Device and method for remediating organically polluted soil with resistance heating coupling oxidant

Abstract

The invention discloses a high-efficiency and energy-saving resistance heating coupled electric transport oxidant delivery device and method for repairing organic polluted soil, comprising a heating unit, an extraction unit, a monitoring unit and a ground treatment unit. Simply using resistance heating requires a long heating time, and simply using chemical oxidation cannot effectively transport the oxidant to the polluted area. Resistance heating can activate oxidants, increase the vapor pressure and solubility of pollutants, and promote their volatilization and dissolution, thereby improving oxidation efficiency and enhancing the contact ability with pollutants, shortening the repair period and reducing repair costs. At the same time, the oxidant can improve the efficiency of resistance heating repair, and the electric transport of oxidant can transport the oxidant to the target contaminated area to enhance precise repair, reduce the energy consumption required for resistance heating, and have strong process compatibility with resistance heating equipment. The invention can be installed according to the specific conditions of local polluted areas, has low investment cost, is suitable for repairing soil polluted by organic non-heavy metals, and has great popularization value.

Description

technical field [0001] The invention relates to the field of contaminated soil remediation devices, in particular to a device and method for remediating organically polluted soil with resistance heating coupled with an oxidant. Background technique [0002] The resistance heating technology forms a closed loop by inserting electrodes into the soil and then discharges the soil. Using the electrical conductivity of the soil, electrical energy can be converted into heat energy. As the temperature rises, volatile and semi-volatile pollutants are desorbed. , volatilization, azeotropy and other reactions escape from the soil and are collected by the extraction system. Although resistance heating has the advantages of relatively uniform heating and strong adaptability to geological environments, it requires a long heating time and long-term input of high-power power supply. Leading to high operating costs; the chemical oxidation method uses the oxidation and reduction characteristi...

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Problems solved by technology

[0002] The resistance heating technology forms a closed loop by inserting electrodes into the soil and then discharges the soil. Using the electrical conductivity of the soil, electrical energy can be converted into heat energy. As the temperature rises, volatile and semi-volatile pollutants are desorbed. , volatilization, azeotropy and other reactions escape from the soil and are collected by the extraction system. Although resistance heating has the advantages of relatively uniform heating and strong adaptability to geological environments, it requires a long heating time and long-term input of high-power power supply. Leading to high operating costs; the chemical oxidation method uses the oxidation and reduction characteristics of the chemical substance itself to undergo redox reactions with the pollutants in the soil, thereby removing the pollutants in the soil. This method has the characteristics of low cost and quick results , can degrade some pollutants that are difficult to volatilize and dissolve in water, and increase the bioavailability of soil. However, when chemical oxidation is used to repair polluted soil, it is easy to cause chemical reagent residues and change the physical and chemical properties of the soil itself. It is very likely to cause secondary pollution of the soil, and the oxidant transport mechanism and soil pollutant contact promotion mechanism in the in-situ oxidation technology are not clear, and the oxidant cannot be effectively transported, which significantly limits its repair effect

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