Method for improving stabilization efficiency of nanometer zero-valent iron in heavy metal composite polluted soil

Abstract

The invention belongs to the field of heavy metal pollution remediation in polluted environment, the invention discloses a method for improving stabilization efficiency of nanometer zero-valent iron in a heavy metal composite polluted soil. The method comprises the following steps of (1) preparing for the modified nanometer zero-valent iron; (2) stabilizing treatment of the modified nanometer zero-valent iron on the heavy metal composite polluted soil; and (3) evaluating a stabilization effect; the method is characterized in that sodium carboxymethylcellulose is adopted to modify the nanometerzero-valent iron, the agglomeration of the nanometer zero-valent iron is reduced through utilizing a steric hindrance effect and an electrostatic steric effect to increase the dispersity of the nanometer zero-valent iron and the mobility of the nanometer zero-valent iron in the soil. According to the method, the stabilizing efficiency of the modified nanometer zero-valent iron to heavy metals inthe heavy metal composite polluted soil is improved; and the method is simple to operate, high in repairing efficiency, low in repairing cost and free of secondary pollution to the environment.

Description

technical field [0001] The invention belongs to the field of remediation of heavy metal pollution in polluted environments, and relates to a method for improving the stabilization efficiency of nano-zero-valent iron in heavy-metal composite polluted soil, in particular to stabilizing heavy metals with nano-zero-valent iron modified by sodium carboxymethyl cellulose Methods for compounding contaminated soils. Background technique [0002] Human activities such as mining, metal smelting, farmland sewage irrigation, sludge agricultural use, and the application of fertilizers and pesticides have caused a large amount of soil heavy metal pollution, which seriously threatens ecological balance, food safety and human health. The "National Soil Pollution Survey Bulletin" shows that the overall state of the national soil environment is not optimistic, the soil pollution is serious in some areas, the soil environment quality of cultivated land is worrying, and the soil environment p...

AI Technical Summary

Problems solved by technology

Among them, nanoscale zero-valent iron (nano-scale zero-valent iron, nZVI) has a reduction and adsorption capacity that cannot be compared with ordinary millimeter-scale or micron-scale zero-valent iron, and can efficiently remove pollutants, such as chlorine-containing organic compounds and toxic metals. , Inorganic compounds are transformed into low-toxic or inert substances, which have been applied in the water environment, but there is still a lack of research and application in soil

[0004] Due to the electrostatic charge attraction, high surface energy, van der Waals attraction between particles, hydrogen bonds and other chemical bonds on the particle surface, nanoparticles are easy to form aggregates, and nano-zero-valent iron is easy to be oxidized. , these two defects restrict its dispersion and mobility in soil, and are the biggest obstacle to its repair ability

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