Environmental issues such as climate change, water pollution and renewable energy have become more and more important in everyday life. Many people recognize chemistry and the chemical industry as harmful to the environment. However, many new advances and scientific researches in the field of chemistry are helping us develop more environment friendly materials and applications, while conserving the quality and the lifestyle we anticipate.
Over the years, the industry and wider public have become aware of the damaging effects of some past practices and the need to protect the environment. In the past, few were aware of the possibly negative effects our modern lifestyle might have on the environment, and rather saw only the positive potential for creating new, useful materials and products.
Research in chemistry has revealed that industrial processes in chemistry could play a role in developing solutions to environmental issues such as climate change, waste management, recycling, and energy efficiency. Without chemists, we might never have truly understood these problems. Profound changes are still being made to provide other solutions.
As you know carbon dioxide is one of the green houses gases which are causing global warming, by knowing the chemistry of these gases you can think of solutions that can reduce the effect of greenhouse gases on our environment. So, chemistry easily helps us in solving most of our current issues on environmental pollution.
Electro Chemistry and its Effect on Environmental Issues
A growing world population with rising industrial demands has led to the situation where the protection of the environment has become a major issue and vital factor for the future development of industrial processes. Electrochemistry offers promising approaches for the prevention of pollution problems in the process industry. The built-in advantage is its environmental compatibility, due to the fact that the main chemical agent, the electron, is a ‘clean reagent’. The approaches include both the treatment of efﬂuents and waste and the development of new processes or products with less harmful effects, often represented as process-integrated environmental protection: cathodic and anodic treatment of efﬂuents and waste.
This includes all methods where toxic material is removed from gases, liquids or even solids at the ﬁnal stage of an industrial process, process-integrated environmental protection. This includes recycling of valuable material and substitution of waste-producing processes by a cleaner electrochemical technology with little or no waste production.
Elimination and destruction of pollutant species can be carried out directly or indirectly by electrochemical oxidation/reduction processes in an electrochemical cell without continuous feed of redox chemicals. In addition, the high selectivity of many electrochemical processes helps to prevent the production of unwanted by-products, which in many cases have to be treated as waste.
Advantages of electrochemical processes are generally:
1. Adaptability — direct or indirect oxidation and reduction, phase separation, concentration or dilution, and treatment of small to large volumes from microliters up to millions of litres.
2. Energy efﬁciency — electrochemical processes generally have lower temperature requirements than their equivalent non-electrochemical counterparts, e.g. thermal incineration. Electrodes and cells can be designed to minimize power losses caused by different current distribution, voltage drop and side reactions.
3. Cost effectiveness — cell constructions and peripheral equipment are generally simple and, if properly designed, also inexpensive.
An increasing demand for off-gas puriﬁcation has encouraged the development of new concepts of electrochemical gas puriﬁcation techniques. Many gaseous pollutants, such as chlorine, hydrogen sulphide, nitrous oxides, or sulphur dioxide permit electrochemical conversion in an aqueous environment, since the standard potentials of the corresponding reactions.
This picture shows electrochemical gas puriﬁcation by inner cell and outer cell processes.
Electrochemical processes can provide valuable contributions to the protection of the environment through application of effluent treatment and production-integrated processes for the minimization of waste and toxic compounds. Examples of effluent treatment include electrochemical reactors for removal of metal ions from waste water, and new electrochemical reduction techniques for the purification of flue gases.
Electrochemical technology is an important and empowering discipline in many areas of environmental treatment, including clean synthesis, monitoring of process efficiency and pollutants, removal of contaminants, water sterilization, clean energy conversion, and the efficient storage and use of electrical energy. The field of environmental electrochemistry has witnessed many developments and has demonstrated many successes.
Chemical Systems and Equilibrium
There is literally thousands of chemical equilibrium present the environment. A very short list is: the solubility of atmospheric gases in
fresh and/or salt water, the solubility of carbonate minerals as a function of pH, photochemical reactions of “greenhouse gases” in the upper atmosphere, the concentration of oxygen as a function of depth and temperature in the ocean. These are but a few of many possible examples.
In a chemical reaction, chemical equilibrium is the state in which both reactants and products are present at concentrations which have no further tendency to change with time. Usually, this state results when the forward reaction proceeds at the same rate as the reverse reaction. The reaction rates of the forward and reverse reactions are generally not zero but, being equal; there are no net changes in the concentrations of the reactant and product. This process is called dynamic equilibrium.
Types of chemical systems and equilibrium in the environments are in the gas phase. Rocket engines, the industrial synthesis such as ammonia in the Haber-Bosch process takes place through a succession of equilibrium steps including adsorption processes. Also atmospheric chemistry, and seawater and other natural waters: Chemical oceanography.