A kind of combined repairing agent formula, method and application of soil heavy metal tin and lead

Abstract

The invention discloses a formula, methods and an application of a combined remediation agent for heavy metals tin and lead in soil. Zeolite, blast furnace slag, biochar formed by firing agriculturalwastes and cement are adopted as raw materials. The remediation agent concretely comprises, by mass, 2-4 parts of cement, 2-4 parts of blast furnace slag, 0.5-2.5 parts of zeolite, 0-1 part of biocharand 2-6.7 parts of cement; the remediation agent accounts for 1-5% of the weight of the contaminated soil, and the water content in a mixed system of the contaminated soil and the remediation agent is 10-30%; and the combined remediation agent is directly prepared by mixing the zeolite, blast furnace slag, biochar and cement, the heavy metal contaminated soil and the remediation agent are evenlymixed through a stirrer, and then a solidified sample is obtained through molding, demolding and curing in sequence. The remediation agent and the remediation method for the heavy metal composite contaminated soil are efficient and environmentally friendly, are suitable for high-concentration composite contaminated heavy metal contaminated soil, and particularly have a good solidification remediation effect on Sn and Pb, and the remediation agent has certain strength and frost resistance.

Description

technical field [0001] The invention belongs to a soil remediation scheme in the field of environmental heavy metal adsorption, and in particular relates to a remediation agent for compound pollution of soil heavy metal Sn and Pb, and a preparation method and application thereof. Background technique [0002] The large number of industrially polluted sites is a huge burden in both developed and developing countries of the world. Moreover, the rapid advancement of industrialization and urbanization has caused a large number of polluted sites. In the process of redevelopment and utilization of polluted sites, the negative impact of heavy metal pollution has gradually emerged, and it has begun to threaten the ecological environment and human health. Therefore, corresponding measures must be taken to control These polluted sites make it meet the requirements of redevelopment and utilization. [0003] my country is rich in tin ore resources. According to proven data, the tin res...

AI Technical Summary

Problems solved by technology

[0006] In summary, the currently adopted heavy metal solidification materials and methods mainly have the following problems: (1) strong alkalinity, one of its main solidification principles is to generate hydroxide precipitation with heavy metals, such products are amphoteric substances, Heavy metal re-leaching is highly likely in overacid and overalkaline environments; (2) The environment is not friendly, and the production process of cement and lime consumes a lot of energy and releases air pollutants such as SO2, NO2, and CO2

(3) The existing formula not only needs to add chemical reagents, but also has many ingredients in the restoration agent. Some materials have complex manufacturing processes and the repair cost is high

(4) The concentration of heavy metals treated is generally low, which cannot meet the restoration requirements of high-concentration heavy metals around tailings

[0007] The common problems of existing soil heavy metal remediation agents are: there are many kinds of remediation materials that need to be added, and the addition ratio is high. Some materials need to be modified, which increases the technical difficulty and leads to high repair costs.

The existing technology lacks a restorative agent with low preparation cost and excellent repair effect

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