CN211125848U

CN211125848U - Sedimentary microbial fuel cell for sludge treatment

Info

Publication number: CN211125848U
Application number: CN201920711317.4U
Authority: CN
Inventors: 吴卿; 付利娟; 彭森; 肖京京; 刘天赐
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2019-05-17
Filing date: 2019-05-17
Publication date: 2020-07-28
Anticipated expiration: 2029-05-17

Abstract

The utility model discloses a sedimentation type microbial fuel cell for oil sludge treatment, wherein oil sludge (waste drilling mud) is arranged in a shell, a cathode is arranged above the oil sludge, the upper surface of the cathode is contacted with air, and the lower surface of the cathode is contacted with the oil sludge; the anode is made of foam nickel material, is arranged in the oil sludge at the lower part of the oil sludge and is positioned 20cm below the cathode; a proton exchange membrane is arranged between the cathode and the anode; the cathode and the anode are connected with a resistor or electric equipment through leads. Compared with the prior art, the utility model, need not the input of medicament or electric energy, simple structure builds with the running cost low, and easy management maintains, is an economic and effective new technology of petroleum hydrocarbon and recovery electric energy in the degradation mud.

Description

Sedimentary microbial fuel cell for sludge treatment

Technical Field

The utility model relates to an industrial waste handles technology, and in particular to a sedimentation type microbial fuel cell who is used for fatlute (abandonment drilling mud) to handle.

Background

The principle of microbial fuel cells is based on the conversion of biodegradable organic substances into electrical energy by bacteria. At the anode, the microorganisms convert the organic matter into electrons and protons. The protons migrate through the proton exchange membrane to the cathode surface, while the electrons are transferred from the outside through the electrical circuit to the cathode where the oxygen gets electrons to combine with the protons, forming water. The technology has the advantages of mild operating conditions, safety, high efficiency, greenness, low cost, simple structure and easy management.

Many factors affect the performance of Microbial Fuel Cells (MFCs), such as Microbial metabolic breakdown of substrates, Microbial-anode electron transfer, cathode electron transfer to electron acceptors, proton hydrogen transfer to the cathode region, etc. Wherein the anode electrode material has a great influence on the electricity generation performance of the MFC. An excellent material should have the following properties: (1) the conductivity is good, the resistivity is low; (2) the chemical property is stable and the corrosion resistance is strong; (3) the biocompatibility is good; (4) the specific surface area is large; and (5) proper mechanical strength and toughness. The foamed nickel has the characteristics of uniform structure, light weight, high strength, good corrosion resistance, high conductivity and the like. The nickel foam as the anode material has great advantages of providing a large specific surface area for microorganisms, promoting the transfer rate of electrons, outputting high power density under proper conditions, having good corrosion resistance in alkaline and neutral media, and being a potential electrode material applied to MFC anode design.

In the production activities of various large oil fields in China, a lot of waste drilling mud is generated at every moment during the drilling operation. Research shows that the waste drilling mud is strong in alkalinity and corrosive. It is a complex multiphase system containing mineral oil, phenolic compounds and heavy metals, and the leachate has high toxicity. The direct discharge of the drilling waste mud can affect the nutritional environmental conditions and the quality of the crop growth, and the long-term accumulation can cause serious damage to surface vegetation, pollute soil and water sources and endanger the survival of human beings. Therefore, in addition to the need for safety engineering, the treatment of waste mud from oil field drilling also requires better methods and processes for the subsequent treatment of waste mud.

The main treatment technical method for the drilling waste mud comprises the following steps: incineration, solidification/stabilization, oxidation, biological methods, and the like. Incineration, curing/stabilization and oxidation processes may result in reduced harmful components therein, thereby having a reduced impact on the environment and human health. However, the three technologies are difficult to balance between treatment effect and cost, and the biological method has the characteristics of energy conservation, low operation cost, lasting effect and the like, and has wide application prospect. Bioremediation methods generally include land farming, composting, biological slurry reactor methods, and biological flotation methods. (1) The land cultivation method has the advantages of low cost, simple operation, high success potential, low energy consumption and large treatment capacity. However, the method of plowing requires a large area of land and is time consuming, especially for those refractory and polymeric PHCs compounds. In addition, the temperature has a significant effect on the treatment efficiency of the field cultivation method, and in cold regions, the treatment of waste drilling mud and oily sludge by the field cultivation method is difficult to achieve. Meanwhile, the field cultivation method also causes environmental problems such as pollution of VOCs and pollution of groundwater. (2) Compared with the field cultivation method, the composting method can remove PHCs in the waste more effectively and can treat more toxic compounds, but the treatment capacity of the composting method is much smaller than that of the field cultivation method, and the treatment of oily mud also needs longer time and larger area. (3) The biological mud reactor is a rapid and effective method for treating waste drilling mud, can shorten the treatment time, and has small occupied area compared with other treatment methods. However, this method is complicated, expensive and energy-consuming, and the VOCs produced during the treatment process also need to be further treated, and after the treatment is completed, dehydration is still required, and all treatments require high costs. (4) The biological flotation method not only effectively utilizes resources and reduces the pollution to the environment, but also can recover oil from the oily sludge, and provides a feasible technical scheme for effectively treating the wastes of oil fields and oil refineries. However, the process of this method is complicated and the treatment cost is high.

