Zero-discharge treatment device for acidic high-salt fluorine-containing wastewater

Abstract

The utility model discloses a zero-discharge treatment device for acidic high-salt fluorine-containing wastewater, which comprises a multi-stage pretreatment device, a plurality of stages of reverse osmosis devices, an evaporation device and a water production tank, and the multi-stage pretreatment device, the reverse osmosis pretreatment device and the first-stage reverse osmosis device are sequentially connected; all stages of reverse osmosis devices are arranged in series, concentrated water generated by the first-stage reverse osmosis device sequentially enters the second-stage reverse osmosis device, the third-stage reverse osmosis device and the fourth-stage reverse osmosis device, and finally concentrated water of the fourth-stage reverse osmosis device enters the evaporation device; the produced water outlet of each stage of reverse osmosis device is communicated with the water inlet of the previous stage of reverse osmosis device; according to the device, calcium fluoride with certain purity can be recycled through multi-stage pretreatment, waste water recycling is achieved, the multi-stage reverse osmosis device can achieve series water inflow and can also achieve parallel independent water inflow, inflow water fluctuation is prevented, the multi-stage reverse osmosis device improves the membrane concentration multiple, the evaporation water inflow amount is reduced, and zero emission of high-fluorine-content waste water is achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of acidic high-salt fluorine-containing wastewater, and particularly relates to a zero-discharge treatment device for acidic high-salt fluorine-containing wastewater. Background Art

[0002] Acidic, high-salinity, fluoride-containing wastewater refers to acidic wastewater with a fluoride content of 1000 mg / L or higher and a high salinity. Direct discharge without treatment can, on the one hand, cause soil or water pollution and harm human health, particularly if the fluoride content exceeds a certain level. On the other hand, high-fluoride wastewater also contains high salinity, mostly sodium chloride, which can be used as a raw material in industrial production, resulting in a waste of resources. Therefore, properly treating high-salinity wastewater while maintaining efficient treatment of acidic, fluoride-containing wastewater is an essential process in modern industrial production.

[0003] Currently, the photovoltaic, semiconductor, glass, and new energy industries generate large quantities of highly concentrated fluoride-containing wastewater. The production of graphite, a mineral used in new energy, also produces large quantities of acidic, highly concentrated fluoride-containing wastewater. Fluoride-containing wastewater is typically treated by precipitation, which relies on calcium-based fluoride removal. This process requires adjusting the wastewater pH, and simple calcium-based fluoride removal methods cannot meet current wastewater discharge standards.

[0004] Therefore, it is necessary to optimize the fluorine pretreatment process and ensure that the wastewater can meet the discharge standards. The utility model removes fluorine from wastewater through several stages of pretreatment, recovers fluorine in the wastewater, and reduces evaporation through several stages of membrane concentration to achieve zero discharge. Summary of the Invention

[0005] The purpose of the utility model is to design a zero-discharge treatment device for acidic, high-salt, fluorine-containing wastewater.

[0006] In order to achieve the above purpose, the technical solution adopted by the present utility model is as follows:

[0007] A zero-discharge treatment device for acidic, high-salt, fluorine-containing wastewater, characterized in that the zero-discharge treatment device includes a multi-stage pretreatment device, several stages of reverse osmosis devices, an evaporation device and a water production tank, the multi-stage pretreatment device, the reverse osmosis pretreatment device and the first-stage reverse osmosis device are connected in sequence, the reverse osmosis devices at each stage are arranged in series, the concentrated water produced by the first-stage reverse osmosis device enters the second-stage reverse osmosis device, the third-stage reverse osmosis device, and the fourth-stage reverse osmosis device in sequence, and finally the concentrated water from the fourth-stage reverse osmosis device enters the evaporation device, and the water production outlet of each stage of the reverse osmosis device is connected to the water inlet of the reverse osmosis device at the previous stage.

[0008] Furthermore, the multi-stage pretreatment device includes a primary sedimentation device, a secondary sedimentation device and a deep treatment device. The clear liquid of the primary sedimentation device enters the secondary sedimentation device, and the water outlet of the secondary sedimentation device is connected to the water inlet of the deep treatment device.

[0009] Furthermore, a first high-pressure pump is installed at the water outlet of the second-stage reverse osmosis device and the third-stage reverse osmosis device, the water inlet of the first high-pressure pump is connected to the water outlet of the second-stage reverse osmosis device and the third-stage reverse osmosis device, and the water outlet of the first high-pressure pump is connected to the water inlet of the first-stage reverse osmosis device.

[0010] Furthermore, a second high-pressure pump is installed at the water outlet of the fourth-stage reverse osmosis device, the water inlet of the second high-pressure pump is connected to the water outlet of the fourth-stage reverse osmosis device, and the water outlet of the second high-pressure pump is connected to the water inlet of the third-stage reverse osmosis device.

