'Environmental engineering'
[1][2]
is the application of
science and
engineering principles to improve the
environment (air, water, and/or land resources), to provide healthy water, air, and land for human habitation and for other organisms, and to
remediate polluted sites.
Environmental engineering involves
water and
air pollution control, recycling,
waste disposal, and
public health issues as well as a knowledge of
environmental engineering law. It also includes studies on the environmental impact of proposed construction projects.
Environmental engineers conduct hazardous-
waste management studies to evaluate the significance of the such hazards, advise on treatment and containment, and develop regulations to prevent mishaps. Environmental engineers also design municipal water supply and
industrial wastewater treatment systems
[3][4] as well as being concerned with local and worldwide environmental issues such as the effects of
acid rain,
ozone depletion, water pollution and air pollution from
automobile exhausts and
industrial sources.
[5][6]
Educational licensing requirements
To become an environmental engineer, at least a
Bachelor's degree in engineering (usually
civil or
chemical, and more frequently environmental engineering) is required, usually followed by specialized training at the
Master's or
Doctoral level. Additionally, engineers are more frequently obtaining specialized training in law (
J.D.) and are utilizing their technical expertise in the practice of
Environmental engineering law.
Most jurisdictions also impose licensing and registration requirements.
Development of environmental engineering
Ever since people first recognized that their health and well-being were related to the quality of their environment, they have applied thoughtful principles to attempt to improve the quality of their environment. The Romans constructed
aqueducts to prevent drought and to create a clean, healthful water supply for the
metropolis of
Rome. In the 15th century,
Bavaria created laws restricting the development and degradation of alpine country that constituted the region's water supply.
Modern environmental engineering began in
London in the mid-19th century when it was realized that proper
sewerage could reduce the incidence of waterborne diseases such as
cholera. The introduction of drinking water treatment and sewage treatment in industrialized countries reduced waterborne diseases from leading causes of death to rarities.
In many cases, as societies grew, actions that were intended to achieve benefits for those societies had longer-term impacts which reduced other environmental qualities. One example is the widespread application of
DDT to control agricultural pests in the years following
World War II. While the
agricultural benefits were outstanding and crop yields increased dramatically, thus reducing world hunger substantially, and
malaria was controlled better than it ever had been, numerous species were brought to the verge of extinction due to the impact of the DDT on their reproductive cycles. The story of DDT as vividly told in
Rachel Carson's "
Silent Spring" is considered to be the birth of the modern environmental movement and the development of the modern field of "environmental engineering."
Conservation movements and
laws restricting public actions that would harm the environment have been developed by various societies for millennia. Notable examples are the laws decreeing the construction of
sewers in
London and
Paris in the 19th century and the creation of the U.S. national park system in the early 20th century.
Briefly speaking, the main task of environmental engineering is to protect (from further degradation), preserve (the present condition), and enhance (the environment).
Scope of environmental engineering
Pollutants may be chemical, biological, thermal, radioactive, or even mechanical. Environmental engineering emphasizes several areas:
process engineering,
environmental chemistry, water and
sewage treatment (
sanitary engineering), waste reduction/management, and pollution prevention/cleanup. Environmental engineering is a synthesis of various disciplines, incorporating elements from the following:
★
Civil engineering
★
Chemical engineering
★
Public health
★
Mechanical engineering
★
Chemistry
★
Biology
★
Geology
★
Ecology
Environmental engineering is the application of science and engineering principles to the environment. Some consider environmental engineering to include the development of sustainable processes. There are several divisions of the field of environmental engineering.
Environmental impact assessment and mitigation
It is a decision making tool. In this division, engineers and scientists assess the impacts of a proposed project on environmental conditions. They apply scientific and engineering principles to evaluate if there are likely to be any adverse impacts to water quality, air quality,
habitat quality,
flora and
fauna, agricultural capacity,
traffic impacts, social impacts, ecological impacts, noise impacts, visual(landscape) impacts, etc. If impacts are expected, they then develop mitigation measures to limit or prevent such impacts. An example of a mitigation measure would be the creation of
wetlands in a nearby location to mitigate the filling in of wetlands necessary for a road development if it is not possible to reroute the road.
