CN103435159A - Organic membrane bioreactor integrating wastewater treatment and electric energy output - Google Patents

Abstract

An organic membrane membrane bioreactor integrating wastewater treatment and electric energy output belongs to the field of environmental protection technology and new energy. It is characterized in that the polymer-based conductive composite film is used as an electrode in the reactor, and the anode in the anaerobic zone is inoculated with electrogenic bacteria, the wastewater first enters the anaerobic zone, and then enters the aerobic zone, and the pollutants in the water are further removed by aerobic microorganisms. The cathode membrane filters water; the anode and cathode are alternately arranged and connected through an external circuit, so that part of the chemical energy present in the organic pollutants in the wastewater is directly converted into electrical energy. The effect and benefit of the invention is that the cathode and the anode use conductive film materials at the same time, so that the reactor can realize electric energy output while degrading wastewater, realize energy saving, emission reduction, energy recovery, and obvious environmental, economic and social benefits.

Description

An organic membrane membrane bioreactor integrating wastewater treatment and electric energy output

technical field

The invention belongs to the technical field of new energy and environmental protection, relates to the field of waste water treatment and energy recycling, and in particular relates to an organic membrane membrane bioreactor integrating waste water treatment and electric energy output which directly converts chemical energy into electric energy .

Background technique

MBR has received extensive attention due to its high wastewater treatment efficiency and small footprint. However, membrane fouling and high energy consumption restrict its development. At present, a lot of research is focused on the development of membrane materials with high flux and good anti-pollution performance; in addition, applying micro electric field and micro magnetic field on the membrane is also an effective way to slow down membrane fouling. In recent years, due to the application of a micro-electric field on the conductive film, it can effectively slow down the membrane fouling and has attracted extensive attention. At present, most conductive films focus on carbon materials and metal oxide materials. Although carbon materials have good electrical conductivity, they are not easy to polymerize, difficult to optimize performance and high in cost, so it is difficult to be applied to actual wastewater treatment; metal oxide materials have good catalytic performance, but there are long-term operational stability problems, and their cost is relatively high. High, there are great limitations in practical applications. Organic polymer materials have potential development value in actual wastewater treatment due to their low cost, wide range of sources, and its redox process is completely reversible. In "Proceedings of the American Academy of Sciences" (2012) 1-6, Pan Lijia and others introduced the use of aniline and phytic acid to form a gel and attach it to carbon cloth to form a highly conductive organic composite carbon film material, but the price of carbon cloth It is expensive and difficult to apply in actual wastewater treatment; in the patent No. CN103100314A, Liu Lifen, Li Na, etc. disclose a method of polymerizing aniline phytic acid gel on a filter cloth to prepare a composite-based conductive membrane, but in In the reactor configuration she introduced, the anode uses graphite particles, and the cathode area is small, and the amount of waste water that can be treated is limited; Zhongjian Li et al. The configuration of the microbial fuel cell is that the annular anode is placed outside the annular cathode, and the anode and the cathode are made of conductive materials, but the conductive material of the cathode has no filtering performance.

Contents of the invention

The purpose of the present invention is to provide a new type of organic membrane membrane bioreactor configuration integrating wastewater treatment and electric energy output. This configuration simplifies the reactor structure, shortens the distance between electrodes, and realizes flow and mass transfer. The reactor uses low-cost organic compound conductive membrane materials as the anode and cathode membranes, which solves the problem of high cost of membrane bioreactors; the filtration area of the anode and cathode membranes in the reactor is increased, and the cathode and cathode membranes are enlarged proportionally. The anode can be applied to the actual wastewater treatment; the reactor can directly convert part of the chemical energy of the wastewater into electrical energy for utilization.

Technical scheme of the present invention is:

1) Both anode and cathode materials are made of organic composite conductive film.

2) There are two types of reactor configurations: ring configuration and flat configuration.

