Environmental engineering

Environmental engineeringis a professionalengineering disciplinerelated toenvironmental science.It encompasses broadscientifictopics likechemistry,biology,ecology,geology,hydraulics,hydrology,microbiology,andmathematicsto create solutions that will protect and also improve the health of living organisms and improve the quality of the environment.^[1]^[2]Environmental engineering is a sub-discipline ofcivil engineeringandchemical engineering.While on the part of civil engineering, the Environmental Engineering is focused mainly onSanitary Engineering.^[3]

Environmental engineering applies scientific and engineering principles to improve and maintain the environment to protect human health, protect nature's beneficial ecosystems, and improve environmental-related enhancement of the quality of human life.^[1] Environmental engineers devise solutions forwastewater management,waterandair pollutioncontrol,recycling,waste disposal,andpublic health.^[2]^[4]They designmunicipal water supplyandindustrial wastewater treatmentsystems,^[5]^[6]and design plans to preventwaterborne diseasesand improve sanitation in urban, rural and recreational areas. They evaluate hazardous-waste managementsystems to evaluate the severity of such hazards, advise on treatment and containment, and develop regulations to prevent mishaps. They implementenvironmental engineering law,as in assessing the environmental impact of proposed construction projects.

Environmental engineers study the effect of technological advances on the environment, addressing local and worldwide environmental issues such asacid rain,global warming,ozone depletion,water pollutionand air pollution fromautomobile exhaustsandindustrial sources.^[2]^[7]^[8]^[9]

Most jurisdictions impose licensing and registration requirements for qualified environmental engineers.^[10]^[11]^[12]

Etymology

The word environmental has its root in the late 19th-century French word environ (verb), meaning to encircle or to encompass. The word environment was used by Carlyle in 1827 to refer to the aggregate of conditions in which a person or thing lives. The meaning shifted again in 1956 when it was used in the ecological sense, whereEcologyis the branch of science dealing with the relationship of living things to their environment.^[13]

The second part of the phrase environmental engineer originates from Latin roots and was used in the 14th century French as engignour, meaning a constructor of military engines such astrebuchets,harquebuses,longbows,cannons,catapults,ballistas,stirrups,armouras well as other deadly or bellicose contraptions. The word engineer was not used to reference public works until the 16th century; and it likely entered the popular vernacular as meaning a contriver of public works duringJohn Smeaton's time.

History

Ancient civilizations

Environmental engineering is a name for work that has been done since early civilizations, as people learned to modify and control the environmental conditions to meet needs.^[4]^[14]As people recognized that their health was related to thequality of their environment,they built systems to improve^[4]it. The ancientIndus Valley Civilization(3300 B.C.E. to 1300 B.C.E.) had advanced control over theirwater resources.^[14]The public work structures found at various sites in the area include wells, public baths, water storage tanks, a drinking water system, and a city-wide sewage collection system.^[14]^[15]They also had an early canalirrigation systemenabling large-scale agriculture.^[16]

From 4000 to 2000 B.C.E., many civilizations had drainage systems and some had sanitation facilities, including theMesopotamian Empire,Mohenjo-Daro,Egypt, Crete, and theOrkney Islandsin Scotland.^[4]The Greeks also had aqueducts and sewer systems that used rain and wastewater to irrigate and fertilize fields.^[4]

The firstaqueductin Rome was constructed in 312 B.C.E., and the Romans continued to constructaqueductsfor irrigation and safe urban water supply during droughts.^[4]They also built an underground sewer system as early as the 7th century B.C.E. that fed into the Tiber River, draining marshes to create farmland as well as removing sewage from the city.^[4]^[14]

Modern era

Very little change was seen from the decline of the Roman Empire until the 19th century, where improvements saw increasing efforts focused on public health.^[14]^[17]Modern environmental engineering began inLondonin the mid-19th century whenJoseph Bazalgettedesigned the first majorseweragesystem following theGreat Stink.^[14]The city's sewer system conveyed raw sewage to theRiver Thames,which also supplied the majority of the city's drinking water, leading to an outbreak ofcholera.^[14]The introduction of drinking water treatment and sewage treatment in industrialized countries reducedwaterborne diseasesfrom leading causes of death to rarities.^[18]

The field emerged as a separate academic discipline during the middle of the 20th century in response to widespread public concern about water and air pollution and otherenvironmental degradation.As society and technology grew more complex, they increasingly produced unintended effects on the natural environment. One example is the widespread application of the pesticideDDTto control agricultural pests in the years followingWorld War II.The story of DDT as vividly told inRachel Carson'sSilent Spring(1962) is considered to be the birth of the modernenvironmental movement,^[19]which led to the modern field of "environmental engineering."

