Microbial fuel cells: A new approach to waste-water treatment
- The use of wastewater for energy generation by biodigestion and generation of biogas is a well established process in use at numerous waste-water treatment plants. ...
- Microbial fuel cells. ...
- MFC construction. ...
- MFC cathode. ...
- MFCs and waste-water treatment. ...
- MFC reactions. ...
- Power output. ...
- Substrate
- Other applications. ...
- Electromethanogenesis. ...
Can microbial fuel cells be used to treat wastewater?
Brewery and food manufacturing wastewater can be treated by microbial fuel cells because their wastewater is rich in organic compounds that can serve as food for the microorganisms.
What is a microbial fuel cell (MFC)?
A microbial fuel cell (MFC) is a bio-electrochemical device that harnesses the power of respiring microbes to convert organic matter in waste-water directly into electrical energy. At its core, the MFC is a fuel cell, which transforms chemical energy into electricity using oxidation-reduction reactions.
What is fosters’ microbial fuel cell project?
Partnered with the University of Queensland, Fosters’ plans to improve the MFC’s cleaning power and electrical output and eventually build a 660 gallon, 2 Kilowatt MFC that cleans all of the company’s wastewater. The power generated from cleaning the brewery wastewater is expected to pay for the initial cost of the Microbial Fuel Cell in ten years.
Can wastewater be used for energy generation?
The use of wastewater for energy generation by biodigestion and generation of biogas is a well established process in use at numerous waste-water treatment plants. A new approach, based on microbial fuel cells, which offers a scalable alternative with much potential, is in the development stages.
What is the purpose of a microbial fuel cell?
Microbial fuel cells (MFCs) are a new bioelectrochemical process that aims to produce electricity by using the electrons derived from biochemical reactions catalyzed by bacteria. The energy generated by MFCs is expected to supply enough energy to partially cover the energy demand in urban WWTPs.
What is microbial wastewater treatment?
Microbial Wastewater Treatment focuses on the exploitation of microorganisms as decontaminating tools to treat polluted wastewater, a worldwide concern. Microorganism-based processes are seen as promising technologies to treat the ever-increasing problem of polluted wastewater.
What is MFC wastewater treatment?
Microbial Fuel Cell (MFC) is a sustainable technology that treats wastewater and generates electricity simultaneously while leaving low concentrations of nutrients in the effluent.
What are the types of microbial fuel cells?
There are two types of microbial fuel cells (MFCs): mediator or mediator-less. The mediator type was demonstrated in the early 20th century and uses a mediator: a chemical that transfers electrons from the bacteria in the cell to the anode.
What is microbial treatment?
Definition. An antimicrobial therapy kills or inhibits the growth of microorganisms such as bacteria, fungi, or protozoans. Therapies that kill microorganisms are called microbiocidal therapies and therapies that only inhibit the growth of microorganisms are called microbiostatic therapies.
How microbes help in waste wastewater treatment?
The aerobic bacteria in the sludge digest the organic material around them in order to reproduce and grow, and change the chemical makeup of the sludge, oxidizing ammonia into nitrate and nitrite in a process called nitrification.
How do you make a microbial fuel cell?
Materials.Get drilling. Drill a hole for the copper wire in the lid of each container. ... Coil the graphite. Strip the ends of two pieces of copper wire and wrap one around each pencil lead. ... Mix the solution. Dissolve 100g per litre of agar in boiling water and mix in the salt. ... Squeeze the oxygen. ... Feed the microbes.
Where are microbial fuel cells being used?
Soil-based MFCs are becoming popular educational tools for science classrooms. Sediment microbial fuel cells (SMFCs) have been applied for wastewater treatment. Simple SMFCs can generate energy while decontaminating wastewater. Most such SMFCs contain plants to mimic constructed wetlands.
How do microbial fuel cells store energy?
Use a suitable rechargeable battery. Professor Yi Cui make microbial battery(MB) by using solid state electrode such as AgO2. (PNAS 2013, 110, 15925; doi: 10.1073/pnas. 1307327110) When the MB is charging by microorganism, microbial oxidize some organic matter then produce electrons to solid state electrode.
How many types of MFC are there?
According to how electrons are transferred from the bacteria to the anode, MFCs can be classified into two types: mediator and mediatorless MFCs.
What are the methods of waste water treatment?
Four common ways to treat wastewater include physical water treatment, biological water treatment, chemical treatment, and sludge treatment.
What are microbes in water?
Of the many infectious microorganisms found in the environment, bacteria (such as Shigella, Escherichia coli, Vibrio, and Salmonella), viruses (such as Norwalk virus and rotaviruses), and protozoans (such as Entamoeba, Giardia, and Cryptosporidium) may be found in water.
