A method for removing polycyclic aromatic hydrocarbons in soil by using persulfate-calcium peroxide compound oxidation

Abstract

The invention discloses a method for removing polycyclic aromatic hydrocarbons in soil by using persulfate-calcium peroxide through compound oxidation, and belongs to the field of soil repairing. The method comprises the following steps: after sieving to-be-measured air-dried soil, mixing the soil with calcium peroxide evenly; then adding distilled water to obtain slurry; successively adding oxalate ions, ferrous ions and peroxydisulfate ions, and stirring uniformly to obtain slurry reaction liquid; then leaving the slurry reaction liquid standstill in a dark place so that the polycyclic aromatic hydrocarbons in the soil can be removed after reaction is finished. By the method, naphthalene, acenaphthylene, acenaphthene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, a component as shown in the specification, benzo[b] fluoranthene, benzo[a]pyrene, dibenzo[a,b]anthracene, benzo[ghi] perylene and indeno[1,2,3-cd] pyrene in a complicated environment of the soil can be removed effectively, the removal rate of the polycyclic aromatic hydrocarbons is high, neutral pH of the soil can be maintained, acidized soil is improved, and a catalyst and a chelating agent are adopted, so that the removal effect and the removal efficiency are enhanced.

Description

technical field [0001] The invention relates to the technical field of soil remediation, and specifically relates to a method for removing polycyclic aromatic hydrocarbons in soil by using persulfate-calcium peroxide composite oxidation. Background technique [0002] Soil is an important component of the ecosystem and the basis for human survival. However, with the development of modern industry and agriculture, and people's lack of awareness of environmental protection, a large amount of waste gas and waste water are improperly discharged into the soil system, directly or indirectly causing soil pollution, endangering the environment and human health. Polycyclic aromatic hydrocarbons (PAHs) are a common high-risk organic pollutant in soil pollution. There are hundreds of known PAHs, among which 16 PAHs have attracted the most attention due to the "three causes" of carcinogenicity, teratogenicity and mutagenicity. [0003] At present, the common methods of oxidation, remov...

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Problems solved by technology

[0003] At present, the common methods of oxidation, removal and restoration of soil organic pollutants are mostly Fenton or Fenton-like oxidation. Because Fenton oxidation often needs to maintain a low pH of the soil to ensure the progress of the reaction, the physical and chemical properties of the soil are seriously damaged, and Hydrogen peroxide is usually used as an oxidant, but due to its characteristics of rapid decomposition, instability, and large amount of heat release, the utilization rate is low, and it is not easy to control during repair, and a large number of problems need to be solved for large-scale use

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