System and method for treating hydrofluoric acid-containing wastewater

A treatment system and treatment method technology, which is applied in the field of sewage recovery and treatment, can solve the problems of large discharge of hydrofluoric acid-containing wastewater and low recovery rate of hydrofluoric acid, shorten the recovery and treatment cycle, increase the value of renewable utilization, and improve The effect of water quality

Active Publication Date: 2021-12-07
CHINA ENFI ENGINEERING CORPORATION
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Problems solved by technology

[0006] The main purpose of the present invention is to provide a treatment system and method for hydrofluoric acid-containing wastewater, to solve the problems of large discharge of hydrofluoric acid-containing wastewater and low recovery rate of hydrofluoric acid in the prior art

Method used

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  • System and method for treating hydrofluoric acid-containing wastewater

Examples

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Comparison scheme
Effect test

Embodiment 1

[0059] The daily water output of silicon ingot cleaning wastewater (ie wastewater containing hydrofluoric acid or influent water) in a monocrystalline silicon factory is 200m 3 / d. use as figure 1 The hydrofluoric acid-containing wastewater treatment system shown above treats the above silicon rod cleaning wastewater to obtain fluorine-containing waste liquid (effluent) that meets the discharge standard. The water quality parameters of the above silicon rod cleaning wastewater are shown in Table 1.

[0060] Table 1

[0061] Water Quality Parameters COD(mg / L) SS(mg / L) f - (mg / L)

pH Silicon rod cleaning wastewater (influent) 108 500 3000 0.8

[0062] After the above silicon rod cleaning wastewater is separated through the filter (filter lining material is fluorine-resistant FRP), the effluent SS is reduced to 20mg / L, and hydrofluoric acid and fluorine ions enter the liquid phase, and the remaining fluorine-containing sludge enters the fluorin...

Embodiment 2

[0069] The difference from Example 1 is that the temperature of the heating liquid is 30°C, and the temperature of the enrichment liquid is 15°C.

[0070] See Table 2 for the water quality parameters of fluorine-containing waste liquid (effluent) that meet the discharge standards.

Embodiment 3

[0072] The difference from Example 1 is that the temperature of the heating liquid is 60°C, and the temperature of the enrichment liquid is 5°C.

[0073] See Table 2 for the water quality parameters of fluorine-containing waste liquid (effluent) that meet the discharge standards.

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Abstract

The invention provides a system and a method for treating hydrofluoric acid-containing wastewater. The system comprises a solid-liquid separation device, a membrane distillation unit, an ultrafiltration device and a reverse osmosis unit, wherein the solid-liquid separation device is provided with a hydrofluoric acid-containing wastewater inlet, a liquid phase outlet and a slurry outlet; the membrane distillation unit is provided with a feed liquid inlet and an enriched liquid outlet, and the feed liquid inlet communicates with the liquid phase outlet through a liquid phase conveying pipeline; the ultrafiltration device is provided with an enriched liquid inlet, a concentrated liquid outlet and a filtered water outlet, and the enriched liquid inlet communicates with the enriched liquid outlet through an enriched liquid conveying pipeline; and the reverse osmosis unit is provided with a concentrated solution inlet, a hydrofluoric acid outlet and a reverse osmosis raffinate outlet, and the concentrated solution inlet communicates with the concentrated solution outlet through a concentrated solution conveying pipeline. According to the invention, hydrofluoric acid can be recovered, and the recovery rate of the hydrofluoric acid is improved; the content of fluorine ions in the hydrofluoric acid-containing wastewater can be reduced, and water quality can be improved; and the system is compact in design and can shorten the recovery treatment period of the hydrofluoric acid.

Description

technical field [0001] The invention relates to the technical field of sewage recovery and treatment, in particular to a treatment system and method for hydrofluoric acid-containing wastewater. Background technique [0002] In the photovoltaic industry, hydrofluoric acid is required for the cleaning of monocrystalline silicon raw materials, silicon wafer etching, and polishing, which will generate a large amount of hydrofluoric acid-containing wastewater. Hydrofluoric acid has low pH value, strong corrosion, strong oxidation and high conductivity, and direct discharge will cause serious pollution to the environment. At present, the treatment process for wastewater containing hydrofluoric acid mainly adopts the precipitation method, that is, adding slaked lime, calcium chloride and coagulant to the wastewater containing hydrofluoric acid to make fluoride ions and calcium ions generate calcium fluoride to achieve The purpose of removing fluorine. [0003] The existing docume...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/04C01B7/19
CPCC02F9/00C01B7/195C01B7/196C02F1/447C02F1/444C02F1/441C02F1/66Y02W10/37
Inventor 武警吴彩琼杨恒田丽森聂宜文赵金刘少非
Owner CHINA ENFI ENGINEERING CORPORATION
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