High-pressure reverse osmosis treatment system for landfill leachate

Abstract

The utility model belongs to the technical field of resourceful treatment of high-concentration and high-salinity organic wastewater, and particularly relates to a high-pressure reverse osmosis treatment system for landfill leachate. The high-pressure reverse osmosis treatment system comprises a water inlet pipe, a softening and MF system, an RO system, a security filter and a reverse osmosis membrane filtration system which are connected in sequence, aiming at the characteristics of high salinity, high hardness, high COD (Chemical Oxygen Demand) and the like of concentrated solution of a leachate membrane system of an incineration plant and a landfill, calcium and magnesium ions and most of metal ions in water can be removed in a softening and MF system, and the operation environment of a back-end concentrated solution treatment system is improved; a concentrated solution of the RO system passes through a security filter and then enters a concentrated water circulating pipeline of the system through a high-pressure pump, a circulating pump is arranged, the cross flow velocity of the membrane surface is ensured, and the concentration polarization condition is reduced; more than 98% of salt in the concentrated solution is removed by the system, so that the recovery rate of water produced by the system reaches more than 60%, and the recovery rate is improved; the concentrated solution treatment operation of the percolate RO system is simplified, and the multi-point fault condition caused by the large number of used DTRO membranes is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of resource treatment of high-concentration and high-salinity organic wastewater, and specifically relates to a high-pressure reverse osmosis treatment system for garbage leachate. Background Art

[0002] Leachate refers to a liquid with high concentration of organic or inorganic components produced during the stacking process of garbage due to biochemical degradation such as compaction and fermentation, as well as the action of precipitation and groundwater seepage; reverse osmosis concentrate is a difficult-to-treat leachate reverse osmosis concentrate liquid produced in the leachate treatment process using membrane separation technology. The amount produced is large, accounting for 13% to 30% of the leachate influent. The water quality is complex, with high salt and heavy metal content, poor biodegradability, and is difficult to treat.

[0003] Currently, it is generally achieved through external transportation, reinjection, membrane reduction, evaporation, membrane distillation, advanced oxidation technology, incineration and other means. Among them, membrane reduction is mostly achieved by methods such as disc tube reverse osmosis (DTRO), and RO pre-treatment is mostly achieved by nanofiltration (NF).

[0004] However, DTRO technology has defects such as large number of DTRO membranes and low system water production rate. Utility Model Content

[0005] The utility model aims to provide a high-pressure reverse osmosis treatment system for landfill leachate, so as to solve the technical problems of large number of membrane branches and low system water production rate existing in the prior art using DTRO technology.

[0006] In order to solve the above technical problems, the utility model provides a high-pressure reverse osmosis treatment system for landfill leachate, comprising: a water inlet pipe, a softening and MF system, an RO system, a security filter, and a reverse osmosis membrane filtration system connected in sequence; wherein

[0007] The water inlet pipe is used to receive the leachate discharged from the leachate MBR system;

[0008] The input port of the softening and MF system is connected to the water inlet pipe for precipitation and filtration of metal ions in the leachate;

[0009] The RO system is used to concentrate the leachate, and its first outlet is used to discharge the clear liquid, and the second outlet is used to discharge the concentrated leachate into the security filter;

[0010] The leachate discharged from the security filter is discharged into the reverse osmosis membrane filtration system.

[0011] In one embodiment of the present application, the high pressure reverse osmosis treatment system comprises:

[0012] A plurality of high-pressure reverse osmosis membrane modules arranged in parallel;

[0013] An input pipeline, one end of which is connected to the security filter, and the other end is connected to the input end of each high-pressure reverse osmosis membrane assembly, and a high-pressure pump is arranged on the input pipeline;

[0014] A concentrated water circulation pipeline, one end of which is connected to the concentrated water output end of the high-pressure reverse osmosis membrane assembly, and the other end of which is connected to the input end of the high-pressure reverse osmosis membrane assembly;

[0015] A cleaning circulation pipeline has one end connected to the water output end of the high-pressure reverse osmosis membrane assembly and the other end connected to the input end of the high-pressure pump.

