Chromium-contaminated soil humic acid green in-situ remediation technique

An in-situ remediation technology for chromium-contaminated soil, applied in the field of green in-situ remediation technology of humic acid in chromium-contaminated soil, can solve the problems of shortening the reduction reaction and aging time, reducing the ratio of agent to soil, etc.

Pending Publication Date: 2017-06-20
CHINA UNIV OF PETROLEUM (EAST CHINA)
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0014] The purpose of the present invention is to overcome the shortcomings of the existing chromium-contaminated soil remediation technology and to invent a humic acid green in-situ remediation process for chromium-contaminated soil, which can reduce the ratio of agent to soil by adding humic acid substances in the crushing process and realize Mix evenly and intensify in-situ reduction to avoid the hidden danger of sudden leachate pollution; and use a strong reducing agent to ensure that the treated soil meets the standards, shorten the reduction reaction and aging time, and eliminate the hidden danger of sudden leachate pollution; it can also be granulated by liquid humic acid Granulating, wrapping and blocking the exudation and migration of hexavalent chromium in the particles, realizing permanent reduction and fixation, restoring the function of soil planting, and realizing safe, low-cost, permanent and sustainable green in-situ restoration

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Example 1, the first step, when chromium-contaminated soil is added to the cone crusher, add 50% sodium humate solution for pre-reduction according to the chromium ratio of 10:1, and strengthen the mixing with sodium humate while the chromium-contaminated soil is crushed ; Due to the full contact of hexavalent chromium and sodium humate on the fresh interface produced by crushing, the in-situ reduction reaction is strengthened, the utilization rate of humic acid substances and the reduction rate (>96%) of hexavalent chromium are improved, dust is eliminated, and the dosage is reduced. Soil ratio, reducing the stacking amount and aging time of chromium-contaminated crushed soil; in the second step, after aging the pre-reduced chromium-contaminated soil less than 3mm for more than 1 hour, according to the detected hexavalent chromium content, according to the dose-chromium ratio 20:1 spray 10% sodium thiosulfate solution, mix evenly and force reduction, shorten the reducti...

Embodiment 2

[0027] Example 2, the first step, while adding chromium-contaminated soil to the cone crusher, add biomass pyrolysis oil for pre-reduction according to the ratio of 10:1 to chromium, and strengthen the mixing with biomass pyrolysis oil while crushing chromium-contaminated soil ; Due to the full contact of hexavalent chromium on the fresh interface produced by crushing with biomass pyrolysis oil, the in-situ reduction reaction is strengthened, the utilization rate of biomass pyrolysis oil and the reduction rate of hexavalent chromium (>96%) are improved, and dust is eliminated , reducing the ratio of agent to soil and remediation cost, and reducing the stacking amount and aging time of chromium-contaminated crushed soil; in the second step, after aging the pre-reduced chromium-contaminated soil less than 3mm for more than 1 hour, according to the detected hexavalent Chromium content, spray 8% sodium dithionite solution according to the chromium ratio of 10:1, mix evenly and forc...

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PUM

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Abstract

A chromium-contaminated soil humic acid green in-situ remediation technique comprises the steps that firstly, when chromium-contaminated soil is crushed, humic acid matter with the agent-chromium ratio being 5-20:1 is added for in-situ reduction; secondly, after the chromium-contaminated soil with the particle size smaller than 3 mm is aged for 1 hour or longer, a strong reductant solution with the agent-chromium ratio being 10-30:1 is sprayed into the soil according to the detected hexavalent chromium content, and uniform mixing and forced reduction are conducted; and thirdly, after reduction, liquid humic acid with the agent-soil ratio being 1-5:100 is sprayed into the chromium-contaminated soil for granulation pelleting, particles are wrapped, seepage and migration of the hexavalent chromium in the particles are prevented, permanent reduction and fixation are achieved, and the planting function of the soil is restored.

Description

[0001] 1. Technical field [0002] The humic acid green in-situ restoration process for chromium-contaminated soil provided by the invention relates to the purification and treatment of polluted soil, in particular to the restoration of chromium-contaminated soil. [0003] 2. Background technology [0004] Soil pollution will pose a serious threat to the ecological environment, food safety and human health. In recent years, soil pollution caused by heavy metal pollutants has been particularly prominent, and soil contaminated by chromium is the most important. [0005] There are nearly 70 major chromium slag-contaminated sites in China, together with a large number of electroplating and leather enterprises, which have caused serious soil chromium pollution, threatening or endangering groundwater and drinking water sources. In addition, municipal solid waste (sludge, fly ash, garbage) and phosphate fertilizers contain chromium. Due to the agricultural reuse of these solid wastes ...

Claims

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Application Information

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IPC IPC(8): B09C1/08
CPCB09C1/08B09C2101/00
Inventor 田原宇乔英云谢克昌田斌
Owner CHINA UNIV OF PETROLEUM (EAST CHINA)
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