Environmental engineering is defined as the branch of engineering that is concerned with protecting the environment from the potentially deleterious effects of human activity, protecting human population from the effects of adverse environmental factors and improving environmental quality for human health and well-being.
* Consists of the atmosphere, the hydrosphere and the lithosphere * Local
Life sustaining resources are withdrawn from the biosphere and wastes are discharged into the biosphere. Waste discharge degrades the local environment and natural systems restore the degraded quality. When pollution load exceeds the assimilative capacity of biosphere, it shows the signs of stress.
The Impact of Humans upon Environment
Human population have thrived and flourished beyond natural constraints. Wastes generated by these increased number of human beings have upset the natural equilibrium.
* Needs human share in common with most of the higher mammals. Acquired needs
* Needs associated with more advanced civilizations.
Satisfying Natural Needs
* Natural needs are met by unprocessed resources and the wastes generated are generally compatible with, or readily assimilated by the environment. * Early civilization produced little pollution load and natural cleansing mechanisms easily restored the quality of the local environment. * Only as early peoples began to gather together in larger groupings did their impact upon their local environments begin to be significant. * Air pollution in 61 A.D.
* Water pollution by the late eighteenth century in the river Rhine and Thames. * Solid waste problem from the middle ages.
Satisfying Acquired Needs
* Industrial revolution enabled human to satisfy their natural needs easily. * Increasingly they turned their attention to other needs beyond those associated with survival. * Meeting the acquired needs had become a major thrust of modern industrial society. * Acquired needs are usually met by items that must be prepared or manufactured or refined and the production, distribution and use of such items usually results in more complex residuals, many of which are not compatible with or readily assimilated by the environment. * Meeting the acquired needs of modern societies generates more residuals than meeting natural needs, and these residuals are likely to be less compatible with the environment and less likely to be readily assimilated into the biosphere. * As societies ascend the socio-economic ladder, the list of acquired needs or luxuries increases, as do the complexity of the production chain and the mass and complexity of the pollutants generated.
The Impact of the Environment upon Human
Human populations generally manage to ignore their impact on the environment until the ill effects of a polluted environment upon their own health and well-being become evident.
* A wide range of communicable diseases can be spread through elements of the environment by human and animal waste products. * Through immunization and environmental control programs, the major diseases transmitted via the environment have all been eliminated in developed countries. No country, however, is totally immune from outbreaks of environmentally transmitted disease. * Pollution of the atmosphere has also posed severe health problems. * London smog of 1952 caused 4000 deaths.
* New York inversion of 1963 claimed several hundred lives. * The widespread use of chemicals in agriculture and industry has introduced many new compounds posing a potential threat to all humans as they can be spread through air, water and soil as well as through the food chain. * Hazardous chemicals such as DDT, Dioxin have been widely used and their concentrations in the general environment are not currently known. * Residuals of hazardous...