Education

Many universities offer environmental engineering programs through either the department ofcivil engineeringorchemical engineeringand also including electronic projects to develop and balance the environmental conditions. Environmental engineers in a civil engineering program often focus on hydrology, water resources management,bioremediation,and water and wastewater treatment plant design. Environmental engineers in a chemical engineering program tend to focus on environmental chemistry, advanced air and water treatment technologies, and separation processes.^[20]^{[citation needed]}Some subdivisions of environmental engineering includenatural resources engineeringandagricultural engineering.

Courses for students fall into a few broad classes:

Mechanical engineeringcourses oriented towards designing machines and mechanical systems for environmental use such aswaterandwastewater treatmentfacilities, pumping stations, garbage segregation plants, and other mechanical facilities.
Environmental engineeringorenvironmental systemscourses oriented towards a civil engineering approach in which structures and the landscape are constructed to blend with or protect the environment.
Environmental chemistry,sustainable chemistryorenvironmental chemical engineeringcourses oriented towards understanding the effects of chemicals in the environment, including any mining processes, pollutants, and also biochemical processes.
Environmental technologycourses oriented towards producing electronic or electrical graduates capable of developing devices and artifacts able to monitor, measure, model and control environmental impact, including monitoring and managing energy generation fromrenewable sources.

Curriculum

The following topics make up a typical curriculum in environmental engineering:^[21]

MassandEnergy transfer
Environmental chemistry
Growth models
Risk assessment
1. Hazard identification
2. Dose-responseAssessment
3. Exposure assessment
4. Risk characterization
5. Comparativerisk analysis
Water pollution
1. Water resourcesandpollutants
2. Oxygen demand
3. Pollutanttransport
4. Waterandwaste water treatment
Air pollution
1. Industry,transportation,commercial and residential emissions
2. Criteria and toxicair pollutants
3. Pollution modelling (e.g.Atmospheric dispersion modeling)
4. Pollution control
5. Air pollution andmeteorology
Global change
1. Greenhouse effectandglobal temperature
2. Carbon,nitrogen,andoxygen cycle
3. IPCC emissions scenarios
4. Oceanic changes (ocean acidification,othereffects of global warming on oceans) and changes in thestratosphere(seePhysical impacts of climate change)
Solid waste managementandresource recovery
1. Life cycle assessment
2. Source reduction
3. Collectionandtransferoperations
4. Recycling
5. Waste-to-energyconversion
6. Landfill

Applications

Water supply and treatment

Environmental engineers evaluate the water balance within awatershedand 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 apotable watersupply, water is treated to minimize the risk ofinfectious diseasetransmission, the risk ofnon-infectiousillness, and to create a palatable water flavor.Water distribution systems^[22]^[23]are designed and built to provide adequate water pressure and flow rates to meet various end-user needs such as domestic use, fire suppression, andirrigation.

Wastewater treatment

Sewage treatmentplant,Australia

There are numerouswastewater treatmenttechnologies. A wastewater treatment train can consist of a primary clarifier system to remove solid and floating materials, a secondary treatment system consisting of anaerationbasin followed byflocculationandsedimentationor anactivated sludgesystem and a secondary clarifier, a tertiary biologicalnitrogenremoval system, and a finaldisinfectionprocess. 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 andphosphorusand to disinfect the water before discharge to a surface water stream or ocean outfall.^[24]

Air pollution management

Scientists have developedair pollution dispersion modelsto evaluate the concentration of a pollutant at a receptor or the impact on overall air quality from vehicleexhaustsand industrialflue gas stackemissions. To some extent, this field overlaps the desire to decreasecarbon dioxideand othergreenhouse gas emissionsfrom combustion processes.

Environmental impact assessment and mitigation

Water pollution

Environmental engineers apply scientific and engineering principles to evaluate if there are likely to be any adverse impacts to water quality, air quality,habitatquality,floraandfauna,agricultural capacity,traffic,ecology, and noise. 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 ofwetlandsin a nearby location to mitigate the filling in of wetlands necessary for a road development if it is not possible to reroute the road.

