Water treatment system and process based on salt lake underground water quality

Abstract

The invention relates to the technical field of water treatment, in particular to a salt lake underground water quality-based water treatment system and process, comprising: an ultrafiltration device for removing suspended particulate matters in water; the primary reverse osmosis device is used for preliminarily removing soluble solids in water; the secondary reverse osmosis device is used for further removing residual salt in water; the boron removal ion exchanger is used for removing boron in water; and the EDI device is used for removing conductive ions in water. Aiming at the characteristic of low plateau temperature, a protective film treatment (ultrafiltration) device is arranged in the system, the treatment efficiency is improved, and a heat exchanger device is added to improve the inlet water temperature; the measures of further treatment of first-stage concentrated water and backflow of second-stage concentrated water and EDI concentrated water are added for lack of plateau water resources, so that the utilization efficiency of the water resources is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular to a water treatment system and process based on the water quality of salt lake groundwater. Background Art

[0002] When carrying out engineering project construction in the salt lake area, the boron and silicon content of groundwater is often high, and some equipment such as steam turbines and air compressor stations have high requirements for water quality. In addition, domestic water also needs to meet relevant national standards. However, the existing single water treatment method is difficult to effectively remove boron and silicon, making it difficult to meet the requirements of equipment and domestic water. Although various water treatment technologies in the prior art, such as reverse osmosis and ion exchange, can remove some pollutants separately, there is no comprehensive water treatment system for plateau salt lake areas. Summary of the invention

[0003] The purpose of the present invention is to solve the deficiencies of the prior art and to provide a boron and silicon removal water treatment system and process based on the water quality characteristics of salt lake groundwater, which is suitable for meeting the water quality requirements of industrial equipment and domestic water.

[0004] To achieve the above object, the present invention provides a water treatment system based on salt lake groundwater quality, comprising: Ultrafiltration device, used to remove suspended particles from water; A primary reverse osmosis unit for the initial removal of dissolved solids from the water; A two-stage reverse osmosis unit to further remove residual salt from the water; Boron removal ion exchanger, used to remove boron from water; EDI device is used to remove conductive ions from water.

[0005] Preferably, the ultrafiltration device comprises an ultrafiltration membrane with a filtration accuracy of 0.1 μm, which is used to remove fine particles in water.

[0006] Preferably, the ultrafiltration device is connected to the primary reverse osmosis device, the primary reverse osmosis device is connected to the secondary reverse osmosis device, the secondary reverse osmosis device is connected to a boron removal ion exchanger, and the boron removal ion exchanger is connected to the EDI device.

[0007] Preferably, the primary reverse osmosis device and the secondary reverse osmosis device each include a plurality of reverse osmosis units, and the particle sizes of soluble solids allowed to pass through the plurality of reverse osmosis units are different.

[0008] The present invention also provides a water treatment process based on salt lake groundwater. The specific process flow is as follows: the production water from the production water supply network enters the raw water tank, is pressurized by the raw water pump and sent to the ultrafiltration device to remove suspended matter in the water, and then enters the primary reverse osmosis device. After desalination by the primary reverse osmosis, it is counted into the primary RO production water tank, and then sent to the secondary reverse osmosis through the secondary RO feed pump for further desalination. The desalted water enters the secondary RO production water tank, and then the exchanger feed pump sends it to the boron removal ion exchanger to remove boron in the water, and then enters the boron removal water tank, and is sent to the EDI device through the EDI feed pump. The resulting water enters the desalted water tank and is pumped to the water use device by the desalted water pump.

[0009] Preferably: After the process, the parameters of the effluent water quality are as follows: Silicon dioxide: ≤20g / L Conductivity: ≤0.2s / cm (25℃).

[0010] Compared with the prior art, the technical solution proposed in this application has the following beneficial effects: in view of the low temperature in the plateau, the present invention adds a heat exchanger device to increase the inlet water temperature in order to protect the membrane treatment (ultrafiltration) device and improve the treatment efficiency in the system; due to the shortage of water resources in the plateau, the measures of "further treatment of primary concentrated water" and "reflux of secondary concentrated water and EDI concentrated water" are added to improve the utilization efficiency of water resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 It is a system structure diagram of the present invention. DETAILED DESCRIPTION

[0012] The following will clearly and completely describe and discuss the technical solutions in the embodiments of the present invention in conjunction with the drawings of the present invention. Obviously, what is described here is only a part of the examples of the present invention, not all the examples. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0013] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a component centered. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a component centered. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a component centered. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0014] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0015] See also Figure 1 This embodiment provides a water treatment system based on salt lake groundwater quality, including Ultrafiltration device, used to remove suspended particles from water; A primary reverse osmosis unit for the initial removal of dissolved solids from the water; A two-stage reverse osmosis unit to further remove residual salt from the water; Boron removal ion exchanger, used to remove boron from water; EDI device is used to remove conductive ions from water.

