Method for primary treatment of sodium monofluorophosphate production wastewater

Abstract

The invention provides a method for producing wastewater by performing primary treatment on sodium monofluorophosphate. The method comprises the following steps: (I) detecting wastewater; (II) preparing a flocculating agent; (III) adjusting the pH value of the wastewater; (IV) feeding a settling agent; (V) feeding the flocculating agent; (VI) performing filtration treatment. By a series of methods of jointly using the proper flocculating agent and a coagulant aid, controlling the use amount of the fed settling agent and the feeding sequence and adjusting the pH value of the solution, fluoride removal and phosphorous removal are completed in one adjustment basin, and fractional precipitation is not needed; after primary treatment, the wastewater produced from the sodium monofluorophosphate can meet the requirements specified in the existing national sewage discharge standard for fluorine and phosphorus elements, so that the influence of polyphosphates on settlement of fluorine and phosphorus ions is effectively eliminated, and sustainable development of the sodium monofluorophosphate is realized; the process is simple, the settling and separating effect is good, the operability is high, the occupied area is small, and the treatment cost is low.

Description

technical field [0001] The invention belongs to a method for primary treatment of chemical production wastewater, in particular to a method for primary treatment of sodium monofluorophosphate production wastewater. Background technique [0002] A large amount of waste water is often produced in chemical production, which contains many harmful substances, which not only endanger human life and health, but also pollute the environment. In recent years, the country has paid more and more attention to environmental protection issues, and has formulated special regulations to clearly stipulate the discharge requirements of industrial wastewater, and strictly prohibits the arbitrary discharge of industrial wastewater. [0003] Sodium monofluorophosphate products have formed a stable and mature production process over the years, with excellent product quality and good economic benefits; however, the problem of wastewater has not been resolved, which directly affects the future deve...

AI Technical Summary

Problems solved by technology

[0003] Sodium monofluorophosphate products have formed a stable and mature production process for many years, with excellent product quality and good economic benefits; however, the problem of wastewater has not been resolved, which directly affects the future development of the product

However, sodium hexametaphosphate, the raw material required for the production of sodium monofluorophosphate, is a good deflocculant and peptizer. There is a relatively large amount of polyphosphate ions brought in by the raw material sodium hexametaphosphate in the wastewater produced by sodium monofluorophosphate. The polyphosphate ion has the chelating ability to prevent the generation of insoluble compounds with multivalent cations, or to peptize the precipitate containing multivalent cations, so the polyphosphate ion and CaF 2 Precipitation forms chelates, making sedimentation difficult and preventing CaF 2 The formation of precipitation causes the content of F ions to not be effectively reduced. The solution first produces precipitation and then dissolves, making the solution turbid after treatment and increasing the turbidity; increasing the difficulty of wastewater treatment

Therefore, the conventional graded wastewater treatment method is difficult to effectively treat the wastewater produced by sodium monofluorophosphate, and cannot meet the requirements of the national "Comprehensive Wastewater Discharge Standard"