A kind of solidifying agent for heavy metal polluted soil and its application method

Abstract

The invention discloses a heavy metal-contaminated soil solidifying agent and an application method thereof. The solidifying agent comprises the following components by mass: on the basis of the dry weight of heavy metal-contaminated soil, 10 to 15% of a binding material, 5% of biochar, 10% of vegetable fiber and 1% of a stabilizing agent. The components are added according a sequence of the stabilizing agent-the biochar-the vegetable fiber-the binding material. Addition of the chemical stabilizing agent and the biochar in the process of stabilization enables heavy metals to be absorbed and passivated and to lose mobility; preparation of heavy metal-contaminated soil slurry provides conditions for a later chemical reaction; the whole processing process is free of dust pollution and discharging of unwanted sewage. Addition of the vegetable fiber enables cracking of heavy metal-contaminated soil solidified by using a conventional solidifying agent to be effectively prevented and endurance of a solidified body to be improved. The method provided by the invention has the advantages of strong operability, low cost, extensive applicability, a high resource utilization rate, low environmental risk and easy large-scale popularization.

Description

technical field [0001] The invention discloses a solidifying agent for heavy metal polluted soil and a using method thereof, and belongs to the technical field of engineering materials and environmental engineering. Background technique [0002] With the acceleration of urbanization and industrialization, more and more land is polluted by heavy metals, the strategic layout of cities has been readjusted, and a large number of heavy metal legacy sites are in urgent need of treatment. At present, nearly 20 million hectares of arable land are polluted by heavy metals such as chromium, cadmium, arsenic, and lead in my country. It is estimated that 12 million tons of grains are polluted by soil every year, causing direct economic losses of more than 20 billion yuan. The remediation and treatment methods of heavy metal contaminated soil mainly include solidification and stabilization, leaching, electrokinetic remediation, phytoremediation, vitrification and steam extraction. one. ...

AI Technical Summary

Problems solved by technology

The current curing and stabilization treatment technology has the following problems: 1) The amount of curing agent added is too large; 2) The cracking caused by the long-term stress load and dry-wet cycle of the cured body accelerates the leaching of heavy metal ions in the cured body; 3. ) high environmental risk

[0004] There are many sugar factories in Sichuan and Guangxi in my country, and there is a large amount of bagasse, which belongs to fiber in terms of its composition and is the waste of sugar factories; most of the cellulose-rich straw is burned as waste or only used as fuel , not only caused a waste of natural resources, but also polluted the deteriorating human living environment, which urgently needs a more effective straw treatment method

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