Composite fluorine removing agent for removing high-concentration fluorine-containing wastewater and application method thereof

Abstract

The invention discloses a composite fluorine removing agent for removing high-concentration fluorine-containing wastewater and an application method thereof, which belong to the field of sewage treatment in environment protection. The composite fluorine removing agent is prepared by compounding polyhydroxyl or polycarboxyl compounds and inorganic matters according to a certain proportion, wherein the polyhydroxyl or polycarboxyl compounds include one or more than two of trifluoromethanesulfonic anhydride, caprylyl chloride, 1R-(-)-camphorsulfonic acid, 3-furoic acid, pentanoyl chloride, and butanetetracarboxylic acid; and the inorganic matters include two or more than two of calcium salt, magnesium salt, phosphate, and ferric salt. The composite fluorine removing agent is added into the high-concentration fluorine-containing wastewater in a weight ratio of 1:100 to 1:1000 according to the concentration of fluorine in the wastewater; the pH value of the wastewater is adjusted to 9.0-11.0 with sodium hydroxide; and the wastewater is stirred for 15-30min, so that the yielding water can meet the national emission standard I. The composite fluorine removing agent and the application method thereof disclosed by the invention have the characteristics of simple technological process, smaller dosage of chemical agent, lower running expense, no sludge, high removal rate, and the like; and the removal rate can reach above 99.9%.

Description

technical field [0001] The invention relates to a composite defluorination agent for removing high-concentration fluorine-containing wastewater and an application method thereof, relates to the removal of fluoride ions in wastewater, and belongs to the field of wastewater treatment in environmental protection. Background technique [0002] Fluorine is one of the essential trace elements for the human body. An appropriate amount of fluorine is beneficial to human health, but too low or too much of it will endanger health, especially too much will cause fluorosis. The fluoride content of people's daily drinking water is generally controlled at 0.4-0.6 mg / L. Long-term drinking of water with a fluoride ion concentration greater than 1 mg / L is not good for the human body. Serious cases will cause dental fluorosis, skeletal fluorosis and other diseases, and even Induces the occurrence of tumors and seriously threatens human health. [0003] At present, there are three common trea...

AI Technical Summary

Problems solved by technology

(1) The precipitation method is to form fluoride precipitation or flocculation precipitation by adding chemicals or other drugs to achieve the purpose of removal; this process is prone to secondary pollution, and the sludge output is large; (2) The chemical precipitation method is added to the wastewater Chemicals such as calcium salts, which make calcium ions react with fluoride ions to form CaF 2 Precipitation, to achieve the removal of F in wastewater － The purpose of this process is simple and convenient, and the cost is low, but the fluorine content in the treated wastewater reaches 15mg / L, and it is difficult to form sediment when adding lime water, so this method is generally suitable for the primary treatment of high-concentration fluorine-containing wastewater Or pretreatment, it is difficult to meet the first-level standard of the national standard

In addition, the produced CaF 2 The precipitate is wrapped in Ca(OH) 2 The surface of the particles is therefore not fully utilized, resulting in waste

(3) The coagulation-sedimentation method is to form positively charged colloidal particles in water by adding two types of coagulants, iron salt and aluminum salt, which can absorb F in water. － The flocs are aggregated and precipitated to achieve the purpose of fluorine removal; however, this method is only suitable for the treatment of low-concentration fluorine-containing wastewater, and it is generally used in conjunction with the precipitation method to achieve the treatment of high-concentration fluorine-containing wastewater; Since the defluoridation effect is affected by factors such as stirring conditions and settling time, the effluent quality is not stable enough

[0004] The Chinese invention patent with the publication number CN101062817A discloses a more effective method for treating wastewater containing fluoride ions, which is to add sulfuric acid solution to the wastewater containing fluoride, after the reaction, add a polymer flocculant, and then carry out flocculation and precipitation. Clear liquid discharge, solid-liquid separation method is realized; this method is only suitable for the treatment of low-concentration fluorine-containing wastewater, in order to realize the treatment of high-concentration fluorine-containing wastewater, it must be used in conjunction with the precipitation method