The presence of radionuclides and heavy metals in our surroundings has become the most serious environmental concern. These contaminants or pollutants fail to degrade on their own over time and must be removed or neutralized. Microorganisms act as natural catalysts in the process of transformation of toxic metals into non-toxic ones. This is why there is an increased interest in the understanding of microbiological processes which help in remediation of these toxic wastes from the environment (Francis 1990).
Microorganisms basically work by mobilization and immobilization of heavy metals and radioactive wastes. Mobilization include processes such as methylation of wastes and thus making them volatile substances, chelation of metals to certain ligands which help to neutralize their toxic effects, autotrophic and heterotrophic leaching.
Alternatively, immobilization occurs as an outcome of sorption to cell components, transport into cells, precipitation as insoluble compounds etc. (Gharieb et al. 1998), (Sayer et al. 1997).
In nature, the radioactive wastes and heavy metals can be present in a number of forms such as oxides, superoxides, peroxides, sulphates, nitrates, citrates, carbonates etc. Microorganisms change these forms or states of toxic substances into less toxic or non toxic states. They carry out these transformations due to their sensitivity towards presence or absence of free electrons. Under aerobic conditions, the microorganisms direct oxygen to act as electron acceptor and under anaerobic conditions the suphate group, nitrate group, phosphate group or carbonate group etc. take up the electrons (Francis 1990).
The process of microbial transformation of radionuclides and heavy metals is considered important becau...
... middle of paper ...
...a (SRB).
3.2.4 Biotransformation of Technetium
Technetium can exist in a large number of oxidation states such as Tc, Tc(III), Tc(IV), Tc(V), Tc(VI) and Tc(VII). It is produced in large amounts during the nuclear fission reaction of U235 and during production and testing of nuclear weapons (Yoshihara 1996). Technetium can precipitate out from the solution by oxidation as well as reduction reactions. During oxidation of Tc(III) and Tc(IV), hydrolysis reaction takes place which gives out precipitates of Technetium from the solution.
Also, Sulphate Reducing Bacteria and many other fermentatie bacteria can bring about the anaerobic reduction of Tc(VII) to Tc(IV) which can easily separate out as precipitates in the solution (Lyalikova and Khiznyak 1996, Pignolet et al. 1989, Tagami and Uchida 1996, Wildung et al. 2000, Francis et al. 2002, Khijniak et al. 2003).
...rogen In Wastewater To Protect A Region's Waterways." BioCycle 44 (2003): 18. BigChalk. 20 Oct. 2005.
What if there was a way to clean up radioactive waste spills? To clean it out of waters for safe consumption? For years and years people have seen the ways that bacteria can clean up oil spills and nuclear waste, and where baffled on how they did so. How did something so small, clean up a mess so big? Gemma Reguera and her team at Michigan State have solved the age long question. They have decided that bacteria do so by a hair like pili. The pili acts much like a conductive wire, by transferring electrons. Geobacter Sulfurreduncen is one of the many bacteria that do so. The energy conducted by the pili, in turn powers the bacteria. Geobacter, for short, is able to both isolate and, in a sense, kill off uranium in contaminated ground water. So my question is, how effective would it be to clean out mass amount of uranium? First I had to learn about Geobacter and the types of waste created.
There are numerous types of bacteria that can be found in every environment. Each bacterium has different morphology which includes shape, texture and pigment production. These bacteria also have different food requirements which are important in being able to identify a microorganism. Microorganisms are a diverse group containing all bacteria a single cell prokaryotic organism that is found in every type of environment, archea single cell microorganism that lacks nuclei and almost all microorganisms are protozoa a unicellular eukaryotic organism. By identifying the causative agent of a bacterium within an individual, an antibiotic can be developed to prevent health issues. Microorganisms are also used to make certain food products for human consumption. An example of this would be the production of yogurt. It has probiotics that help with digestive abnormalities amongst other things. Probiotics are microorganisms that are consumed to provide health benefits in the body. Probiotics work by replacing the disturbed microbe with ones that are useful to digest. With the methods that wer...
“[…] a treatability technology that uses biological activity to reduce the concentration or toxicity of a pollutant. It commonly uses processes by which microorganisms transform or degrade substances hazardous to human health or the environment.” This statement is often used to describe the fundamental aim of bioremediation around the world. Richard Raymond, who is thought by some the father of bioremediation, foresaw that “adding acclimated microorganisms to contaminated sites could become a common practice” thus benefiting society by attacking the pollutants and converting them into harmless products to humanity and animal habitat. Bioremediation technologies can be generally classified as ex situ in which treatments involve the physical removal of the contaminated material for treatment process and in situ techniques that involve treatment of the contaminated material in place. Although the use of living systems to make a product has an established history, bioremediation have generated many social and ethical controversies to the foreground. The idea promoted by Richard Raymond illustrates a direct connection between bioremediation and its potential to restore contaminated environments inexpensively yet effectively.
Technetium-99m was used in an imaging demonstration in 1964. As a result of its favorable physical and chemical properties, it quickly became one of the most used radioisotopes for nuclear medical procedures (Keevil). This radioisotope can be found in nuclear medicine procedures that involve diagnostics of the heart, kidneys, lungs, liver, spleen, bones, and blood flow (GE Hitachi Nuclear Energy).
