Wastewater recovery and comprehensive utilization system

Abstract

The utility model discloses a waste water recycling and comprehensive utilization system which comprises a regulating tank; a chemical softening tank; a mechanical filter; an ultrafiltration device; a water outlet of the ultrafiltration equipment is connected with a softening resin tank through a pipeline, a water outlet of the softening resin tank is connected with multi-stage reverse osmosis equipment through a pipeline, and a water production port of the multi-stage reverse osmosis equipment is connected with a water production pool through a pipeline; a water outlet of the multi-stage reverse osmosis equipment is connected with multi-stage nanofiltration equipment through a pipeline, a water outlet of the multi-stage nanofiltration equipment is connected with multi-stage concentrated water reverse osmosis equipment through a pipeline, and a water outlet of the multi-stage concentrated water reverse osmosis equipment is connected with a water inlet of the softening resin tank through a pipeline; and a water outlet of the softened resin tank is connected with a water inlet of the multi-stage nanofiltration equipment through a pipeline. The wastewater recycling and comprehensive utilization system is simple in structure and high in water resource utilization rate, and the wastewater treatment cost is reduced.

Description

Technical Field

[0001] The utility model relates to a comprehensive wastewater recovery and utilization system. Background Art

[0002] In the process of continuous improvement of industrial development and people's living standards, the generated wastewater has far exceeded the bearing capacity of the environment. Wastewater can be divided into: municipal sewage, industrial sewage, treated effluent (discharge standard), wastewater, etc. according to different sources. At present, the wastewater recovery rate in China is generally low. According to different sources of wastewater, after treatment, the wastewater can be reused for: 1. Use in power plants, coal chemical industries and industrial parks; 2. Domestic drinking and miscellaneous water. After purification treatment to meet the standards of domestic drinking water and urban miscellaneous water, it is supplied to the residents in the mining area (factory) and its surrounding areas; 3. Agricultural and forestry irrigation water, mainly used for greening in mining areas, irrigation of surrounding farmland, etc.

[0003] According to the characteristics of wastewater quality and the purpose of reuse, different treatment processes are selected. Currently, common treatment methods include evaporation method, ion exchange method, membrane separation method, etc. Membrane separation method mainly includes two types: electrodialysis (ED) method and reverse osmosis (RO) method; this is the mainstream process method for current wastewater purification treatment. At the same time, in order to extend the cleaning cycle and service life of ED and RO, chemical hardness removal and ion exchange resin are often set at the water inlet end. The ED method is to use the selective permeability of ion exchange membranes to ions in the solution under the action of an externally applied direct current electric field force, so as to separate inorganic salts from water. However, when using the ED method to treat wastewater, there are problems such as low purification degree, low water recovery rate, and high energy consumption; while the RO method is a method of separating substances by means of a semi-permeable membrane under pressure. The purification effect of the RO method is relatively good. Its advantages are good desalination effect and relatively low recovery rate of purified water; the disadvantage is that the recycling and comprehensive utilization of concentrated brine have not been realized. Summary of the Utility Model

[0004] The utility model overcomes the deficiencies existing in the prior art and provides a comprehensive wastewater recovery and utilization system.

[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is: a comprehensive wastewater recovery and utilization system, including:

[0006] Regulating tank;

[0007] Chemical softening tank, connected to the drainage outlet of the regulating tank through a pipeline;

[0008] Mechanical filter, connected to the drainage outlet of the chemical softening tank through a pipeline;

[0009] Ultrafiltration device, connected to the drainage outlet of the mechanical filter through a pipeline;

[0010] It is characterized in that: the drain outlet of the ultrafiltration device is connected to a softening resin tank through a pipeline, the drain outlet of the softening resin tank is connected to a multi-stage reverse osmosis device through a pipeline, the water production outlet of the multi-stage reverse osmosis device is connected to a water production pool through a pipeline, the drain outlet of the multi-stage reverse osmosis device is connected to a multi-stage nanofiltration device through a pipeline, the drain outlet of the multi-stage nanofiltration device is connected to a multi-stage concentrated water reverse osmosis device through a pipeline, the water production outlet of the multi-stage concentrated water reverse osmosis device is connected to the water production pool through a pipeline, the drain outlet of the multi-stage concentrated water reverse osmosis device is connected to the water inlet of the softening resin tank through a pipeline, and a pipeline connection is provided between the drain outlet of the softening resin tank and the water inlet of the multi-stage nanofiltration device.

