Method for treating fluorine-containing and ammonia nitrogen-containing waste water in electronic industry

Abstract

The invention relates to a method for treating fluorine-containing and ammonia nitrogen-containing waste water in electronic industry. The method comprises an ammonia nitrogen removal procedure and a fluorine removal procedure, wherein the ammonia nitrogen removal procedure is as follows: Cl2 is added into waste water, wherein 7.6-8.0mg of Cl2 is added into every one liter of waste water containing 1mg of ammonia nitrogen, and the Cl2 is added in two batches; the addition amount for the first batch is 65-75%, and the addition amount for the second batch is the rest; after the first batch of Cl2 is added, alkali equivalent to the added Cl2 for the first batch is added to neutralize hydrochloric acid produced by the reaction of the Cl2 and ammonia nitrogen, and then, the second batch of Cl2 is added; and the fluorine removal procedure combines chemical reaction precipitation and coagulative precipitation separation. By firstly removing ammonia nitrogen and then removing fluorine, the invention achieves the advantages of stable and favorable treatment effect, high efficiency and high speed. The fluorine ion content and ammonia nitrogen content in the waste water treated by the invention are effectively reduced, and the waste water can be discharged or be subjected to further reclamation treatment to be reclaimed according to different environmental protection requirements.

Description

technical field [0001] The invention belongs to the technical field of waste water treatment, and in particular relates to a treatment method for fluorine-containing ammonia nitrogen-containing waste water in the electronic industry. Background technique [0002] With the development of electronic industry technology, especially integrated circuit chip industry technology, the treatment of electronic industrial wastewater, especially electronic industry wastewater containing fluorine and ammonia nitrogen, has become a prominent problem in the water treatment industry. The electronics industry usually uses a large number of chemicals such as hydrofluoric acid, sulfuric acid, phosphoric acid, ammonia water, hydrochloric acid, and organic solvents in the production process, making the discharged wastewater contain a large number of components that pollute the surrounding environment, which has aggravated my country's water pollution. and the severity of the water shortage situat...

AI Technical Summary

Problems solved by technology

Due to the poor biodegradability of this type of wastewater (BOD / COD<0.1), and due to the limitations of the process technology of urban sewage treatment plants, the total nitrogen in the effluent is often not up to the standard, which may easily lead to eutrophication of the discharged water, especially for some specific Pollutants (such as fluorine) cannot be effectively removed but can only be reduced by dilution

Facing the increasingly serious ecological environment, the state requires industrial enterprises to implement the policy of "energy saving and emission reduction". In the environmental impact assessment approval for large water users of industrial enterprises, in addition to requiring the discharge of waste water to meet the standard, it also clearly requires that waste water must reach a certain reuse rate , conventional treatment methods can no longer effectively reduce the discharge of pollutants, and it is even more impossible to effectively reduce the discharge of wastewater through wastewater regeneration and reuse, and realize a circular economy

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