms is explained in detail in the following with reference to the attached drawings of the specification.

The invention relates to a method suitable for comprehensive treatment of feces in medium and small-sized livestock farms, which comprises feces (A), livestock breeding sewage (B), domestic sewage (C) and rainwater (D). Collecting excrement (A) by a dry excrement cleaning process, adding a small amount of dry materials, performing high-temperature aerobic composting or directly composting (A1) and then transporting the excrement to return to the field (A2); livestock breeding sewage (B) is collected by a sewage collecting pipe and then enters a methane tank or a three-grid septic tank (B1) for treatment, generated methane (1) is used for in-situ domestic energy, generated methane slag (B2) and dry manure are composted together (A1) and then returned to the field (A2), generated methane liquid enters a methane liquid storage tank (2), a small amount of methane generated by the methane liquid storage tank (2) and the methane (1) generated by the methane tank or the three-grid septic tank (B1) are dehydrated and desulfurized together and then are used for in-situ domestic energy, part of the methane liquid (3) in the methane liquid storage tank (2) is transported to a peripheral farmland (A2) by a methane liquid transport vehicle, and the rest of the methane liquid in the methane liquid storage tank (2) sequentially enters an aeration tank (C1), a plant pond (4), an ecological ditch (5) and an ecological pond (D1) for treatment, and then a part of the effluent is used for flushing water in-yard after ultraviolet disinfection, and the rest of the water is discharged, the aeration tank (C1), the plant pond (4), the ecological ditch (5) and the ecological pond (D1) are connected in series through pipelines or sewage ditches, and sewage flows to the next stage step by step in a self-overflow mode; domestic sewage generated in the culture area is collected by a pipeline and then enters an aeration tank (C1) to be purified together with the effluent of the biogas slurry storage tank; rainwater in the culture field needs to be collected separately from sewage, and the collected rainwater (D) enters an ecological pond (D1) and is recycled or discharged after reaching the standard after being purified by the ecological pond (D1).

The invention relates to a method for comprehensively treating feces in a medium and small livestock farm, which has the specific flow and part of structures shown in the attached drawings. Facilities such as a methane tank, a three-grid septic tank, an aeration tank, a plant pond, an ecological ditch, an ecological pond and the like related to the method are known by the technical personnel in the field except for the technical characteristics described in the specification.

The advantageous effects of the present invention are further illustrated by the following examples.

Example 1

Taking 1500 live pigs in one stock pen, wherein, taking a pig farm with about 100 sows as an example, the pig farm produces about 650 tons of pig manure per year, the actual collectable amount is about 600 tons, and the annual sewage is about 4400 tons. The total volume of the pig farm is 300m³1 biogas generating pit with total volume of 70m³Sewage storage pool of 170m³Aeration tank, 216m³Biogas slurry storage pool and 120m²1 dry manure piling site is arranged in each, and a fishpond with the area of about 20 mu is arranged in each dry manure piling site. The pig farm has farmlands of only more than ten mu, but has a large number of farmlands near the pig farm, and the condition for treating the excrement by adopting the process is met.