[0011] In the above structure, the multi-stage reverse osmosis device is one of a spiral wound membrane system, a plate membrane system, and a DTRO membrane system.

[0012] In the above structure, the multi-stage nanofiltration device is one of a spiral wound membrane system and a plate membrane system.

[0013] In the above structure, the multi-stage concentrated water reverse osmosis device is one of a spiral wound membrane system, a plate membrane system, and a DTRO membrane system.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0015] 1) It is not affected by the quantity and quality of wastewater, and has a simple structure;

[0016] 2) The hardness index of the chemically softened effluent is broad, with hardness ≤ 200 ppm (calculated as calcium carbonate), the chemical dosage is reduced, it is easy to control, and the management is convenient;

[0017] 3) By adopting the operation mode of salt separation nanofiltration plus multi-stage concentrated water reverse osmosis, the water resource utilization rate is increased to more than 90%;

[0018] 4) The oxygen consumption for the regeneration of the softening resin is saved by 100% (no need to purchase salt externally), reducing the wastewater treatment cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of a wastewater recovery and comprehensive utilization system according to an embodiment of the present utility model.

[0020] In the figure:

[0021] 1, regulating tank; 2, chemical softening tank; 3, mechanical filter; 4, ultrafiltration device; 5, softening resin tank; 6, multi-stage reverse osmosis device; 7, water production pool; 8, multi-stage nanofiltration device; 9, multi-stage concentrated water reverse osmosis device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following will further describe in detail the specific implementation manners of the present utility model in conjunction with the accompanying drawings and embodiments. The following embodiments are used to illustrate the present utility model, but are not used to limit the scope of the present utility model.

[0023] As Figure 1 shown, a comprehensive wastewater recycling and utilization system includes:

[0024] Regulating tank 1;

[0025] Chemical softening tank 2, which is connected to the drainage outlet of the regulating tank 1 through a pipeline;

[0026] Mechanical filter 3, which is connected to the drainage outlet of the chemical softening tank 2 through a pipeline;

[0027] Ultrafiltration device 4, which is connected to the drainage outlet of the mechanical filter 3 through a pipeline;

[0028] It is characterized in that: the drainage outlet of the ultrafiltration device 4 is connected with a softening resin tank 5 through a pipeline, the drainage outlet of the softening resin tank 5 is connected with a multi-stage reverse osmosis device 6 through a pipeline, the water production outlet of the multi-stage reverse osmosis device 6 is connected with a product water tank 7 through a pipeline, the drainage outlet of the multi-stage reverse osmosis device 6 is connected with a multi-stage nanofiltration device 8 through a pipeline, the drainage outlet of the multi-stage nanofiltration device 8 is connected with a multi-stage concentrated water reverse osmosis device 9 through a pipeline, the water production outlet of the multi-stage concentrated water reverse osmosis device 9 is connected with the product water tank 7 through a pipeline, the drainage outlet of the multi-stage concentrated water reverse osmosis device 9 is connected with the water inlet of the softening resin tank 5 through a pipeline, and is connected through a pipeline between the drainage outlet of the softening resin tank 5 and the water inlet of the multi-stage nanofiltration device 8.

[0029] In the above structure, the multi-stage reverse osmosis device 6 is one of a spiral wound membrane system, a plate membrane system, and a DTRO membrane system.

[0030] In the above structure, the multi-stage nanofiltration device 8 is one of a spiral wound membrane system and a plate membrane system.

