Stacked circulatable microbial electrochemical reactor and degradation method of petroleum hydrocarbon contaminated soil

Patent metadata

Field	Value
Publication number	US-12257615-B2
Application number	US-202117225974-A
Country	US
Kind code	B2
Filing date	Apr 8, 2021
Priority date	Jan 8, 2021
Publication date	Mar 25, 2025
Grant date	Mar 25, 2025

Abstract

A stacked circulatable microbial electrochemical reactor and a degradation method of petroleum hydrocarbon contaminated soil are provided, which belong to the field of microbial electrochemical soil remediation. The stacked circulatable microbial electrochemical reactor of the present disclosure expands influence range of anodes by a stacked microbial electrochemical system, accelerates the movement of the petroleum hydrocarbon molecules in the contaminated soil by a water circulation system, and improves the mass transfer capacity of soil, thereby increasing the degradation efficiency of petroleum hydrocarbon in the contaminated soil with microbial electrochemical technology from different aspects. The degradation method of petroleum hydrocarbon contaminated soil is provided. The degradation method of the present disclosure is simple in operation and has a high degradation efficiency of petroleum hydrocarbon in contaminated soil.

First claim

What is claimed is:

1. A stacked microbial electrochemical reactor, comprising:
a reactor body, comprising a reactor housing, and an inner bottom of the reactor housing being in a slope shape;
a water circulation system, located outside the reactor body;
an electrode group, being partially inserted into soil and located inside the reactor housing, and the electrode group being laid perpendicularly onto the inner bottom, the electrode group comprising a plurality of electrode couples inserted into the soil which are placed in parallel to each other, wherein a distance between adjacent electrode couples in the plurality of electrode couples is about 15 cm to about 25 cm; and
a DC power supply, connected with the electrode group via a wire;
wherein the plurality of electrode couples each comprise a working electrode and a counter electrode arranged in parallel to each other;
the working electrode comprises two sheets of steel mesh arranged in parallel to each other and a mixture of biochar particles and soil particles filled between the two sheets of steel mesh, a distance between the two sheets of steel mesh is about 4 cm to about 6 cm, wherein the soil particles are farmland soil particles;
the counter electrode is a conductive steel mesh;
a distance between the counter electrode and a steel mesh in the working electrode which is adjacent to the counter electrode is about 4 cm to about 6 cm in each of the plurality of electrode couples;
a water outlet is provided at a bottom of the reactor housing at a first side of the reactor housing;
the water circulation system comprises a water storing and regulating tank located at a top of the reactor housing, at a second side of the reactor housing, the second side of the reactor housing provided with the water storing and regulating tank is opposite to the first side of the reactor housing provided with the water outlet, wherein the water outlet is in communication with the water storing and regulating tank via a water circulating pipe located outside the reactor housing.

2. The stacked microbial electrochemical reactor of claim 1 , wherein a slope of the inner bottom of the reactor housing is about 30 degrees with respect to a horizontal plane.

3. The stacked microbial electrochemical reactor of claim 1 , wherein the two sheets of steel mesh and the conductive steel mesh each have an aperture of 10-20 meshes.

4. The stacked microbial electrochemical reactor of claim 1 , wherein the biochar particles and soil particles in the mixture of biochar particles and soil particles have mass ratio of 1:1-1:5.

5. The stackable microbial electrochemical reactor of claim 1 , wherein the water circulating pipe is provided with a water outlet switch and a speed-regulating water circulating pump.

6. The stacked microbial electrochemical reactor of claim 1 , wherein the water circulation system further comprises an external water pipe in communication with a water inlet of the water storing and regulating tank.

7. A degradation method of petroleum hydrocarbon contaminated soil using the stacked circulatable microbial electrochemical reactor of claim 5 , comprising:
filling the petroleum hydrocarbon contaminated soil to be degraded between the working electrode and the counter electrode of the stacked circulatable microbial electrochemical reactor;
closing the water outlet switch, wetting the petroleum hydrocarbon contaminated soil in the stacked circulatable microbial electrochemical reactor with water in the water storing and regulating tank, and turning on the wireless-internet-supplying-power collector to provide a voltage between the working electrode and the counter electrode after the petroleum hydrocarbon contamination soil is completely wetted;
opening water outlet switch when an electrical signal reaches a maximum current activating the speed-regulating water circulating pump such that water circulates through the water circulating pipe and the reactor housing for performing degradation.

8. The degradation method of claim 7 , wherein the voltage is about 0.7 V to about 0.8 V.

9. The degradation method of claim 7 , wherein the water circulating through the water circulating pipe has a flow rate of about 1 mL/min to about 10 mL/min during the degradation.

Assignees

• Univ Nankai

Inventors

• Zhou Qixing
• Li Tian
• Wang Xin

Classifications

• B09C1/10 Primary

  microbiologically, {biologically} or by using enzymes · CPC title

• B09C2101/00

  In situ · CPC title

• B09C1/085 Primary

  electrochemically, e.g. by electrokinetics · CPC title