Microfiltration device for household garbage leachate

Abstract

The utility model discloses a household garbage leachate microfiltration device which comprises a microfiltration membrane assembly, the microfiltration membrane assembly is used for filtering leachate, the microfiltration membrane assembly is further connected with a storage tank assembly, a backwashing assembly and an acid pickling assembly, the storage tank assembly is used for storing crystal substances, and the backwashing assembly is connected with the acid pickling assembly; by the adoption of the method, the functions of normal water production, crystallization accumulated sludge discharge, backwashing dredging, chemical cleaning and the like are integrated, the production function integration characteristic is achieved, operation is easy and convenient, efficient interception is conducted through the microfiltration membrane assembly, the production efficiency is improved, and the production cost is reduced. The problem that crystals cannot be efficiently removed independently by means of precipitation and other measures is avoided, the standing time and the occupied area are reduced, the microfiltration membrane assembly is convenient to discharge sludge, rapid sludge discharge and rapid production can be achieved according to the combined action of gravity and air pressure, meanwhile, cleaning and overhauling are convenient, hydrochloric acid liquid can be recycled, the use amount of cleaning acid liquid is reduced, and the cost is reduced. And the use cost is lower.

Description

A microfiltration device for leachate from municipal solid waste Technical Field

[0001] This utility model relates to the field of wastewater leachate treatment technology, and in particular to a microfiltration device for leachate from municipal solid waste. Background Technology

[0002] Leachate from waste-to-energy incineration plants is produced after waste has fermented in the waste storage area for 5-7 days before being fed into the incinerator; it is considered fresh leachate. The composition of this leachate varies greatly depending on the nature of the waste. It is characterized by high concentrations of organic pollutants, high suspended solids, high salt content, and the presence of toxic and harmful substances. It has a strong, foul odor and is yellowish-brown or grayish-brown in color, representing a high concentration of organic wastewater that is difficult to biodegrade. The gases emitted from the leachate from incineration power plants have a strong, foul odor and are harmful to human health, causing symptoms such as nausea, hematuria, and dizziness. Mass spectrometry analysis reveals that the leachate contains over a hundred types of organic matter, mostly high-molecular-weight humic carbohydrates and medium-molecular-weight griseofulvin acids. Improper treatment can easily lead to pollution of the surrounding water environment, threaten residents' health, and cause serious environmental and social incidents.

[0003] Currently, the advanced treatment technology for leachate from waste incineration plants mainly uses a dual-membrane method combining nanofiltration and reverse osmosis. This technology boasts advantages such as stable operation, high automation, simple operation, and good permeate quality. Reverse osmosis, in particular, can remove most of the dissolved salts in the leachate, effectively reducing the total dissolved solids (TDS) and is the most effective means of removing monovalent ions such as Na, K, and chloride. However, as filtration technologies, nanofiltration and reverse osmosis suffer from problems such as poor concentrate quality, low permeate recovery rate, scaling and crystallization on the concentrate side, high energy consumption, and short service life, which restrict their widespread application and limit the zero discharge and full reuse of leachate from waste incineration plants.

[0004] Therefore, there is an urgent need to design a microfiltration device for municipal solid waste leachate to solve one or more technical problems that are lacking in the existing technology. Summary of the Invention

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is: a microfiltration device for leachate from municipal solid waste, characterized in that it includes: a microfiltration membrane assembly, wherein the microfiltration membrane assembly is used to filter leachate by adding lime to crystallize calcium and magnesium to form a suspension, the microfiltration membrane assembly is also connected to a storage tank assembly, a backwashing assembly, and an acid washing assembly, the storage tank assembly is used to store the crystals filtered by the microfiltration membrane assembly, and the backwashing assembly and acid washing assembly are used to clean the adhering substances inside the microfiltration membrane assembly;

[0006] The backwashing assembly includes a backwashing pump, a backwashing tank, and a compressed air tank. The backwashing pump is connected to the microfiltration membrane assembly. The backwashing tank stores cleaning liquid and is connected to the backwashing pump. The compressed air tank is connected to the microfiltration membrane assembly. The backwashing pump draws the liquid from the backwashing tank and uses compressed air to clean the adhering substances in the microfiltration membrane assembly.

[0007] In a preferred embodiment, the storage tank assembly includes a mud storage tank, which is connected to the microfiltration membrane assembly via a pipeline, and the mud storage tank is also connected to a mud delivery pump.

[0008] In a preferred embodiment, the pickling assembly includes: a pickling tank containing acidic liquid, the pickling tank being connected to a microfiltration cleaning pump, the microfiltration cleaning pump being connected to the microfiltration membrane assembly via a pipeline, and the microfiltration cleaning pump drawing acidic liquid to clean the adhering substances inside the microfiltration membrane assembly.