[0011] Furthermore, the reverse osmosis devices at each stage are replaced by a parallel arrangement instead of a series arrangement, the water production outlets of the reverse osmosis devices at each stage are connected to the water production tank, the concentrated water outlets of the reverse osmosis devices at each stage are connected to the evaporation device, and the water inlet of the reverse osmosis devices at each stage enters the corresponding reverse osmosis device for concentration treatment according to the conductivity of the raw water.

[0012] The above technical solution can achieve the following beneficial effects:

[0013] The utility model connects multiple pretreatment devices and multiple reverse osmosis devices for acidic, high-salt, and fluorine-containing wastewater. The highly concentrated brine in the upper reverse osmosis device is diluted with the saline purified water from the lower reverse osmosis device to reduce the pressure difference on both sides of the osmotic membrane, thereby minimizing damage to the membrane and concentrating the purified water again. The system can significantly concentrate high-salt wastewater at room temperature and medium pressure, has low cost, and is suitable for promotion.

[0014] The several stages of pretreatment described in this utility model can recover calcium fluoride of a certain purity, realize wastewater resource utilization, and the multi-stage reverse osmosis can be connected in series or in parallel to prevent water inlet fluctuations. The multi-stage reverse osmosis device increases the multiple of membrane concentration, reduces the amount of water inlet for evaporation, and realizes zero discharge of high-fluorine-containing wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of a zero-discharge treatment device for acidic, high-salt, fluoride-containing wastewater.

[0016] In the picture:

[0017] In the figure: 1. Multi-stage pretreatment device; 2. Reverse osmosis pretreatment device; 3. First-stage reverse osmosis device; 4. Second-stage reverse osmosis device; 5. Third-stage reverse osmosis device; 6. Fourth-stage reverse osmosis device; 7. Evaporation device, C5, water production tank. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings:

[0019] like Figure 1 As shown, in this solution, high-fluorine-containing wastewater passes through the water inlet R1, enters the multi-stage pretreatment device 1, and then enters the reverse osmosis pretreatment device 2 one by one.

[0020] Example 1: When several stages of reverse osmosis devices are connected in series, the concentrated water R2 outlet of the first-stage reverse osmosis device 3 is connected to the water inlet of the second-stage reverse osmosis device 4, the concentrated water R3 outlet of the second-stage reverse osmosis device 4 is connected to the water inlet of the third-stage reverse osmosis device 5, and the produced water C2 and produced water C3 of the second-stage reverse osmosis device 4 and the third-stage reverse osmosis device 5 are returned to the water inlet of the first-stage reverse osmosis device 3, the concentrated water R4 outlet of the third-stage reverse osmosis device 5 is connected to the water inlet of the fourth-stage reverse osmosis device 6, the produced water C4 of the fourth-stage reverse osmosis device 6 is returned to the water inlet of the third-stage reverse osmosis device 5, and the concentrated water of the fourth-stage reverse osmosis device 6 enters the evaporation device 7;

[0021] Example 2: When several stages of reverse osmosis devices are used in parallel, the produced water C1, C2, C3 and C4 of the several stages of reverse osmosis devices are all returned to the produced water tank C5, and the multi-stage reverse osmosis inlet water enters the corresponding reverse osmosis device for concentration treatment according to the conductivity of the raw water; the concentrated water outlet of each stage of reverse osmosis device is connected to the evaporation device.

[0022] The several reverse osmosis devices used in the embodiment are all common models on the market. The first high-pressure pump HP1 is arranged at the water outlet of the second-stage reverse osmosis device 4 and the third-stage reverse osmosis device 5. The water inlet of the first high-pressure pump is connected to the water outlet of the second-stage reverse osmosis device 4 and the third-stage reverse osmosis device 5, and the water outlet of the first high-pressure pump is connected to the water inlet of the first-stage reverse osmosis device 3; the second high-pressure pump HP2 is arranged at the outlet of the water C4 of the fourth-stage reverse osmosis device 6, the water inlet of the second high-pressure pump is connected to the water outlet of the water C4, and the water outlet of the second high-pressure pump is connected to the water inlet of the third-stage reverse osmosis device 5.