[0016] In one embodiment of the present application, the concentrate output end of the high-pressure reverse osmosis membrane assembly is divided into two paths, one path is connected to the concentrate outlet pipeline, and the other path is connected to the concentrate circulation pipeline.

[0017] In one embodiment of the present application, a circulation pump is provided on the concentrated water circulation pipeline.

[0018] In one embodiment of the present application, the water output end of the high-pressure reverse osmosis membrane assembly is divided into two paths, one path is connected to the clear liquid pipeline, and the other path is connected to the cleaning circulation pipeline.

[0019] In one embodiment of the present application, a cleaning tank and a cleaning pump are provided on the cleaning circulation pipeline.

[0020] In one embodiment of the present application, the input end of the high-pressure pump is also connected to a flushing water inlet pipeline.

[0021] In one embodiment of the present application, the working pressure of the high-pressure pump is greater than or equal to 120 bar.

[0022] The beneficial effects of the utility model are as follows: the high-pressure reverse osmosis treatment system for landfill leachate of the utility model comprises an inlet pipe, a softening and MF system, an RO system, a security filter, and a reverse osmosis membrane filtration system which are connected in sequence; the concentrated liquid water quality of the leachate membrane system of the incineration plant and the landfill has the characteristics of high salinity, high hardness, high COD, etc., and the calcium, magnesium ions and most of the metal ions in the water can be removed in the softening and MF system, thereby improving the operating environment of the rear-end concentrated liquid treatment system; the concentrated liquid of the RO system passes through the security filter and then enters the concentrated water circulation pipeline of the system through a high-pressure pump, and a circulation pump is configured to ensure the cross-flow flow rate on the membrane surface and reduce the concentration polarization; the system removes more than 98% of the salt in the concentrated liquid, so that the system water production recovery rate reaches more than 60%, thereby improving the recovery rate; the operation of the concentrated liquid treatment of the leachate RO system is simplified, and the multi-point failure caused by the use of a large number of DTRO membranes is reduced.

[0023] Other features and advantages of the utility model will be described in the following description, and partly become apparent from the description, or understood by practicing the utility model. The purpose and other advantages of the utility model are realized and obtained by the structures particularly pointed out in the description and the drawings.

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a schematic diagram of a preferred embodiment of the high-pressure reverse osmosis treatment system for landfill leachate of the utility model.

[0027] In the figure:

[0028] Water inlet pipe 1, softening and MF system 2, RO system 3, security filter 4, high-pressure reverse osmosis membrane assembly 5, input pipeline 6, high-pressure pump 7, concentrated water circulation pipeline 8, cleaning circulation pipeline 9, concentrated liquid outlet pipeline 10, circulation pump 11, clear liquid pipeline 12, cleaning tank 13, cleaning pump 14, flushing water inlet pipeline 15. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0030] Glossary:

[0031] MBR is the abbreviation of Membrane Bio-Reactor, which is a new water treatment technology that organically combines membrane separation technology with biotechnology. It uses membrane separation equipment to intercept activated sludge and macromolecular organic matter in the biochemical reaction tank, eliminating the secondary sedimentation tank.

[0032] The softening and MF system is a system for softening and micro-filtering water.

[0033] The RO system is a reverse osmosis water treatment system. Its principle is that raw water passes through a reverse osmosis membrane under high pressure, and the solvent in the water diffuses from high concentration to low concentration to achieve the purpose of separation, purification, and concentration. Since it is opposite to the osmosis direction in nature, it is called reverse osmosis.

[0034] See also Figure 1 In one embodiment of the present application, a high-pressure reverse osmosis treatment system for landfill leachate includes: an inlet pipe 1, a softening and MF system 2, a RO system 3, a security filter 4, and a reverse osmosis membrane filtration system connected in sequence; wherein the inlet pipe 1 is used to receive the leachate discharged from the leachate MBR system; the input port of the softening and MF system 2 is connected to the inlet pipe 1, and is used to precipitate and filter the metal ions in the leachate; the RO system 3 is used to concentrate the leachate, and its first output port is used to discharge the clear liquid, and the second output port is used to discharge the concentrated leachate into the security filter 4; the leachate discharged from the security filter 4 is discharged into the reverse osmosis membrane filtration system.

