Process for reducing heavy metals with reinforcement nanometer iron based on circulating flow field during soil remediation

Abstract

The invention relates to a process for reducing heavy metals with reinforcement nanometer iron based on a circulating flow field during soil remediation, belonging to the technical field of soil remediation. The process comprises the following steps: (1) dissolving CMC into distilled water, vibrating and heating in an oxygen insulation container at constant temperature, introducing nitrogen to the CMC solution, mixing by adding an FeSO4.7H2O solution into the CMC solution, uniformly, dropwise adding NaBH4 solution, and vibrating at constant temperature with uniform speed to prepare a stable nanometer zero-valent iron suspension; (2) drilling a feeding well in a soil region; (3) injecting the stable nanometer zero-valent iron suspension into an inlet pipe by using a circulating pump, temporarily stopping injection till the suspension enters an injection well and an extraction well, extracting from the extraction well, injecting into the injection well and stopping injection till 24 hours; (4) extracting a reduction liquid from the extraction well and injecting into the injecting well, carrying out constant temperature treatment on the reduction liquid with a heating rod and a temperature control instrument, and adjusting the pH value of the reduction liquid by adding an acid-alkali buffer solution. The process disclosed by the invention has the advantages of promoting nanometer zero-valent iron to reduce heavy metals in soil, eliminating the toxicity of heavy metal ions and the like.

Description

technical field [0001] The invention belongs to the technical field of soil remediation in the field of environmental pollution control, and specifically relates to a process for remediating heavy metals in soil by strengthening nano-iron with a circulating flow field Background technique [0002] Soil heavy metal pollution is one of the core issues in the field of environmental protection in my country. Soil heavy metal pollution control is difficult, concealed and lagging. The research on soil pollution and its remediation technology has strong practical significance and long-term value. Although there have been many soil remediation techniques in recent years, including physical treatment methods (physical separation method, guest soil or deep plowing method, solidification method and solidification landfill method, steam extraction method, thermal desorption method); chemical treatment method ( chemical improvement method, oxidation method, reduction method, chemical l...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the shortcomings of using sodium carboxymethyl cellulose to realize the stabilization of nano-iron, such as large dosage, poor fluidity, and great influence by the acidity and alkalinity of the solution, and to provide a method that can promote the stabilization of nano-zero-valent iron. Heavy metals in the soil are reduced and the toxicity of heavy metal ions is eliminated by circulating flow field enhanced nano-iron remediation of heavy metals in soil