According to the process requirement, the facilities for collecting, storing and treating the excrement in the pig farm are modified, and a rainwater and domestic sewage collecting pipe network is added. The construction content comprises the following steps: firstly, according to the requirements of rainwater and sewage diversion and dry-wet separation, respectively building a sewage and rainwater collection pipe network, respectively collecting aquaculture sewage, domestic sewage and rainwater in a field, sealing the aquaculture sewage and domestic sewage collection pipe channels to prevent rainwater from entering, and building a rain shelter at the top of a sewage collection pool; replacing submerged aerators in the aeration tank with submersible jet aerators, wherein the two submerged aerators are distributed diagonally in the aeration tank; (iii) construction of plant ponds 480m³The specification is 16m multiplied by 10m multiplied by 3m, the brick-concrete structure is evenly divided into 4 grids along the length direction, and different floating plants are planted in each grid; fourthly, newly building an ecological ditch with the cross section as shown in figure 2, digging earth by using an excavator, then laying a layer of bricks, covering an impermeable film on the bricks, finally backfilling soil with at least 30cm on the impermeable film, planting a large number of emergent aquatic plants, submerged plants and floating plants in the ecological ditch, dividing the ecological ditch into 4 sections along the length direction, separating each two sections by pebbles or broken stones, forming natural falling water by the difference of the height of the separation of the previous section and the separation of the next section by 15cm, and forming natural falling water by the previous two sectionsAquatic plants with strong pollution resistance and high growth speed are selected, and finally, water cress and water bamboo are planted in the two sections, river snails and crucian are bred, so that the water body is purified, and certain economic benefit is realized; fifthly, transforming a 20 mu fish pond in the field into an ecological pond as the last stage of ecological sewage purification treatment, planting a large amount of emergent aquatic and floating plants including reed, calamus, cattail, thalictrum, arundo donax, juncus, sowthistle, potamogeton crispatus and watermifoil in a fan shape near a water inlet of the ecological pond, planting a large amount of reed, cattail and watermifoil plants around the pond to form an emergent aquatic plant zone with the width of 2m, planting a large amount of bamboo willow and shrub willow on a river bank to protect a slope, planting waterweed, ulva pulchroo, watery foxtail and eyeweed submerged plants at the bottom of the pond, and planting perennial bermuda grass, clover and ryegrass on the peripheral slope of the ecological pond. The land-aquatic plant coverage area of the slope protection accounts for more than 50% of the engineering construction area, wherein the cold-resistant aquatic plant accounts for more than 75% of the total area of the aquatic plant, a small amount of fishes such as spotted silver carps, silver carps and the like which eat plankton, snails and freshwater mussels are cultivated in the pond, and the plan schematic diagram of the ecological pond is shown in figure 3; sixthly, the open space near the aeration tank in the field is transformed into a biogas slurry storage tank with the total volume of 800m³The specification is 20m multiplied by 10m multiplied by 4m, the top of the device is not required to be sealed by adopting a mode of covering an anti-seepage film after the excavator digs earth, but the edge of the storage pool is required to be at least 20cm higher than the earth surface to prevent peripheral rainwater from flowing in, and the biogas slurry storage pool is mainly used for storing sewage in winter and temporarily storing biogas slurry in farmlands at ordinary times.

In the embodiment, the excrement collected by the dry excrement cleaning process is composted in a dry excrement piling shed and then used for vegetable planting by peripheral farmers; after the culture sewage is firstly fermented by biogas, half of biogas slurry enters a newly-built biogas slurry storage tank and is used for returning to the field after being stored, the rest biogas slurry stays for 36 days in an old biogas slurry storage tank in the field, and then enters an aeration tank for treatment, and is subjected to purification treatment by a plant pond, an ecological ditch and an ecological pond, the COD of the effluent is 40 mg/L-60 mg/L, the total nitrogen is 10 mg/L-15 mg/L, the total phosphorus is 0.5 mg/L-1.0 mg/L, and the quality of the effluent reaches or even exceeds the first-level B standard of the Integrated wastewater discharge Standard (GB 8978-2002).

Example 2

With a storage column 1For example, a pig farm for 500 pigs produces 650 tons of pig manure per year, 600 tons of pig manure can be collected actually, and 4400 tons of sewage per year. The pig farm has been constructed with a total volume of 500m³The number of the biogas tanks is 1, 6 biogas slurry storage pools have the total volume of 2200m³Dry manure piling-up greenhouse 200m²(ii) a In the field, two pigsties are arranged with 5 ponds with total volume of 800m³All are in a waste state at present; total volume 120m³The rain pool; total volume 100m³The three-grid septic tank; the area outside the culture region is 5600m²The pond of (2). The pig farm has no farmland, but has a large number of farmlands nearby, and has the condition for treating the excrement by adopting the process. The pig farm has no field which can be reconstructed and expanded, so the manure treatment facility can be reconstructed only under the existing conditions, and the sewage treatment mainly adopts returning to the field and the treatment in the farm is auxiliary. The sewage treatment process comprises the following steps: after solid-liquid separation, the liquid part of the sewage enters a methane tank for fermentation, and the total volume of the effluent entering the methane tank reaches 2200m³Most of the biogas slurry is used for returning to the field, and after a small part of biogas slurry enters the aeration tank from the biogas slurry storage tank, the effluent sequentially enters the two stages of plant ponds, is finally treated by the ecological pond and is used for in-field washing water.