[0023] In the embodiment, the above device was used to treat acidic high-salt fluoride-containing wastewater R1 with a pH of 1.9, a salt content of 8.9%, and a fluoride content of 0.2%. 3 The flow rate of / h enters the multi-stage pretreatment device for treatment, with a flow rate of 1.8m 3 / h flow into the reverse osmosis pretreatment device, at this time the pH is 7.56, the salt content is 4000mg / L, and the fluorine content is 1.8mg / L; the salt content is low, and reverse osmosis can be selected in series for multi-stage concentration. The water produced by the reverse osmosis pretreatment device 2 enters the first-stage reverse osmosis device for concentration, and the produced water C1 is concentrated at 0.9m 3 / h flow, neutral, salt content 0.0% or more discharge standard into the water tank C5, concentrated water R2 at 1.2m 3 / h flow rate, and the salt content is 9000 mg / L and enters the second-stage reverse osmosis device 4 for concentration.

[0024] After the concentrated water R2 enters the second stage reverse osmosis device 4 for treatment, its produced water C2 is 0.6m 3 / h flow rate, salt content 2000mg / L under the action of the first high pressure pump and mixed with the reverse osmosis pretreatment device into the first stage reverse osmosis device, concentrated water R3 at 0.9m 3 / h flow rate, containing 14000mg of salt / enters the third stage reverse osmosis device 5 for concentration;

[0025] After the concentrated water R3 enters the third-stage reverse osmosis device 5 for treatment, its produced water C3 is 0.8m 3 / h flow rate, the salt content 2200mg / L is mixed with the reverse osmosis pretreatment device under the action of the first high-pressure pump and enters the first-stage reverse osmosis device 3, and the concentrated water R4 is 0.9m 3 / h flow rate containing 16000 mg / h of salt enters the fourth-stage reverse osmosis device 6.

[0026] After the concentrated water R4 enters the fourth-stage reverse osmosis device 6 for treatment, its produced water C4 is 0.675m 3 / h flow rate with salt content of 500mg / L is mixed with the concentrated water of the second stage reverse osmosis device 4 under the action of the second high pressure pump and enters the third stage reverse osmosis device 5. The concentrated water is 0.675m 3 / h flow rate, and 32000 mg / L of salt enters the evaporation device 7 for evaporation concentration to recover the salt.

[0027] The above are all preferred embodiments of the present invention. For ordinary technicians in this technical field, without departing from the principle of the present invention, various equivalent modifications to the present invention are within the scope of protection of the claims attached to this application.

Claims

1. A zero-discharge treatment device for acidic, high-salt, fluorine-containing wastewater, characterized by: The zero-discharge treatment device includes a multi-stage pretreatment device, several stages of reverse osmosis devices, an evaporation device and a water production tank. The multi-stage pretreatment device, the reverse osmosis pretreatment device and the first-stage reverse osmosis device are connected in sequence, and the reverse osmosis devices at each stage are arranged in series. The concentrated water produced by the first-stage reverse osmosis device enters the second-stage reverse osmosis device, the third-stage reverse osmosis device, and the fourth-stage reverse osmosis device in sequence. Finally, the concentrated water from the fourth-stage reverse osmosis device enters the evaporation device, and the water production outlet of each stage of the reverse osmosis device is connected to the water inlet of the previous stage reverse osmosis device.

2. A zero-discharge treatment device for acidic, high-salt, fluorine-containing wastewater according to claim 1, characterized in that: The multi-stage pretreatment device includes a primary sedimentation device, a secondary sedimentation device and a deep treatment device. The clear liquid of the primary sedimentation device enters the secondary sedimentation device, and the water outlet of the secondary sedimentation device is connected to the water inlet of the deep treatment device.

3. The zero-discharge treatment device for acidic, high-salt, fluorine-containing wastewater according to claim 1, characterized in that: A first high-pressure pump is installed at the water outlet of the second-stage reverse osmosis device and the third-stage reverse osmosis device. The water inlet of the first high-pressure pump is connected to the water outlet of the second-stage reverse osmosis device and the third-stage reverse osmosis device, and the water outlet of the first high-pressure pump is connected to the water inlet of the first-stage reverse osmosis device.

4. The zero-discharge treatment device for acidic, high-salt, fluorine-containing wastewater according to claim 1, characterized in that: A second high-pressure pump is installed at the water outlet of the fourth-stage reverse osmosis device. The water inlet of the second high-pressure pump is connected to the water outlet of the fourth-stage reverse osmosis device, and the water outlet of the second high-pressure pump is connected to the water inlet of the third-stage reverse osmosis device.

5. The zero-discharge treatment device for acidic, high-salt, fluorine-containing wastewater according to claim 1, characterized in that: The reverse osmosis devices at each level will be replaced by a parallel arrangement instead of a series arrangement. The water production outlets of the reverse osmosis devices at each level are connected to the water production tank, and the concentrated water outlets of the reverse osmosis devices at each level are connected to the evaporation device. The water inlet of the reverse osmosis devices at each level enters the corresponding reverse osmosis device for concentration treatment according to the conductivity of the raw water.

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