Method for remediating PAEs polluted soil by using microwave enhanced calcium peroxide

Abstract

The invention belongs to the technical field of organic polluted soil remediation and discloses a method for remediating phthalic acid esters (PAEs) polluted soil by using microwave enhanced calcium peroxide. The method comprises the steps of preparing a slurry soil mixed solution from the PAEs polluted soil according to a certain liquid-solid ratio; adding a certain quantity of citric acid, ferrous sulfate and calcium peroxide into the solution; and carrying out microwave treatment and standing to enable the degradation rate of PAEs in the soil to reach more than 80%. The method has the advantages of simple process condition, low operation requirement, high treatment efficiency, low oxidizing agent waste and the like and is suitable for remediating the PAEs polluted soil.

Description

technical field [0001] The invention belongs to the technical field of remediation engineering of organic polluted sites, and in particular relates to a method for remediating phthalate esters (PAEs) polluted soil by using microwaves to strengthen calcium peroxide. Background technique [0002] Phthalates (PAEs), also known as phthalates, are an important class of environmental hormone compounds. They often enter the food chain through the bioaccumulation of animals and plants, interfere with the normal level of hormones in the blood, and affect the growth of organisms. developmental behavior. Both Chinese and American environmental protection departments have included various PAEs in the blacklist of priority pollutants. PAEs are hydrophobic and lipophilic organic substances. PAEs entering the environment will be adsorbed on soil particles, and the soil becomes a storage and transfer station for PAEs in the environment. At present, there are serious PAEs pollution problem...

AI Technical Summary

Problems solved by technology

[0004] However, the following problems exist when using Fenton’s reagent to remediate PAEs-contaminated soil: the content of soil organic matter is usually higher than that of PAEs, and PAEs mainly exist in the form of adsorption in soil, and the main adsorption carrier is soil organic matter, so hydrogen peroxide is easy to combine with soil organic matter. Oxidation-reduction reaction occurs, and it is easy to decompose in the soil under the action of microorganisms, catalysis on the surface of soil particles, catalysis of transition metal ions in the soil, etc., to generate oxygen and water, so that hydrogen peroxide loses its oxidative properties

[0005] After years of research by the applicant, the present invention discloses a method of using microwaves to strengthen the desorption of soil PAEs, using calcium peroxide—a solid hydrogen peroxide slow-release agent to replace hydrogen peroxide, and increasing the desorption rate of soil PAEs through microwave treatment , adjust the decomposition rate of calcium peroxide by adjusting soil acidity and alkalinity, and realize the synergy between the two, so as to overcome the problem of low contact between Fenton's reagent and soil PAEs and affect the repair effect, and can be used for rapid recovery of PAEs-contaminated soil efficient repair