In the United States, the practice of environmental assessment was formally initiated on January 1, 1970, the effective date of theNational Environmental Policy Act(NEPA). Since that time, more than 100 developing and developed nations either have planned specific analogous laws or have adopted procedure used elsewhere. NEPA is applicable to all federal agencies in the United States.^[25]

Regulatory agencies

Environmental Protection Agency

TheU.S. Environmental Protection Agency(EPA) is one of the many agencies that work with environmental engineers to solve critical issues. An essential component of EPA's mission is to protect and improve air, water, and overall environmental quality to avoid or mitigate the consequences of harmful effects.

References

^^a ^b"Careers in Environmental Engineering and Environmental Science".American Academy of Environmental Engineers & Scientists.Archived fromthe originalon 2021-02-24.Retrieved2019-03-23.
^^a ^b ^c"Architecture and Engineering Occupations".Occupational Outlook Handbook.Bureau of Labor Statistics. 20 February 2019.Retrieved23 March2019.
^Mahamud-López, Manuel María; Menéndez-Aguado, Juan Mariá (September 2005)."Environmental engineering in mining engineering education".European Journal of Engineering Education.30(3): 329–339.doi:10.1080/03043790500114490.ISSN 0304-3797.S2CID 109093239.
^^a ^b ^c ^d ^e ^f ^g"10 Advancements in Environmental Engineering".HowStuffWorks.2014-05-18.Retrieved2019-03-23.
^Beychok, Milton R. (1967).Aqueous Wastes from Petroleum and Petrochemical Plants(1st ed.). John Wiley & Sons.LCCN 67019834.
^Tchobanoglous, G.; Burton, F.L. & Stensel, H.D. (2003).Wastewater Engineering (Treatment Disposal Reuse) / Bailey Alatoree Inc(4th ed.). McGraw-Hill Book Company.ISBN 978-0-07-041878-3.
^Turner, D.B. (1994).Workbook of atmospheric dispersion estimates: an introduction to dispersion modeling(2nd ed.). CRC Press.ISBN 978-1-56670-023-8.
^Beychok, M.R. (2005).Fundamentals Of Stack Gas Dispersion(4th ed.). author-published.ISBN 978-0-9644588-0-2.
^Career Information Center. Agribusiness, Environment, and Natural Resources(9th ed.). Macmillan Reference. 2007.
^"Become Board Certified in Environmental Engineering".American Academy of Environmental Engineers & Scientists.Archived fromthe originalon 2021-01-18.Retrieved2019-03-23.
^"NCEES PE Environmental exam information".NCEES.Retrieved2019-03-23.
^"Professional Engineering Institutions".Engineering Council.Retrieved2019-03-23.
^"environ | Search Online Etymology Dictionary".www.etymonline.com.Retrieved2020-12-14.
^^a ^b ^c ^d ^e ^f ^gMason, Matthew."Environmental Engineering: Why It's Vital for Our Future".Environmental Science.Retrieved2019-03-23.
^Jansen, M. (October 1989). "Water Supply and Sewage Disposal at Mohenjo-Daro".World Archaeology.21(2): 177–192.doi:10.1080/00438243.1989.9980100.JSTOR 124907.PMID 16470995.
^Angelakis, Andreas N.;Rose, Joan B. (2014). "Chapter 2:" Sanitation and wastewater technologies in Harappa/Indus valley civilization (ca. 2600-1900 BC) ".Evolution of Sanitation and Wastewater Technologies through the Centuries.IWA Publishing. pp. 25–40.ISBN 9781780404851.
^"Funding - Environmental Engineering".US National Science Foundation.Retrieved2013-07-01.
^"Waterborne Infections".Encyclopedia.com.Retrieved2019-03-23.
^Radniecki, Tyler."What is Environmental Engineering?".College of Engineering.Oregon State University.Retrieved2019-03-23.
^"What is Environmental Engineering?".Civil and Environmental Engineering.2012-07-04.Retrieved2023-01-27.
^Masters, Gilbert (2008).Introduction to environmental engineering and science.Upper Saddle River, N.J: Prentice Hall.ISBN 978-0-13-148193-0.
^Drinking water distribution systems: assessing and reducing risks.National Academies Press. 2006.doi:10.17226/11728.ISBN 978-0-309-10306-0.Retrieved6 October2019.
^"Water Distribution Networks CE370"(PDF).King Fahd University of Petroleum and Minerals.Retrieved6 October2019.
^Sims, J. (2003).Activated sludge, Environmental Encyclopedia.Detroit.
^McGraw-Hill Encyclopedia of Environmental Science and Engineering(3rd ed.). McGraw-Hill, Inc. 1993.ISBN 9780070513969.