[0016] The ultrafiltration device includes an ultrafiltration membrane with a filtration accuracy of 0.1 μm, which is used to remove fine particles in water. The ultrafiltration device is connected to the primary reverse osmosis device, the primary reverse osmosis device is connected to the secondary reverse osmosis device, the secondary reverse osmosis device is connected to a boron removal ion exchanger, and the boron removal ion exchanger is connected to the EDI device. The primary reverse osmosis device and the secondary reverse osmosis device each include a plurality of reverse osmosis units, and the particle sizes of soluble solids allowed to pass through the plurality of reverse osmosis units are different.

[0017] Specifically, the system is set up as follows: (1) Self-cleaning filter The system is equipped with 2 self-cleaning filters, which adopt electric suction head type, with a filtration accuracy of 100μm, and are set in parallel, 1 in operation and 1 in standby, to intercept particles in the raw water.

[0018] A differential pressure gauge is installed at the inlet and outlet of each self-cleaning filter. When the inlet and outlet water pressure difference exceeds 0.1MPa, the self-cleaning filter will automatically stop operating for cleaning.

[0019] (2) Ultrafiltration device The system is equipped with 2 sets of ultrafiltration devices, which are set in parallel, 1 for operation and 1 for equipment use. The net water output of each set of ultrafiltration device is 55m3 / h, and the recovery rate is ≥90%. It is used to remove particles, suspended matter, organic matter, colloids, bacteria and most viruses in the water, so that the effluent water quality reaches turbidity ≤1.0NTU, SDI ≤3, meets the water inlet requirements of reverse osmosis, and ensures the safe operation of the reverse osmosis device.

[0020] The ultrafiltration membrane is selected from ultrafiltration membrane elements with strong strength, good anti-pollution performance, thorough and convenient backwashing, and high water utilization rate. Pressure gauges and flow meters are installed at the water inlet and outlet of each ultrafiltration device to realize the operation of the ultrafiltration device. Online monitoring is implemented, and pneumatic valves are installed at the water inlet, outlet and drain to realize automatic operation of equipment start, stop and cleaning.

[0021] (3) Reverse osmosis system The reverse osmosis system includes a security filter, a high-pressure pump and a reverse osmosis device. The reverse osmosis system undertakes the main desalination task, mainly removing dissolved salts in the water, while removing some organic macromolecules, small particles that were not removed in the previous stage, etc.

[0022] The system is equipped with 2 sets of first-stage reverse osmosis devices, which are set in parallel, 1 set is in operation and 1 set is in equipment use. The water production of a single set is 40m3 / h and the recovery rate is ≥75%.

[0023] The system is equipped with 2 sets of two-stage reverse osmosis devices, which are set in parallel. One unit is in operation. The water production of one device is 40m3 / h, and the recovery rate is ≥90%.

[0024] The system is equipped with 1 set of concentrated water reverse osmosis device, with a single set of water production of 8m3 / h and a recovery rate of ≥50%.

[0025] An electric valve is set for the reverse osmosis water inlet, and a pneumatic valve is set for the cleaning water inlet and drainage, realizing the online operation of the reverse osmosis system during operation and shutdown.

[0026] The reverse osmosis high-pressure pump adopts frequency conversion regulation. A low-pressure protection switch is set before each high-pressure pump, and a high-pressure protection switch is set after the pump.

[0027] The reverse osmosis system is designed for automatic operation, and the control system is incorporated into the desalted water treatment control system.

[0028] (4) EDI system The EDI system includes a security filter and an EDI device, which is mainly used to further remove ions from water.

[0029] The system is equipped with 2 sets of EDI devices, which are set in parallel, 1 set is in operation and 1 set is for equipment use. The water output of a single set is 30m3 / h and the recovery rate is ≥90%.

[0030] (5) Cleaning and dosing system The ultrafiltration device, reverse osmosis device and EDI device are each provided with a set of cleaning devices.

[0031] The dosing device includes one set of sodium hypochlorite, scale inhibitor, reducing agent, acid, alkali and non-oxidizing bactericide dosing device.

[0032] (6) Wastewater discharge system The main wastewater from the desalination station includes filter backwash drainage, reverse osmosis concentrated water and softener regeneration salt-containing wastewater. All wastewater flows into the wastewater pool through the ditch, and then is pressurized and transported to the sewage treatment station by the wastewater pump.

[0033] (7) Storage system The system is equipped with 1 raw water tank, 1 ultrafiltration water tank, 1 primary RO water production tank, 1 secondary RO water production tank, 1 boron removal water tank, 2 desalted water tanks and 1 concentrated water tank. The capacity of each tank is V=100m3. The secondary RO water production tank, boron removal water tank and desalted water tank are made of stainless steel, and the other water tanks are made of carbon steel for corrosion resistance. The water tank is equipped with a remote liquid level gauge and is interlocked with the tank outlet water pump. When the liquid level is low, the pump is stopped by the interlock.

[0034] The same type of equipment in the chemical water treatment system is connected in parallel, and connected to subsequent equipment in series.

[0035] The operation, backwashing and regeneration of the chemical water treatment system are all controlled by DCS computer programs. In the event of accidents, they can also be operated locally or remotely. Centralized control instruments and local indicating instruments are also provided. The system is controlled and monitored by the host computer in the control room, and can also be controlled manually.

