Silicon removal process and silicon removal system for photovoltaic concentrated alkaline water

Abstract

The invention discloses a silicon removal process and a silicon removal system for photovoltaic concentrated alkaline water, concentrated alkaline water and concentrated acid water are respectively collected through a concentrated acid wastewater adjusting tank and a concentrated alkaline water adjusting tank, the concentrated alkaline water and the concentrated acid water are fed to be neutralized, the pH is controlled to be 4-9, the effluent of an acid-base mixing tank is discharged into a gelation silicon removal tank, a silicon-containing gel solution is generated through stirring, and the silicon-containing gel solution is discharged into the gelation silicon removal tank. According to the method, no extra chemical agent needs to be added, more than 90% of silicon in the concentrated alkaline water is removed, the purity of calcium fluoride in a fluorine removal system is improved, and the sludge treatment cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and in particular to a silicon removal process and treatment equipment for photovoltaic concentrated alkaline water. Background Art

[0002] With the introduction of the sustainable development strategy, the use of non-renewable resources such as coal and oil is being gradually replaced by new energy. As a clean energy with relatively mature technology, solar photovoltaic energy is developing rapidly. In 2023, the newly installed photovoltaic capacity will reach 216.3GW, a year-on-year increase of 147.5%. The cumulative installed capacity has reached 608.92GW, surpassing the installed capacity of hydropower and becoming the second largest power source after thermal power. (Data source: China Photovoltaic Industry Association CPIA, 2024.2)

[0003] The photovoltaic industry mainly uses solar cells (monocrystalline silicon, polycrystalline silicon, etc.) for energy conversion. During the production process of the cells, a large amount of hydrofluoric acid and sodium hydroxide are used for etching, texturing, cleaning and other operations, which will produce acidic wastewater containing high concentrations of fluoride ions and alkaline wastewater containing high concentrations of silicon. Since the emission standards of the photovoltaic industry have higher requirements for fluorine and there are no clear emission index requirements for silicon, the defluorination of high-concentration acidic fluoride-containing wastewater is the focus of photovoltaic cell wastewater treatment. The usual practice is to homogenize all wastewater and use chemical precipitation and coagulation precipitation to remove the fluoride in the wastewater by forming calcium fluoride sludge precipitation. The agents used are generally soluble calcium salts such as lime and calcium chloride. The alkaline wastewater containing silicon is usually diluted in the acidic wastewater as a pH adjuster. This method can reduce the fluoride in water to below the discharge standard, but due to the presence of a large amount of silicon in alkaline water, the calcium fluoride sludge produced by defluorination contains a large amount of silicon dioxide, which not only increases the sludge output, but also greatly reduces the sludge purity (the calcium fluoride content is only 40%-65%), seriously affecting the sludge quality and resource value. The silicon concentration from concentrated alkaline water is as high as 3000mg / L or more, and the total amount of silicon accounts for more than 80% of the total silicon content in wastewater. Therefore, removing silicon from concentrated alkaline water is of great significance for improving the purity of calcium fluoride sludge.

[0004] At present, there is no special method for removing silicon from concentrated alkaline water in the photovoltaic industry. Chinese invention patent CN112158983A provides a high-efficiency silicon removal and fluorine removal system and method for photovoltaic wastewater, and proposes a system using homogenization, flotation, primary silicon removal and fluorine removal, secondary fluorine removal, and subsequent treatment. After the wastewater is homogenized, flotation is used and flocculants are added to remove silicon in elemental and colloidal form, and then calcium oxide is added to adjust the pH to alkaline and then calcium chloride is added to generate calcium silicate precipitation to remove silicon. This method can remove silicon from water, but due to the addition of calcium salts, a large amount of fluorine will be removed while removing silicon, resulting in a large amount of calcium fluoride in the produced calcium silicate sludge, that is, the produced sludge is still mixed sludge, and it causes insufficient fluorine recovery in the subsequent secondary fluorine removal unit. Summary of the invention

