CN103848539A - Organic wastewater treatment device coupled with low-energy-consumption membrane biological reactor of microbial fuel cell - Google Patents

Abstract

The invention provides an organic wastewater treatment device coupled with a low-energy consumption membrane bioreactor of a microbial fuel cell, and belongs to the technical field of organic wastewater recycling. The purpose of the present invention is to solve the problems of poor water quality of microbial fuel cell (MFC), high energy consumption of membrane bioreactor (MBR) and serious membrane pollution. It is an anaerobic reaction zone, and the cathode chamber is composed of deflectors, MBR membrane modules (and MFC cathodes), and aeration tubes. It is an aerobic reaction zone, and the deflector zone is an anoxic reaction zone; The proton exchange membrane in ordinary MFC has good denitrification effect and low construction cost. Compared with the traditional MBR system, the energy consumption per ton of wastewater treatment of the device of the present invention is reduced by 30% to 70%, and the effluent quality meets the pollutants of urban sewage treatment plants in China. Class A standard in the emission standard (GB18918-2002).

Description

An organic wastewater treatment device coupled with a microbial fuel cell low-energy membrane bioreactor

technical field

The invention relates to an organic wastewater treatment device coupled with a low-energy consumption membrane bioreactor of a microbial fuel cell, belonging to the technical field of organic wastewater treatment.

Background technique

In recent years, as an advantageous combination of wastewater physical and biological treatment technologies, the Membrane Bioreactor (Membrane Bioreactor) is known for its low yield of excess sludge and high-efficiency denitrification, and its ultimate goal is to turn sewage into a resource (or reuse) and make it harmless. , MBR) technology has been widely used in the field of sewage treatment. According to statistics, there are more than 300 MBR sewage treatment projects put into operation or under construction in my country, among which nearly 10 sets of MBR systems of 10,000-ton level. However, domestic and foreign practices have shown that operating costs and membrane fouling are always the main obstacles restricting the stable operation of MBR. In terms of its operating cost, the average power consumption of traditional municipal sewage treatment plants is 0.3kWh/ ^m3 sewage, but the energy consumption of MBR sewage treatment is as high as 0.5-1.0kWh/ ^m3 sewage. On the other hand, no matter what kind of membrane fouling prevention measures are adopted, once the membrane comes into contact with the sludge mixture, membrane fouling begins. Therefore, it is necessary to find a sewage treatment method that has low energy consumption and can effectively solve the problem of MBR membrane fouling.

Microbial Fuel Cell (MFC) is a new technology that degrades organic matter in sewage and generates sustainable electricity through anode-generated biofilm. Like all fuel cells, MFC power generation does not burn fuel (organic matter in wastewater or waste), but strips electrons (that is, electrons produced by microbial respiration) from fuel molecules under anaerobic conditions and passes them through predetermined The pathway (electrode and external circuit) is transferred to oxygen, which converts the energy originally used for oxidative phosphorylation biosynthesis of ATP into electricity, where microorganisms are catalysts for biochemical reactions, and the electricity production process of MFC is through the oxidation of organic matter (electron donor) at the anode and the reduction of cathode oxygen (electron acceptor) is achieved. However, as one of the anaerobic biological treatment technologies, MFC is difficult to obtain excellent effluent quality. If it is combined with nitrification process, sequencing batch reactor, biological turntable, biological contact oxidation, etc. In the aeration tank, the water quality of the MFC effluent can be improved, but the above-mentioned processes cannot effectively remove the suspended solids in the effluent of the system, and the effluent is difficult to reuse or discharge.

The present invention takes domestic sewage or organic industrial wastewater as the processing object, and organically combines MFC and MBR to form a new organic wastewater treatment device. The surface of the MBR membrane is negatively charged to generate electrostatic repulsion, which effectively reduces membrane pollution and reduces operating costs. At the same time, MBR ensures that the device has good effluent water quality.

Contents of the invention

The object of the present invention is to provide a treatment device for domestic sewage or organic industrial wastewater with low energy consumption and excellent effluent quality.