[0035] In this embodiment, the concentrated liquid water quality of the leachate membrane system of the incineration plant and landfill has the characteristics of high salinity, high hardness, and high COD. The calcium, magnesium ions and most of the metal ions in the water are removed in the softening and MF system 2 to improve the operating environment of the back-end concentrated liquid treatment system.

[0036] Optionally, in the softening and MF system 2, alkali can be added to the leachate deep treatment inlet water to adjust the wastewater pH to an appropriate value, so that the calcium ions and magnesium ions and most of the metal ions in the water can react to form precipitates, which are filtered through MF to remove these ions from the water and reduce the tendency of divalent ions to form scale at the reverse osmosis concentrate end.

[0037] Furthermore, the high-pressure reverse osmosis treatment system includes: a plurality of high-pressure reverse osmosis membrane assemblies 5 arranged in parallel; an input pipeline 6, one end of which is connected to the security filter 4, and the other end is connected to the input end of each high-pressure reverse osmosis membrane assembly 5, and a high-pressure pump 7 is arranged on the input pipeline 6; a concentrated water circulation pipeline 8, one end of which is connected to the concentrated water output end of the high-pressure reverse osmosis membrane assembly 5, and the other end is connected to the input end of the high-pressure reverse osmosis membrane assembly 5; a cleaning circulation pipeline 9, one end of which is connected to the produced water output end of the high-pressure reverse osmosis membrane assembly 5, and the other end is connected to the input end of the high-pressure pump 7.

[0038] In this embodiment, the outlet water of the security filter 4 is pressurized by the high-pressure pump 7 and then enters the high-pressure reverse osmosis membrane assembly 5; the output end of the high-pressure reverse osmosis membrane assembly 5 includes a concentrated water output end and a produced water output end; the concentrated water at the concentrated water output end can be further circulated and treated, and can be discharged after meeting the standards; part of the water at the produced water output end can be used for cleaning.

[0039] Specifically, the concentrated water output end of the high-pressure reverse osmosis membrane assembly 5 is divided into two paths, one path is connected to the concentrated liquid outlet pipeline 10, and the other path is connected to the concentrated water circulation pipeline 8; optionally, a circulation pump 11 is provided on the concentrated water circulation pipeline 8.

[0040] Specifically, the water output end of the high-pressure reverse osmosis membrane assembly 5 is divided into two paths, one connected to the clear liquid pipeline 12, and the other connected to the cleaning circulation pipeline 9; optionally, the cleaning circulation pipeline 9 is provided with a cleaning tank 13 and a cleaning pump 14.

[0041] In this embodiment, the cleaning tank 13 can store produced water, and the cleaning pump 14 can input the stored water in the cleaning tank 13 into the high-pressure reverse osmosis membrane assembly 5 when the high-pressure reverse osmosis membrane assembly 5 needs to be cleaned.

[0042] Furthermore, the input end of the high-pressure pump 7 is also connected to a flushing water inlet pipeline 15, which can supply flushing water when the high-pressure reverse osmosis membrane assembly 5 needs to be flushed.

[0043] In this embodiment, preferably, the working pressure of the high-pressure pump 7 is greater than or equal to 120 bar.

[0044] In this embodiment, the concentrated liquid of the RO system 3 passes through the security filter 4 and then enters the high-pressure circulation pipeline of the system through the high-pressure pump 7 greater than or equal to 120 bar, and passes through the high-pressure reverse osmosis membrane assembly 5; the membrane system is equipped with a circulation pump 11 to ensure the cross-flow flow rate on the membrane surface and reduce concentration polarization; the system removes more than 98% of the salt in the concentrated liquid, so that the system water recovery rate reaches more than 60%; when the water treatment volume is large, it can be considered to add a two-stage design to further improve the system recovery rate.

