Chelating agent for treating heavy metals in waste incineration fly ash and preparation method thereof

Abstract

The invention discloses a chelating agent for treating heavy metals in waste incineration fly ash and a preparation method thereof. The chelating agent is prepared from the following components: 20-40parts of an organic chelating agent body, 10-20 parts of an inorganic chelating agent body, 20-40 parts of hydrochloric acid, 20-30 parts of nitric acid and 4-8 parts of a surfactant. The chelating agent and the preparation method thereof have the advantages that the content of the treated heavy metals is greatly decreased, the chelating agent has no leaching toxicity, and meanwhile the heavy metals can be reused.

Description

technical field [0001] The invention relates to the field of domestic waste treatment, in particular to a chelating agent for treating heavy metals in waste incineration fly ash and a preparation method thereof. Background technique [0002] Domestic waste incineration fly ash has complex components and contains heavy metals with high leaching concentrations, such as Pb, Cr, Cd, Cu, Hg and Zn, etc., which are listed as hazardous wastes. Heavy metals with high leaching toxicity have serious harm to the environment. . Heavy metals are constantly migrating and transforming in the environment. The polluted soil and water environment cannot be eliminated through its own purification, and cannot be decomposed by microorganisms, and will be enriched through the biological chain. Therefore, improper treatment of fly ash will lead to pollutants in it. Heavy metals are lost to the environment, causing serious harm to human health and the natural environment. [0003] At present, the...

AI Technical Summary

Problems solved by technology

Heavy metals are constantly migrating and transforming in the environment. The polluted soil and water environment cannot be eliminated through its own purification, and cannot be decomposed by microorganisms, and will be enriched through the biological chain. Therefore, improper treatment of fly ash will lead to pollutants in it. Heavy metals are lost to the environment, causing serious harm to human health and the natural environment

[0003] At present, there are three main treatment methods for heavy metal components in fly ash. One is to use cement solidification technology to solidify heavy metals. Heavy metals react with cement through ion exchange, passivation, adsorption, chemical adsorption, sedimentation and hydration. On the surface of the hydrated silicate colloid C-H-S, relatively stable compounds such as hydroxide or complexes are formed, but this method has the disadvantages of increasing the capacity of fly ash and increasing the volume of landfill; the second is the melting and solidification method, This method is currently recognized as the safest and most stable incineration fly ash stabilization / solidification technology. This method is mainly to mix incineration fly ash and glassy powder into granules, and melt them at a high temperature of 1000-1400 °C for a period of time. This method has the disadvantage of high energy consumption; the third is the chemical agent stabilization method. Chemical agents transform their ions into low-solubility, low-mobility polymer complexes or inorganic minerals through chemical reactions with heavy metals. The choice of chemical chelating agents, especially the selectivity of chemical agents to the main polluting heavy metal ions, and the stability of the complexes, especially the leaching properties of acidic solutions;