Method for treating high-concentration acidic wastewater containing phosphorus and fluorine

Abstract

The invention discloses a method for treating acidic wastewater containing phosphorus and fluorine, which comprises the following steps: (1) firstly, adding calcium hydroxide into the acidic wastewater containing phosphorus and fluorine, and controlling the pH value of the system at 12-14 to obtain a precipitate-containing reaction system which is marked as a reaction system 1; (2) removing the precipitate in the reaction system 1, adding sulfuric acid into the residual liquid to regulate the pH value to 9-11, and then, adding aluminum sulfate to regulate the pH value to 6-7, thereby obtaining a precipitate-containing reaction system 2; and (3) settling down the precipitate in the reaction system 2, and removing the precipitate to obtain the treated wastewater. In the wastewater treated by the method disclosed by the invention, the content of fluorine is lower than 10 mg / L, the content of phosphorus is lower than 0.5 mg / L, and the pH value is 6-7, thus the treated wastewater achieves the Discharge Standard of Water Pollutants for Phosphate Fertilizer Industry (GB 15580-95). In the whole technological process, water overflows under the action of the gravity without an external energy supply, thereby saving the energy.

Description

technical field [0001] The invention relates to a method for treating high-concentration acidic phosphorus-containing and fluorine-containing wastewater. Background technique [0002] In the production process of phosphorus compound fertilizer, a large amount of phosphorus-containing and fluorine-containing industrial wastewater will be produced, and the ion with the most content is F - 、PO 4 3- and so on; and the direct discharge of wastewater containing these ions into the surrounding environment will acidify the water body and soil, among which fluorine will be life-threatening to the human body, and phosphorus will cause eutrophication of the water body. Phosphate Fertilizer Industry Water Pollutant Discharge Standard (GB 15580-95) stipulates that the primary standard for the maximum allowable discharge concentration of fluoride in wastewater is 10mg / L, and the maximum allowable discharge concentration of phosphate (calculated as P) is 0.5mg / L , The primary standard f...

AI Technical Summary

Problems solved by technology

[0005] These wastewater treatment processes and equipment are either based on the original aeration and sedimentation, and added devices such as concentration and filtration. Although the treatment effect has been greatly improved, the concentration and filtration equipment are expensive, and the cost of wastewater treatment also increases. or the use of biological filtration methods increases the complexity and cost of wastewater treatment; and some rely on external power for wastewater treatment

In addition, the processes and equipment used in these wastewater treatment processes only consider how to remove the sediment, without considering the investment and treatment costs of the industrialization process; this brings great economic pressure to the enterprise

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