Device of the present invention is made of following parts:

Pool body (1), MFC anode (2), water inlet pipe (3), feed water pump (4), sealing plug (16), baffle plate (8), MBR membrane module (9), aeration pipe (10) , electrode/water pipe fixing plug (13), outlet pipe (11), outlet pump (12), load (14), wire (15), valve (5), sludge pump (6), sludge pipe (7) It consists of 3 to 7 baffles (8) forming a baffle area, which divides the entire wastewater treatment device into an MFC anode chamber and an MBR; the water inlet pipe (3) connects to the inlet at the bottom of the MFC anode chamber through a feed pump (4) The water outlet is connected; the water outlet pipe (11) is communicated with the water outlet of the conductive polymer membrane module (9) through the water outlet pump (12); the MFC anode (2) and the conductive polymer membrane module (9) are connected by the wire (15) and the load ( 14) are connected; the sludge pump (6), valve (5) communicates with the anode chamber, the baffle area and the bottom of the MBR reaction chamber through the sludge pipe (7), forming a sludge return and discharge system.

The MFC anode (2) is made of carbon felt, carbon cloth, graphite and its modified materials, and the MBR membrane module (9) is also used as the MFC cathode, and the material is stainless steel mesh modified by conductive polymer, non-woven fabric, carbon felt, carbon cloth.

Advantages of the invention

1. Most of the organic matter in the sewage, including glucose, undergoes an oxidation reaction at the MFC anode (2), and the generated electrons are transferred to the cathode through the MFC anode (2), the wire (15) and the load (14), and the generated electric energy is used for Compensating the power consumption of the MBR can effectively reduce the operating cost.

2. The protons produced by the oxidation of the MFC anode (2) pass through the baffles with the water flow to reach the MBR, and combine with electrons and oxygen to form water, which eliminates the problems of easy acidification of ordinary MFC anodes and feedback inhibition of the activity of electricity-producing microorganisms. A very small amount of remaining organic matter also passes through the baffle plate with the water flow to reach the cathode aerobic zone, and is further removed by aerobic mineralization.

3. The MBR composed of conductive polymer membrane module (9), aeration pipe (10), electrode/water pipe fixing plug (13), outlet pipe (11) and pool body (1) can also be used as MFC cathode chamber, for In the aerobic area, the MBR membrane module (9) is also used as the MFC cathode, and its material is stainless steel mesh, non-woven fabric, carbon felt, and carbon cloth modified by conductive polymers, which can pollute the surface of the MBR membrane and the membrane surface while transmitting electrons. Electrostatic repulsion is provided between objects to effectively alleviate membrane fouling.

4. The bow-shaped baffle area composed of 3 to 7 baffles (8) and the pool body (1) is an anoxic area, which ensures the anaerobic state of the anode chamber and the aerobic state of the MBR. Due to this anoxic area The existence of nitrification and denitrification reactions can occur, and the denitrification effect of the system is good. At the same time, the baffles are also used to intercept the sludge in the anaerobic zone, preventing the sludge from flowing into the MBR and affecting the quality of the effluent water. In addition, the protons produced by the anode are The channel for water to flow to the cathode in the aerobic zone; through the number of partitions and the position of the partitions in the pool body, the hydraulic retention time of each part can be adjusted to meet the treatment requirements of different water quality.

5. The device has a simple structure and is easy to operate and manage. Baffles are used to replace the proton exchange membrane in ordinary MFC, which greatly reduces the system construction cost.

6. Compared with the traditional MBR system, the energy consumption per ton of sewage treatment is reduced by 30% to 70%, the COD and ammonia nitrogen removal rates of the system are both 70.0% to 99.8%, and the effluent water quality meets the industry reuse standard.

Description of drawings

Accompanying drawing is the device diagram of the present invention.

Detailed ways

Example 1: MFC anode (2) adopts carbon felt, deflector (8) adopts 3 pieces of cross arrangement, MBR membrane module (9) and MFC cathode adopt graphene, polyvinylidene fluoride 1: 2 mixed modification non-woven fabric . The water quality of the system is as follows: COD concentration is 500mg/L, ammonia nitrogen is 20mg/L, and the pH value is 7; the HRT of the MFC anode chamber is 8h; the HRT of the baffle area is 10h, and the dissolved oxygen concentration is 0.2mg/L; the MBR unit The HRT is 6h, the dissolved oxygen concentration is 4.0mg/L; the temperature is 25°C.

Example 2: The MFC anode (2) is made of carbon cloth, the deflector (8) is arranged in five intersections, and the MBR membrane module (9) and the MFC cathode are made of polyaniline-modified stainless steel mesh. The water quality of the system feed water is as follows: COD concentration is 1000mg/L, ammonia nitrogen is 50mg/L, and the pH value is 8; the HRT of the MFC anode chamber is 10h; the HRT of the baffle area is 12h, and the dissolved oxygen concentration is 0.5mg/L; the MBR unit The HRT is 8h, the dissolved oxygen concentration is 2.0mg/L; the temperature is 30℃.