[0005] In order to overcome the above defects, the present invention provides a silicon removal process and a silicon removal system for photovoltaic concentrated alkaline water, which can effectively remove silicon from concentrated alkaline water without adding additional chemicals.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a process for removing silicon from photovoltaic concentrated alkaline water, characterized in that the specific steps are as follows:

[0007] Step 1: The concentrated alkaline water (silicon concentration range 2000-20000 mg / L) and concentrated acid water discharged from the photovoltaic cell production line are sent to the acid-base mixing tank in a certain proportion for neutralization reaction, so that the pH of the mixed wastewater is controlled in the range of 4-9. During mixing, the water inlet ratio of concentrated acid water to concentrated alkaline water is controlled according to the pH of the mixed wastewater;

[0008] Step 2: Discharge the effluent from the acid-base mixing tank into the gelation silicon removal tank, and stir the acid-base mixture to react to generate a silicon-containing gel solution, so that the silicon in the wastewater is precipitated in the form of gel;

[0009] Step 3: Send the silicon-containing gel solution to a dehydration device for dehydration. The dehydrated silicon gel is treated as solid waste. The silicon-removed filtrate is pumped and piped into a comprehensive wastewater regulating tank for subsequent fluoride removal treatment.

[0010] After the above treatment, more than 90% of the silicon in the desiliconization filtrate is removed, so that the silicon ion concentration in the desiliconization filtrate is greatly reduced. The wastewater after desiliconization enters the defluorination system again, and the purity of the calcium fluoride sludge is significantly improved. While increasing the value of the calcium fluoride sludge, the sludge treatment cost is reduced.

[0011] As a further improvement of the present invention, in step one, the concentrated alkaline water discharged from the photovoltaic cell production line is first collected in a concentrated alkaline water regulating tank, and the concentrated acid water is collected in a concentrated acid wastewater regulating tank, and then the concentrated alkaline water in the concentrated alkaline water regulating tank and the concentrated acid water in the concentrated acid wastewater regulating tank are sent to the acid-base mixing tank in proportion by a lifting pump. The concentrated acid water and the concentrated alkaline water are collected separately in advance, so that the concentrated acid water and the concentrated alkaline water can be homogenized in the concentrated acid wastewater regulating tank and the concentrated alkaline water regulating tank, which is conducive to subsequent uniform mixing.

[0012] As a further improvement of the present invention, in step 3, 10% to 60% of the dehydrated silica gel is sent to the concentrated alkaline water regulating tank, and the concentrated alkaline water and the refluxed silica gel are mixed and dissolved by a stirring device. The dehydrated part of the silica gel is returned to the concentrated alkaline water regulating tank at the front end, and dissolved by the concentrated alkaline water, which can increase the silicon content in the concentrated alkaline water regulating tank. When the silicon concentration increases, on the one hand, it helps to shorten the desiliconization gelation reaction time, and on the other hand, it enhances the neutral desiliconization effect of alkaline water with low silicon concentration, and expands the applicable range of silicon concentration of concentrated alkaline water.

[0013] As a further improvement of the present invention, the concentrated alkaline water and the refluxed silica gel are dissolved and regulated in the concentrated alkaline water regulating tank for no less than 12 hours to ensure sufficient dissolution of the refluxed silica gel and the subsequent gelation effect.

[0014] As a further improvement of the present invention, in step three, the dehydration device adopts a screw stacking machine and a filter press, wherein part of the silicon-containing gel solution is squeezed and dehydrated by the screw stacking machine to form a silicon gel filter cake and a filtrate, the silicon gel filter cake is returned to and dissolved in the concentrated alkaline water regulating tank at the front end, and the filtrate enters the comprehensive wastewater regulating tank for subsequent treatment; the remaining silicon-containing gel solution is sent to the filter press for filtration and dehydration, and the silicon gel sludge cake after filtration is transported out for disposal as solid waste, and the filtrate enters the comprehensive wastewater regulating tank through a pump and a pipeline for subsequent treatment.

