Process for reducing fluorine ion concentration in wastewater without using medicament

Abstract

The invention relates to the field of wastewater treatment. The invention discloses a process for reducing fluorine ion concentration in wastewater without using a medicament. The method comprises thefollowing steps: mixing the fluorine-containing wastewater generated in the solar cell production process with the reverse osmosis concentrated water generated in the solar cell production process, adding the fluorine-containing wastewater or the reverse osmosis concentrated water again to adjust pH to 7, and finally, carrying out standing overflow to obtain water of which the fluorine ion concentration content is less than 100 mg/L. Reverse osmosis concentrated water generated in the solar cell production process is mixed with fluorine-containing wastewater generated in the solar cell production process, so that the concentration of fluorine ions in the wastewater is reduced; meanwhile, the concentration of metal ions such as calcium and magnesium in the wastewater is also reduced, and the wastewater can be recycled.

Description

technical field [0001] The invention relates to the field of wastewater treatment. Background technique [0002] A large amount of HF acid is used in the production process of solar cells, which will produce a large amount of fluorine-containing wastewater (slightly acidic). The fluoride-containing wastewater is relatively polluting to the environment. It must be defluoridated and then eliminated. At present, the fluoride-containing wastewater treatment process mainly includes calcium Ion precipitation method, coagulation precipitation method, adsorption method, and calcium ion precipitation method add lime to fluorine-containing wastewater to generate calcium fluoride precipitation, and then remove fluorine ions. The hardness of low-fluorine water after calcium ion precipitation method reaches Above 2000mg / L, it cannot enter the single-stage reverse osmosis membrane, and thus cannot be recycled and reused. In addition, the amount of chemical used is large. Although the coa...

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Problems solved by technology

[0002] A large amount of HF acid is used in the production process of solar cells, which will produce a large amount of fluorine-containing wastewater (slightly acidic). The fluoride-containing wastewater has a relatively large environmental pollution, and it must be removed after defluoridation. At present, the fluoride-containing wastewater treatment process mainly includes calcium Ion precipitation method, coagulation precipitation method, adsorption method, and calcium ion precipitation method add lime to fluorine-containing wastewater to generate calcium fluoride precipitation, and then remove fluorine ions. The hardness of low-fluorine water after calcium ion precipitation method reaches Above 2000mg / L, it cannot enter the single-stage reverse osmosis membrane, and thus cannot be recycled and reused. In addition, the amount of chemical used is large

Although the coagulation sedimentation method and the adsorption method have good treatment effects, the cost is high and the treatment speed is slow

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