[0031] In the above structure, the multi-stage concentrated water reverse osmosis device 9 is one of a spiral wound membrane system, a plate membrane system, and a DTRO membrane system.

[0032] When the wastewater recycling and comprehensive utilization system of the present utility model is working specifically, the chemical softening tank mainly performs primary hardness removal on the wastewater, filters out pollutants such as colloids and suspended solids in the wastewater through mechanical filtration and ultrafiltration; then adsorbs and exchanges the scale-forming ions in the wastewater through the softening resin tank; finally, it is concentrated by a multi-stage reverse osmosis device, and the produced water is introduced into the production pool through a pipeline; realizing the efficient and green recycling of water resources. In addition, the regeneration waste liquid generated by the softening resin tank is a mixed solution mainly composed of sodium chloride, calcium ions, and magnesium ions. The regeneration liquid and the concentrated water generated by the multi-stage reverse osmosis device enter the multi-stage nanofiltration device through a pipeline together; the multi-stage nanofiltration device separates monovalent ions from divalent and higher-valent ions, and the produced water is concentrated by a multi-stage concentrated water reverse osmosis device again. The produced water of the multi-stage concentrated water reverse osmosis device is introduced into the production pool through a pipeline; while the concentrated water generated by the multi-stage concentrated water reverse osmosis device is introduced into the softening resin tank through a pipeline. The concentrated water is sodium chloride concentrated brine with a concentration ≥ 5%, which can be used as the regeneration liquid of the softening resin. The water resource recovery rate is increased to more than 90%, realizing the efficient and green recycling of salt resources; the oxygen consumption for softening resin regeneration is saved by 100% (no need to purchase salt externally), reducing the treatment cost of wastewater.

[0033] The above are only the preferred embodiments of the present utility model. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the technical principle of the present utility model, several improvements and modifications can still be made, and these improvements and modifications should also be regarded as the protection scope of the present utility model.

Claims

1. A wastewater recycling and comprehensive utilization system, comprising: Regulating tank (1); A chemical softening tank (2) connected to the drain outlet of the regulating tank (1) via a pipeline; A mechanical filter (3) connected to the drain outlet of the chemical softening tank (2) via a pipeline; An ultrafiltration device (4) connected to the drain outlet of the mechanical filter (3) via a pipeline; The invention is characterized in that: the drain outlet of the ultrafiltration device (4) is connected to a softening resin tank (5) through a pipeline, the drain outlet of the softening resin tank (5) is connected to a multi-stage reverse osmosis device (6) through a pipeline, the water outlet of the multi-stage reverse osmosis device (6) is connected to a water production pool (7) through a pipeline, the drain outlet of the multi-stage reverse osmosis device (6) is connected to a multi-stage nanofiltration device (8) through a pipeline, the drain outlet of the multi-stage nanofiltration device (8) is connected to a multi-stage concentrated water reverse osmosis device (9) through a pipeline, the water outlet of the multi-stage concentrated water reverse osmosis device (9) is connected to the water production pool (7) through a pipeline, the drain outlet of the multi-stage concentrated water reverse osmosis device (9) is connected to the water inlet of the softening resin tank (5) through a pipeline, and the drain outlet of the softening resin tank (5) and the water inlet of the multi-stage nanofiltration device (8) are connected through a pipeline.

2. The wastewater recycling and comprehensive utilization system according to claim 1 is characterized in that: The multi-stage reverse osmosis equipment (6) is one of a roll membrane system, a plate membrane system, and a DTRO membrane system.

3. The wastewater recycling and comprehensive utilization system according to claim 1 is characterized in that: The multi-stage nanofiltration device (8) is a type of roll membrane system or a plate membrane system.

4. The wastewater recycling and comprehensive utilization system according to claim 1 is characterized in that: The multi-stage concentrated water reverse osmosis equipment (9) is one of a roll membrane system, a plate membrane system, and a DTRO membrane system.

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