[0015] A screw stacking machine and a filter press are respectively used to dehydrate the silicon gel solution, which is convenient for quantitative control of the silicon gel refluxed into the concentrated alkaline water regulating tank. The screw stacking machine is convenient for the real-time discharge and reflux of the silicon gel filter cake, and the filter press can fully dehydrate the silicon gel. In this way, the automatic quantitative reflux of the silicon gel can be achieved while reducing the water content of the solid waste, which is beneficial to the solid waste treatment. Of course, the dehydration device can also adopt one of the above two dehydration devices. After dehydration, a part of the silicon gel is refluxed as solid waste for treatment. This is an equivalent replacement scheme that can be easily thought of by technical personnel in this field based on this application, and it also falls within the scope of protection of this patent.

[0016] As a further improvement of the present invention, in step 1, the concentrated alkaline water and the concentrated acid water are mixed in the acid-base mixing tank for 10-60 minutes, and the inlet ratio of the concentrated acid water to the concentrated alkaline water is controlled by pH.

[0017] As a further improvement of the present invention, the effluent from the acid-base mixing tank enters the gelation and silicon removal tank for gelation reaction for 0.5-24 hours.

[0018] A photovoltaic concentrated alkaline water desiliconization system comprises an acid-base mixing tank, a gelled desiliconization tank, a dehydration device and a comprehensive wastewater regulating tank, wherein the acid-base mixing tank is provided with a concentrated alkaline water inlet and a concentrated acid water inlet, and the concentrated alkaline water and the concentrated acid water can enter the acid-base mixing tank through the concentrated alkaline water inlet and the concentrated acid water inlet respectively, and the acid-base mixing tank is also provided with a pH detection device, and the pH detection device can perform real-time detection of the pH value of the mixed wastewater in the acid-base mixing tank, and the acid-base mixing tank is connected with the gelled desiliconization tank through a pipeline, and the wastewater mixed in the acid-base mixing tank can be discharged along the The wastewater is discharged into a gelling desiliconization tank through a pipeline. A stirrer is arranged in the gelling desiliconization tank. The stirrer can stir the mixed wastewater in the gelling desiliconization tank so as to make the mixed wastewater form a gel state through acid-base neutralization reaction. The gelling desiliconization tank is connected with a dehydration device through a pipeline. The silicon-containing gel solution in the gelling desiliconization tank can be sent to the dehydration device along the pipeline. The dehydration device can dehydrate the silicon-containing gel solution. The drain outlet of the dehydration device is connected with a comprehensive wastewater regulating tank through a pipeline. The wastewater discharged from the dehydration device can enter the comprehensive wastewater regulating tank along the pipeline for subsequent treatment.

[0019] The mixed wastewater in the acid-base mixing tank can be sent to the gel desiliconization tank by a lifting pump, or it can be drained by gravity. Similarly, the silicon-containing gel solution in the gel desiliconization tank can be sent to the dehydration device by a lifting pump, or it can be drained by gravity.

[0020] As a further improvement of the present invention, a concentrated acid wastewater regulating tank, a concentrated alkaline water regulating tank, a lifting pump, a silicone gel reflux conveying device and a control system are also provided. The concentrated alkaline water regulating tank is used to collect the concentrated alkaline water discharged from the photovoltaic cell production line, and the concentrated acid wastewater regulating tank is used to collect the concentrated acid water discharged from the photovoltaic cell production line. The concentrated alkaline water regulating tank and the concentrated acid wastewater regulating tank are connected to the concentrated alkaline water inlet and the concentrated acid water inlet on the acid-base mixing tank through pipelines, respectively. The concentrated acid water in the concentrated acid wastewater regulating tank and the concentrated alkaline water in the concentrated alkaline water regulating tank can be respectively sent into the acid-base mixing tank through their respective lifting pumps. Mixing tank, one end of the silicone gel reflux conveying device is connected with the discharge of the dehydration device, and the other end of the silicone gel reflux conveying device is connected with the concentrated alkaline water regulating tank. The silicone gel reflux conveying device can convey the dehydrated silicone gel discharged from the dehydration device to the concentrated alkaline water regulating tank. The pH detection device in the acid-base mixing tank communicates with the control system to transmit the pH data in the acid-base mixing tank to the control system in real time. The control system controls the lifting pumps in the concentrated acid wastewater regulating tank and the concentrated alkaline water regulating tank to adjust the flow and start and stop. The control system also controls the start and stop of the silicone gel reflux conveying device.

