Microbial Fuel Cell: Green Energy From Wastewater

Microbial Fuel Cell: Green Energy From Wastewater

Roopalatha H, 0

Water treatment and water purification technology are the most important protective lines to remove mycobacterium, pollutants, and chemicals from water. Water sources can be sources of pollution but should be treated to prevent them from causing disease. Maintaining water purification to ensure a clean supply to meet the growing population worldwide has been an ongoing challenge throughout human history. Water treatment consists of several stages. This includes pretreatment with sedimentation or the use of coarse media, filtration, and subsequent chlorination, the so called multi-barrier principle. The latter enables effective water treatment, allowing each stage to treat and prepare quality water suitable for the next downstream process.

For example, you can use filtration to adjust the water to make sure it is suitable for UV disinfection. The Indian Institute of Technology, Guwahati (IIT) has recently developed a bio-electrochemical device, Microbial Fuel Cell (MFC). An MFC is a bioelectrochemical system that converts an organic compound's chemical or renewable energy into electrical or bioelectrochemical energy through a microbial catalytic reaction at the anode. It can generate green energy by treating wastewater. Organic material such as wastewater in the MFC makes it an eco-friendly device that offers a dual benefit of bioelectricity generation and waste management.

How does the Microbial Fuel Cell Work?
MFC is an attractive alternative technology for wastewater treatment or generating electricity from industrial waste. It uses Bacteria to directly convert organic matter into electrical energy, a new way to recover renewable energy. MFC technology converts chemical energy into electrical energy from organic waste or carbon sources carried out by oxidation processes and electrochemically active bacteria. Power is generated using the electrons generated during the anaerobic oxidation process of the substrate. It consists of two chambers anode and cathode. They are separated by a special membrane, the so-called exchange membrane. The microorganisms used in MFC technology are bio electrochemically active bacteria. The output density produced by the MFC is 1kW/m 3 reactor volume.

The function of Microbial Fuel Cell Technology (MFC) is based on the principle of redox reaction. Bacteria oxidize organic matter to produce carbon dioxide(CO2 ), electrons, and protons. The natural metabolism of microorganisms is used to generate electricity. The substrate is converted into electrons by bacteria. The anode chamber is anaerobic and the cathode chamber is aerobic, while the exchange membrane is either a proton exchange membrane or a proton exchange membrane, connecting the two chambers and diffusing only the protons. At the anode, microorganisms or microorganisms oxidize the fuel/substrate to produce protons, electrons and CO2 . As the protons move through the exchange membrane to the cathode compartment, the electrons use an external circuit to move from the anode compartment to the cathode compartment, producing electrical energy. At the cathode, protons and electrons are consumed and combined with oxygen (O2) to form water. The MFC technology can be further classified as:

Mediator Free Microbial Fuel Cell (MFC)
This type of MFC uses bioelectrochemically activated
bacteria to transfer electrons to the electrodes. It contains electrochemically active redox enzymes such as cytochromes that are present in the outer membrane and aid in the movement of electrons. The biofilm forms on the surface of the anode chamber and transfers electrons directly to the anode via conductivity. Examples of bioelectrochemically active bacteria used in this type are Aeromonas hydrophila and Shewanella putrefaciens.

MFCIs An Attractive Alternative Technology For Wastewater Treatment Or Generating Electricity From Industrial Waste

Mediator Microbial Fuel Cell(MFC)
This type of MFC is electrochemically inert. This means that bacteria in fuel cannot transfer electrons without the help of intermediates such as humic acid. The mediators used in this type are undesirable, toxic, and expensive. The mediator reduces the oxidation state by capturing electrons and transferring them to the anode for the reoxidation process. This type is most commonly used in the laboratory.

Advanced Green technologies in Water Treatment
Advanced green technologies are used in the treatment of wastewater, and they are the most environmentally and economically friendly techniques. Today, growing environmental awareness and tightening government regulations make some traditional wastewater treatment systems questionable. To fill the gaps left by inadequate conventional techniques, AGT has been tested, validated, and deployed as a clean alternative to wastewater treatment.

Generally, every wastewater treatment process involves several steps. The first is to separate the solids from the liquid water. This is achieved by gravity, as solids are heavier than liquid water. Other solid components, such as oil and wood, which are less dense than liquid water, can be removed from the surface by separation. The effluent is then filtered to remove fine solids, chemical particles, and colloidal suspensions of impurities. The resulting filtered water is finally oxidized to reduce or eliminate the toxicity of residual pollutants and disinfect the wastewater before it is released into the environment.

The most commonly used AGT for wastewater treatment is based on the concept of bioreactor. Essentially, a bioreactor comprises bacteria and microorganisms that are placed or immobilized in or on a moving bed biofilm reactor, deposited on a packed bed or fiber bed, or attached to a membrane to form a biofilm. It is a device. Bioreactors are usually equipped with a separator connected to a continuous tank and a mechanical separator intended to facilitate the separation of liquid water from the biosolid. In addition, they contain an aerator to supply oxygen to accelerate the biochemical reactions of living microorganisms. Contact between wastewater and bacteria/microorganisms present on the bioreactor platform triggers biochemical reactions, ultimately converting contaminants or contaminants into less or less toxic forms. In the case of metal containing effluents, the bioreactor inoculated with sulfate-reducing bacteria (SRB) produces hydrogen sulfide, which causes the dissolved metal to precipitate as insoluble metal sulfide and is recovered as a valuable by product.

The technique developed by Chiranjib Bhattacharjee, a professor of chemical engineering at Jadavpur University in Kolkata, uses a combination of electrocoagulation and electroflotation reinforced membrane module (ECEFMM) technology for wastewater treatment. Electrocoagulation is a wastewater treatment technology that uses electric charges to change the surface charge of particles to form aggregates of suspended solids. Electric buoyancy is the production of hydrogen and oxygen produced by passing electricity through water. It also uses bubbles to separate suspended particles from water.