Saline-alkali soil improvement method and system

Abstract

The invention discloses a saline-alkali soil improvement method and system, and the method comprises the steps: S1, uniformly mixing sludge generated by sewage treatment and plant ash, and composting to obtain an organic fertilizer; s2, the frame is sequentially filled with the plant ash and the organic fertilizer and compacted, and a pressed cake is formed; and S3, plants are cultivated in the pressed cakes, and then the pressed cakes are integrally transplanted into the saline-alkali soil to be treated. After the briquette fuel prepared from the straw is used for heat supply, the ash is mixed and composted, the sludge is not dewatered, the moisture requirement in the composting process can be ensured, then the organic fertilizer obtained through composting is used for saline-alkali soil treatment, the effect is good, and the cost is low.

Description

Technical Field

[0001] The invention relates to the field of saline-alkali land improvement, and in particular to a saline-alkali land improvement method and system. Background Art

[0002] There are four main treatment methods, but each treatment process often has certain problems, as follows:

[0003] Engineering improvement measures: Use comprehensive water conservancy measures that combine irrigation, drainage, diversion, storage and use to regulate water resources, and drain salt while irrigating. This engineering measure is effective quickly, but it requires a large investment in manpower and material resources, and the subsequent engineering maintenance is also relatively difficult.

[0004] Agronomic improvement measures: Create loose interlayers in the soil such as deep plowing and drying, imported soil, straw interlayers, and biochar alkali compression to cut off soil capillaries, reduce the upward migration of water and salt, locally reduce the degree of soil salinization, and improve soil structure. This process has significant control effects, simple principles, easy acceptance, and easy promotion, but it is extremely short-lived.

[0005] Chemical improvement measures: Apply chemical improvers to change the parent material of the soil, mainly based on the principle of ion exchange, to carry out acid-base neutralization reaction in the soil, so that the ions in the soil and the ions of the improver are replaced. When the physical and chemical properties of the soil reach the ideal state, leaching and digestion are carried out. This process is fast-acting, flexible in formula, with a wide range of material choices and strong targeting, but its effect is single, short-lived, expensive, and easy to cause secondary pollution to saline-alkali land. Leaching requires a lot of water resources.

[0006] Biological improvement measures: Biological control measures improve soil quality by adaptive crop planting, removing part of the salt in the root system or changing the diversity of soil microbial communities, so as to make saline-alkali land ecologically balanced and have long-term stability. This method is the most economical and effective, but it has a long action cycle and weak impact resistance.

[0007] In some areas of Xinjiang, my country, due to very little rainfall, dry climate and high temperature, water is easily evaporated, and salt rises to the surface with capillary water, accumulating to form saline-alkali land. At the same time, with the increasing degree of land salinization, the accompanying ecological problems such as soil desertification are becoming increasingly prominent. The existing methods of saline-alkali land management often have certain problems, and there is an urgent need to find a more complete way to manage saline-alkali land and restore soil fertility.

[0008] A Chinese patent application with publication number CN107879422A discloses a novel water ecological circulation system, in which the qualified water treated by domestic sewage treatment equipment, industrial sewage treatment equipment and hazardous waste treatment equipment is sent to the sewage treatment and regeneration equipment through a river or directly, and the treated regenerated water meets the industrial water standard and is supplied to industrial enterprises for production water, circulating cooling water, etc.; the hazardous wastes and sludge generated by industrial enterprises in the production process are harmlessly treated in the sludge hazardous waste harmless treatment equipment; the concentrated brine generated in the sewage treatment and regeneration process is discharged to the wetland for natural degradation after ozone + catalytic oxidation treatment, and then flows into the ocean; the sludge generated by the domestic sewage treatment equipment is produced into an in-situ improver for saline-alkali land original soil in the sludge composting equipment, and is applied to the in-situ improvement of saline-alkali land original soil with part of the regenerated water. The invention composts the sludge on the surface of the saline-alkali land, and the sludge is easily blown away by wind and sand, and the composting effect of sludge alone is often poor. Summary of the invention

[0009] The present invention aims to provide a saline-alkali land improvement method and system, which have good saline-alkali land treatment effect and low cost.

[0010] In order to achieve the above object, the technical solution adopted by the present invention is:

[0011] A method for improving saline-alkali land comprises the following steps:

[0012] S1, mixing the sludge and plant ash produced by sewage treatment evenly, composting and obtaining organic fertilizer;

[0013] S2, filling plant ash and organic fertilizer into the frame in sequence and compacting them to form a pressed cake;

[0014] S3. Cultivate plants in the pressed cakes and then transplant them as a whole into the sandy soil of the saline-alkali land to be treated.