Example 3: The MFC anode (2) is made of graphite, the deflector (8) is arranged in 7 intersections, and the MBR membrane module (9) and the MFC cathode are made of graphene-modified carbon cloth. The water quality of the system inlet water is as follows: COD concentration is 10000mg/L, ammonia nitrogen is 2000mg/L, and the pH value is 9; the HRT of the MFC anode chamber is 22h; the HRT of the baffle area is 18h, and the dissolved oxygen concentration is 0.1mg/L; the MBR unit The HRT is 12h, the dissolved oxygen concentration is 6.0mg/L; the temperature is 35°C.

Claims (5)

1. An organic wastewater treatment device coupled to a low-energy consumption membrane bioreactor of a microbial fuel cell, characterized in that: the device consists of a pool body (1), a micro-dust fuel cell (MFC) anode (2), a water inlet pipe (3 ), feed water pump (4), sealing plug (16), baffle plate (8), MBR membrane module (9), aeration pipe (10), electrode/water pipe fixing plug (13), outlet pipe (11), Composed of outlet pump (12), load (14), wire (15), valve (5), sludge pump (6), and sludge pipe (7); The flow plate area divides the whole wastewater treatment device into an MFC anode chamber and a membrane bioreactor (MBR); the water inlet pipe (3) is connected to the water inlet at the bottom of the MFC anode chamber through a feed pump (4); the water outlet pipe (11) is connected through The outlet pump (12) communicates with the water outlet of the MBR membrane module (9); the MFC anode (2) and the MBR membrane module (9) are connected with the load (14) by a wire (15); the sludge pump (6), the valve ( 5) It communicates with the anode chamber, the baffle area and the bottom of the MBR reaction chamber through the sludge pipe (7) to form a sludge return and discharge system. 2. The organic wastewater treatment device of a kind of coupling microbial fuel cell low-energy consumption membrane bioreactor according to claim 1, it is characterized in that: most of the organic matters in the sewage are oxidized at the MFC anode (2), and the electrons produced pass through The MFC anode (2), the wire (15) and the load (14) are transmitted to the MBR membrane module (also the MFC cathode), and the generated electric energy is used to compensate the power consumption of the MBR, which can effectively reduce the operating cost. 3. The organic wastewater treatment device of a kind of coupled microbial fuel cell low energy consumption film dust reactor according to claim 1, characterized in that: by the pool body (1), MFC anode (2), water inlet pipe (3 ), the baffle plate (8), and the sealing plug (16) constitute the MFC anode chamber as an anaerobic zone, the MFC anode (2) is made of carbon felt, carbon cloth, graphite and its modified materials, and the MFC anode (2) The protons produced by oxidation pass through the baffles with the water flow to reach the MBR aerobic zone, and combine with electrons and oxygen to form water, which eliminates the problems of easy acidification of ordinary MFC anodes and feedback inhibition of the activity of electricity-producing microorganisms, and a very small amount of residual organic matter after anodic oxidation It also passes through the baffle plate with the water flow to reach the cathode aerobic zone for further aerobic removal. 4. A kind of organic wastewater treatment device coupled with microbial fuel cell low energy consumption membrane bioreactor according to claim 1, characterized in that: it is fixed by MBR membrane module (9), aeration pipe (10), electrode/water pipe The MBR composed of the plug (13), the outlet pipe (11) and the cell body (1) doubles as the MFC cathode chamber, which is an aerobic zone, and the MBR membrane module (9) doubles as the MFC cathode, and its material is stainless steel modified by conductive polymer Mesh, non-woven fabric, carbon felt, and carbon cloth can provide electrostatic repulsion between the MBR membrane surface and membrane surface pollutants while transmitting electrons, effectively alleviating membrane fouling. 5. An organic wastewater treatment device coupled to a low-energy consumption membrane bioreactor of a microbial fuel cell according to claim 1, characterized in that: it is composed of 3 to 7 baffles (8) and a pool body (1) The bow-shaped baffle area is an anoxic area, which ensures the anaerobic state of the MFC anode chamber and the aerobic state of the MBR. Due to the existence of this anoxic area, nitrification and denitrification reactions can occur, and the system has a good denitrification effect, thus ensuring In addition, the baffles are also used to intercept the sludge in the anaerobic zone to prevent the sludge from flowing into the aerobic zone of the MBR. In addition, it is also the channel for the protons generated by the anode to flow to the cathode in the aerobic zone with the water; by adjusting the baffle The number and the position of the baffles in the pool can adjust the hydraulic retention time of each part to meet the treatment requirements of different water quality.

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