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Mean, green cleaning machine
THE establishment of organisations like the Environmental Protection Agency (EPA) and the celebration of World Earth Day in 1970 reveal that environmental studies have always been deemed important by most scientific agencies.
Besides this, several other regulations for environmental safety have been passed which include the 1970 Clean Air Act, Clean Water Act (1971), International Dumping Act (1972) and the Pollution Prevention Act (1990). Efforts are also being made to explain the “greenness” of a chemical process, controlling the chemical yield, the safety in the handling and processing of environmentally hazardous chemicals, the demands of environmentally safe products, conservation methods of energy and the easiness of product workup and purification. Thus, the theory of green chemistry is based on the notions of preserving our environment from polluting chemicals.
What does it mean?
Green chemistry was basically a research topic initiated by Professor John Warner and his colleagues at the University of Massachusetts, Lowell. Green chemistry is the art of designing chemical products and methods for decreasing or removing the use and creation of hazardous substances. Safer chemical design or green chemistry helps in modifying the chemicals synthetically as environmentally sound and friendly; for example, the discarded plastic casing of a laptop which is made up of chemicals and may end up as a dumped landfill, increasing toxic waste. However, the idea of green chemistry promotes methods which can be used for making that plastic casing from natural, biodegradable compounds and can be reformed and reused as raw material by the action of certain enzymes. By this method there will lesser chances of producing waste materials and resulting pollution. Another aspect of green chemistry is its low demands of energy which would assist in reducing the requirement of petroleum, the main component of modern plastics.
Green chemistry is meant to reduce waste, pollution and energy consumption. Research has proved that the generation of chemicals, plastics and other non-fuel petroleum products use about one million barrels of oil per day, thus forming a huge collection of industries finding new substitutes to products based on petroleum use and waste energy consuming processes. Scientists are looking into trees as a source of obtaining environmentally harmless benign substances which can reduce energy demands. One such substance is lignin, a sticky chemical compound commonly burned as waste in pulp and paper industries. Researchers are also investigating methods to use lignin in making resins, coatings and the binders in glue, all of which are conventionally made from petroleum or natural gas.
Developing methods to design solar cells with paper which will be helpful in lowering the cost of solar energy are also being looked into. However, the biggest obstacle in this regard is converting light into electricity at low temperatures at which the paper may not burn. The green chemistry methodology stresses on the importance of considering the long-term effects on environment of chemicals and metatarsals before they are designed and made, along with its ability to use lesser energy sources than the one it is replacing. The green chemistry programme has persuaded the academia, industries, government agencies and the non-governmental organisations for endorsing the use of chemistry for pollution control by designing the chemical products and methods that are aimed at decreasing the manufacturing of hazardous chemicals.
Green chemistry is now associated with organic and inorganic chemistry, biochemistry, analytical chemistry and the physical chemistry. Up till now, the key achievements in the development of green chemistry are some chemical procedures like the use of supercritical carbon dioxide as a green solvent, aqueous hydrogen peroxide for purifying oxidations and the utilisation of hydrogen in asymmetric synthesis. A few examples of practical green chemistry sciences are the supercritical water oxidation, water reactions and dry media reactions. The study of bioengineering is also being considered as a capable technical method for attaining green chemistry objectives. For example, many vital chemical processes can be synthesised in biologically engineered organisms, one of them being Shikimate, which is a Tamiflu precursor, and is fermented by Roche in the bacterial body.
Uses
Green chemistry can be helpful in designing chemical synthesis for preventing the production of waste products, leaving no traces of waste for chemical processing or cleaning. Thus, it can develop effective and safer products. Green chemistry can also use raw materials and feed stocks made from agricultural products, which are renewable instead of depleting feed stocks which are made from fossil fuels like petroleum, natural gas or coal. It is aimed at using catalytic reactions which are capable of being used many times and decreasing the collection of waste as compared to Stoichiometric reagents – used in surplus and cannot be used the second time. Green chemistry helps in carrying out chemical reactions at an ambient temperature and pressure. It also evaluates the chemical procedures for controlling the formation of harmful by-products and for reducing the chances of chemical accidents like explosions, fires and the release of toxic gases in the environment. The Supra molecular chemistry project is a part of the green chemistry programme and is working to design reactions capable of occurring in the solid state without the use of solvents. The solid state reaction can take place in the presence of ultra violet light with 100 per cent productivity. Another green chemistry project is green embalming which will help in lowering the use of millions of gallons of formaldehyde and phenol-based preserving fluids which are being interred with the deceased.
Green chemistry projects are being considered as one of the most effective ways of combating pollution hazards to the environment. The success and efficacy of these projects depend greatly on the practical usage of the proposed methods of product design and consumption. For that, we need to keep our fingers crossed and wait.
The writer is a qualified dentist and a freelance contributor
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