3) In the ring-shaped organic membrane bioreactor integrating wastewater treatment and electric energy output, the anode membrane and the cathode membrane are made into a cylindrical ring at the same time. There are two options for the reactor configuration: one is the anode The inner ring is placed in the cathode membrane in an anaerobic environment, the cathode membrane is in an aerobic environment as an outer ring, and the anode area and the cathode area are separated by an oxygen barrier medium; the other is that the anode membrane is used as the outer ring and the cathode membrane is used as the outer ring. The inner ring is placed in the anode membrane, the inner ring is in an aerobic environment, and the outer ring is in an anaerobic environment; the ring-shaped electrode is stitched by a double-layer membrane covered with a porous support material plastic mesh; the anode ring membrane and the cathode ring membrane There is little difference in area, and the distance between the anode ring-shaped membrane electrode and the cathode ring-shaped membrane electrode is 10 mm.

4) The flat plate organic membrane bioreactor integrating wastewater treatment and electric energy output is a thin and tall configuration. The reactor is equipped with three cathode membrane modules and two anode membrane modules. The configurations of the cathode and anode membrane modules are both closed cuboids, and the anode is relatively higher than the cathode; the membrane module adopts the form of cathode-anode-cathode-anode-cathode. The groove is clamped and arranged in the reactor; the closed cuboids of the positive and negative poles are composed of two flat plates, and two rows of parallel rectangular holes are punched on each plate; in order to connect the water outlet pipe, the top of the cathode cuboid is connected to a round pipe, and the water in the anode is self-contained. For overflow, a round hole is set on the top of the anode cuboid; the base of the reactor is equipped with a main water inlet, which is connected to the two anodes with rubber tubes through the two connections, and is used for anode water intake; the main aeration inlet is opposite to the main water inlet. On the other side of the reactor, it is respectively connected to three cathodes through three universal rubber tubes to aerate the cathodes; the main feature of the present invention is that both electrodes maintain a slender and narrow space.

5) Compared with the reactor of the same size, the organic membrane membrane bioreactor integrating wastewater treatment and electric energy output in the ring configuration has more than doubled the cathode membrane filtration area, which improves the sewage treatment efficiency and scales up It can be applied to actual wastewater treatment.

6) In the ring-shaped organic membrane bioreactor integrating wastewater treatment and electrical energy output, the upper half of the cathode membrane can also be exposed to the air vertically, and the aeration is turned off to form an air cathode.

7) The organic composite conductive film used as the anode is polymerized by aniline phytic acid gel; there are two kinds of organic polymer conductive films used as the cathode: one is that the cathode material is the same as the anode material; the other is that the cathode material is made of aniline plant Acid gel doped with ionic liquid is polymerized.

8) The organic polymer conductive membrane material is placed in the reactor as the anode and cathode membranes, and the anode and cathode membranes are placed alternately. The influent water first enters the anaerobic anode area, and then enters the aerobic cathode area.

9) The anode and cathode membranes are connected to the external circuit with carbon fiber cloth, and the cathode membrane filters water through a suction pump.

10) The anode and cathode are separated by an oxygen-impermeable medium to achieve an anaerobic environment in the anode area.

11) In the initial stage of operation, the anode is loaded with electrogenic bacteria, and the electrogenic bacteria are used to oxidize the substrate to generate electrons.

12) The electrogenic bacteria in the anode area produce electrons, and the electrons reach the cathode membrane through the external circuit, and the electrons combine with oxygen on the cathode membrane to produce water.

The effects and benefits of the present invention are that the organic polymer conductive film used as an electrode has low cost, wide sources, and high practical value; the area of the cathode film is increased, and the filtration efficiency is improved; the area of the anode and the cathode is large, and can be applied in proportion In actual wastewater treatment; the reactor realizes the output of electric energy while efficiently treating sewage, and achieves the goal of energy recycling; the reactor of this configuration reduces the footprint of sewage treatment, and the cathode adopts a conductive film to integrate wastewater treatment and electric energy output As a whole, the micro-electric field in the reactor effectively slows down the membrane fouling.

Description of drawings

Figure 1 is a schematic side view of an organic membrane bioreactor in a ring configuration integrating wastewater treatment and electrical energy output.