[0021] By setting up a control system, the pH detection device can perform real-time detection and data feedback to achieve intelligent automatic control for wastewater desiliconization treatment without manual operation. The processing time of each step can be set through software in the control system, such as the mixing time and mixing ratio of concentrated acid water and concentrated alkaline water in the acid-base mixing tank, the gelation reaction time of the mixed wastewater in the gelation desiliconization tank, the stirring speed of the agitator, the amount of silicone gel refluxed by the silicone gel reflux conveying device to the concentrated alkaline water regulating tank, etc. A silicone concentration detection device can also be set in the concentrated alkaline water regulating tank to detect the silicon concentration in the concentrated alkaline water in real time, and then accurately control the silicone gel reflux amount to ensure the silicon content in the concentrated alkaline water in the concentrated alkaline water regulating tank to ensure the subsequent efficient gelation reaction.

[0022] As a further improvement of the present invention, the dehydration device includes a snail stacking machine and a filter press, the gelled silicon removal tank is connected to the liquid inlets of the snail stacking machine and the filter press through pipelines, two lifting pumps are provided in the gelled silicon removal tank, and the two lifting pumps in the gelled silicon removal tank respectively pump the silicon-containing gel solution in the gelled silicon removal tank into the snail stacking machine and the filter press through pipelines, one end of the silicone gel reflux conveying device is connected to the discharge port of the snail stacking machine, and the drain outlets of the snail stacking machine and the filter press are connected to the comprehensive wastewater regulating tank, and the control system controls the flow and start and stop of the two lifting pumps in the gelled silicon removal tank.

[0023] Two dehydration devices are used to carry out targeted dehydration of the silicon-containing gel solution respectively. The reflux amount of the silicon gel can be controlled by controlling the flow of two lifting pumps in the gelation and silicon removal tank, which is convenient to control.

[0024] The beneficial effects of the present invention are as follows: the present invention mixes and stirs the concentrated alkaline water and concentrated acid water discharged from the photovoltaic cell production line in proportion, so that silicon ions form a gel material, which is removed by dehydration. After the concentrated alkaline water is treated by the process of the present invention, the silicon concentration is removed by more than 90%, and the wastewater after silicon removal enters the defluorination system again, and the purity of the calcium fluoride sludge is significantly improved. While improving the value of the calcium fluoride sludge, the sludge treatment cost is reduced. The present invention can directly use the concentrated acid water generated in the photovoltaic enterprise to remove silicon from the concentrated alkaline water, realizing waste treatment with waste, without the need to add other additional agents, which helps to reduce the operating cost. In the process of the present invention, the silicon content in the concentrated alkaline water regulating tank is increased by dissolving the silicon gel in the front concentrated alkaline water regulating tank in the reflux, which helps to shorten the desiliconization gelation reaction time on the one hand, and enhances the neutral desiliconization effect of alkaline water with a low silicon concentration on the other hand, expands the applicable range of silicon concentration of concentrated alkaline water, and realizes efficient desiliconization. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0026] Example 1: The water quality and quantity of wastewater produced by a photovoltaic industry are as follows:

[0027] The volume of concentrated acid water is 350t / d, the fluoride ion concentration is 4590-9964mg / L, and the silicon ion concentration is 12-18mg / L;

[0028] The amount of concentrated alkaline water is 100t / d, the fluoride ion concentration is 15-22mg / L, and the silicon ion concentration is 5400-6250mg / L.