Slaughterhouses produce high strength wastewater (EC, 2005), which contain high levels of biodegradable organic matter, as faecal, undigested food, blood, suspended material (Jian and Zhang, 1999). Slaughterhouse wastewater composition in terms of organic strength, inorganic elements, alkalinity, and pH is adequate for biological treatment (Massé and Masse, 2000). Design criteria for slaughterhouse wastewater treatment plants are widely published (Travers & Lovett, 1984; Li et al, 2008).
Activate sludge system: Using natural biological such bacteria in which they help to remove contaminant.
When the water comes into contact with the pyrite, the chemical reactions that take place causes the water to increase in pH which will dissolve heavy metals which stay in solution. However, when the pH levels reach a certain stage, the iron can then precipitate out, coating sediments with the characteristic yellow, red or orange colourings (D.E.P. 2, 2002; U.S.G.S.; U.S.E.P.A., 2002). The rate that A.M.D. advances is also influenced by the presence of certain bacteria (Doyle; U.S.G.S). A.M.D that has dissolved heavy metals such as copper, lead and mercury can contaminate ground and surface water. Especially at risk are mines that are located above the water table (Keller, 2000; D.E.P. 2, 2002). The sources of water that get polluted can be surface water that permeates into the mine, shallow ground water flowing through the mine or any water that comes into contact with the waste tailings produced by mines.
Microbial decomposition releases nutrients into the environment that are needed by other organisms. Microbes are also involved in the cycling of many other important compounds in — and between — ecosystems, including oxygen, carbon and nitrogen. Many microbes use the energy of sunlight to convert carbon dioxide to oxygen, which we need to breathe. As they do this, they create new organic material — themselves — which are then eaten by other organisms. In this way, the cycling of nutrients and energy
Oxygen (O) is one of the most important ions present in the body, making up 61% of the body’s mass. It aids in the destruction of harmful bacteria, while preserving the bacteria that is beneficial for the body. Oxygen takes on its role, and transfers the bacteria absorbed into the lungs, to the cells, allowing for cell respiration. Oxygen allows for the replacement of old cells, protection of the new ones, production of energy from the food, and decomposition of other foods (“Oxygen and Human Body,” n.d.). Oxygen is also vital to produce an activity known as metabolism, which is ‘the sum of the physical and chemical processes in an organism by which its material substance is ...
Microorganisms play an important role in our life: helps us to digest our food, decompose wastes and participate in various life cycles. They are diverse and have adapted to inhabit different environments including extreme conditions, such as hot vents under the ocean to ice caps; hence known as extremophiles. There are more microorganisms present in us than there are cells, and the various microorganisms are bacteria, viruses, fungi and protozoa. Many people associate microorganisms as death and diseases causing agents; also frequently compared to dirt. Although some microorganisms are responsible for causing diseases, most microorganisms’ original hosts are not the human body so are not pathogenic, but commensal. This essay will discuss the numerous beneficial microorganisms that carry out processes in biotechnology, agriculture, industries and environment; necessary to sustain life. First of all, essential uses of microorganisms are seen in the environment, as they play a vital role in many of the nutrient cycles. For instance, carbon fixation from the atmosphere during the carbon cycle by autotrophic bacteria, such as cyanobacteria; synthesizes organic molecules for other organisms and release oxygen for our consumption. In addition, microorganisms are vital participants of the food chain since they act as decomposers; breaking down dead organisms and organic materials and releasing minerals for uptake by living organisms and CO2 back into the atmosphere for photosynthetic organisms. Microorganisms, known as methanogens, influence the carbon cycle by converting CO2 in their cells to methane and releasing it into atmosphere; thus increasing methane concentration whereas methanothrophs consume methane from the atmosphere, lead...
When a chemical penetrates an organism's cells from the environment, a process called bioaccumulation begins. One type of bioaccumulation is uptake, which is a complex process that is still not fully understood. Researchers have learned that chemicals tend to move, passively from a place of high concentration to one of low concentration. There are many factors that may increase the chemical potential of certain substances.
One of the greatest environmental issues that the world faces is throwing away thrash and products that contain hazardous chemicals that affect the environment negatively. The most common way people throw away their trash is by dumping chemicals down the drains. Many communities, wastewater treatments plants, and private septic systems contain a biological process that breaks down sewage when it goes through. When chemicals go down...
The main aim of wastewater treatment is to produce wastewater that can be safely disposed off, without causing harm or infection in humans and other animals. Wastewater generated by all processes - ranging from the personal use of water to industrial use - needs to be disposed in rivers and lakes. The pathogens present in wastewater can cause serious enteric infections and therefore need to be removed before they can proliferate via the sources of water such as lakes and rivers. The conventional methods of wastewater treatment are successful in a considerable reduction of organic and microbial load in wastewater. They also make use of certain microorganisms that aid the purification process. Further studies in the field have lead
...ow of anthropogenic carbon, the mobilization probably occurred from a complex combination of redox changes. The organic carbon influenced the microbially mediated dissolution of Fe-oxyhydroxides and freed surface bound arsenic. As(V) is not the stable form of dissolved arsenic in highly reducing conditions, so it’s quickly reduced to the more mobile and toxic As(III). Future remediation efforts may utilize iron, aluminum and manganese oxides or microbial communities as As(III) remediation techniques. But before remediation efforts begin, a more complete understanding of arsenic mobilization is needed. Future studies need to focus on the rate that As(V) is desorbed from surface binding sites of Fe-oxyhydroxides. Quantifying the rate will confirm or disprove whether dissolution reduction Fe-oxyhydroxides play a major role on the arsenic concentrations in groundwater.