[0015] In S3, windbreak and sand-fixing plants are cultivated on the pressed cakes. The windbreak and sand-fixing plants may be windbreak and sand-fixing plants, such as Haloxylon ammodendron.

[0016] This combined utilization process combines the treatment of solid wastes such as sludge and ash with the management of saline-alkali land in desert areas. At the same time, the ash and organic fertilizer are compacted into cakes to meet the needs of saline-alkali land management, effectively overcoming the shortcomings of general management processes such as high cost and difficult operation, and solving the problem of difficulty in stabilizing the management process system.

[0017] According to the embodiments of the present invention, the present invention can be further optimized. The following is the technical solution formed after optimization:

[0018] In one preferred embodiment, the sludge generated by the sewage treatment in S1 includes excess sludge and return sludge. The excess sludge is first concentrated and then evenly mixed with plant ash for composting.

[0019] In one preferred embodiment, 10-20% of the return sludge in S1 is mixed with the sandy soil of the saline-alkali land to be treated, and then mixed evenly with plant ash to be composted;

[0020] 80-90% of the return sludge is directly returned.

[0021] 10-20% of the return sludge produced by the sewage treatment in S1 is mixed with the sand of the saline-alkali land to be treated. If the return ratio is lower than 10%, it will affect the efficiency of sludge reduction in the system, because the sand that reacts with the sludge is reduced, the salt provided for cell lysis is reduced, and the cell lysis efficiency is reduced; if the sand ratio is higher than 20%, the sludge return volume may not meet the requirement of supplementary sludge concentration (the role of sludge return is to ensure that there are enough microorganisms to mix with the influent, so that there is enough MLSS in the aeration tank to maintain a suitable sludge load), which will eventually lead to the collapse of the sewage treatment system. 80-90% of the return sludge produced by sewage treatment is directly returned.

[0022] In one of the preferred embodiments, easily degradable organic solid waste is added to S1.

[0023] In one preferred embodiment, the compost raw materials in S1 are composed of ash, easily degradable organic solid waste, and sludge in a ratio of 20-30%: 0-40%: 70%-80%, wherein ash is an important raw material, which can improve the fluffiness of the compost raw materials, increase contact with air, increase the porosity of the raw materials, reduce the moisture content of the materials, and improve the composting efficiency. Among them, the easily degradable organic solid waste is mainly kitchen waste, livestock and poultry manure, etc. This raw material is used as a supplement to the sludge, and the ash ratio is about 20-30%. If it is higher than this ratio, the organic matter content of the raw material is low, and the organic matter is difficult to meet the composting requirements. If it is lower than this ratio, the composting effect will be affected, because in addition to providing potassium fertilizer, plant ash also needs to increase the porosity of the material.

[0024] The weight ratio of plant ash and organic fertilizer in S2 is 20% to 50%. If the ratio is lower than 20%, its adsorption capacity for saline-alkali soil will be reduced and it will not be able to effectively absorb the salt in saline-alkali soil. At the same time, water is difficult to evaporate in this type of material, which can reduce the water demand of the system. If the ratio is higher than 50%, the organic matter nutrients are insufficient for plants, affecting plant growth. At the same time, the weight of the entire system will be lighter and easily blown away by the wind.

[0025] The present invention also discloses a saline-alkali land improvement system, comprising a sewage treatment system and a composting system, wherein the sludge discharge port of the sewage treatment system is connected to the feed port of a sludge mixing facility, the discharge port of the sludge mixing facility is connected to the feed port of a mixing facility, the discharge port of the mixing facility is connected to the feed port of the composting system, the feed port of the composting system is also connected to an ash temporary storage system, and the discharge port of the composting system is connected to a layered cake pressing system.

[0026] Among them, the sewage treatment system, composting system, sludge mixing facility, ash temporary storage system, and layered cake pressing system, for example, the sewage treatment system can adopt the device in the Chinese patent with publication number CN108217967B, the composting system can adopt the device in the Chinese patent with publication number CN1104400C, the sludge mixing facility can adopt the device in the Chinese patent with publication number CN101358153B, and the ash temporary storage system can adopt the device in the Chinese patent with publication number CN112228876A.

[0027] In one of the preferred embodiments, the sludge discharge port of the sewage treatment system is connected to a residual sludge temporary storage facility, the discharge port of the residual sludge temporary storage facility is connected to the feed port of a plant temporary storage facility, the discharge port of the plant temporary storage facility is connected to the feed port of a molded fuel processing system, and the discharge port of the molded fuel processing system is connected to the feed port of a heating system.

