Stabilization repairing agent for soil pollution and preparation and application

Abstract

The invention provides a stabilization repairing agent for soil pollution, wherein the agent includes components such as quicklime, potassium dihydrogen phosphate, phosphate rock powder and demineralized and modified humic acid, and is prepared from, by mass, combination of the components. After the stabilization repairing agent is applied to soil contaminated by lead and cadmium and is subjectedto stabilized treatment and maintenance for one week, the concentration of lead and cadmium in a leach liquor of the soil can meet standards of groundwater quality class IV. The mixed component in thestabilization repairing agent of the invention fully exerts a synergistic effect, the effective state of heavy metals in the soil can be reduced by the action of precipitation, adsorption, improvement, pH adjustment, and the like, and the prepared soil repairing agent has good effects in repairing lead and cadmium contaminated soil. The stabilization repairing agent for the soil pollution has theadvantages of simple preparation method, feasibility and good treatment effect.

Description

technical field [0001] The invention belongs to the technical field of stable restoration of polluted soil, and in particular relates to a stable restoration agent for soil pollution and its preparation and application. Background technique [0002] With the rapid development of modern industry and agriculture, the situation of heavy metal pollution in soil is becoming more and more severe. my country's heavy metal pollution incidents are entering a period of high incidence. Among many polluted sites, heavy metal pollution is a prominent problem. In 2014, the National Soil Pollution Survey Bulletin released by the Ministry of Environmental Protection and the Ministry of Land and Resources showed that the point-exceeding rates of cadmium, mercury, arsenic, copper, lead, chromium, zinc, and nickel were 7.0%, 1.6%, 2.7%, 2.1%, 1.5%, 1.1%, 0.9%, 4.8%. Among them, the rate of excessive farmland soil points in my country is 19.4%, and heavy metal pollution such as Cd, Ni, and Cu is...

AI Technical Summary

Problems solved by technology

The following problems exist in the existing restoration agents: 1) The agent itself pollutes the environment

For example, the background value of some heavy metals in general mineral materials is high. Although it can effectively repair the characteristic target pollutants, it often introduces new pollutants or promotes the release of other heavy metals in the soil, resulting in secondary pollution; sulfur-based substances are generally It has a pungent smell or is corrosive, which is a great hazard to the health of the on-site personnel.

2) Compound pollution of various heavy metals is common, and the compatibility of existing stabilized restoration materials on the market is poor

For example: phosphate materials have a good effect on repairing lead-contaminated soil, but the introduction of phosphate often promotes the release of arsenic in the soil, and even causes the arsenic in the treated soil leachate to exceed the standard, causing secondary pollution

3) It cannot meet the requirements of two or more heavy metals at the same time. For example, alkaline materials have a good remediation effect on cadmium-contaminated soil, but it will cause an increase in soil pH, and the remediation effect on lead-cadmium compound polluted soil is poor, often The lead in the soil leachate after remediation is not up to the standard; the introduction of single ferrous sulfate often reduces the pH of the soil

4) Reagents with good treatment effect are often imported pharmaceutical materials, which are expensive and economical

However, the polyacrylamide used in it is easy to degrade in the soil, and its heavy metal passivation and stabilization effect will be seriously weakened after degradation.

Moreover, compared with other components, the price of polyacrylamide is relatively expensive, which is 3-5 times that of other materials

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