Compound micro iron agent facilitating in-situ injection and preparation method of compound micro iron agent

Abstract

The invention discloses a compound micro iron agent facilitating in-situ injection and relates to the technical field of in-situ remediation of soil and underground water. The compound micro zero-valent iron agent is prepared from zero-valent ion powder, a dispersant, a thickener and water through uniform mixing in a high-speed stirring manner. The zero-valent iron powder, the dispersant and the thickener account for 5%-40%, 0.3%-1% and 2%-6% of the total water quantity respectively in percentage by weight. Compared with existing commercially available micro iron compound agents, the compound micro zero-valent iron agent has very high stability and excellent migration liquidity, facilitates in-situ injection of the agent during remediation, can be injected into a target remediation layer under lower pressure, has larger diffusion radius and has good removal effects on heavy metals and organic pollutants. The compound micro zero-valent iron agent comprises green and environmentally friendly components, is wide in application range, is beneficial to sustainable development of the enjoinment and cannot exert adverse effects on the underground water environment.

Description

technical field [0001] The invention relates to the technical field of in-situ remediation of soil and groundwater, in particular to a compound micron zero-valent iron medicament for in-situ injection. Background technique [0002] Micronized zero-valent iron (mZVI) was first used as a restorative agent in the 1990s, when granular zero-valent iron was used in conjunction with permeable reactive grid (PRB) technology. The grid spans the migration path of the groundwater pollution zone, allowing the polluted groundwater to pass through the iron wall, and remove pollutants by reduction, degradation, precipitation, adsorption or ion exchange. The removal efficiency of pollutants is much greater than the degradation process under natural conditions, but the cost of this osmotic reaction grid is too high, and once the grid is fixed, it cannot be rebuilt, which limits its further promotion in the field of water environment restoration application. After that, the development and ...

AI Technical Summary

Problems solved by technology

However, also due to the large particle size of micron-sized zero-valent iron (mZVI), it faces a series of challenges in the implementation of in-situ restoration projects: 1) It has poor mobility in the underground environment, which is not conducive to the release of chemicals. In situ injection, the migration distance is limited; 2) The injected micron-sized zero-valent iron (mZVI) reacts with conventional ionic components, dissolved oxygen, and natural organic matter in groundwater during the migration process to the target contaminated area, making the particle surface Oxidation and mineral deposition lead to the coverage of surface active sites, which further affects its ability to remove target pollutants