[0028] The residual sludge temporary storage facility is connected to the sludge thickening facility and the plant temporary storage facility respectively. A part of the residual sludge flows from the residual sludge temporary storage facility to the sludge thickening facility and then is concentrated by gravity. The supernatant flows to the sewage treatment system for treatment, and the lower concentrated sludge flows to the mixing facility. The plant temporary storage facility crushes the dead plants collected from the saline-alkali land and adds another part of the residual sludge. The residual sludge generates adhesion, and is mixed in the molded fuel processing system and then pressed and dried to form molded fuel.

[0029] In one of the preferred embodiments, the discharge port of the excess sludge temporary storage facility is connected to a sludge thickening facility, and the discharge port of the sludge thickening facility is connected to the feed port of the mixing facility.

[0030] The main function of the mixing facility is to evenly mix the concentrated sludge with the return sedimentation sludge.

[0031] In one of the preferred embodiments, the layered cake pressing system comprises a base plate, a frame is placed on the upper surface of the base plate, a plurality of partitions are arranged in the frame, and basin membranes are laid in the partitions.

[0032] The basin membrane is a thin film formed into a basin shape, preferably a regular hexagonal basin shape.

[0033] In one of the preferred embodiments, a plurality of water inlet holes are opened on the bottom plate, and the plurality of water inlet holes are respectively located in the plurality of partitions, and the water inlet holes are all connected through pipes.

[0034] In one of the preferred embodiments, the sludge mixing facility includes a film storage bin and a stirring inner bin arranged in the inner cavity of the film storage bin, a stirring paddle is installed in the stirring inner bin, an inlet is provided at the top of the stirring inner bin, a supernatant outlet is provided at the top of the stirring inner bin, and a sludge outlet is provided at the bottom of the stirring inner bin.

[0035] An annular ceramic membrane is provided on the lower periphery of the stirring inner chamber, the supernatant outlet is located above the space formed by the stirring inner chamber and the annular ceramic membrane, and the annular ceramic membrane is provided with a membrane port.

[0036] Preferably, a supporting base is provided at the bottom of the inner mixing chamber.

[0037] Preferably, an electric switch is installed at the membrane port, and the membrane port is connected to a connecting hose and a pump in sequence.

[0038] Preferably, an electric switch is installed at the supernatant outlet.

[0039] Preferably, an electric switch is installed at the mud outlet.

[0040] Preferably, a modifier release device is provided in one of the partitions, and the pipe in the partition where the modifier release device is placed is installed at a higher height than other pipes, so that moisture can flow to every place by gravity, while reducing the situation of excessive local moisture.

[0041] Preferably, the modifier releasing device comprises a storage bin, a telescopic tube is installed at the sample outlet at the bottom of the storage bin, a spring is installed inside the telescopic tube, and the water content in the storage bin can be determined by the height of the storage bin to determine whether the storage bin needs to be replaced.

[0042] Specifically, it also includes a shell, in which a drain port is opened, and the drain port is communicated with one end of the telescopic tube.

[0043] Preferably, the outside of the storage bin is covered with a sealed insulation layer, which can effectively lower the water temperature, reduce water evaporation and damage to plants caused by high-temperature water.

[0044] Preferably, the partition is a honeycomb frame, which is more stable than the existing square structure.

[0045] Preferably, the pipeline includes a main pipe, one end of which is a water inlet, and the other end of which is connected to multiple branch pipes in sequence through an inflection point connecting pipe, so that there is no need to lay a long pipeline, thereby reducing costs.

[0046] Preferably, the water outlet of the sewage treatment system is connected to a temporary water storage facility.

[0047] Preferably, the feed inlet of the composting system is also connected to a temporary storage facility for easily degradable organic solid waste.

[0048] Preferably, the feed inlet of the sludge mixing facility is also connected to the discharge outlet of the saline-alkali land sand temporary storage device.

[0049] Preferably, the feed inlet of the saline-alkali land sand temporary storage device is connected to the liquid outlet of the improver temporary storage facility. The existing practical technology for using improvers is generally direct spraying. However, for desert areas, due to their extremely strong evaporation ability, direct spraying often makes it difficult for the improver to penetrate deeply into the ground, making it difficult to improve the saline-alkali land. The present invention takes into account the particularity of desert areas and adopts this method to reduce evaporation and improve efficiency.

[0050] Due to the large area of ​​Xinjiang and the poor economic conditions in some rural areas, the residual sludge from sewage treatment plants, kitchen waste, and livestock manure are often piled up on site and then directly landfilled, which easily causes secondary pollution. This invention considers combining solid waste treatment with saline-alkali land management. At the same time, in view of the particularity of the desert environment, it is equipped with a treatment process and equipment that is simple to operate, low in energy consumption, simple in later operation and maintenance, and low in cost, providing new technologies for improving saline-alkali land and recycling solid waste.

