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Fundamentals of green chemistry
- Date_TXT
- Indian : Bookboon , 2019
- Auteur
- BASHIR AHMAD DAR
- Type de document
- Livre
Description :
The term “green chemistry” was introduced by Paul Anastas in 1991. There can be no denying that in years past, and even at present, chemistry has been misused in many respects, such as the release of pollutants and toxic substances and the production of non-biodegradable materials, resulting in harm to the environment and living things, including humans. It is now obvious that chemical science must be turned away from emphasis upon the exploitation of limited resources and the production of increasing amounts of products that ultimately end up as waste and toward the application of chemistry in ways that provide for human needs without damaging the Earth support system upon which all living things depend. Fortunately, the practice of chemical science and industry is moving steadily in the direction of environmental friendliness and resource sustainability. The practice of chemistry in a manner that maximizes its benefits while eliminating or at least greatly reducing its adverse impacts has come to be known as green chemistry.
There may be a confusion that green chemical pathway is almost benign, but it is not a perfectly true statement because there cannot be any chemical, which is perfectly benign and therefore, green chemistry diverts use of chemicals from malign to benign manner. Common salt is necessary for life, but it may develop hypertension, if taken in excess; so is the case with carbohydrates (sugar), which are required for providing energy for daily routine life but if given in excess, it may be harmful to humans.
Therefore, shifting from less benign (more malign) to more benign (less malign) process may be considered as a green chemical approach. Someone has well said that “A matter may act as poison if given in large amount, and a poison if given in very small amount may act as nectar”.
This is the basic concept of homoeopathy, which deals with very small concentrations of toxic chemicals and surprisingly enough, it may cure many dreadful diseases. The efficiency of these homoeopathic medicines increases on dilutions.