Water supply and treatment
Engineers and scientists work to secure water supplies for potable and agricultural use. They evaluate the water balance within a
watershed and determine the available water supply, the water needed for various needs in that watershed, the seasonal cycles of water movement through the watershed and they develop systems to store, treat, and convey water for various uses. Water is treated to achieve water quality objectives for the end uses. In the case of potable water supply, water is treated to minimize risk of
infectious disease transmittal, risk of non-infectious illness, and create a palatable water flavor. Water distribution systems are designed and built to provide adequate water pressure and flow rates to meet various end-user needs such as domestic use, fire suppression, and
irrigation.
Wastewater conveyance and treatment
Water pollution
Most urban and many rural areas no longer discharge human waste directly to the land through
outhouse,
septic, and/or
honey bucket systems, but rather deposit such waste into water and convey it from households via
sewer systems. Engineers and scientists develop collection and treatment systems to carry this waste material away from where people live and produce the waste and discharge it into the environment. In
developed countries, substantial resources are applied to the treatment and
detoxification of this waste before it is discharged into a river, lake, or ocean system. Developing nations are striving to obtain the resources to develop such systems so that they can improve water quality in their surface waters and reduce the risk of water-borne infectious disease.
There are numerous wastewater treatment technologies. A wastewater treatment train can consist of a primary clarifier system to remove solid and floating materials, a secondary treatment system consisting of an
aeration basin followed by
flocculation and
sedimentation or an
activated sludge system and a secondary clarifier, a tertiary biological
nitrogen removal system, and a final
disinfection process. The aeration basin/activated sludge system removes organic material by growing bacteria (activated sludge). The secondary clarifier removes the activated sludge from the water. The tertiary system, although not always included due to costs, is becoming more prevalent to remove nitrogen and
phosphorus and to disinfect the water before discharge to a surface water stream or ocean outfall.
Air quality management
Industrial air pollution source
Engineers apply scientific and engineering principles to the design of manufacturing and
combustion processes to reduce air
pollutant emissions to acceptable levels.
Scrubbers,
electrostatic precipitators,
catalytic converters, and various processes are utilized to remove
particulate matter,
nitrogen oxides,
sulfur oxides,
volatile organic compounds (VOC), reactive organic gases (ROG) and other air pollutants from
flue gases and other
sources prior to allowing their emission to the atmosphere.
Scientists have developed
air pollution dispersion models to evaluate the concentration of a pollutant at a receptor or the impact on overall air quality from vehicle
exhausts and industrial
flue gas stack emissions.
To some extent, this field overlaps the desire to decrease
carbon dioxide and other
greenhouse gas emissions from combustion processes.
Other applications
★
Contaminated land management and site remediation
★
Risk assessment
★
Environmental policy and
regulation development
★ Solid waste management
★
Hazardous waste management
★
Environmental health and
safety
★
Natural resource management
★
Noise pollution
See also
★
Association of Environmental Professionals
★
Atmospheric dispersion modeling
★
Biofiltration
★
Ecological sanitation
★
Environmental engineering law
★
Engineering geology
★
Environmental design
★
Environmental management
★
Environmental restoration
★
Environmental studies
★
Hydraulic engineering
★
Hydrology
★
Wastewater
★
Water purification
★
Water quality modeling
External links
★
American Academy of Environmental Engineers
★
Confederation of European Environmental Engineering Societies
★
Association of Environmental Engineering and Science Professors
★
European Federation of Association of Environmental Professionals
References
1. Fundamentals of Environmental Engineering, Danny D. Reible, , , CRC Publishers, 1998, ISBN 1-56670-047-7
2. Fundamentals of Environmental Engineering, James R. Mihelcic, Martin T. Auer, and others, , , John Wiley, 1999, ISBN 0-471-24313-2
3. Aqueous Wastes from Petroleum and Petrochemical Plants, Beychok, Milton R., , , John Wiley & Sons, 1967, LCCN 67019834
4. Wastewater Engineering (Treatment Disposal Reuse) / Metcalf & Eddy, Inc., Tchobanoglous, G., Burton, F.L., and Stensel, H.D., , , McGraw-Hill Book Company, 2003, ISBN 0-07-041878-0
5. Workbook of atmospheric dispersion estimates: an introduction to dispersion modeling, Turner, D.B., , , CRC Press, 1994, ISBN 1-56670-023-X www.crcpress.com
6. Fundamentals Of Stack Gas Dispersion, Beychok, M.R., , , author-published, 2005, ISBN 0-9644588-0-2 www.air-dispersion.com
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