[0051] The sewage treatment system is connected to the effluent temporary storage facility, which is used to store the recycled water generated by the sewage treatment system. On the one hand, it provides water for the seedling cultivation system, and on the other hand, it provides water for the plants in the saline-alkali sandy soil to be treated. This can realize the recycling of recycled water and improve the survival rate of plants, thereby improving the efficiency of saline-alkali land treatment.

[0052] The sewage treatment system is connected to a sludge mixing facility, which mixes the return sludge from the sewage treatment plant with the sandy soil of the saline-alkali land to be treated, and utilizes the salt in the sandy soil of the saline-alkali land to be treated to break the sludge cell walls and release the intracellular substances, thereby ultimately reducing the sludge output of the sewage treatment system, while returning organic matter to supplement the carbon source of the sewage treatment system. In addition, a portion of the sludge-sand mixture after the reaction is used for composting, which can further degrade and utilize the difficult-to-degrade organic matter in the sludge, and the other portion is directly used for the bottom layer of the layered cake pressing system, so that the layered cake pressing system has a certain weight to prevent it from being blown away by wind and sand.

[0053] The residual sludge temporary storage facility is connected to the plant temporary storage facility to provide adhesive for the molded fuel processing system. The plant temporary storage facility will crush the dead plants collected from the saline-alkali land, and add another part of the residual sludge to the molded fuel processing system to make molded fuel. Compared with directly burning straw for heating, the molded fuel heating will be cleaner. In addition, due to the fact that some areas with serious saline-alkali land have very little rainfall and dry climate, the water content of the plants themselves is extremely low and they are difficult to compress and shape. After adding residual sludge, the molding rate can be improved.

[0054] The composting system is connected to an ash temporary storage system, which provides ash for the composting system. Due to the fact that some areas with serious saline-alkali land have very little rainfall, dry climate, and extremely low moisture content of plants themselves, direct composting is difficult to achieve. The ash after the combustion of the molded fuel is a good fertilizer (the main component is potassium chloride, commonly known as wood ash). Mixing and fermenting with sludge and other easily degradable organic matter can increase the porosity of organic fertilizer in the composting process and supplement potassium, thereby improving the quality of organic fertilizer.

[0055] The composting system is connected to a mixing facility, which provides sludge for the composting system. The composting system can flexibly adopt a variety of composting processes including trough composting or windrow composting processes. Since the composting site has heat supply, the composting efficiency can be effectively improved and the composting time can be reduced.

[0056] The layered cake pressing system provides organic fertilizer and water to the seedling cultivation system.

[0057] The pot membrane is placed in the frame and is punctured by a perforated cone on the bottom plate to form a hole. The roots of the planted plants grow on the saline-alkali land through the hole and absorb the salt of the saline-alkali land.

[0058] The pipeline is connected to each basin membrane and can provide moisture to each basin membrane. The height level is reduced, and gravity can be used to drain the moisture. No additional power is required, and the moisture distribution will be more uniform.

[0059] The molding fuel processing system is connected to the heating system. When the molding raw materials are in use, the heating system provides a heat source for the heating system. When the temperature is low, the heating system provides a heat source for the composting system to ensure the temperature during composting and improve the composting efficiency.

[0060] The temporary storage facility for the improver includes a storage bin, which is connected to a telescopic leg. The telescopic leg has a spring inside. The telescopic leg will change under the action of gravity, thereby showing the content of the substance in the storage bin. At the same time, the telescopic leg can support the storage bin to make it stable. The outside of the storage bin is covered with a closed insulation layer to reduce water evaporation and save water resources. In addition, if an extreme situation occurs and the salinization degree of the land is extremely high and plants are difficult to survive, the temporary storage facility for the improver is filled with liquid improver, and then inserted into the drain upside down. The improver flows through the pipe to each basin membrane, and then flows to the land through the holes on the basin membrane. The salinization degree of the land is quickly reduced by chemical methods, and then seedlings are planted to ensure the effect of saline-alkali land management.

[0061] Compared with the Chinese patent application with publication number CN107879422A, the present invention takes into account the problems existing in sludge composting alone, combines the resource utilization of annual plants in Xinjiang, utilizes the ash after plant incineration, and uses ash and sludge for joint composting. In the process of saline-alkali land treatment, no single organic fertilizer is used for conditioning, because the conditioning effect of a single organic fertilizer is extremely slow. The present invention treats saline-alkali land by combining organic fertilizer cultivation plants with wood ash, activated carbon adsorption combined improver and water supply project, which effectively reduces the difficulty and investment of treatment and improves the treatment efficiency.