[0029] The above wastewater is treated by the photovoltaic concentrated alkaline water desiliconization process of the present invention, and the specific steps are as follows:

[0030] Step 1: collect the concentrated alkaline water in a regulating tank for homogenization, mix and dissolve the concentrated alkaline water with the subsequent silica gel refluxed from the spiral press through a stirring device, and adjust for 10 hours; collect the concentrated acid water in a concentrated acid water regulating tank for homogenization;

[0031] Step 2: Send the concentrated alkaline water and concentrated acid water after adjustment and homogenization into the acid-base mixing tank at a certain flow rate for neutralization reaction, the mixing time is 10 minutes, and the mixed pH is controlled in the range of 5.5-6.0;

[0032] Step 3: The effluent from the acid-base mixing tank enters the gelation silicon removal tank. The reaction time is 2 hours. The reaction is stirred to generate a gel solution, so that the silicon in the water is precipitated in the form of gel.

[0033] Step 4: 10%-20% of the gel solution generated in the gelation silicon removal tank is sent to the screw stacking machine for dehydration to form a gel filter cake and a filtrate. The gel filter cake is refluxed and dissolved in the concentrated alkaline water regulating tank. The silicon concentration in the filtrate is reduced to below 80 mg / L, and the filtrate enters the comprehensive wastewater regulating tank;

[0034] Step 5: The remaining gel-containing solution enters the plate-and-frame filter press for mud-water separation. The obtained silicon-containing sludge cake (dry mud output is 1.09-1.27t / d) can be outsourced for solid waste treatment; the filtrate has a silicon concentration below 80mg / L and a fluorine concentration consistent with the raw water, and will enter the comprehensive wastewater regulating tank;

[0035] Step 6: The purity of calcium fluoride sludge generated by the subsequent defluorination device of the wastewater in the comprehensive wastewater regulating tank reaches 92.2%-94.3%.

[0036] Example 2: The water quality and quantity of wastewater produced by a photovoltaic industry are as follows:

[0037] The volume of concentrated acid water is 150t / d, the fluoride ion concentration is 10286-15433mg / L, and the silicon ion concentration is 9.3-21.8mg / L;

[0038] The volume of concentrated alkaline water is 80t / d, the fluoride ion concentration is 12.3-21.1mg / L, and the silicon ion concentration is 2266-2844mg / L.

[0039] The above wastewater is treated by the photovoltaic concentrated alkaline water desiliconization process of the present invention, and the specific steps are as follows:

[0040] Step 1: collect the concentrated alkaline water in a regulating tank for homogenization, mix and dissolve the concentrated alkaline water with the subsequent silica gel refluxed from the spiral stacking machine through a stirring device, and adjust the time for 16 hours; collect the concentrated acid water in a concentrated acid water regulating tank for homogenization;

[0041] Step 2: Send the concentrated alkaline water and concentrated acid water after adjustment and homogenization into the acid-base mixing tank at a certain flow rate for neutralization reaction, the mixing time is 50 minutes, and the mixed pH is controlled in the range of 7.5-8.5;

[0042] Step 3: The effluent from the acid-base mixing tank enters the gelation silicon removal tank. The reaction time is 10 hours. The reaction generates a gel solution through stirring, so that the silicon in the water is precipitated in the form of gel.

[0043] Step 4: 50%-60% of the gel solution generated in the gelation silicon removal tank is sent to the screw stacking machine for dehydration to form a gel filter cake and a filtrate. The gel filter cake is refluxed and dissolved in the concentrated alkaline water regulating tank. The silicon concentration in the filtrate is reduced to below 60 mg / L, and the filtrate enters the comprehensive wastewater regulating tank;

[0044] Step 5: The remaining gel-containing solution enters the plate-and-frame filter press for mud-water separation. The obtained silicon-containing sludge cake (dry mud output is 0.37-0.45t / d) can be outsourced for solid waste treatment; the filtrate has a silicon concentration below 60mg / L and a fluorine concentration consistent with the raw water, and will enter the comprehensive wastewater regulating tank;

[0045] Step 6: The purity of calcium fluoride sludge generated by the subsequent defluorination device of the wastewater in the comprehensive wastewater regulating tank reaches 94.5%-96.6%.