In the figure: ① water inlet; ② outlet peristaltic pump; ③ annular membrane module and cathode; ④ anode; ⑤ aeration device.

Accompanying drawing 2 is the schematic top view of the organic membrane membrane bioreactor integrating wastewater treatment and electric energy output in a ring configuration.

In the figure: ⑥Oxygen barrier membrane material.

Accompanying drawing 3 is a schematic diagram of an organic membrane membrane bioreactor integrating wastewater treatment and electric energy output in a flat plate configuration.

In the figure: 1 water inlet; 2 aeration hole; 3 anode membrane module; 4 cathode membrane module; 5 outlet pump; 6 carbon fiber wire from cathode; 7 carbon fiber wire from anode;

Accompanying drawing 4 is the potential diagram of the battery of the integrated device for wastewater treatment and electric energy output.

The figure shows the change of anode potential (V) with time (h) during the operation of the reactor. The abscissa in the figure represents the running time of the reactor, the ordinate represents the anode potential, and the external resistance is 500Ω; it can be seen from the figure that the anode potential presents a relatively stable potential for a long period of time.

Accompanying drawing 5 is the anode potential diagram of the integrated device integrating wastewater treatment and electric energy output.

The figure shows the change of battery potential (V) with time (h) during operation. The abscissa in the figure indicates the running time of the reactor, the ordinate indicates the battery potential, and the external resistance is 500Ω; the figure shows that the reactor has a high battery potential during operation for a long time, and then membrane fouling occurs as time goes by, The battery potential has weakened. Detailed ways

The specific embodiments of the present invention will be described in detail below in conjunction with the technical solutions and accompanying drawings.

Example 1

The reactor adopts a ring configuration reactor, the anode is placed in the inner ring, and the cathode is placed in the outer ring. Aniline and phytic acid are polymerized on the surface of the filter cloth for the cathode and the anode to form a polymer-based conductive composite film. In the early stage of reactor operation, the anode first introduced electricity-producing Shewanella bacteria, cultivated for 7 days, and added nutrients regularly to complete the bacterial growth. The carbon fiber thread is used as a wire to run through the polymer-based conductive composite film, and it is used as a wire to connect to an external circuit, and an external 500Ω resistor is connected. Use a gas flow meter to adjust the amount of aeration to keep the cathode dissolved oxygen in the aerobic zone at a normal level. Influent water first enters the anode area and then enters the cathode area. During the stable operation of the reactor, the battery potential reached 0.12V, the anode potential reached 0.4V, and the COD removal rate was as high as 99.5%.

Example 2

The reactor adopts a ring configuration reactor, the anode is placed in the outer ring, and the cathode is placed in the outer ring. The area of the anode is larger than the area of the cathode. The anode and cathode membranes are polymerized with aniline and phytic acid on the surface of the filter cloth to form a polymer-based conductive composite membrane material, and an external 500Ω resistor is connected. The battery potential can reach up to 0.13V during the stable operation period.

Example 3

The reactor adopts a ring configuration reactor, the anode is placed in the outer ring, and the cathode is placed in the outer ring. The anode film uses aniline phytic acid to polymerize on the surface of the filter cloth to form a polymer-based conductive composite membrane material, and the cathode uses aniline and phytic acid doped 1-butyl-3-methylimidazolium bromide ionic liquid to polymerize on the surface of the filter cloth to form an organic polymer Material-based conductive composite membrane material, the aeration of the cathode is closed, and part of the cathode material is exposed to the air to form an air cathode. The external 500Ω battery potential can reach up to 0.17V during the stable period.