[0062] Compared with the prior art, the present invention has the following beneficial effects:

[0063] 1. The present invention makes full use of solid wastes such as sludge generated by sewage treatment plants in desert areas, kitchen waste from residents, and livestock and poultry manure to form raw materials that can be used for saline-alkali land treatment, thereby reducing the cost of saline-alkali land treatment and solid waste treatment costs, which is economical and environmentally friendly.

[0064] 2. Configure a recycled water utilization system to utilize the water resources generated after the sewage treatment plant is treated, save energy and protect the environment, and improve the comprehensive utilization efficiency of the system;

[0065] 3. The present invention utilizes the physical and chemical properties of saline-alkali land to transform the sewage treatment plant, which can reduce the output of sludge, and the sludge dewatering process is cancelled. For the operation of the sewage treatment plant, the process steps are reduced, and the operating costs and personnel investment are reduced;

[0066] 4. Compared with laying a long irrigation water transportation pipeline with a large diameter, the present invention is equipped with an improver storage tank (which can also hold water) and a pipeline with a smaller diameter, which not only saves the investment in laying pipelines, but also avoids the waste of water during pipeline transportation, and the water consumption will be greatly reduced;

[0067] 5. Configure an improver storage tank. The present invention can provide different improvers according to the types and degrees of different saline-alkali lands, and can adjust the improver concentration at any time according to the growth of plants, thereby reducing the processing cost;

[0068] 6. The seedling cultivation system is configured. Compared with directly planting salt-alkali tolerant plants on saline-alkali land, the survival efficiency of plants is improved. The membrane system is configured, which is not only convenient for laying, but also reduces water evaporation. Moreover, compared with the current square planting of plants, this invention is configured in a honeycomb shape. In areas such as Xinjiang where desertification is relatively serious, it can reduce the tearing of plant land by wind and sand, and has higher stability, further improving the efficiency of saline-alkali land management;

[0069] 7. Taking into account the particularity of the desert environment, plant straw was not mixed with sludge for direct composting. Instead, molded fuel made of straw was used for heating and then mixed with ash for composting. The sludge was not dehydrated to ensure the moisture demand of the composting process. In addition, due to the large temperature difference between day and night in Xinjiang, direct composting may be affected. The heating system can increase the temperature of the pile at night to ensure the composting effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 is a flow chart of an embodiment of the present invention;

[0071] Figure 2 is an axial view of a sludge mixing facility according to one embodiment of the present invention;

[0072] Figure 3 is an axial view of a layered cake pressing system in one embodiment of the present invention;

[0073] Figure 4 Schematic diagram of a layered cake pressing system according to an embodiment of the present invention Figure 1 ;

[0074] Figure 5 The structure of the layered cake pressing system in one embodiment of the present invention is shown in FIG. Figure 1 ;

[0075] Figure 6 It is a structural schematic diagram of a frame in a layered cake pressing system in one embodiment of the present invention;

[0076] Figure 7 The structure of the layered cake pressing system in one embodiment of the present invention is shown in FIG. Figure 2 ;

[0077] Figure 8 The structure of the layered cake pressing system in one embodiment of the present invention is shown in FIG. Figure 3 ;

[0078] Fig. 9The structure of the layered cake pressing system in one embodiment of the present invention is shown in FIG. Figure 4 ;

[0079] Fig.10 Schematic diagram of a layered cake pressing system according to an embodiment of the present invention Figure 2 ;

[0080] Fig.11 The structure of the layered cake pressing system in one embodiment of the present invention is shown in FIG. Figure 5 ;

[0081] Fig.12 The structure of the modifier release device in one embodiment of the present invention is shown in FIG. Figure 1 ;

[0082] Fig.13 The structure of the modifier release device in one embodiment of the present invention is shown in FIG. Figure 2 ;

[0083] Fig.14 The structure of the modifier release device in one embodiment of the present invention is shown in FIG. Figure 3 ;

[0084] Fig.15 The structure of the modifier release device in one embodiment of the present invention is shown in FIG. Figure 4 ;

[0085] Fig.16 It is a schematic diagram of the structure of a pipeline in one embodiment of the present invention.

[0086] In the figure:

[0087] 1- sewage treatment system; 2- effluent temporary storage facilities; 3- residual sludge temporary storage facilities; 4- sludge concentration facilities; 5- other easily degradable organic solid waste temporary storage facilities; 6- sludge mixing facilities; 7- mixing facilities; 8- composting system; 9- layered cake pressing system; 10- saline-alkali sand to be treated; 11- plant temporary storage facilities; 12- molded fuel processing system; 13- ash temporary storage system; 14- seedling cultivation system; 15- heating system; 16- improver temporary storage facilities. DETAILED DESCRIPTION

[0088] The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict. For the convenience of description, if the words "upper", "lower", "left" and "right" appear in the following, they only indicate that the upper, lower, left and right directions are consistent with the drawings themselves, and do not limit the structure.