Claims

1. A process for removing silicon from concentrated alkaline water in photovoltaic industry, characterized in that: The specific steps are as follows: Step 1: The concentrated alkaline water and concentrated acid water discharged from the photovoltaic cell production line are sent to the acid-base mixing tank in a certain proportion for neutralization reaction, so that the pH of the mixed wastewater is controlled within the range of 4-9; Step 2: Discharge the effluent from the acid-base mixing tank into the gelation silicon removal tank, and stir the acid-base mixture to react to generate a silicon-containing gel solution, so that the silicon in the wastewater is precipitated in the form of gel; Step 3: Send the silicon-containing gel solution to a dehydration device for dehydration. The dehydrated silicon gel is treated as solid waste. The silicon-removed filtrate is pumped and piped into a comprehensive wastewater regulating tank for subsequent fluoride removal treatment.

2. The desiliconization process for photovoltaic concentrated alkaline water according to claim 1, characterized in that: In step one, the concentrated alkaline water discharged from the photovoltaic cell production line is first collected in a concentrated alkaline water regulating tank, and the concentrated acid water is collected in a concentrated acid wastewater regulating tank, and then the concentrated alkaline water in the concentrated alkaline water regulating tank and the concentrated acid water in the concentrated acid wastewater regulating tank are sent to the acid-base mixing tank in proportion through a lifting pump.

3. The desiliconization process for photovoltaic concentrated alkaline water according to claim 2, characterized in that: In step three, 10% to 60% of the dehydrated silica gel is sent to a concentrated alkaline water regulating tank, and the concentrated alkaline water and the refluxed silica gel are mixed and dissolved by a stirring device.

4. The desiliconization process for photovoltaic concentrated alkaline water according to claim 3, characterized in that: The concentrated alkaline water and the refluxed silicone gel are dissolved and regulated in the concentrated alkaline water regulating tank for no less than 12 hours.

5. The desiliconization process for photovoltaic concentrated alkaline water according to claim 3, characterized in that: In step three, the dehydration device adopts a screw stacking machine and a filter press, wherein part of the silicon-containing gel solution is squeezed and dehydrated by the screw stacking machine to form a silicon gel filter cake and a filtrate, the silicon gel filter cake is returned to and dissolved in the concentrated alkaline water regulating tank at the front end, and the filtrate enters the comprehensive wastewater regulating tank for subsequent treatment; the remaining silicon-containing gel solution is sent to the filter press for filtration and dehydration, and the silicon gel sludge cake after filtration is transported out for disposal as solid waste, and the filtrate enters the comprehensive wastewater regulating tank through a pump and a pipeline for subsequent treatment.

6. The desiliconization process for photovoltaic concentrated alkaline water according to claim 1, characterized in that: In step 1, concentrated alkaline water and concentrated acid water are mixed in an acid-base mixing tank for 10-60 minutes, and the inlet ratio of concentrated acid water to concentrated alkaline water is controlled by pH.

7. The desiliconization process for photovoltaic concentrated alkaline water according to claim 1, characterized in that: The effluent from the acid-base mixing tank enters the gelation and silicon removal tank for gelation reaction for 0.5-24 hours.