Only the microbial fuel cell adopting the nickel foam material as the anode treats the oil sludge, can quickly and effectively degrade pollutants such as petroleum hydrocarbon and the like, and has simple operation and easy management.

Disclosure of Invention

The waste drilling mud contains petroleum hydrocarbons, phenolic compounds and the like, and is strongly alkaline and corrosive. Long-term accumulation can cause serious damage to surface vegetation, pollute soil and water sources and endanger human survival. The existing waste slurry treatment method has respective defects and shortcomings, such as long treatment time, complex process, high treatment cost and the like.

The utility model aims at providing a microbial fuel cell which adopts a foam nickel material as an anode to treat waste drilling mud (namely oil sludge) mainly aiming at the defects and shortcomings of the prior waste drilling mud treatment method.

The utility model discloses a following technical scheme realizes.

A sedimentary microbial fuel cell for sludge treatment comprises a cathode, an anode, a resistor and a shell; the method is characterized in that oil sludge 6 which is waste drilling mud is arranged in a shell 7, a cathode 1 is arranged at the upper part of the oil sludge 6, the upper surface of the cathode is exposed in the air and is used as an air cathode, and the lower surface of the cathode is contacted with the oil sludge; the anode 2 is made of foam nickel material, is arranged in the oil sludge at the lower part of the oil sludge 6 and is positioned 5-25 cm below the cathode 1, the proton exchange membrane 4 is arranged between the cathode 1 and the anode 2, and the cathode 1 and the anode 2 are connected with a resistor or an electric device 5 through a lead 3.

The cathode 1 is a graphite plate with the length of 5-20 cm, the width of 5-20 cm and the thickness of 0.3-1 cm.

The anode 2 is a foamed nickel material with the length of 5-20 cm, the width of 5-20 cm and the thickness of 0.3-1 cm.

The lead 3 is a copper lead.

The diameter of the shell 7 is 15cm, and the height is 30 cm. At this time, the cathode and the anode are 10cm long, 10cm wide and 1cm thick, and the distance between the lower surface of the cathode and the upper surface of the anode is 20 cm.

The utility model discloses microbial fuel cell is used for the degradation of abandonment drilling mud petroleum hydrocarbon, compares with other techniques and need not the input of electric energy, and simple structure builds with the running cost low, and pollutants such as petroleum hydrocarbon in the easy management maintenance can effective degradation mud. The foamed nickel material is used as an anode to provide higher power density, and can generate enough high electric energy while processing the petroleum hydrocarbon slurry, so that the method is an economical and effective technology for degrading the petroleum hydrocarbon in the slurry and recovering the electric energy.

Drawings

Fig. 1 is a schematic diagram of a sedimentary microbial fuel cell for treating oil sludge according to the present invention.

The reference numbers are as follows:

1-cathode 2-anode

3-conducting wire 4-proton exchange membrane

5-electric equipment 6-sludge

7-casing

Detailed Description

The invention will be further described below by means of specific embodiments.