How Does a Microbial Fuel Cell Work?
As shown in Fig. 2, the Microbial Fuel Cell is divided into two halves: aerobic and anaerobic. The aerobic half has a positively charged electrode and is bubbled with oxygen, much like a fish tank. The anaerobic half does not have oxygen, allowing a negatively charged electrode to act as the electron receptor for the bacterial processes. The chambers are separated by a semi-permeable membrane to keep oxygen out of the anaerobic chamber while still allowing hydrogen ions (H+) pass through.
What is the final step of the process in a microbial fuel cell?
In many ways, a microbial fuel cell is an extension of the electron transport chain where the final step of the process (the combination of oxygen, electrons, and H+ to form water) is transferred outside of the bacterial cell from which energy can be harvested. Figure 3: The electron transport chain.
How do microbes generate electricity?
These bacteria break down food wastes and sewage to generate an electric current. Using microbes to generate electricity implies that the processes in an MFC are self-sustaining; the bacteria replicate and continue to produce power indefinitely as long as there is a food source to nourish the bacteria.
How do bacteria produce energy?
The bacteria metabolize food by first breaking apart the food molecules into hydrogen ions, carbon dioxide, and electrons. As shown in Fig. 3, bacteria use the electrons to produce energy by way of the electron transport chain. The microbial fuel cell disrupts the electron transport chain using a mediator molecule to shuttle electrons to the anode. In many ways, a microbial fuel cell is an extension of the electron transport chain where the final step of the process (the combination of oxygen, electrons, and H+ to form water) is transferred outside of the bacterial cell from which energy can be harvested.
How do electrons flow in bacteria?
3. The electrons flow up from the anode, through a wire, and onto the cathode. While flowing through the wire, an electrical current is generated that can be used to perform work. 4.
Who invented the fuel cell?
In fact, little development occurred on his primitive designs until the 1980s. M. J. Allen and H. Peter Bennetto from Kings College in London revolutionized the original microbial fuel cell design. Spurred by their desire to provide cheap and reliable power to third world countries, Allen and Bennetto combined advancements in the understanding of the electron transport chain and significant advancements in technology to produce the basic design that is still used in MFCs today. However, use of MFCs in third world countries is still in the pilot stages because of the complexities of simplifying the design enough to allow poor rural farmers to build them. The advancements by the Kings College team have shown the scientific community that the microbial fuel cell can be useful technology and generate increased interest in its development.
Where does the electron continue in a bacterial cell?
4. In a normal bacterial cell, the electron continues along the dotted red path where it combines with oxygen to make water. 5. In a microbial fuel cell, the electron continues along the solid red path, where it is picked up by a mediator molecule and taken to the anode.
How do municipal plants treat sewage?
The majority of municipal plants treat the settled sewage liquor using aerobic biological processes. To be effective, the biota require both oxygen and food to live. The bacteria and protozoa consume biodegradable soluble organic contaminants (e.g. sugars, fats, organic short-chain carbon molecules, etc.) and bind much of the less soluble fractions into floc. Secondary treatment systems are classified as fixed-film or suspended-growth.
What is tertiary treatment?
Finally, the purpose of tertiary treatment is to provide a final treatment stage to raise effluent quality before it is discharged to the receiving environment (sea, river, lake, ground, etc.). More than one tertiary treatment process may be used at any treatment plant. If disinfection is performed, it is always the final process. It is also called “effluent polishing”. The organic matter concentration in wastewater is usually evaluated in terms of either its biochemical oxygen demand (BOD) in a five day test (BOD5) or its chemical oxygen demand (COD) in a rapid chemical oxidation test. Total BOD or COD can be viewed as consisting of two fractions: soluble BOD (sBOD) and particulate BOD (pBOD). Most pBOD is removed in the primary clarifier sludge and sBOD is converted to bacterial biomass (Logan, 2008).
What is a primary sedimentation tank?
In the primary sedimentation stage, tanks commonly called “primary clarifiers” or “primary sedimentation tanks” are used to settle sludge while grease and oils rise to the surface and are skimmed off. Primary settling tanks are usually equipped with mechanically driven scrapers which continually drive the collected sludge towards a hopper in the base of the tank where it is pumped to sludge treatment facilities. Grease and oil from the floating material can sometimes be recovered for saponification. The dimensions of the tank should be designed to effect removal of a high percentage of the floatables and sludge. A typical sedimentation tank may remove from 60% to 65% of suspended solids, and from 30% to 35% of biochemical oxygen demand (BOD) from the sewage.
What is microbial fuel cell?
