Repairing method and device for mercury-polluted soil by using low-temperature pyrolysis treatment

Abstract

The invention discloses a repairing method and device for mercury-polluted soil by using low-temperature pyrolysis treatment. The repairing method for the mercury-polluted soil comprises the following steps: crashing excavated mercury-polluted soil and drying the excavated mercury-polluted soil with air, wherein the soil moisture content is less than or equal to 10%; and secondly, putting the soil dried with the air into a pyrolysis device, wherein the original temperature of the pyrolysis device is 250 DEG C, heating within 30 minutes to be at a temperature within 400 DEG C, and condensing and recycling mercury steam evaporated in the soil through a gas recycling device. The invention provides the method and the device for properly repairing and recycling mercury. The method for repairing the mercury-polluted soil by using a low-temperature pyrolysis treatment repairing technology and separating pollutants from the soil by using a physical heating method is adopted, so that not only can the soil cultivation capability be kept, but also can realize the purpose of absolutely removing the mercury from the polluted soil. Clean soil and organic matters can be properly added in the treated soil, so that the agriculture production can be rapidly repaired, and the operation cost is low.

Description

technical field [0001] The invention relates to the technical field of environmental protection, in particular to a low-temperature pyrolysis treatment repair method and device for mercury-contaminated soil. Background technique [0002] Mercury and its compounds have strong neurotoxicity and teratogenic effects, and the accumulation effect and genotoxicity are obvious. They have always been the priority pollutants of great concern at home and abroad. The cultivated land area polluted by Hg in my country is 3.2×10 4 hectares, the annual production of "mercury rice" reaches 1.9×10 8 kg. From the 1950s to the mid-1980s, Guizhou Province was once an important mercury-producing area in China and even in the world, accounting for about 70% of the country's mercury production. An important base for the production of mercury products. The long-term mercury mining and smelting production in my country has seriously affected the surrounding ecological environment, especially the ...

AI Technical Summary

Problems solved by technology

Contaminated soil remediation can also be divided into in-situ remediation and ex-situ remediation. The former does not need to excavate and transport soil, which can save treatment costs, but it usually requires a longer implementation period, and due to differences in soil and aquifer The consistency of the treatment cannot be guaranteed; the restoration cycle required by the latter is relatively short, and the consistency of the treatment can be better controlled by means of homogenization, sieving, continuous stirring, etc., but it needs to excavate the soil, and the required Higher cost and need to increase engineering facilities

[0005] At present, there is no mature technical method for the treatment and remediation of mercury-contaminated soil at home and abroad.

Images