Method for restoring heavy metal contaminated soil through cooperation of magnetic activated carbon and activating agent

Abstract

The invention discloses a method for restoring heavy metal contaminated soil through cooperation of magnetic activated carbon and an activating agent. The method includes the following steps that firstly, the activating agent is added to the heavy metal contaminated soil, and the soil is tilled evenly and activated for 20 d to 30 d; secondly, the magnetic activated carbon is added to the activated heavy metal contaminated soil, and the soil is tilled evenly and adsorbed for 20 d to 30 d; thirdly, the magnetic activated carbon is recycled in a magnetic separation manner; fourthly, the magnetic activated carbon recycled in the third step is soaked in 0.1 mol/L to 0.5 mol/L of acid liquid for 1 h to 2 h and washed through deionized water to be neutral so as to be recycled; fifthly, heavy metal ions in the acid liquid for washing the magnetic activated carbon in the fourth step are recycled; and sixthly, the first step to the fifth step are cycled till the content of heavy metal in the soil reaches the standard. After the method is adopted for cyclically restoring the soil at three times, the content of heavy metal in the heavy metal contaminated soil can reach the secondary standard, and the method is simple, efficient and short in period.

Description

technical field [0001] The invention relates to the field of contaminated soil treatment, in particular to a method for repairing heavy metal-contaminated soil with magnetic activated carbon and an activator. Background technique [0002] my country's existing heavy metal polluted cultivated land is about 300 million mu, most of which have not been properly treated, and with the rapid development of industry and agriculture, the discharge of waste generated by mining, smelting, electroplating, chemical and other industries, as well as irrigation, pesticides and fertilizers The irrational use of metals is also exacerbating the pollution of heavy metals in the soil. [0003] In the prior art, there are mainly two ways to control soil heavy metal pollution. One is to change the existing state of heavy metals in the soil and reduce their mobility and bioavailability in the environment, including deep tillage, soil dumping and amendments. Among them, the deep tillage method will ...

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Problems solved by technology

[0002] my country's existing heavy metal polluted cultivated land is about 300 million mu, most of which have not been properly treated, and with the rapid development of industry and agriculture, the discharge of waste generated by mining, smelting, electroplating, chemical and other industries, as well as irrigation, pesticides and fertilizers The irrational use of metals is also exacerbating the pollution of heavy metals in the soil

[0003] In the prior art, there are mainly two ways to control soil heavy metal pollution. One is to change the existing state of heavy metals in the soil and reduce their mobility and bioavailability in the environment, including deep tillage, soil dumping and amendments. Among them, the deep tillage method will lead to the diffusion of pollutants in the surface soil, and the heavy metals may be activated in the deep soil; although the soil discharge method will greatly reduce the content of heavy metals, it will also cause the loss of fertile soil on the surface and excavation. The resulting soil is difficult to post-process and other

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