Role Of Chemistry In Environment Protection

Role Of Chemistry In Environment Protection

Bijoylal Bandyopadhyay

Department Of Chemistry, Vidyasagar University

 

Abstract

 In the modern era where researchers are working to establish a human presence in the entire solar system,  AI assisting in the efficient reduction of the human workforce efficiently, biologists are decoding genes and DNAs to create vaccines and medications for diseases that were incurable previously, nuclear fission and fusion providing enormous opportunities to achieve reliable energy supply, etc. Along with the advancement of science and technology, major threats are thriving rapidly such as pollution and depletion of natural resources. On the one hand, uncontrolled natural resource consumption leads to irreversible depletion and pollutes nature. On the other hand, pollution harshly affects the atmosphere, causes health hazards, destroys biospheres, tempers the food cycles, denatures biological processes in living beings, etc. In such a vulnerable situation chemistry shows alternative and innovative paths that are sustainable and environmentally friendly simultaneously.

Introduction

Every physical and biological process in nature is primarily a chemical reaction whether it causes negative or affirmative effects but in the conservation of nature, chemical science involves two main approaches such as green chemistry and environmental chemistry. 

Green Chemistry

Green Chemistry is a relatively new emerging field that strives to work at the molecular level to achieve sustainability. Green Chemistry is defined as the “design of chemical products and processes to reduce or eliminate the use and generation of hazardous substances.” The most important aspect of Green Chemistry is the concept of design. Design is a statement of human intention and one cannot do design by accident. It includes novelty, planning and systematic conception. The Twelve Principles of Green Chemistry are “design rules” to help chemists achieve the intentional goal of sustainability. Green Chemistry is characterised by careful planning of chemical synthesis and molecular design to reduce adverse consequences. Because of this goal, it is not surprising it has been applied to all industry sectors. From aerospace, automobile, cosmetics, electronics, energy, household products, and pharmaceutical, to agriculture, there are hundreds of examples of successful applications of award-winning, economically competitive technologies.

The Twelve Principles

The twelve principles are a guiding framework for the design of new chemical products and processes, applying to all aspects of the process life-cycle from the raw materials used to the efficiency and safety of the transformation, the toxicity and biodegradability of products and reagents used. Those are

1. Prevention
2. Atom economy
3. Less hazardous chemical synthesis
4. Designing safer chemicals
5. Safer solvent and auxiliaries 
6. Design of energy efficiency 
7. Use of renewable feedstocks
8. Reduce derivatives
9. Catalysis
10. Design for degradation
11. Real-time analysis for pollution prevention
12. Inherently safer chemistry for accident prevention 

Accomplishments by industry

There are numerous examples of successful industrial changes using Green Chemistry. The following section is not intended to present an exhaustive list of the awards winners but rather introduce a few key examples to show how the industry has been adapting to the new challenges of Green Chemistry.

As a first example, a greener synthetic pathway was attributed to Eastman for its enzymatic esterifications. This biocatalytic process runs under mild conditions, minimises the formation of byproducts and saves energy, resulting in increased efficiency. Overall hundreds of litres of organic solvents were eliminated from the previous process.

In 2008, researchers at Dow AgroSciences were rewarded for the design of green pesticides. While trying to understand the structure–activity relationships of natural biopesticides in an effort to predict analogues that would be more active, they designed Spinetoram. The company expects that the production of this new pesticide will eliminate “about 1.8 million pounds of organophosphate insecticides during its first five years of use.”

In 2006, Merck developed a greener synthetic pathway for Sitagliptin, a chiral β-amino acid derivative used for the treatment of type 2 diabetes. The approach was based on a novel asymmetric catalytic hydrogenation of unprotected enamines which avoided the need for excessive derivatization. Merck presented a three-step synthesis, claiming an increase in the overall yield. Implementing the new route on a manufacturing scale showed a significant reduction in the amount of waste, making the new process a more cost-effective option.

In 2004, BMS developed a new approach to Paclitaxel, the active ingredient in the anticancer drug Taxol®. Paclitaxel is commercially produced from the naturally occurring precursor 10-deacetylbaccatin III (10-DAB) through an 11-step synthesis. This “semisynthetic route”, which was first developed as an economically viable approach to the molecule, was not without certain environmental concerns. A more sustainable process was therefore investigated by BMS using the latest biotechnological advances. Instead of synthesising Paclitaxel from a precursor, the active compound was extracted directly from plant cell cultures. This method eliminated all organic solvents, hazardous reagents, and additional steps associated with the previous process. BMS is now manufacturing Paclitaxel using only plant cell cultures.