[0009] In a preferred embodiment, the acidic liquid is hydrochloric acid.

[0010] The beneficial effects of this utility model are as follows: By integrating functions such as normal water production, discharge of crystallized sludge, backwashing and dredging, and chemical cleaning into one unit, it has the characteristics of integrated production functions, is easy to operate, and uses microfiltration membrane components for efficient interception, avoiding the problem that relying solely on sedimentation and other measures cannot efficiently remove crystals. It reduces residence time and floor space, and the microfiltration membrane components facilitate sludge discharge. Based on the combined action of gravity and air pressure, sludge can be discharged quickly, allowing for rapid production. At the same time, it is easy to clean and maintain, and the hydrochloric acid solution can be recycled, reducing the amount of cleaning acid solution used and lowering the operating cost. Attached Figure Description

[0011] Figure 1 is a schematic diagram of the planar structure of this utility model.

[0012] In the picture:

[0013] 10. Microfiltration membrane module; 11. Storage tank module; 111. Mud storage tank; 112. Mud transfer pump; 12. Pickling module; 121. Pickling tank; 122. Microfiltration cleaning pump; 13. Backwash module; 131. Backwash pump; 132. Backwash tank; 133. Compressed air tank; 14. Electrical control cabinet. Detailed Implementation

[0014] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0015] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection" and "installation" should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Furthermore, "connection" can be a direct connection or an indirect connection through an intermediate medium. "Fixed" means that the relative positional relationship remains unchanged after the connection. The directional terms mentioned in the embodiments of this utility model, such as "inner," "outer," "top," and "bottom," are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of this utility model, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model.

[0016] In this embodiment of the invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0017] In this embodiment of the utility model, "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0018] References to "one embodiment" or "some embodiments" as used in this specification mean that one or more embodiments of the present invention include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0019] As shown in Figure 1, this utility model provides a microfiltration device for leachate from municipal solid waste, characterized in that it includes: a microfiltration membrane assembly 10, which is used to filter the suspended liquid formed by adding lime to leachate to crystallize calcium and magnesium; the microfiltration membrane assembly 10 is also connected to a storage tank assembly 11, a backwashing assembly 13, and an acid washing assembly 12; the storage tank assembly 11 is used to store the crystals filtered by the microfiltration membrane assembly 10; and the backwashing assembly 13 and the acid washing assembly 12 are used to clean the adhering substances inside the microfiltration membrane assembly 10.

[0020] The backwash assembly 13 includes a backwash pump 131, a backwash tank 132, and a compressed air tank 133. The backwash pump 131 is connected to the microfiltration membrane assembly 10. The backwash tank 132 stores cleaning liquid and is connected to the backwash pump 131. The compressed air tank 133 is connected to the microfiltration membrane assembly 10. The backwash pump 131 draws the liquid in the backwash tank 132 and uses compressed air to clean the adhering substances in the microfiltration membrane assembly 10.

[0021] Furthermore, the storage tank assembly 11 includes a mud storage tank 111, which is connected to the microfiltration membrane assembly 10 via a pipe, and the mud storage tank 111 is also connected to a mud delivery pump 112.

[0022] Furthermore, the pickling assembly 12 includes: a pickling tank 121 containing acidic liquid; a microfiltration cleaning pump 122 connected to the pickling tank 121; and the microfiltration cleaning pump 122 connected to the microfiltration membrane assembly 10 via a pipeline. The microfiltration cleaning pump 122 draws acidic liquid to clean the adhering substances in the microfiltration membrane assembly 10.

[0023] Furthermore, the acidic liquid is hydrochloric acid.

[0024] Specifically, before filtering the leachate, lime is added to raise the pH value of the leachate, causing calcium ions, magnesium hydroxide, and alkalinity in the leachate to crystallize and form a suspension. This suspension is then pumped into the microfiltration membrane module 10, where it is filtered through a PTFE (polytetrafluoroethylene) membrane. This PTFE membrane can withstand long-term erosion by strong alkalis and strong acid cleaning processes. It has improved permanent hydrophilicity and excellent permeability, which improves permeability, saves filtration area, reduces investment, and increases service life (normal service life is over 5 years). The membrane uses a 0.1-micron pore size, allowing water and dissolved substances to pass through while crystals are filtered out. The crystals will be blocked, avoiding the problem that relying solely on sedimentation and other measures cannot efficiently remove crystals. This reduces residence time and floor space, and the turbidity of the filtered water is below 0.1 NTU, providing excellent protection for subsequent reverse osmosis. The blocked crystals will accumulate on the surface of the microfiltration membrane. When the fouling reaches a certain level, the pumping of leachate is stopped, the valve is switched, and the backwash assembly 13 is started. The backwash pump 131 applies high pressure to the water in the backwash tank 132 and pumps it back into the microfiltration membrane assembly 10 to flush the filter membrane, remove the accumulated crystals, and discharge them through a pipeline into the sludge storage tank 111. When the crystals in the sludge storage tank 111 reach a certain volume, they are discharged by the sludge transfer pump 112 and pumped to the subsequent sludge tank for dewatering treatment by plate and frame filter press. To improve backwashing efficiency, compressed air is also pumped into the microfiltration membrane assembly 10 simultaneously during the backwashing process. The air agitation, combined with backwashing, quickly removes the crystals accumulated on the filter membrane surface, making the filter membrane ready for filtration again.

