System and method for repairing organic contaminated soil through sludge microwave gasification residues in targeting mode

Abstract

The invention discloses a system and method for repairing organic contaminated soil through sludge microwave gasification residues in a targeting mode, and belongs to the technical field of contaminated soil repairing. The system comprises a first stirring and mixing device, a gasification reactor, a second stirring and mixing device, a desorption reactor and a screening device. Dewatered sludge is pyrolyzed and carbonized in the gasification reactor to form sludge carbon, through the characteristic of multi-pore adsorption and absorption of microwave assisted heating, the desorption of pollutants in the soil can be effectively promoted in the process of mixing the sludge with the organic contaminated soil, and organic matter in the soil is adsorbed; and in the subsequent microwave heating process of the desorption reactor, the organic matter adsorbed on the sludge carbon is volatilized in a gas form, and the residual sludge carbon returns to the first stirring and mixing device and the second stirring and mixing device to participate in sludge carbonization and organic matter adsorption. Sludge treatment and organic contaminated soil treatment are combined to achieve the purpose of treating waste with waste, the sludge carbon can be recycled after adsorption and desorption, and the cost is lowered.

Description

technical field [0001] The invention relates to the technical field of contaminated soil remediation, in particular to a system and method for targeted remediation of organic contaminated soil by microwave gasification residues of sludge. Background technique [0002] With the country's increasing requirements for industrial transformation and upgrading and environmental protection, a large number of organically polluted soils have appeared in industrial areas such as decommissioned or relocated pesticide factories and chemical factories. At present, soil organic pollution in my country has the following characteristics: 1. The pollution area has increased significantly, and soil pollution in some areas has been continuously distributed from local areas; 2. The types of pollutants have increased, and the characteristics of compound pollution have become increasingly prominent; 3. The content of pollutants has increased; There is a certain correlation between the degree of org...

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Problems solved by technology

[0005] Urban sewage sludge is a by-product of urban sewage treatment. Since the moisture content of the wet sludge produced by the sewage treatment plant is generally about 85%, it cannot directly enter the landfill. Other methods such as incineration and digestion are expensive and difficult to promote.

Sludge is rich in elements needed for soil fertilization such as nitrogen and phosphorus, but if it is directly used in agriculture without treatment, it will have a long digestion cycle and may cause secondary pollution.

Chinese patent application (Application No. 200910241334.7) discloses a method for remediating PAH-contaminated soil using excess activated sludge, using straw and sludge compost for soil remediation, but this method has a long reaction cycle

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