Method for restoring heavy metal contaminated soil by utilizing combination of microorganisms and EK-PRBs

Abstract

The invention discloses a method for restoring heavy metal contaminated soil by utilizing combination of microorganisms and EK-PRBs. According to the method, the heavy metal contaminated soil is repaired by using an electrokinetic (EK) repairing device, the electrokinetic repairing device is composed of a reactive tank, two electrodes, two permeable reactive barriers (PRB) and a direct-current power supply, the detachable permeable reactive barriers are arranged in front of the two electrodes respectively, the heavy metal composite contaminated soil, humus and a microbial reactive tank are arranged between the permeable reaction barriers, voltage is applied to the two electrodes, after electrification, cadmium in the soil is transferred to the cathode under the effect of the electric force and is adsorbed and fixed by the permeable reactive barrier before the cathode, chromium in the soil is transferred to the anode under the effect of the electric force and is adsorbed and fixed by the permeable reactive barrier before the anode, and the permeable reactive barriers for adsorbing and fixing heavy metal ions are removed so as to obtain the soil with pollution of the heavy metal ions removed. The method is simple to operate, low in cost and convenient to use, on-site repairing of the heavy metal contaminated soil can be realized, the repairing efficiency is high, and no new pollution is generated in the repairing process.

Description

technical field

[0001] The invention relates to a method for repairing heavy metal-contaminated soil by using microorganisms combined with Electrokinetic (EK)-permeable reactive barrier (Permeable Reactive Barrier, PRB), which belongs to the technical field of environmental protection.

[0002] technical background

[0003] In the process of urbanization and the improvement of urban living environment in my country, the industrially polluted soil left in urban areas due to the upgrading of industrial structure, adjustment of urban layout, and the relocation of enterprises such as polluting and disturbing residents has seriously threatened the surrounding environment and the health of residents. Especially in the industrial soil left over from heavily polluted industries in developed areas, the common compound heavy metal pollutants in the soil, such as cadmium, chromium, nickel, lead and other elements, will endanger the stability of the ecosystem, especially pose a serious th...