8. A photovoltaic concentrated alkaline water desiliconization system used in the photovoltaic concentrated alkaline water desiliconization process according to claim 1, characterized in that: The invention comprises an acid-base mixing tank, a gelled silicon removal tank, a dehydration device and a comprehensive wastewater regulating tank. The acid-base mixing tank is provided with a concentrated alkaline water inlet and a concentrated acid water inlet. The concentrated alkaline water and the concentrated acid water can enter the acid-base mixing tank through the concentrated alkaline water inlet and the concentrated acid water inlet respectively. The acid-base mixing tank is also provided with a pH detection device. The pH detection device can detect the pH value of the mixed wastewater in the acid-base mixing tank in real time. The acid-base mixing tank is connected with the gelled silicon removal tank through a pipeline. The wastewater mixed in the acid-base mixing tank can be discharged into the gelled silicon removal tank along the pipeline. Silicon pool, the gelled silicon removal pool is provided with a stirrer, the stirrer is used to stir the mixed wastewater in the gelled silicon removal pool so that the acid-base neutralization reaction of the mixed wastewater forms a gel state, the gelled silicon removal pool is connected with the dehydration device through a pipeline, the silicon-containing gel solution in the gelled silicon removal pool can be sent to the dehydration device along the pipeline, the dehydration device can dehydrate the silicon-containing gel solution, the drain outlet of the dehydration device is connected with the comprehensive wastewater regulating pool through a pipeline, and the wastewater discharged from the dehydration device enters the comprehensive wastewater regulating pool along the pipeline for subsequent treatment.

9. The photovoltaic concentrated alkaline water desiliconization system according to claim 8, characterized in that: A concentrated acid wastewater regulating tank, a concentrated alkaline water regulating tank, a lifting pump, a silicone gel reflux conveying device and a control system are also provided. The concentrated alkaline water regulating tank is used to collect concentrated alkaline water discharged from the photovoltaic cell production line, and the concentrated acid wastewater regulating tank is used to collect concentrated acid water discharged from the photovoltaic cell production line. The concentrated alkaline water regulating tank and the concentrated acid wastewater regulating tank are connected to the concentrated alkaline water inlet and the concentrated acid water inlet of the acid-base mixing tank through pipelines respectively. The concentrated acid water in the concentrated acid wastewater regulating tank and the concentrated alkaline water in the concentrated alkaline water regulating tank can be respectively sent into the acid-base mixing tank through their own lifting pumps. The silicone gel reflux conveying device and the control system are also provided. The concentrated alkaline water regulating tank is used to collect concentrated alkaline water discharged from the photovoltaic cell production line, and the concentrated acid wastewater regulating tank is used to collect concentrated acid water discharged from the photovoltaic cell production line. The concentrated alkaline water in the concentrated acid wastewater regulating tank and the concentrated alkaline water in the concentrated alkaline water regulating tank can be respectively sent into the acid-base mixing tank through their own lifting pumps. One end of the silicone gel reflux conveying device is connected to the discharge of the dehydration device, and the other end of the silicone gel reflux conveying device is connected to the concentrated alkaline water regulating tank. The silicone gel reflux conveying device can convey the dehydrated silicone gel discharged from the dehydration device to the concentrated alkaline water regulating tank. The pH detection device in the acid-base mixing tank communicates with the control system to transmit the pH data in the acid-base mixing tank to the control system in real time. The control system controls the lifting pumps in the concentrated acid wastewater regulating tank and the concentrated alkaline water regulating tank to adjust the flow and start and stop. The control system also controls the start and stop of the silicone gel reflux conveying device.

10. The photovoltaic concentrated alkaline water desiliconization system according to claim 9, characterized in that: The dehydration device includes a screw stacking machine and a filter press. The gelled silicon removal tank is connected to the liquid inlets of the screw stacking machine and the filter press through pipelines, respectively. Two lifting pumps are arranged in the gelled silicon removal tank. The two lifting pumps in the gelled silicon removal tank pump the silicon-containing gel solution in the gelled silicon removal tank into the screw stacking machine and the filter press through pipelines, respectively. One end of the silicone gel reflux conveying device is connected to the discharge port of the screw stacking machine. The drain ports of the screw stacking machine and the filter press are both connected to the comprehensive wastewater regulating tank. The control system controls the flow rate and start and stop of the two lifting pumps in the gelled silicon removal tank.

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