Application of soil washing and remediation technology in the treatment of typical coking contaminated sites
Coke production areas are often close to iron and steel metallurgical plants, and the area is also directly polluted by heavy metals caused by metallurgical waste slag, fly ash, etc. Coking by-products related to polycyclic aromatic hydrocarbons and heavy metals, such as soot, tar, fly ash and waste
Coke production areas are often close to iron and steel metallurgical plants, and the area is also directly polluted by heavy metals caused by metallurgical waste slag, fly ash, etc. Coking by-products related to polycyclic aromatic hydrocarbons and heavy metals, such as soot, tar, fly ash and waste residue, are deposited into the soil. PAHs and heavy metals may remain in the soil for a long time by interacting with soil particles, causing harm to ecosystems and human health.
Typical coking contaminated sites have obvious composite pollution characteristics of polycyclic aromatic hydrocarbons and heavy metals, and it is often difficult to complete the treatment with a single remediation technology. The combined use of multiple technologies to remediate soil from coking contaminated sites has been applied in practice, but there are few reports on the site pollution characteristics and engineering technical issues applicable to the combined technologies.
Polycyclic aromatic hydrocarbons and heavy metals at the coking site are mainly distributed in shallow soil, and composite pollution is common. However, the interaction of type 2 pollutants has little impact. It is suitable to use joint remediation technology with soil washing as the core, which can save the remediation cycle and cost. Engineering application advantages, secondary pollution prevention and control is a technical difficulty. In the future, combined soil washing + chemical oxidation + biological remediation technology can be developed to carry out green remediation.
Research has found that most heavy metals and organic pollutants are concentrated in fine soil particles. Soil washing technology uses this characteristic to classify and screen contaminated soil, and leaches soil of each particle size through clean water or chemicals, and finally the surface of coarse particles is contaminated. The substances are eluted and removed, and the fine soil particles form mud cakes for further processing. Soil washing technology can be used as an intermediate link in conjunction with thermal desorption, chemical oxidation, solidification/stabilization, electric remediation, microbial remediation and other technologies to further increase the removal effect of soil pollutants. Soil washing is suitable for rapid remediation of soil and sediment contaminated by high concentrations of heavy metals and organic matter. It has the advantages of wide application range, quick results, large processing capacity, and obvious reduction effect.
Desen Environment focuses on chemical remediation methods and uses soil washing technology to recently develop a Desen washing truck. It is my country's first mobile washing truck, filling a gap in the domestic and foreign markets and playing a landmark role in the soil remediation industry. This mobile soil washing equipment can also integrate biological, chemical, physical and other comprehensive remediation technologies, greatly improving the remediation efficiency and saving a lot of costs. It can be used for soil washing and restoration of organic/heavy metal contaminated sites such as chemical industry, medicine, metallurgy, steel, etc. It can also be used for various types of physical washing, washing, and classification of ditch mud, river silt, shield mud, mine restoration, etc. required project site.
