A photovoltaic acid wastewater and alkali wastewater recycling treatment system

Abstract

The utility model belongs to photovoltaic wastewater treatment technical field especially, is a kind of photovoltaic acid wastewater, alkali wastewater recovery treatment system.The utility model includes silica gel reaction pool, temporary storage pool, calcium fluoride reaction pool, first-stage reaction pool, secondary reaction pool, tertiary reaction pool, flocculation tank and sedimentation tank connected in proper order;The sludge outlet of sedimentation tank is connected with the import of pretreatment reaction tank by sludge backflow pipeline, the sludge outlet of sedimentation tank is also connected with the import of sludge storage pool by shunt pipe, sludge storage pool is connected with second filter press by sludge pump, and the liquid outlet of second filter press is connected with first-stage reaction pool by filter liquor recovery pipe.The utility model realizes to treat waste with waste, change waste into treasure;Not only calcium agent consumption is less, and not introduce sulfuric acid, need not repeatedly adjust pH value, greatly reduce cost.

Description

Technical Field

[0001] This utility model belongs to the field of photovoltaic wastewater treatment technology, and in particular relates to a photovoltaic acid wastewater and alkaline wastewater recycling and treatment system. Background Technology

[0002] As a part of green energy, the photovoltaic industry generates a large amount of wastewater during its production process. Among them, concentrated acid wastewater contains fluoride and is highly acidic, while concentrated alkaline wastewater contains silicon and is highly alkaline.

[0003] Current treatment methods typically involve first thoroughly mixing the two substances, then adding lime slurry, calcium chloride, and sulfuric acid for fluoride removal. During production, to ensure the effluent meets fluoride standards, large amounts of calcium agents are added, generating substantial amounts of mixed sludge of calcium fluoride, calcium silicate, and calcium sulfate. This sludge cannot be recycled and requires third-party disposal, posing a significant risk of secondary environmental pollution. This high-dose, high-volume, and costly treatment method contradicts the principles of "green energy," necessitating a new treatment system to address these issues. Utility Model Content

[0004] To overcome the shortcomings of the existing technology, this invention provides a photovoltaic acid and alkaline wastewater recycling and treatment system. This invention can recycle and reuse calcium fluoride without introducing sulfuric acid, eliminates the need for repeated pH adjustments, and significantly reduces costs.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A photovoltaic acid and alkali wastewater recycling and treatment system includes a silica gel reaction tank, a temporary storage tank, a primary reaction tank, a secondary reaction tank, a tertiary reaction tank, a flocculation tank, and a sedimentation tank connected in sequence. The inlet of the silica gel reaction tank is connected to the outlet of a fluoride-containing wastewater pipe and the outlet of a fluoride-containing alkali wastewater pipe. The sludge outlet of the sedimentation tank is connected to the inlet of a pretreatment reaction tank through a sludge return pipe. The sludge outlet of the sedimentation tank is also connected to the inlet of a sludge storage tank through a diversion pipe. The sludge storage tank is connected to a second filter press through a sludge pump. The outlet of the second filter press is connected to the primary reaction tank through a filter press liquid recovery pipe.

[0007] The silica gel reaction tank is connected to the temporary storage tank via a first filter press. The solid outlet of the first filter press is connected to the washing tank. The washing tank is connected to the third filter press. The liquid outlet of the third filter press is connected to the primary reaction tank.

[0008] The primary, secondary, and tertiary reaction tanks are all connected to the lime slurry dosing tank. The primary reaction tank is also connected to the calcium chloride dosing tank, and the flocculation tank is connected to the flocculant dosing tank.

[0009] pH meters are installed on the primary, secondary, and tertiary reaction tanks.

[0010] The outlet of the primary reaction tank is higher than the inlet of the secondary reaction tank, the outlet of the secondary reaction tank is higher than the inlet of the tertiary reaction tank, the outlet of the tertiary reaction tank is higher than the inlet of the flocculation tank, and the outlet of the flocculation tank is higher than the inlet of the sedimentation tank. This allows wastewater in the higher-level reaction tanks to flow by gravity into the lower-level reaction tanks or sedimentation tanks, effectively reducing costs.