[0089] like Figure 1As shown, this embodiment discloses a saline-alkali land improvement system, including a sewage treatment system 1, an effluent temporary storage facility 2, a residual sludge temporary storage facility 3, a sludge concentration facility 4, other easily degradable organic solid waste temporary storage facilities 5, a sludge mixing facility 6, a mixing facility 7, a composting system 8, a layered cake pressing system 9, saline-alkali land sand to be treated 10, a plant temporary storage facility 11, a molded fuel processing system 12, an ash temporary storage system 13, a seedling cultivation system 14, a heating system 15 and an improver temporary storage facility 16.

[0090] The sludge mixing facility 6 includes a stirring inner chamber 6.1, a film storage chamber 6.2, a stirring paddle 6.3, a sample inlet 6.4, a supernatant outlet 6.5, an electric switch 1 6.6, an annular ceramic membrane 6.7, a membrane port 6.8, an electric switch 2 6.9, a sludge outlet 6.10, an electric switch 3 6.11, a supporting base 6.12, a connecting hose 6.13, and a pump 6.14.

[0091] The layered cake pressing system 9 includes a bottom plate 9.1, a frame 9.2, a perforated cone 9.3, a pipeline 9.4, and a basin membrane 9.5.

[0092] like Fig.16 As shown, the pipeline 9.4 includes a water inlet 9.4.1, a main pipe 9.4.2, a branch pipe 9.4.3, and an inflection point connecting pipe 9.4.4.

[0093] The temporary storage facility 16 for the improver includes a storage bin 9.16.1, telescopic legs 9.16.2, a supporting circular opening 9.16.3, and a drain opening 9.16.4. The temporary storage facility 16 for the improver can store not only the improver but also water.

[0094] This combined utilization process combines the treatment of solid wastes such as sludge, other organic solid wastes, ash and slag with the management of saline-alkali land in desert areas. It is equipped with a layered cake pressing system and temporary storage facilities for improvers and corresponding pipeline facilities to meet the needs of saline-alkali land management, effectively overcoming the shortcomings of general management processes such as high cost and difficult operation, and solving the problem of difficulty in stabilizing the management process system.

[0095] In this embodiment, the sewage treatment system 1 is connected to the effluent temporary storage facility 2, the residual sludge temporary storage facility 3, the sludge mixing facility 6 and the sludge concentration facility 4 respectively. The sewage treatment system 1 treats the municipal sewage, and the regenerated water that meets the treatment standards is temporarily stored in the effluent temporary storage facility 2. The generated sludge and residual sludge are stored in the residual sludge temporary storage facility 3. The sewage treatment system 1 includes a sludge return process. This time, it is considered that 10% to 20% of the returned sludge enters the sludge mixing facility 6, and the rest is directly returned to replenish the sludge for the sewage treatment system 1.

[0096] In this embodiment, the sludge mixing facility 6 is as follows Figure 2 As shown, the relevant usage steps are:

[0097] A part of the sludge of the sludge return system of the sewage treatment system 1 is diverted through the pipe connected to the sampling port 6.4 and enters the mixing chamber 6.1 of the sludge mixing facility 6. At the same time, a part of the sandy soil of the saline-alkali land to be treated is also entered into the mixing chamber 6.1 of the sludge mixing facility 6 through the sampling port 6.4, and the proportion of sandy soil to the sludge volume is about 20-30%. Under the action of stirring 6.3, the sludge and sandy soil are fully stirred for 8 hours. After the stirring stops, the sludge is settled for 8 hours. Then the electric switch 1 6.6 is turned on, and the sludge supernatant enters the membrane storage chamber 6.2 through the supernatant outlet 6.5. The membrane port 6.8 of the annular ceramic membrane 6.7 is connected to the pump 6.14 through the connecting hose 6.13. The pump and the electric switch 2 6.9 are turned on, and the organic acid in the sludge supernatant returns to the sewage treatment system 1 through the hose outlet to supplement the carbon source. The electric switch 3 6.11 is turned on, and the precipitated sludge flows out through the mud outlet 6.10. Finally, part of it is used for composting, and the other part is directly pressed into cakes. The entire system is supported upright by a support base 6.12.

