Contaminated soil remediation method

Abstract

The invention provides a contaminated soil remediation method, comprising the steps of 1, mixing contaminated soil with quick lime, granulating the contaminated soil, and removing impurities from themixture of the contaminated soil and quick lime through a drum screening machine; 2, preheating the contaminated soil treated in the step 1, through flue gas generated by the combustion of a fuel of athermal desorption device, and secondarily heating the contaminated soil in the thermal desorption device; 3, spraying cooling water to mixed steam generated by secondary heating of the step 2, demisting, adsorbing with activated carbon, and discharging to aerial air; discharging directly, the soil heated in the step 2; 4, spraying mist to the soil discharged in the step 3, humidifying, and removing duct; 5, transporting the soil, treated in the step 4, to a specified zone. The contaminated soil is preheated with the flue gas, generated by the combustion of the fuel of the thermal desorptiondevice; waste heat of the high-temperature flue gas can be made full use; energy is fully utilized.

Description

technical field [0001] The invention relates to the remediation of chemical plant sites, in particular to a method for remediating polluted soil. Background technique [0002] The current treatment of heavy metal pollution has become an urgent global environmental problem. Among them, water pollution mainly refers to the pollution of water bodies (including rivers, lakes, reservoirs, oceans, industrial water, discharge water and domestic drinking water, etc.) by heavy metal pollutants, including cadmium, lead, mercury, chromium, arsenic, etc. It is mainly industrial wastewater, such as wastewater discharged from mineral processing plants, electroplating plants, and steel plants. [0003] In addition to the heavy metals contained in the soil itself, the rest are due to the pollution of heavy metals into the soil. Soil heavy metal pollution mainly comes from various aspects: the deposition of heavy metals in the atmosphere, for example, waste gas from industrial production, ...

AI Technical Summary

Problems solved by technology

Soil heavy metal pollution mainly comes from various aspects: the deposition of heavy metals in the atmosphere, for example, waste gas from industrial production, lead-containing automobile exhaust, etc. enter the soil through natural deposition and rain deposition; the use of sewage containing heavy metals for irrigation, resulting in soil heavy Cd, The content of As, Cu, etc. increases; in addition, the plastic film used in daily life and chemical fertilizers and pesticides used in agriculture also lead to soil pollution

[0004] The chemical methods used in chemical plants will have a destructive effect on soil properties. Nitrogen, phosphorus, and organic matter in the soil will be lost through leaching and other steps, making it difficult to be used as normal soil backfill. If it is used in a large area, it will inevitably cause water and soil erosion.

[0005] In recent years, phytoremediation technology has become one of the research hotspots in the remediation of heavy metal pollution. Compared with other remediation technologies, it has the characteristics of low cost, easy operation and management, and no secondary pollution. However, most of the heavy metals found so far are enriched Plants have weak reproductive ability, slow growth, and small aboveground biomass, which are limited in practical application; in addition, most of the heavy metals in the soil are combined with solid phases and are difficult to be absorbed and utilized by restoration plants, resulting in low restoration efficiency and restoration. Long time, not suitable for long-term development and use

Images