In 2002, Pfizer developed a new greener synthetic pathway for the redesigned synthesis of sertraline, an active ingredient used to treat depression. The new process offered substantial environmental benefits while improving the overall efficiency and selectivity of the synthesis. Specifically, a three-step sequence in the original manufacturing process was streamlined to a single one.91 Raw material use was significantly cut and the process was optimised so that all steps could be performed in ethanol. This last change eliminated the need to use, distil, and recover four toxic solvents (methylene chloride, tetrahydrofuran, toluene, and hexane).

One final noteworthy example is the work accomplished in 1998 by Solutia, Inc. on the elimination of chlorine from the synthesis of 4-aminodiphenylamine. Researchers at the company explored new routes to a variety of aromatic amines, including 4-aminodiphenylamine (4-ADPA), in order to eliminate the formation of aqueous waste streams containing high levels of inorganic salts. There were also concerns about the hazard associated with the storage and handling of large quantities of chlorine gas. The solution came with a new synthesis to 4-ADPA that utilises the base-promoted, direct coupling of aniline and nitrobenzene. The environmental benefits were significant and included a dramatic reduction in waste generated.

 

Environmental Chemistry:

Environmental chemistry is a field of study that examines the chemical and biochemical processes that occur in the environment and the impacts of human activities on these processes. It involves the study of the sources, transport, fate, and effects of chemical species in the air, water, and soil, as well as the interactions between these species and living organisms. Environmental chemistry also includes the development of technologies and strategies for reducing or eliminating the release of harmful chemicals into the environment, and for cleaning up contaminated sites.

 

Environmental chemistry also encompasses many sub-disciplines, including

• Air pollution chemistry: the study of the chemical compounds and processes that contribute to air pollution, and the effects of these pollutants on human health and the environment.
• Aquatic chemistry: the study of chemical processes that occur in freshwater and marine environments, including the behaviour of pollutants in these systems and their impacts on aquatic life.
• Soil chemistry: the study of the chemical and biological processes that occur in soils, including nutrient cycling and the behaviour of pollutants in soil.
• Environmental analytical chemistry: the use of analytical techniques to measure the presence and concentration of chemical pollutants in various environmental matrices, such as air, water, soil, and living organisms.
• Green chemistry: the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances, to make industries more sustainable.
• Environmental toxicology: the study of the impacts of chemical pollutants on living organisms and ecosystems.

Overall, Environmental chemistry is an interdisciplinary field that involves knowledge from chemistry, biology, physics, geology, and other sciences to understand, prevent and mitigate the impacts of human activities and natural phenomena on the environment and human health.

In addition to the sub-disciplines I mentioned earlier, here are a few more topics that are often studied within the field of environmental chemistry:

• Climate change: the study of the chemical and physical processes that contribute to changes in the Earth's climate, and the impacts of these changes on human and natural systems.
• Acid rain: the study of the chemical processes that lead to the formation of acidic precipitation, and the effects of acid rain on forests, lakes, rivers, and other natural resources.
• Ozone depletion: the study of the chemical processes that lead to the depletion of the ozone layer, and the effects of this depletion on human health and the environment.
• Hazardous waste: the study of the properties and behaviour of hazardous waste materials, and the development of technologies and management strategies for their safe disposal.
• Water treatment: the study of the chemical and physical processes used to treat drinking water and wastewater, to remove or neutralise pollutants and make them safe for human consumption and/or release back into the environment.
• Bioremediation: the use of microorganisms or other biological agents to break down or neutralise pollutants in the environment
• Environmental radioactivity: the study of radioactive substances in the environment and how they impact the health of humans and other organisms.

As you can see, Environmental chemistry is a broad field that covers a wide range of topics, and it is crucial for the protection of human and environmental health and the sustainability of our planet.

Another critical area of research within environmental chemistry is the study of endocrine-disrupting chemicals (EDCs), which are chemicals that can interfere with the normal functioning of hormones in living organisms. These chemicals can have a wide range of effects on human and animal health, including reproductive and developmental problems, cancer, and immune system dysfunction. EDCs can be found in many common consumer products such as plastics, pesticides, and personal care products, and their persistence in the environment and potential to bioaccumulate in living organisms make them a major concern for environmental health.

