Composite remediation agent for heavy metal contaminated soil and application method

Abstract

The invention discloses a composite remediation agent for heavy metal contaminated soil and an application method, and belongs to the field of remediation of heavy metal contaminated soil. The composite remediation agent is prepared from, by mass, 25-40 parts of an iron-based agent, 5-15 parts of a sulfur-based agent, 40-60 parts of a calcium-based agent and 5-10 parts of organic matters, whereinthe organic matters are fulvic acid and at least one of ulmic acid and humic acid. The agent provided by the invention can adjust the dosage and component proportion of each agent according to the content of heavy metals in soil, and is widely applied to different types of polluted soil. The composite remediation agent has a good remediation effect on cadmium, lead, zinc, arsenic and other heavy metal composite contaminated soil, and has the advantages of long-term stability, short remediation time, flexible agent proportioning, low consumption and treatment cost saving.

Description

technical field [0001] The invention belongs to the technical field of remediation of heavy metal-contaminated soil, and in particular relates to a compound remediation agent for heavy metal-contaminated soil and an application method. Background technique [0002] Soil pollution can be divided into heavy metal pollution, pesticide pollution and organic pollution and other types. According to relevant data, the most serious pollution in China is heavy metal pollution. The main pollutants are cadmium, arsenic, chromium, lead, etc. More than half of this kind of pollution is caused by the discharge of industrial "three wastes". [0003] At present, the commonly used remediation technologies for heavy metal-contaminated soil include soil improvement method, electrodynamic remediation technology, solidification / stabilization, soil leaching method, and bioremediation technology. The soil improvement method consumes a lot of money, manpower and material resources. In the process ...

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Problems solved by technology

The soil improvement method consumes a lot of money, manpower and material resources. In the process of soil replacement, there are defects such as land occupation, leakage, and environmental pollution; the electric restoration technology is economical and reasonable, but it is easy to cause secondary soil pollution and has high permeability and poor conductivity. The effect of the sandy soil is poor; the separation of mud and water after the soil leaching method is difficult, the sewage treatment is more difficult, the soil structure will be destroyed, and it is not suitable for resource reuse; the bioremediation technology has a long repair period, and the growth rate of hyperaccumulator plants is generally high. Slow, the microbial biomass is small, and subsequent treatment is required, it is difficult to meet the application requirements of large-scale engineering restoration; solidification / stabilization is to put solidifying agents, organic matter, chemical reagents, natural minerals, etc. into the soil to change the pH value of the soil, Eh The physical and chemical properties, such as oxidation, reduction, precipitation, adsorption, inhibition, complexation and chelation, are used to reduce the bioavailability of pollutants, and finally achieve the purpose of remediating contaminated soil. This method has been successfully applied in engineering practice

However, the existing soil remediation agents have disadvantages such as high price, large dosage, high treatment cost, low treatment efficiency, and long-term safety cannot be guaranteed.

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