[0045] In this embodiment, the clear liquid pipeline 12 can recycle the clear liquid to the cooling tower water of the incineration power plant, which can meet the landfill discharge standards; improve the recovery rate of the concentrated liquid treatment of the leachate RO system, simplify the operation of the concentrated liquid treatment of the leachate RO system, and reduce the multi-point failure caused by the use of DTRO.

[0046] It should be noted that the utility model aims to improve the overall structure and connection coordination method of the high-pressure reverse osmosis treatment system for landfill leachate. The independent devices in the system, such as the softening and MF system 2, the RO system 3, the security filter 4, the high-pressure reverse osmosis membrane assembly 5, etc., can all be obtained by using existing technologies or purchasing on the market. The utility model mainly improves the coordination relationship between them.

[0047] The various devices selected in this application (components whose specific structures are not described) are all universal standard parts or components known to technical personnel in this field, and their structures and principles can be known to technical personnel through technical manuals or through conventional experimental methods.

[0048] In the description of the embodiments of the present utility model, unless otherwise clearly stipulated and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection;.

[0049] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0050] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without deviating from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A high-pressure reverse osmosis treatment system for landfill leachate, characterized in that: include: The water inlet pipe (1), softening and MF system (2), RO system (3), security filter (4), and reverse osmosis membrane filtration system are connected in sequence; in The water inlet pipe (1) is used to receive the leachate discharged from the leachate MBR system; The input port of the softening and MF system (2) is connected to the water inlet pipe (1) and is used to precipitate and filter metal ions in the leachate; The RO system (3) is used to concentrate the leachate, and its first output port is used to discharge the clear liquid, and the second output port is used to discharge the concentrated leachate into the security filter (4); The leachate discharged from the security filter (4) is discharged into the reverse osmosis membrane filtration system.

2. The high pressure reverse osmosis treatment system according to claim 1, characterized in that: The high pressure reverse osmosis treatment system comprises: A plurality of high-pressure reverse osmosis membrane modules (5) arranged in parallel; An input pipeline (6), one end of which is connected to the security filter (4) and the other end of which is connected to the input end of each high-pressure reverse osmosis membrane assembly (5), and a high-pressure pump (7) is provided on the input pipeline (6); A concentrated water circulation pipeline (8), one end of which is connected to the concentrated water output end of the high-pressure reverse osmosis membrane assembly (5), and the other end of which is connected to the input end of the high-pressure reverse osmosis membrane assembly (5); A cleaning circulation pipeline (9) has one end connected to the water output end of the high-pressure reverse osmosis membrane assembly (5) and the other end connected to the input end of the high-pressure pump (7).

3. The high pressure reverse osmosis treatment system according to claim 2, characterized in that: The concentrated water output end of the high-pressure reverse osmosis membrane assembly (5) is divided into two paths, one of which is connected to the concentrated liquid outlet pipeline (10) and the other is connected to the concentrated water circulation pipeline (8).

4. The high pressure reverse osmosis treatment system according to claim 3, characterized in that: The concentrated water circulation pipeline (8) is provided with a circulation pump (11).

5. The high pressure reverse osmosis treatment system according to claim 2, characterized in that: The water output end of the high-pressure reverse osmosis membrane assembly (5) is divided into two paths, one of which is connected to the clear liquid pipeline (12) and the other is connected to the cleaning circulation pipeline (9).

6. The high pressure reverse osmosis treatment system according to claim 5, characterized in that: The cleaning circulation pipeline (9) is provided with a cleaning tank (13) and a cleaning pump (14).

7. The high pressure reverse osmosis treatment system according to claim 5, characterized in that: The input end of the high-pressure pump (7) is also connected to a flushing water inlet pipeline (15).

8. The high pressure reverse osmosis treatment system according to claim 2, characterized in that: The working pressure of the high-pressure pump (7) is greater than or equal to 120 bar.

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