System for repairing heavy metal contaminated soil and processing method

Abstract

The invention discloses a system for repairing heavy metal contaminated soil and a processing method. The system comprises a progressive electric repair system and a vacuum drainage system, wherein the progressive electric repair system comprises a plurality of lines of electrodes which are laid in to-be-processed soil according to a certain sequence and a direct current power supply which is respectively connected with the electrodes of each layer or each row by virtue of conducting wires; the vacuum drainage system comprises a water pumping pipe which extends to a cathode, a vacuum pump which communicates with the water pumping pipe and a pool which communicates with the outlet end of the vacuum pump; during operation, the electrodes are adjusted to be connected with an anode or the cathode of the direct current power supply according to a preset order, so that the direction of current is the same direction all the time, heavy metal ions are driven to move to the predetermined direction, an enriching area is formed in the preset cathode, and the heavy metal contaminated soil is repaired by injecting a chemical solution, circularly electrifying for many times and solidifying and stabilizing the enriching area. According to the system, secondary pollution caused by the heavy metal contaminated soil to the environment is avoided, the heavy metal removal rate is increased, the repair cost of the contaminated soil is reduced, and the system has the advantages of simple construction process, high operability and convenience in quality control.

Description

technical field [0001] The invention belongs to the field of environmental protection, in particular to the technology for in-situ restoration of heavy metal polluted soil in the field of environmental protection. Background technique [0002] With the intensification of industrial and urban pollution and the increase in the types and quantities of agricultural chemicals, China's soil pollution situation is quite serious, and the area of ​​land with heavy metals such as arsenic, mercury, lead, and cadmium exceeding the standard is constantly increasing. It leads to the continuous decline of food quality and output, as well as other secondary ecological environmental problems such as surface water and groundwater pollution, air pollution and ecosystem degradation, which directly endanger human health and affect the sustainable development of human beings. [0003] The electric restoration technology can avoid the traditional technology from seriously affecting the soil struct...

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Problems solved by technology

[0003] The electric restoration technology can avoid the traditional technology from seriously affecting the soil layer structure and the ecological environment of the groundwater, and can overcome the shortcomings of the on-site bioremediation process being very slow and low in efficiency, and has less investment and low cost

[0004] However, the existing electrokinetic repair technology has the following problems: (1) Even in the case of high water content in the soil, as the water near the anode continues to flow to the cathode, the interface resistance at the anode continues to increase, resulting in a long time for electromigration Very short, the shorter the electric repair time, the worse the repair effect

(2) With pure electrokinetic restoration technology, heavy metals enriched in the cathode cannot be effectively removed or harmlessly treated, which severely limits the development and application of electrokinetic restoration technology in heavy metal-contaminated soils

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