A composite heavy metal chelating agent for waste incineration fly ash and a preparation method thereof

Abstract

A composite heavy metal chelating agent for waste incineration fly ash and a preparation method thereof are disclosed. The composite heavy metal chelating agent includes, by weight, 15-20 parts of anorganic chelating agent, 5-10 parts of an inorganic chelating agent, 2-10 parts of an inhibitor, 2-5 parts of a dispersant and 50-80 parts of water. The organic chelating agent is a mixture of sodiumbutyl dithioxanthate and sodium dimethyldithiocarbamate. The inorganic chelating agent is sodium hexametaphosphate. The inhibitor is sodium lignosulphonate, and the dispersant is sodium silicate. Thecomposite heavy metal chelating agent is a multi-formula composite heavy metal chelating agent, has strong chelation performance for heavy metals in waste incineration fly ash through synergistic effects of organic and inorganic components, can efficiently achieve stabilization treatment of the waste incineration fly ash and can ensure that pollutant concentrations of leach liquor meet standards.The preparation method of the composite heavy metal chelating agent is also provided.

Description

technical field [0001] The invention relates to the field of environmental protection management, in particular to a composite waste incineration fly ash heavy metal chelating agent and a preparation method thereof. Background technique [0002] With the rapid development of my country's economy and the rapid growth of urban population, municipal solid waste has become a social problem that pollutes the environment and affects life. While realizing the reduction of domestic waste, waste incineration produces a large amount of fly ash, which is enriched with highly toxic heavy metals and dioxin-like pollutants. "Standards for Pollution Control of Domestic Garbage Landfill" GB16889-2008 clearly stipulates that after the fly ash of domestic garbage incineration is treated, the concentration of hazardous components in the leaching solution prepared in accordance with "Solid Waste Leaching Toxic Leaching Method Acetic Acid Buffer Solution Method" HJ / T300-2007 If it is lower than...

AI Technical Summary

Problems solved by technology

The current heavy metal chelating agents, such as sodium dithioformate and EDTA chelating agents commonly used in the market, mainly have the following problems: weak chelating ability, poor stability, and adaptability to different types of fly ash Not strong, easy to cause secondary pollution

At the same time, these chelating agents have poor selectivity to metal elements. In addition to heavy metal elements, there are more alkaline earth metals in the fly ash, resulting in a large amount of chelating agents and high operating costs.

In addition, the water content of landfill after domestic waste incineration fly ash treatment should not be too high, the current chelating agent has poor dispersion in fly ash slurry, and the chelating effect is not good

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