Example 4

This example is an organic membrane membrane bioreactor integrating flat plate wastewater treatment and electric energy output. The reactor is equipped with three cathodes and two anodes. The cathode and anode membrane components are all closed cuboids with a width of 5 mm; the cathode cuboid is composed of two flat plates with a length of 150 mm and a width of 50 mm. Make two rows of rectangular holes with a length of 15mm and a width of 3mm to facilitate the entry of sewage. The area where the rectangle is located is 15mm and 5mm from the upper and lower sides of the plate, and 5mm from the left and right sides of the plate. To connect the outlet pipe, the top of the cathode cuboid is connected with A circular tube with a diameter of 5mm; the anode cuboid is composed of two plates with a length of 200mm and a width of 50mm, and two rows of rectangular holes with a length of 15mm and a width of 3mm are drilled on each plate to facilitate the contact between microorganisms and the membrane and the export of electrons. The area is 15mm and 70mm away from the upper and lower sides of the plate, 5mm from the left and right sides of the plate, and the diameter of the top of the anode is 5mm. The membrane module adopts the form of cathode-anode-cathode-anode-cathode, and is intermittently arranged in the reactor with card slots, and the distance between the membrane modules is 10mm.

Use aniline and phytic acid to polymerize on the surface of the filter cloth to form a conductive composite membrane, which is glued to both sides of each membrane module with glass glue. In order to make the two poles have better conductivity, carbon fiber filaments are vertically glued to the membrane module with conductive glue on both sides of the membrane. In order to maintain an anaerobic environment for better growth of anaerobic Shewanella bacteria, the anode membrane module is wrapped with a hydrophilic plastic wrap; the aeration head is placed under the cathode membrane module, and the flow rate is controlled by a flow meter.

Sewage is pumped in from the general water inlet on the bottom support of the anode, injected into the anode by the two-way of the reactor respectively, flows from bottom to top, and flows out from the round hole at the top of the anode; under anaerobic conditions, the pollutants in the anode Degraded by Shewanella bacteria to generate electrons, the electrons are exported from the carbon fiber filaments, flow through the 500Ω external resistance, the electrode potential is 0.1v, and the anode potential is 0.4v; after anaerobic degradation, the sewage is filtered through the cathode membrane and enters the cathode, and is pumped out by the COD The removal rate is 99%.

Claims (4)

1. collection wastewater treatment and electric energy are exported integrated organic membrane membrane bioreactor, it is characterized in that: the polymer-matrix electric conduction composite membrane is as anode and negative electrode, anonite membrane and cathodic coating adopt loop configurations or flat sheet configuration, anode and cathodic coating are alternately placed, anode and cathode spacing are 10mm, the middle oxygen barrier material of placing, the positive column anaerobism, cathodic area is aerobic, waste water enters aerobic zone after being introduced into anaerobic zone, plate load electrogenesis bacterium, connect external circuit, formed electric energy output and the integrated membrane bioreactor of wastewater treatment.

2. a kind of collection wastewater treatment according to claim 1 and electric energy are exported integrated organic membrane membrane bioreactor, it is characterized in that: in the reactor of loop configurations, negative electrode and positive electrode is the cylindric film of being made by the membrane-coated porous propping material plastic wire of double-deck organic composite, the negative electrode and positive electrode position can realize exchanging, anode is placed in to outer shroud, negative electrode is placed in interior ring, perhaps anode is placed in to interior ring, negative electrode is placed in outer shroud; The reactor anode and cathode membrane module configuration of flat sheet configuration is elongated and rectangular parallelepiped sealing, and membrane module adopts K-A-K-A-negative electrode form, with draw-in groove, intermittently is arranged in reactor.

3. a kind of collection wastewater treatment according to claim 1 and electric energy are exported integrated organic membrane membrane bioreactor, it is characterized in that: in the reactor of loop configurations, cathodic coating doubles above than the reactor filtration area of equal size; The polymer-matrix electric conduction composite membrane of flat sheet configuration is with the glass gluing in each membrane module both sides, and carbon fiber wire vertically is bonded on membrane module two side forms with conductive resin.

4. a kind of collection wastewater treatment according to claim 1 and electric energy are exported integrated organic membrane membrane bioreactor, and it is characterized in that: in the reactor of loop configurations, upper part of cathodic coating vertically is exposed in air, closes aeration pump, form air cathode.

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