As shown in fig. 1, the casing 7 is provided with sludge 6 therein, and a graphite plate cathode 1 is placed on the upper portion of the slurry, and the surface of the graphite plate cathode is exposed to the air to serve as an air cathode, and is a graphite plate having a length of 10cm, a width of 10cm, and a thickness of 1 cm. The housing 7 is 15cm in diameter and 30cm in height and is made of a plastic material. The anode 2 is a nickel foam material and is placed in the slurry at the bottom of the casing 7 20cm below the cathode (which can be adjusted depending on the size of the vessel used and the amount of sludge to be treated), and has a length of 10cm, a width of 10cm and a thickness of 1cm (the nickel foam material is a commercially available product and has a high porosity and a large specific surface area). A proton exchange membrane 4 is arranged between the cathode 1 and the anode 2, so that protons generated by the anode migrate to the surface of the cathode through the proton exchange membrane. The cathode 1 and the anode 2 are connected with a resistor or electric equipment 5 through a lead 3, and the lead 3 is a copper lead; when the lead 3 is connected with the resistor, the treatment of the waste drilling mud is simply carried out, the resistance value is 100-1000 ohms, and when the lead 3 is connected with the electric equipment, the electric equipment is driven by the energy generated by the microbial fuel cell, for example, the electric equipment can be supplied with power by electrodes such as a temperature and humidity meter, a pH meter and the like.

At present, the utility model discloses mainly used abandonment drilling mud petroleum hydrocarbon's pollutant's degradation, the electric energy of production is not enough yet drives great consumer.

The most used anode material at present is a carbon-based material, and the maximum power density which can be obtained under the condition of using foamed nickel as the anode of the microbial fuel cell is 28-32W/m³Compared with a common carbon felt anode, the power density is improved by about 40 percent; the removal rate of the petroleum hydrocarbon reaches 87 to 93 percent, and the removal effect is greatly improved. The above shows that the nickel foam as the anode material has great advantages, not only can provide large specific surface area for microorganisms and promote the transfer rate of electrons, but also can output high power density under proper conditions, and is a potential electrode material applied to MFC anode design.

The principle of microbial fuel cells is based on the conversion of biodegradable organic substances into electrical energy by bacteria.

The utility model discloses handle fatlute with the microbial fuel cell of foam nickel material conduct positive pole, the petroleum hydrocarbon through being arranged in the microorganism consumption mud of positive pole produces the electric energy, and simple structure need not the input of outside electric energy. The generated electric energy can supply power for electrodes such as a temperature and humidity meter, a pH meter and the like. The technology is an economical and effective technology for degrading petroleum hydrocarbon in oil sludge.

The utility model discloses mainly be the microorganism of microbial fuel cell positive pole utilizes the petroleum hydrocarbon in the mud to produce the electric energy, anode material foam nickel can provide high conductivity, the three-dimensional structure who has high porosity and high electric conductivity, provide big specific surface area for the microorganism, be favorable to the biomembrane to grow, thereby be favorable to the extracellular electron transfer among the electrochemical reaction process, provide higher power density, can reach the purpose of petroleum hydrocarbon in the quick high-efficient degradation mud, make microbial fuel cell throughput and electrogenesis performance strengthen, be the technique of petroleum hydrocarbon and recovery electric energy in the economic effectual degradation mud.

Claims

1. A sedimentary microbial fuel cell for sludge treatment comprises a cathode, an anode, a resistor and a shell; the device is characterized in that the casing (7) is internally provided with oil sludge (6) which is waste drilling mud, the cathode (1) is arranged at the upper part of the oil sludge (6), the upper surface of the cathode is exposed in the air and is used as an air cathode, and the lower surface of the cathode is contacted with the oil sludge; the anode (2) is made of foamed nickel material, is placed in the oil sludge at the lower part of the oil sludge (6) and is located 5-25 cm below the cathode (1), a proton exchange membrane (4) is arranged between the cathode (1) and the anode (2), and the cathode (1) and the anode (2) are connected with electric equipment (5) through leads (3).

2. The sedimentary microbial fuel cell for sludge treatment according to claim 1, wherein the cathode (1) is a graphite plate having a length of 5 to 20cm, a width of 5 to 20cm, and a thickness of 0.3 to 1 cm.

3. The sedimentary microbial fuel cell for sludge treatment according to claim 1, wherein the anode (2) is a foamed nickel material having a length of 5 to 20cm, a width of 5 to 20cm, and a thickness of 0.3 to 1 cm.

4. The sedimentary microbial fuel cell for sludge treatment according to claim 1, wherein the lead wire (3) is a copper lead wire.

5. The sedimentary microbial fuel cell for sludge treatment according to claim 1, wherein the casing (7) has a diameter of 15cm and a height of 30 cm; at this time, the cathode and the anode are 10cm long, 10cm wide and 1cm thick, and the distance between the lower surface of the cathode and the upper surface of the anode is 20 cm.