[0011] The sludge storage tank is equipped with a stirring device, which can be either mechanical stirring or aeration stirring.

[0012] The second filter press is a plate and frame filter press.

[0013] The advantages of this utility model are:

[0014] This invention utilizes a chemical reaction to neutralize concentrated acid and alkali wastewater generated in the photovoltaic industry. The silicate ions in the concentrated alkali wastewater are completely reacted to produce silica gel. The silica gel is then purified through washing. Finally, fluoride ions in the neutralization solution are converted into calcium fluoride using a calcium agent, achieving waste-to-waste treatment and turning waste into treasure. Not only is the calcium agent consumption low, but sulfuric acid is not introduced, and repeated pH adjustments are unnecessary, significantly reducing costs. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the present invention.

[0016] The meanings of the symbols marked in the figure are as follows:

[0017] 1-Silica gel reaction tank, 2-Primary reaction tank, 3-Secondary reaction tank, 4-Tertiary reaction tank, 5-Flocculation tank, 6-Sedimentation tank, 7-Sludge storage tank, 8-Agitation device. Detailed Implementation

[0018] like Figure 1As shown, a photovoltaic acid and alkali wastewater recycling and treatment system includes a silica gel reaction tank 1, a temporary storage tank, a primary reaction tank 2, a secondary reaction tank 3, a tertiary reaction tank 4, a flocculation tank 5, a sedimentation tank 6, a sludge storage tank 7, and a second filter press (a plate and frame filter press). The silica gel reaction tank 1 is connected to the temporary storage tank via the first filter press, and the silica gel reaction tank 2 is also connected to the temporary storage tank via the first filter press. The solid outlet of the first filter press is connected to a washing tank, which is connected to the third filter press. The liquid outlet of the third filter press is connected to the primary reaction tank. The filtrate from the first filter press is fed into the temporary storage tank. The filtered solids are stirred and washed with pure water, followed by a second filter press to obtain high-purity silica gel. The second filter press is a plate and frame filter press, and the amount of pure water added is sufficient to ensure that the conductivity reaches below 1000 μS / cm after thorough stirring. The final product meets industrial requirements. The filtrate from the filter press enters the primary reaction tank, and the filter cake is high-purity silica gel for industrial recycling.

[0019] Specifically, silica gel reaction tank 1 is connected to pipelines for concentrated alkaline wastewater and concentrated acid wastewater, and is used to receive the incoming concentrated alkaline wastewater and concentrated acid wastewater; the wastewater treated by silica gel reaction tank 1 flows into temporary storage tank through pipeline after being filtered by the first filter press, and the temporary storage tank is connected to primary reaction tank 2 through pipeline.

[0020] The primary reaction tank 2 is connected to the lime slurry addition tank and the calcium chloride addition tank for pretreatment of fluoride-containing concentrated acid wastewater. The wastewater treated in the primary reaction tank 2 is sequentially piped into the secondary reaction tank 3, the tertiary reaction tank 4, the flocculation tank 5, and the sedimentation tank 6. The lime slurry addition tank is connected to each of these tanks. Each of the primary, secondary, and tertiary reaction tanks is equipped with a pH meter to adjust the pH of the wastewater in a gradient manner, ensuring more complete reagent reactions and higher purity of calcium fluoride. The outlet of the primary reaction tank 2 is higher than the inlet of the secondary reaction tank 3, the outlet of the secondary reaction tank 3 is higher than the inlet of the tertiary reaction tank 4, the outlet of the tertiary reaction tank 4 is higher than the inlet of the flocculation tank 5, and the outlet of the flocculation tank is higher than the inlet of the sedimentation tank 6. This allows wastewater in the higher-level reaction tanks to flow by gravity into the lower-level reaction tanks or sedimentation tank 6, effectively reducing costs.

