Apparatus and method for remediating trichloroethylene-polluting soils by integrated rotated migration and PRB

A device for remediating soil, comprising:

• a device of electrokinetic remediation and Permeable Reactive Barriers (PRBs), wherein the device of electrokinetic remediation comprises:
• at least two pairs of electrodes including a cathode part and an anode part for each pair, wherein the cathode parts and anode parts are arranged alternately with adjacent parts having different polarities, and forming a radially distributed pattern with an intersection angle between the adjacent parts in a range of 60°-90°, configured to generate a voltage gradient of 1.5-4.5 V/cm, wherein the trichloroethylene is absorbed by the PRBs distributed in a middle of the intersection angle coaxial with the radially distributed pattern, in a course of rotating migration along the radially distributed pattern, wherein the cathode parts and anode parts are plate electrodes disposed perpendicular to a horizontal plane of the trichloroethylene-polluted soil with an axis of the radially distributed pattern placed at a most polluted region,
• a stabilized voltage supply, in which electrodes connect with the supply by parallel connection,
• electrode chambers including an anode chamber and a cathode chamber accommodating the anode parts and cathode parts, respectively, wherein pH of the anode chamber and the cathode chamber are kept at approximately 11 and 3.5, respectively,
• an electrolytic bath with an anolyte tank for storing alkaline electrolyte and a catholyte tank for storing acidic electrolyte, in which the anolyte tank and the catholyte tank connect with the anode chamber and the cathode chamber respectively by a first peristaltic multi-channel pump to carry the alkaline electrolyte and the acidic electrolyte to the anode chamber and the cathode chamber through channels,
• a first control system, connected with various electrode chambers via the first peristaltic multi-channel pump to control delivery of the alkaline electrolyte from the anolyte tank to the anode chamber and the acidic electrolyte from the catholyte tank to the cathode chamber, wherein the first control system is further configured to monitor electrolyte saturation of each electrode chamber,
• an electrolyte treatment tank, connecting with various electrode chambers via a second peristaltic multi-channel pump to receive discharged electrolytes,
• a second control system, connected with various electrode chambers via the second peristaltic multi-channel pump to control discharge of electrolytes from various electrode chambers to the electrolyte treatment tank upon the electrolyte saturation as monitored by the first control system;
• and
• a device of injection configured to inject surface active agents comprising a 0.025 g/L rhamnolipid solution at an injection rate of 1.5-2.5 ml/min, including:
• a liquid injection pipe, installed in soil between various electrodes and PRBs for injecting surface active agents into polluted soil,
• a reservoir of surface active agents, connecting with the liquid injection pipe for storing surface active agents, and
• a third control system, connecting the liquid injection pipe and the reservoir of surface active agents to control injection of surface active agents.