Another area that is of major concern is Nanoparticles. They are extremely small particles, measuring less than 100 nanometers in diameter, that have unique properties and behaviour compared to bulk materials. They are widely used in many industrial and consumer products, such as electronics, cosmetics, and medical devices. However, their small size and large surface area can also make them more toxic and more easily transported through the environment than larger particles.

Microplastics, tiny plastic particles measuring less than 5mm, are widely spread in the environment, they can be found in oceans, rivers, soils, and even in the air. They are usually the result of larger plastic debris breaking down over time, but they can also be released into the environment through cosmetics, cleaning products, and industrial processes. Microplastics can have negative effects on aquatic life, wildlife, and human health.

Lastly, Environmental chemistry also focuses on the study of new emerging contaminants, which are new chemical compounds that are not yet regulated or well understood, but that have the potential to cause harm to human health and the environment. These contaminants can come from a wide range of sources, including industrial processes, consumer products, and emerging technologies.

All these topics and many more are important areas of study within environmental chemistry, as understanding the chemical processes and impacts on the environment and human health is crucial to developing effective solutions to environmental problems and creating a sustainable future.

Another area is that environmental chemistry plays a crucial role in the assessment and management of contaminated sites such as landfills, Superfund sites, and brownfield sites. These sites may contain a variety of hazardous chemicals and pollutants that can pose a risk to human health and the environment. Environmental chemists are involved in characterising the nature and extent of the contamination, developing plans for cleaning up the site and monitoring the effectiveness of the cleanup efforts. This can involve a wide range of activities, such as soil and groundwater sampling, laboratory analysis of samples, risk assessment, and the design and implementation of remediation technologies.

In addition to the above, Environmental chemistry plays an important role in the study of climate change and its impacts on the environment. Environmental chemistry research can help understand the causes, consequences, and potential solutions to climate change, including the study of the chemistry of greenhouse gases and the role of the ocean in absorbing carbon dioxide.

Overall, Environmental chemistry has a wide range of applications and is essential to many aspects of environmental protection and sustainability. Understanding the chemical processes that occur in the environment and the impacts of human activities on these processes is crucial to developing effective strategies for protecting human health and the environment, and for managing and preserving the Earth's natural resources.

Another crucial area where environmental chemistry is applied is the study of the environmental fate and transport of pollutants, which refers to how contaminants move through the environment and how they are affected by physical and chemical processes such as evaporation, dissolution, adsorption, and biodegradation. This knowledge is important for determining the potential risks of pollutants to human health and the environment, as well as for developing strategies for reducing or preventing their release into the environment.

Another area where environmental chemistry plays a vital role is the monitoring and assessment of water quality. Environmental chemists often analyse samples of surface water, groundwater, and drinking water for the presence of pollutants such as heavy metals, pesticides, and microorganisms. This data is used to assess the overall water quality and to identify potential sources of pollution that need to be addressed.

Environmental Chemistry also has a vital role in the design and assessment of sustainable technologies. Many of today's most pressing environmental problems, such as climate change and air pollution, are caused by the burning of fossil fuels. Environmental chemists are helping to develop alternative energy technologies, such as solar and wind power, and to understand the environmental impacts of these technologies. They also help evaluate the life cycle of products and processes, including the raw materials, production, use and disposal stages, to identify opportunities to reduce environmental impact.

Overall, Environmental chemistry is a wide and interdisciplinary field, it encompasses a broad range of areas and disciplines, from air and water pollution to climate change, toxicology, and the fate and transport of pollutants. Environmental chemists play a vital role in identifying, understanding, and addressing the chemical and environmental challenges facing our world, and developing solutions for a sustainable future.

Conclusion

In conclusion, chemistry plays a crucial role in environmental protection by providing the tools and knowledge necessary to understand and address ecological problems. Chemistry helps us understand how pollutants and contaminants are created, how they interact with the environment, and how to best remove or reduce them. It also helps us understand how to develop sustainable and renewable resources that can replace fossil fuels and other non-renewable resources that are harmful to the environment. The future of our planet depends on the continued collaboration of chemistry and other sciences to find sustainable solutions that preserve our natural resources and protect the environment for future generations.

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