Treatment method for simultaneous removal of fluoride ions and chloride ions in industrial wastewater

Abstract

The invention discloses a treatment method for simultaneous removal of fluoride ions and chloride ions in industrial wastewater. The method removes fluoride ions and chloride ions in industrial wastewater through a two-stage process consisting of pretreatment and advanced treatment, wherein Ca(OH)2 and NaAlO2 are used for precipitation in pretreatment, and a biological coagulant is used for coagulation and sedimentation in advanced treatment. According to the invention, the biological coagulant is prepared from directionally domesticated Thiobacillus ferrooxidans and has the advantages of no toxicity, high efficiency, no secondary pollution, national degradability and the like. The treatment method provided by the invention can simultaneously remove fluoride ions and chloride ions in high-concentration industrial wastewater, has low sediment amount, low residual concentration of fluoride ions and chloride ions and good application prospects, and is of great significance to the development of treatment of industrial water pollution in China.

Description

technical field [0001] The invention relates to the technical field of industrial wastewater containing fluoride ions and chloride ions, in particular to a treatment method for synchronously removing fluoride ions and chloride ions in industrial wastewater. Background technique [0002] With the development of modern science and technology, the production scale of the non-ferrous metal smelting industry continues to grow. During the zinc hydrometallurgy roasting process, the fluorine and chlorine impurities in the zinc concentrate enter the flue gas acid system and the wet system, resulting in flue gas A large amount of sulfuric acid wastewater containing high concentrations of fluorine and chlorine is produced during the acid production process. These waste water containing fluoride ions and chloride ions not only have a great corrosive effect on pipeline equipment, but also cause varying degrees of pollution to the water in the environment after being discharged into the e...

AI Technical Summary

Problems solved by technology

However, the adsorption method has limited its scope of application due to the low capacity of the adsorbent, and is limited to the treatment of low-concentration fluoride- and chloride-ion-containing wastewater; in the chemical precipitation method, calcium salt and aluminum salt precipitation are used to treat fluoride-containing ions and chloride ion wastewater are currently the most commonly used method. This method is simple and easy to implement, and the treatment cost is low, but the amount of sludge after treatment is large, the water content is the highest, it is difficult to dehydrate, and it is easy to cause secondary pollution. And the experiment found that the single use of lime Precipitation method, the fluoride ion concentration in the effluent is generally between 20-30mg / L, it is difficult to achieve the standard discharge; the coagulation sedimentation method has the characteristics of small dosage, low fluoride ion and chloride ion concentration in the effluent, but this method is suitable for Low-concentration fluorine-containing wastewater is often used as an auxiliary means for advanced treatment