[0098] The residual sludge temporary storage facility 3 configured in this embodiment is connected to the sludge thickening facility 4 and the plant temporary storage facility 11 respectively. A part of the residual sludge flows from the residual sludge temporary storage facility 3 to the sludge thickening facility 4 and then is concentrated by gravity, wherein the supernatant flows to the sewage treatment system 1 for treatment, and the lower concentrated sludge flows to the mixing facility 7. The plant temporary storage facility 11 crushes the dead plants collected from the saline-alkali land and adds another part of the residual sludge. The residual sludge generates adhesion, and is pressed and dried after mixing in the molded fuel processing system 12 to form molded fuel.

[0099] The effluent temporary storage facility 2 configured in this embodiment is respectively connected to the seedling cultivation system 14 and the saline-alkali land sand 10 to be treated. The effluent temporary storage facility 2 provides the seedling cultivation system 14 with the moisture required for plant growth. After the seedling cultivation system 14 is transplanted to the saline-alkali land to be treated, it provides water to the saline-alkali land sand 10 to be treated.

[0100] In this embodiment, the mixing facility 7 is connected to the sludge thickening facility 4 and the sludge mixing facility 6 respectively, and its main function is to evenly mix the concentrated sludge with the returned sedimentation sludge.

[0101] In this embodiment, the composting system 8 is connected to the mixing facility 7, the temporary storage facility 5 for other easily degradable organic solid waste, the layered cake pressing system 9, the ash temporary storage system 13 and the heating system 15 respectively. The mixing facility 7 provides the composting system 8 with evenly mixed sludge, and the temporary storage facility 5 for other easily degradable organic solid waste provides the composting system 8 with organic solid waste including livestock and poultry manure and kitchen waste. If this part of solid waste is not available on site, it is not necessary to provide it. The ash temporary storage system 13 provides the composting system 8 with ash produced after the incineration of molded fuel, and the residual sludge, other easily degradable organic solid waste and organic fertilizer are produced after the ash is composted. When the temperature is low, the heating system 15 provides the composting system 8 with a heat source.

[0102] In this embodiment, the layered cake pressing system 9 is configured to be connected to the seedling cultivation system 14, the ash temporary storage system 13, the composting system 8 and other easily degradable organic solid waste temporary storage facilities 5 respectively. The ash temporary storage system 13 provides ash for the layered cake pressing system 9, the composting system 8 provides organic fertilizer for the layered cake pressing system 9, and other easily degradable organic solid waste temporary storage facilities 5 provide other organic matter for the layered cake pressing system 9.

[0103] like Figure 3-11 As shown, the layered cake pressing system 9 in this embodiment includes a bottom plate 9.1, a frame 9.2, a water inlet 9.3, a pipe 9.4, and a basin membrane 9.5. The water inlet 9.3 is fixed on the bottom plate 9.1, and the frame 9.2 is a whole formed by connecting multiple honeycomb frames, including a solid hole 9.2.1 and multiple hollow holes 9.2.2 (such as Figure 5 As shown), Fig.10 As shown, the relevant usage steps are:

[0104] Place the base plate 9.1 on the ground of the composting plant, place the frame 9.2 on the base plate 9.1, place the basin film 9.5 in the hollow holes 9.2.2 one by one, then spread the ash in the ash temporary storage system 13 on the layered cake pressing system 9, and then compact it, then spread the organic fertilizer produced by the composting system 8 on the layered cake pressing system 9, and then compact it to form a seedling cultivation system 14.

[0105] Take out the frame 9.2, and lay the pipe 9.4 in the seedling cultivation system 14. The pipe 9.4 is higher than the end of the solid hole 9.2.1 and descends along the pipe.

[0106] Afterwards, plants that can control saline-alkali land, such as Salicornia herba, are planted on the seedling cultivation system 14. However, considering that the treated land is extremely dry and there are problems with wind and sand, several wind-proof and sand-fixing plants, such as Haloxylon ammodendron, can be selected in each pot film 9.5 for planting.

[0107] The plant pots cultivated by the seedling cultivation system 14 are transplanted to the saline-alkali sandy soil 10 to be treated, and the water from the water temporary storage facility 2 is placed in the storage bin 9.16.1 through the supporting circular port 9.16.3 of the modifier temporary storage facility 16, transported to the saline-alkali sandy soil 10 to be treated by a vehicle, and then inserted upside down into the drainage port 9.16.4 to provide water for plant growth.

[0108] If an extreme situation occurs, where the salinization level of the land is extremely high and plants cannot survive, the liquid improver is filled into the improver temporary storage facility 16 and then inserted upside down into the drain outlet 9.16.4 to quickly reduce the salinization level of the land through chemical methods, and then seedlings are planted to further absorb and transfer the salt in the soil.