[0025] Since the microfiltration membrane module 10 is reused, after multiple water production and sludge discharges, the sludge accumulated on the surface of the filter membrane may not be able to be washed away by backwashing and air agitation. Therefore, when the water production efficiency is still too low after backwashing, the hydrochloric acid liquid in the acid washing tank 121 can be pressurized and pumped into the microfiltration membrane module 10 by the microfiltration cleaning pump 122. The hydrochloric acid reacts chemically with the calcium and magnesium crystals, converting the calcium and magnesium crystals into soluble substances, thereby clearing the accumulated calcium and magnesium salts. The hydrochloric acid liquid after acid washing will be returned to the acid washing tank 121 for subsequent use. If the acidity of the hydrochloric acid liquid decreases, the hydrochloric acid liquid can be added as needed to make it usable again, reducing the amount of hydrochloric acid liquid used and reducing costs.

[0026] It should be noted that in this embodiment, an electrical control cabinet 14 is also included to control the start-up of each water pump. The air supply pipeline is laid out horizontally and vertically, which is convenient for maintenance and simple and beautiful. This reduces the problem that valve components are prone to short service life due to poor production conditions, and ensures long-term stable operation. The microfiltration membrane module 10 can quickly discharge sludge and start production under the combined action of gravity and air pressure, while also being convenient for cleaning and maintenance.

[0027] In summary, by integrating functions such as normal water production, discharge of accumulated sludge, backwashing and dredging, and chemical cleaning into one unit, it features integrated production functions, is easy to operate, and uses microfiltration membrane module 10 for efficient interception, avoiding the problem that relying solely on sedimentation and other measures cannot effectively remove crystals. It reduces residence time and floor space, and the microfiltration membrane module 10 facilitates sludge discharge. Based on the combined action of gravity and air pressure, sludge can be discharged quickly, allowing for rapid production. It is also easy to clean and maintain, and the hydrochloric acid solution can be recycled, reducing the amount of cleaning acid used and lowering operating costs.

[0028] This invention is not limited to the description in the specification and embodiments. Therefore, other advantages and modifications can be readily realized by those skilled in the art. Thus, without departing from the spirit and scope of the general concept as defined by the claims and their equivalents, this invention is not limited to the specific details, representative devices and illustrated examples shown and described herein.

Claims

1. A microfiltration device for leachate from municipal solid waste, characterized in that, include: A microfiltration membrane module is used to filter leachate by adding lime to crystallize calcium and magnesium into a suspension. The microfiltration membrane module is also connected to a storage tank assembly, a backwashing assembly, and an acid washing assembly. The storage tank assembly stores the crystals filtered by the microfiltration membrane module. The backwashing and acid washing assemblies are used to clean the adhering substances within the microfiltration membrane module. The backwashing assembly includes a backwash pump, a backwash tank, and a compressed air tank. The backwash pump is connected to the microfiltration membrane module. The backwash tank stores cleaning liquid and is connected to the backwash pump. The compressed air tank is connected to the microfiltration membrane module. The backwash pump draws liquid from the backwash tank and, in conjunction with compressed air, cleans the adhering substances within the microfiltration membrane module.

2. The microfiltration device for municipal solid waste leachate according to claim 1, characterized in that, The storage tank assembly includes a mud storage tank, which is connected to the microfiltration membrane assembly via a pipeline, and the mud storage tank is also connected to a mud delivery pump.

3. The microfiltration device for municipal solid waste leachate according to claim 1, characterized in that, The pickling assembly includes: a pickling tank containing acidic liquid; a microfiltration cleaning pump connected to the pickling tank; and the microfiltration cleaning pump connected to the microfiltration membrane assembly via a pipeline. The microfiltration cleaning pump draws acidic liquid to clean the adhering substances inside the microfiltration membrane assembly.

4. The microfiltration device for municipal solid waste leachate according to claim 3, characterized in that, The acidic liquid is hydrochloric acid.

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