According to the process requirement, the facilities for collecting, storing and treating the excrement in the pig farm are modified, and a rainwater and domestic sewage collecting pipe network is added. The construction content comprises the following steps: firstly, according to the requirements of rainwater and sewage diversion and dry-wet separation, perfecting the existing sewage pipe network, building a domestic sewage and rainwater collecting pipe network, respectively collecting the aquaculture sewage, the domestic sewage and the rainwater in a field, sealing the aquaculture sewage and the domestic sewage pipe channel to prevent the rainwater from entering, and building a rain shelter at the top of a sewage collecting pool; secondly, a platform is built above the sewage collecting pool, the solid-liquid separator is erected above the liquid dung collecting pool, and the sewage is subjected to solid-liquid separation before entering the methane tank so as to reduce the concentration of the sewage entering the methane tank; thirdly, the existing biogas slurry storage tanks are improved, the tank bottom is desilted, the periphery and the bottom of the tank body are prevented from seepage, the top of the tank is sealed, each tank top is additionally provided with an inspection hole and a biogas outlet, 6 biogas slurry storage tanks are connected in series, namely the 6 biogas slurry storage tanks form a whole volume of 2200m³The push flow type anaerobic fermentation system is used for further treating the fermented biogas slurry in the tank; pumping out biogas slurry for returning to the field from a water inlet of the biogas slurry storage tank to a water outlet of the 3 rd cell tank by using a pump, and enabling water discharged from the 6 th cell biogas slurry storage tank to enter an aeration tank; transforming a rainwater collecting tank with the built specification of 13.3m multiplied by 4.5m multiplied by 2m in a field into an aeration tank, and uniformly arranging 3 submersible centrifugal aerators along the length direction of the aeration tank; sixthly, the effluent of the aeration tank enters a first-stage ecological pond which is formed by transforming a built three-grid septic tank in a field and has the specification of 19m multiplied by 4.5m multiplied by 1.2m (the total volume is about 100 m)³) Dividing the water into 3 grids along the length direction, gradually reducing the height of the partition wall between every two grids by 20cm from the water inlet direction, and planting duckweed, water peanuts and water hyacinth in the three grids in sequence; seventhly, 3 oxidation ponds with the specifications of 24m multiplied by 5.2m multiplied by 1.5m, 24m multiplied by 6m multiplied by 1.5m and 24m multiplied by 6m multiplied by 1.5m (the total volume is nearly 620 m) are arranged in the field³) The pond is transformed into a secondary plant pond and is connected in series, and because the periphery of the pond is of a brick structure, only some emergent aquatic and floating plants such as religious flowers, iris, canna and the like can be planted in the pond, and some loaches and carps are properly cultured in the pond; eighty percent of about 5600m of area in the field²The pond is transformed into an ecological pond, after effluent of the secondary plant pond enters the ecological pond for treatment, the effluent is used for in-site flushing water, and the transformation content comprises the following steps: dredging and slope protection treatment, planting enough moisture-proof tree species such as weeping willow, shrub willow, golden willow, winter jasmine and the like near the water bank to protect the slope, planting emergent aquatic plants such as reed, cattail and the like in a pond, planting maltsfoot, microtooth eyed herb and the like at the bottom of the pond, and planting perennial bermuda grass, clover, ryegrass and the like on the side slope around the pond. The land-water plant coverage area of the slope protection accounts for more than 50% of the engineering construction area, wherein the cold-resistant water plants account for more than 75% of the total area of the water plants.