An overview of microbial fuel cell usage in wastewater treatment, resource recovery and energy production. Wastewater treatment is a high-cost and energy-intensive process not only due to large amounts of pollutants but also for the large volumes of water to be treated, which are mainly generate d by human activities and different industrie s.
Is biological wastewater treatment expensive?
In this regard, biological wastewater treatments have become su …. Wastewater treatment is a high-cost and energy-intensive process not only due to large amounts of pollutants but also for the large volumes of water to be treated, which are mainly generated by human activities and different industries. In this regard, biological wastewater ...
Is wastewater treatment energy intensive?
Wastewater treatment is a high-cost and energy-intensive process not only due to large amounts of pollutants but also for the large volumes of water to be treated, which are mainly generated by human activities and different industries. In this regard, biological wastewater treatments have become substitutes to the current technologies, ...
Why are MFCs recommended for wastewater treatment?
Thus, MFCs are recommendable for wastewater treatment over the typical technologies due to the utilization of microbial metabolic activities for energy production without high energy input ( Sekar et al., 2019; Singh, 2020 ).
Why are MFCs used in wastewater?
This is because electricigens in wastewater can act as catalysts for destroying organic pollutants ...
Why are MFCs not energy consumers?
MFCs are theoretically net energy producers and not energy consumers because there is no need for aeration or strict temperature control, and there is little waste generation.
How does sediment fuel work?
In sediment (or benthic) MFCs, power is autonomously generated at the anode in an anaerobic environment using wastewater. However, the ORR occurs at the cathode present outside the water. No membrane separator is employed in this type of MFC because of oxygen diffusion resistance caused by the aqueous solution between the electrodes. In this case, modifications of electrodes with cerium nitrate can help maximize power generation ( Imran et al., 2019 ). Sediment MFCs possess promising application prospects in wastewater treatment, bioremediation, and renewable power supply of long-range or deep-sea sensors ( Ma et al., 2020 ).
How does a microbial electrolysis cell produce hydrogen?
A microbial electrolysis cell (MEC) utilizes exoelectrogens to electrochemically generate hydrogen from electrons derived from organic matter in wastewater ( Kim and Logan, 2019 ), which allows simultaneous energy production and wastewater treatment ( Shao et al., 2019; Huang et al., 2020 ). A high energy input (theoretically >1.2 V) is required to produce hydrogen via water electrolysis, while a MEC requires only a small additional voltage (>0.14 V) to induce the hydrogen evolution reaction (HER) at the cathode ( Kim and Logan, 2019 ). Hydrogen is widely used as an efficient renewable energy carrier due to its various advantages ( Sun et al., 2009) such as clean-burning properties ( Kumar et al., 2018 ). Domestic wastewater, swine wastewater, and fermentation effluent have been tested in the production of hydrogen gas in MEC, which converts organic substrates present in wastewater hydrogen through a microbial catalyzed process ( Rahimnejad et al., 2020 ). These types of cells can be also used for simultaneous gas production of hydrogen and methane ( Segundo-Aguilar et al., 2021 ). Accordingly, it can be concluded that all of these MFCs have their advantages through modifications in their design to be effectively utilized with the available resources.
How do MFCs generate electricity?
The primary application of MFCs is electricity generation through the utilization of various kinds of organic-rich wastes and biomasses ( Zhao et al., 2018; Catal et al., 2019; Guo et al., 2019 ). It can convert chemical energy into electrical energy using bacteria as catalysts ( Huang et al., 2018 ). At the anode, oxidation of organic matter into electrons, protons, and carbon dioxide takes place in the presence of exoelectrogenic microorganisms such as biocatalysts. Electrons are transferred to the cathode, while protons diffuse into the cathode through an external circuit. In the cathode, these electrons and protons combine with oxygen or another oxidant to generate electricity. The electricity produced can be used directly. Some recent studies of the performance of MFCs for electricity generation are summarized in Table S1.
What are the main contributors to water pollution?
In wastewater production, textile industries are considered as major contributors to water pollution due to the wide variety of synthetic dyestuffs used for the coloration of textile fibers ( Rathour et al., 2019 ). The wastewater from synthetic industries is typically composed of several dyes (azo, direct, disperse, reactive, etc.), metals (copper, lead, cadmium, mercury, nickel, cobalt, etc.), surfactants, solvents, salts, organic matter, and certain other chemicals. In addition to the synthetic industry , several other sources such as leakage of various chemicals (oil, cleaning agents, fuel, lubricating oils, solvents, and hydraulic oils) in the sea during their shipments, and domestic use of various chemicals without proper drainage management. ( Hwang et al., 2019; Rossi et al., 2019 ).