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...
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...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).
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.
...rogen In Wastewater To Protect A Region's Waterways." BioCycle 44 (2003): 18. BigChalk. 20 Oct. 2005.
“[…] 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.
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.
Survey, collection of samples, isolation, identification and preservation of microbes and characterization of OSW and Physico-chemical studies
ECOSYSTEMS: Microbes obtain energy from their environment. Like humans, many microbes do this by eating plant and animal material. A typical microbe buffet consists of waste from humans and other animals, dead plants and animals, and food scraps. Bacteria, fungi and algae all take part in decomposing — or breaking down — this waste material. Without them, the world would quickly be overrun with discarded food scraps, raw sewage and dead organisms.
Bioremediation is the use of microbes to clean up contaminated soil and groundwater. Microbes are very small organisms, such as bacteria, that live naturall...
...ate minerals from ores containing low-levels of minerals (Hofkin, 2010). Microorganisms have been beneficial to humans in the past too - the Weil-Felix test for typhus. A patient infected with Rickettsia prosecute will have antibodies to this bacterial species circulating in their blood which can bind to Proteus OX19, harmless soil bacterium. Physicians used to diagnose typhus by mixing patient's blood serum with Proteus OX19, positive test for typhus is confirmed when Proteus OX19 is clumped together (Hofkin, 2010). Overall, microorganisms are vital for life on Earth and are more than disease causing agents. Few microorganisms are pathogenic, but many more has an important role in various ecological and industrial processes, maintaining human health; and every day new discoveries are made that shows microorganisms are crucial for scientific advances to be made.
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 ...
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 reason behind using these specific elements is behind their ability to generate ionizing radiation. When cobalt 60 goes through radioactive decay, “the spontaneous breakdown of an atomic nucleus resulting in the release of energy and matter from the nucleus” (Crouse, n.d.), that released energy can penetrate items and break down the chemical bonds. These chemical bonds are the DNA of microbes and bacteria. If a bacteria’s DNA cannot be transcribed it loses its ability to reproduce and therefore it dies. This accomplishes the goal of irradiation which is to inhibit the growth of microbes and bacteria to increase the shelf life of consumable foodstuffs. “The effectiveness of the process depends also on the organism’s sensitivity to irradiation, on the rate at which it can repair damaged DNA, and especially on the amount of DNA in the target organism”. (“The effectiveness of the”, n.d)
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.
Bioaccumulation is the slow process of increasing chemical content in a living organism over time. This happens either because the chemical is taken up faster than it can be used. It is also because the chemical cannot be broken down for use by the organism. Compounds that are harmful to health, such as mercury, can accumulate in living tissues of organism. Contamination with mercury is a good example of the bioaccumulation process. Usually, mercury is taken up by phytoplankton and bacteria. Small fish consume the phytoplankton and bacteria and accumulate the mercury. The small fish are in turn consumed by larger fish, which can become food for humans and animals. The result can be the buildup of large concentrations of mercury in human and