[0021] Furthermore, the wastewater treated in the tertiary reaction tank 4 flows into the flocculation tank 5 through a pipeline. The flocculation tank 5 is connected to the flocculant dosing tank, which causes impurities in the wastewater to flocculate, facilitating sedimentation and separation in the sedimentation tank 6. The outlet of the flocculation tank 5 is connected to the inlet of the sedimentation tank 6. The flocculated fluoride-containing concentrated acid wastewater is separated by sedimentation in the sedimentation tank 6, and the wastewater that meets the standards can be discharged and recycled.

[0022] Furthermore, the sludge outlet of sedimentation tank 6 is connected to the inlet of primary reaction tank 2 via a sludge return pipe. The sludge outlet of sedimentation tank 6 is also connected to the inlet of sludge storage tank 7 via a diversion pipe. Sludge storage tank 7 is connected to a second filter press via a sludge pump to obtain high-purity calcium fluoride. The outlet of the second filter press is connected to primary reaction tank 2 via a filtrate recovery pipe, facilitating filtrate recovery and reuse. Sludge storage tank 7 is equipped with a stirring device 8, which can be either mechanical stirring or aeration stirring. The filter presses mentioned above are either centrifugal or belt-driven.

[0023] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A photovoltaic acid wastewater and alkaline wastewater recycling and treatment system, characterized in that, The system includes a silica gel reaction tank (1), a temporary storage tank, a primary reaction tank (2), a secondary reaction tank (3), a tertiary reaction tank (4), a flocculation tank (5), and a sedimentation tank (6) connected in sequence. The inlet of the silica gel reaction tank (1) is connected to the outlet of the fluoride wastewater pipe and the outlet of the fluoride alkali wastewater pipe. The sludge outlet of the sedimentation tank (6) is connected to the inlet of the pretreatment reaction tank through a sludge return pipe. The sludge outlet of the sedimentation tank (6) is also connected to the inlet of the sludge storage tank (7) through a diversion pipe. The sludge storage tank (7) is connected to the second filter press through a sludge pump. The outlet of the second filter press is connected to the primary reaction tank (2) through a filter liquid recovery pipe.

2. The photovoltaic acid wastewater and alkaline wastewater recovery and treatment system according to claim 1, characterized in that: The silica gel reaction tank (1) is connected to the temporary storage tank via a first filter press. The solid outlet of the first filter press is connected to the cleaning tank. The cleaning tank is connected to the third filter press. The liquid outlet of the third filter press is connected to the primary reaction tank (2).

3. The photovoltaic acid wastewater and alkaline wastewater recovery and treatment system according to claim 1, characterized in that: The primary reaction tank (2), secondary reaction tank (3) and tertiary reaction tank (4) are all connected to the lime slurry addition tank. The primary reaction tank (2) is also connected to the calcium chloride addition tank. The flocculation tank (5) is connected to the flocculant addition tank.

4. The photovoltaic acid wastewater and alkaline wastewater recycling and treatment system according to claim 1, characterized in that: pH meters are installed on the primary reaction tank (2), the secondary reaction tank (3), and the tertiary reaction tank (4).

5. The photovoltaic acid wastewater and alkaline wastewater recovery and treatment system according to claim 1, characterized in that: The outlet of the primary reaction tank (2) is higher than the inlet of the secondary reaction tank (3), the outlet of the secondary reaction tank (3) is higher than the inlet of the tertiary reaction tank (4), the outlet of the tertiary reaction tank (4) is higher than the inlet of the flocculation tank (5), and the outlet of the flocculation tank (5) is higher than the inlet of the sedimentation tank (6).

6. The photovoltaic acid wastewater and alkaline wastewater recovery and treatment system according to claim 1, characterized in that: The sludge storage tank (7) is equipped with a stirring device (8).

7. The photovoltaic acid wastewater and alkaline wastewater recovery and treatment system according to claim 1, characterized in that: The second filter press is a plate and frame filter press.

Images