Method for remedying contaminated site through combination of nanoscale zero-valent iron and reducing microorganisms

Abstract

The invention relates to a contaminated site remediation method, in particular to utilization of nanoscale zero-valent iron particles and orthotopic injection of microbial bacteria in a site, namely, a contaminated site remediation technology adopting nanoscale zero-valent iron and a microorganism remediation technology. The method for remedying the contaminated site through combination of the nanoscale zero-valent iron and reducing microorganisms comprises steps as follows: a nanoscale zero-valent iron injection is injected to contaminated soil through an injection well, and the nanoscale zero-valent iron in the injection is coated with an organic polymer coating layer. The method is characterized in that after the nanoscale zero-valent iron injection coated with the organic polymer coating layer is injected and the nanoscale zero-valent iron in the injection is completely oxidized, a reducing bacterium solution is injected into the contaminated soil for microorganism remediation. The organic polymer layer on the surface of the nanoscale zero-valent iron can stop agglomeration of the nanoscale zero-valent iron, can promote growth of indigenous microorganisms and accelerates pollutant degradation. According to the remediation method, the synergistic effect for the nanoscale zero-valent iron remediation technology and the microorganism remediation technology for the contaminated site remediation is realized.

Description

technical field [0001] The invention relates to a method for remediating a polluted site, in particular to the use of nanometer zero-valent iron particles and in-situ injection of microbial fungi, that is, nanometer zero-valent iron contaminated site remediation technology and microbial remediation technology. Background technique [0002] Due to the extremely small particle size and the resulting large specific surface area of ​​nano-zero-valent iron, it exhibits a high oxidation-reduction potential, which can reduce a variety of halogenated organic pollutants, high-priced heavy metal ions, and inorganic pollutants (such as Nitric acid / nitrite), etc., and nano-zero-valent iron can be injected into the underground of the polluted site to achieve the purpose of in-situ rapid repair of the polluted site. However, the nano-zero-valent iron particles are oxidized while reducing pollutant molecules, forming a layer of iron oxide layer on the surface of the nano-zero-valent iron p...

AI Technical Summary

Problems solved by technology

However, the nano-zero-valent iron particles are oxidized while reducing pollutant molecules, forming a layer of iron oxide layer on the surface of the nano-zero-valent iron particles, and as the reaction progresses, the thickness of the oxide layer increases, which will hinder pollution. Matter and the effective Fe in the core of nano-zero-valent iron particles 0 The mass transfer of nanometer zero-valent iron particles, which limits the reaction, especially when the concentration of pollutants becomes low in the later stage of remediation, due to the mass transfer hindrance caused by the oxide layer on the surface of nano-zero-valent iron particles, the remediation of pollutants by nano-zero-valent iron Significantly less effective

At the same time, when nano-zero-valent iron is used to remediate polluted sites, it is prone to incomplete reduction of pollutants by nano-zero-valent iron and the occurrence of intermediate pollutants

The effect of microbial remediation technology on low-concentration pollutants is better, but when high-concentration nano-zero-valent iron is mixed with microorganisms, nano-zero-valent iron shows a certain degree of toxicity to microorganisms and inhibits the growth of microorganisms