Preparation method of stabilizer for passivating heavy metals in soil

Abstract

The invention discloses a preparation method of a stabilizer for passivating heavy metals in soil, and belongs to the field of soil stabilizing materials and regeneration of contaminated soil. In allusion to the problems that the conventional stabilizer is high in price, the soil is solidified after stabilization, and soil reclamation is difficult, raw materials used by the stabilizer are wide insources and low in price, some of the raw materials are alkali metal oxides and silicon-containing compounds of industrial wastes, and contamination is controlled by the wastes; the stabilizer has thecharacteristics of not destroying the soil structure, providing a good stabilizing effect, supplementing a silicon source, promoting the crop yield increase and the like, and can stabilize the heavymetal form of the soil, inhibit the heavy metal absorption of crops, reduce the bioavailability of the heavy metals in the soil and improve the acidity of the soil. The operating method is simple, thepracticability is strong, the application range is wide, and a good stabilizing repairing effect on the soil contaminated by composite heavy metals such as Cu, Pb, Zn, Cd and Cr is achieved.

Description

technical field [0001] The invention relates to a preparation method of a stabilizer for passivating heavy metals in soil, which belongs to the field of soil stabilization materials and regeneration of polluted soil. Background technique [0002] Soil heavy metals have the characteristics of universality, persistence, concealment or latentness, refractory, irreversible, indirect harmfulness, easy migration, bioaccumulation and biotoxicity. They are important environmental toxic and harmful substances, which are harmful to human health. pose a huge threat to the ecological environment. [0003] Soil heavy metal stabilization and remediation refers to adding heavy metal stabilizing agents to contaminated soil, through a series of reactions such as adsorption, precipitation, complexation, ion exchange, and redox, to change the existing form of heavy metal pollutants in the soil and reduce harmful components. The leaching toxicity, migration, and bioavailability of leaching can...

AI Technical Summary

Problems solved by technology

[0004] The existing stabilization technology mainly adopts substances such as carbonate, phosphate, silicate, and forms insoluble or slightly soluble heavy metal precipitates after adding a stabilizer. CN 103834410 A discloses a heavy metal curing agent and the use of the heavy metal A method for solidifying and stabilizing soil heavy metals with a solidifying agent. The heavy metal solidifying agent is prepared from fly ash, cement, carbide slag and sodium silicate with a modulus of 2.0. A part of industrial waste is used to treat waste with waste, and the solidification effect is better. Under the hydration reaction of cement, harmful substances in the polluted soil are sealed inside the solidified body, thereby achieving the purpose of harmlessness and stabilization, but it is difficult to grow plants in completely solidified soil; CN 107955626 A discloses stabilizers, A method for preparing a stabilizer and a method for repairing heavy metal-contaminated soil. The stabilizer is made of montmorillonite, diatomaceous earth, phosphate, potassium sulfide, magnesium oxide, and a metal complexing agent, which can form a stable complexing and encapsulating substance. Reach good stabilizing effect, but need to add sodium hydroxide in montmorillonite and carry out modification, sodium hydroxide has strong alkalinity, and it is easy to burn seedlings, reduce the fertilizer efficiency of phosphate fertilizer, etc.; CN 107722987 A discloses a heavy metal ion stabilizer The preparation of the agent and its repairing method for cultivated land soil, mixing sawdust, bean dregs and bran, controlling temperature and humidity, aerobic fermentation in the presence of subtilis bacteria, to obtain heavy metal ion stabilizer, no special machinery or Too much labor to carry out large-scale earthworks, but work like farmers spreading fertilizers and pesticides, but the application of stabilizers is large, and it is vulnerable to weather

[0005] The existing stabilizers have the disadvantages of serious compaction or solidification of the stabilized soil, which makes it difficult for plants to grow, or the stabilizer changes the physical and chemical properties of the soil, reduces soil fertility, the treatment effect and the treatment agent are greatly affected by the environment, and the amount of the agent added is large.