[0109] In this embodiment, the molded fuel processing system 12 is connected to the plant temporary storage facility 11, the heating system 15 and the ash temporary storage system 13 respectively. The plant temporary storage facility 11 provides raw materials for the molded fuel processing system 12. When the molded raw materials are used, they provide a heat source for the heating system. At the same time, the ash generated is temporarily stored in the ash temporary storage system 13.

[0110] In this embodiment, Figure 12-15 As shown, the temporary storage facility 16 for the improver includes a storage bin 9.16.1, telescopic legs 9.16.2, a supporting circular opening 9.16.3, and a drainage opening 9.16.4, wherein the storage bin 9.16.1 is covered with a sealed insulation layer on the outside, and the telescopic legs 9.16.2 have springs inside. When there is more moisture, the storage bin 9.16.1 is heavier and the telescopic legs 9.16.2 become shorter. When there is less moisture, the storage bin 9.16.1 is lighter and the telescopic legs 9.16.2 become longer. Therefore, it is possible to determine whether water needs to be added based on the length of the telescopic legs 9.16.2. The way to add water is to directly replace the temporary storage facility 16 for the improver.

[0111] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the embodiments made by those skilled in the art fall within the scope defined by the claims attached to the present invention.

Claims

1. A method for improving saline-alkali land, characterized in that: The following steps are involved: S1, mixing the sludge and plant ash produced by sewage treatment evenly, composting and obtaining organic fertilizer; S2, filling plant ash and organic fertilizer into the frame in sequence and compacting them to form a pressed cake; S3. Cultivate plants in the pressed cakes and then transplant them as a whole into the sandy soil of the saline-alkali land to be treated.

2. The method for improving saline-alkali land according to claim 1, characterized in that: The sludge generated by the sewage treatment in S1 includes excess sludge and return sludge. The excess sludge is first concentrated and then evenly mixed with plant ash for composting.

3. The method for improving saline-alkali land according to claim 2, characterized in that: 10-20% of the return sludge in S1 is mixed with the sandy soil of the saline-alkali land to be treated, and then mixed evenly with plant ash to make compost; 80-90% of the return sludge is directly returned.

4. The method for improving saline-alkali land according to claim 1, characterized in that: The volume of saline-alkali sand in S1 is 20-30% of the sludge volume.

5. A saline-alkali land improvement system, comprising a sewage treatment system (1) and a composting system (8), characterized in that: The sludge discharge port of the sewage treatment system (1) is connected to the feed port of the sludge mixing facility (6), the discharge port of the sludge mixing facility (6) is connected to the feed port of the mixing facility (7), the discharge port of the mixing facility (7) is connected to the feed port of the composting system (8), the feed port of the composting system (8) is also connected to the ash temporary storage system (13), and the discharge port of the composting system (8) is connected to the layered cake pressing system (9).

6. The saline-alkali land improvement system according to claim 4, characterized in that: The sludge discharge port of the sewage treatment system (1) is connected to a residual sludge temporary storage facility (3), the discharge port of the residual sludge temporary storage facility (3) is connected to a feed port of a plant temporary storage facility (11), the discharge port of the plant temporary storage facility (11) is connected to a feed port of a molded fuel processing system (12), and the discharge port of the molded fuel processing system (12) is connected to a feed port of a heating system (15).

7. The saline-alkali land improvement system according to claim 4, characterized in that: The discharge port of the excess sludge temporary storage facility (3) is connected to the sludge concentration facility (4), and the discharge port of the sludge concentration facility (4) is connected to the feed port of the mixing facility (7).

8. The saline-alkali land improvement system according to claim 4, characterized in that: The layered cake pressing system (9) comprises a bottom plate (9.1), a frame (9.2) is placed on the upper surface of the bottom plate (9.1), a plurality of partitions (9.2.1) are arranged in the frame (9.2), and a basin membrane (9.5) is laid in the partitions (9.2.1).

9. The saline-alkali land improvement system according to claim 4, characterized in that: The bottom plate (9.1) is provided with a plurality of water inlet holes (9.3), the plurality of water inlet holes (9.3) are respectively located in the plurality of partitions (9.2.1), and the water inlet holes (9.3) are all connected via pipes (9.4).

10. The saline-alkali land improvement system according to claim 4, characterized in that: The sludge mixing facility (6) comprises a film storage bin (6.2), a stirring inner bin (6.1) arranged in the inner cavity of the film storage bin (6.2), a stirring paddle (6.3) installed in the stirring inner bin (6.1), a sample inlet (6.4) provided at the top of the stirring inner bin (6.1), a supernatant outlet (6.5) provided at the top of the stirring inner bin (6.1), and a sludge outlet (6.10) provided at the bottom of the stirring inner bin (6.1).

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