In the embodiment, the dry manure is composted in a dry manure piling shed and then used for vegetable planting by surrounding farmers; the cultivation sewage is firstly fermented by biogas, 3200 tons of biogas slurry is stored and returned to the field every year, and the rest 1200 tons of biogas slurry are purified and recycled in the field. The effluent quality of the ecological pond reaches the first grade B standard of Integrated wastewater discharge Standard (GB 8978-2002).

The above detailed description of a method for the integrated treatment of fecal sewage in small and medium-sized livestock farms with reference to the embodiments is illustrative and not restrictive, and several embodiments can be cited within the limits, so that variations and modifications without departing from the general concept of the present invention shall fall within the protection scope of the present invention.

Claims (2)

1. A method suitable for the comprehensive treatment of the excrement and sewage in the medium and small-sized livestock farms, the excrement and sewage comprises excrement, livestock breeding sewage, domestic sewage and rainwater, and the method is characterized in that the excrement and sewage are transported outside and returned to the field after aerobic composting fermentation or stack retting fermentation; the livestock breeding sewage is treated by a methane tank or a three-grid septic tank, the generated methane slag and excrement are composted together or composted and returned to the field, the generated methane liquid enters a methane liquid storage tank, the methane generated by the methane liquid storage tank and the methane generated by the methane tank or the three-grid septic tank are dehydrated and desulfurized together and then are used for in-field living energy, and part of the methane liquid in the methane liquid storage tank is transported outside and returned to the field; the domestic sewage and the other part of biogas slurry enter an aeration tank together for treatment, and the effluent of the aeration tank sequentially enters a plant pond, an ecological ditch and an ecological pond; the rainwater and the effluent of the ecological ditch enter an ecological pond, and the effluent of the ecological pond is partially used as the water for washing the colony houses in the farm and is partially directly discharged;

the aeration tank, the plant pond, the ecological ditch and the ecological pond are sequentially connected in series, and the effluent flows to the next stage step by step in a self-overflow mode;

three manure pits of cutting into squares comprise the sealed manure pit of three check rooms of two excrement pipe intercommunications, the first pond of the sealed manure pit of three check rooms: a second pool: the volume ratio of the third pool is 2: 1: 3, the sewage depth of the first pool and the second pool is kept to be not less than 1.0 m;

the biogas slurry in the biogas slurry storage tank can enter the next treatment process after being stored for at least 3 months, and the highest position of the wall of the biogas slurry storage tank needs to be higher than the ground surface by more than 20 cm;

the aeration tank adopts a sequencing batch activated sludge process, namely a batch water feeding and discharging mode is adopted, and two jet aeration machines are arranged at the bottom of the aeration tank in an oblique and diagonal manner;

the plant pond is divided into 3-5 grids along the length direction of the pond, the height of a partition wall between every two grids is gradually reduced by 20-30 cm from the water inlet direction, and aquatic plants are planted in each unit grid;

the side surface of the ecological ditch is trapezoidal, brick layers are laid on the bottom and the soil layers on the side surface of the whole ecological ditch, impermeable films are covered on the brick layers, and soil layers of 30-50 cm are backfilled on the impermeable films;

the ecological ditch is divided into 3-5 grids, the height difference between the division of the former grid and the division of the latter grid is 10-20 cm, and emergent aquatic plants and submerged plants are planted in each grid; aquaculture is carried out in the last two compartments;

the water inlet of the ecological pond is in a fan shape, emergent aquatic plants and floating plants are planted around the water inlet, emergent aquatic plants are planted around the ecological pond to form an emergent aquatic plant zone, and shrubs are planted on a river bank to protect the slope; submerged plants are planted at the bottom of the pond, perennial herbaceous plants are planted on the side slope, and aquaculture is carried out in the pond.

2. The method as claimed in claim 1, wherein the manure is collected by a dry manure cleaning process, and if the moisture content of the manure is higher than 80%, the manure is subjected to solid-liquid separation by a solid-liquid separator and then subjected to aerobic composting fermentation or composting fermentation, or the moisture content of the manure is adjusted to 50% -60% by adding dry materials and then subjected to composting treatment.

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