[0036] This embodiment also provides a process flow of a chemical water treatment system as follows: Raw water, raw water tank, raw water pump, heat exchanger, ultrafiltration device, ultrafiltration water production tank, first-stage RO feed water pump, first-stage reverse osmosis device, first-stage RO water production tank, second-stage RO feed water pump, second-stage reverse osmosis device, second-stage RO water production tank, exchanger, feed water pump, boron removal, ion exchanger, boron removal water tank, EDI feed water pump, EDI device, desalted water tank, desalted water pump outside the boundary.

[0037] First-stage reverse osmosis concentrated water, concentrated water tank, concentrated water RO water feed pump, concentrated water reverse osmosis device, first-stage RO water production tank.

[0038] The produced water from the produced water supply network enters the raw water tank and is pressurized by the raw water pump and sent to the ultrafiltration device to remove water. After removing the suspended solids in the water, it enters the primary reverse osmosis device, and after desalination by the primary reverse osmosis, it is counted into the primary RO water production tank, and then is sent to the secondary reverse osmosis through the secondary RO water feed pump for further desalination. The desalted water enters the secondary RO water production tank, and then is sent to the boron removal ion exchanger by the exchanger water feed pump to remove the boron in the water, and then enters the boron removal water tank, and is sent to the EDI device through the EDI water feed pump. The obtained water enters the desalted water tank and is sent to the water use device by the desalted water pump.

[0039] The primary reverse osmosis concentrated water enters the concentrated water tank, and is sent to the concentrated water reverse osmosis device through the concentrated water RO feed pump, and the produced water enters the primary RO produced water tank.

[0040] The secondary reverse osmosis concentrated water returns to the ultrafiltration water tank as supplementary water for the system.

[0041] EDI concentrated water returns to the primary RO water tank as system make-up water.

[0042] The task of the ultrafiltration device is to remove particles, suspended matter, organic matter, colloids, etc. in the water to make it meet the reverse osmosis water inlet requirements. The task of the boron removal resin is to remove boron ions in the water. The reverse osmosis system undertakes the main desalination task, mainly removing dissolved salts in the water, while removing some organic macromolecules, small particles that were not removed in the previous stage, etc. The EDI device is used for further desalination to ensure that indicators such as the conductivity of the effluent meet the water quality requirements.

[0043] The boron removal resin is regenerated using hydrochloric acid and caustic soda. The acid and alkali are transported by tank trucks and pumped into high-level acid and alkali storage tanks. It then flows into the acid and alkali metering box by gravity, and after being transported by the acid and alkali regeneration pump with desalted water and diluted with water, it is sent to the ion exchanger to regenerate the resin and restore its exchange capacity.

[0044] The system outlet water quality is controlled as follows: Silica: ≤20 g / L Conductivity: ≤0.2 s / cm (25℃).

[0045] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and one or more of the above embodiments are combined into one embodiment. Those skilled in the art can make various changes or modifications or combinations within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other at will.

Claims

1. A water treatment system based on salt lake groundwater quality, characterized in that: include Ultrafiltration device, used to remove suspended particles from water; A primary reverse osmosis unit for the initial removal of dissolved solids from the water; A two-stage reverse osmosis unit to further remove residual salt from the water; Boron removal ion exchanger, used to remove boron from water; EDI device is used to remove conductive ions from water.

2. A water treatment system based on salt lake groundwater quality according to claim 1, characterized in that: The ultrafiltration device comprises an ultrafiltration membrane with a filtration accuracy of 0.1 μm, which is used to remove fine particles in water.

3. A water treatment system based on salt lake groundwater quality according to claim 1, characterized in that: The ultrafiltration device is connected to the primary reverse osmosis device, the primary reverse osmosis device is connected to the secondary reverse osmosis device, the secondary reverse osmosis device is connected to a boron removal ion exchanger, and the boron removal ion exchanger is connected to the EDI device.

4. A water treatment system based on salt lake groundwater quality according to claim 3, characterized in that: The primary reverse osmosis device and the secondary reverse osmosis device each include a plurality of reverse osmosis units, and the particle sizes of dissolved solids allowed to pass through the plurality of reverse osmosis units are different.

5. A water treatment process based on salt lake groundwater, characterized in that: The specific process flow is as follows: the production water from the production water supply network enters the raw water tank, is pressurized by the raw water pump and sent to the ultrafiltration device to remove suspended matter in the water, and then enters the primary reverse osmosis device. After desalination by the primary reverse osmosis, it is counted into the primary RO production water tank, and then sent to the secondary reverse osmosis through the secondary RO feed water pump for further desalination. The desalted water enters the secondary RO production water tank, and then the exchanger feed water pump sends it to the boron removal ion exchanger to remove boron in the water, and then enters the boron removal water tank, and is sent to the EDI device through the EDI feed water pump. The obtained water enters the desalted water tank and is pumped to the water use device by the desalted water pump.

6. A water treatment process based on salt lake groundwater according to claim 5, characterized in that: After the process described above, the parameters of the effluent water quality are as follows: Silicon dioxide: ≤20g / L Conductivity: ≤0.2s / cm (25℃).

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