environmental engg i lec 1-3.pdf

7/27/2019 Environmental Engg I lec 1-3.pdf

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Lecture # 01: Introduction to Environmental Engineering

Environment:

The conditions that surround someone or something ORthe conditions and influences that affect

the growth, health, progress, etc., of someone or something.

Engineering:

The branch of science and technology concerned with the design, building, and use of engines,

machines, and structures.

Environmental Engineering:

Is the application of science and engineering principles to improve the natural environment (air,

water, and/or land resources), to provide healthy water, air, and land for human habitation (houseor home) and for other organisms, and to remediate polluted sites.

It involves waste water management and air pollution control, recycling, waste disposal,

radiation protection, industrial hygiene, environmental sustainability, and public health issues as

well as 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 such hazards, advice on treatment and containment, and develop regulations to

prevent mishaps. Environmental engineers also design municipal water supply and industrial

wastewater treatment systems as well as address local and worldwide environmental issues such

as the effects of acid rain, global warming, ozone depletion, water pollution and air pollution

from automobile exhausts and industrial sources.

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 ancient Harappan civilization utilized early sewers in some cities. 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.


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Scope of Environmental Engineering

Briefly speaking, the main task of environmental engineers is to protect public health by

protecting (from further degradation), preserving (the present condition of), and enhancing the

environment. Environmental engineering is the application of science and engineering principles

to the environment. There are several divisions of the field of environmental engineering.

1. Environmental impact assessment and mitigationIn this division, engineers and scientists use a systemic identification and evaluation process to

assess the potential impacts of a proposed project , plans, programs, policies, or legislative

actions upon the physical-chemical, biological, cultural, and socioeconomic components 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.

2. Water supply and treatmentEngineers 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 the risk of infectious disease

transmission, the risk of non-infectious illness, and to 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.

3. Air quality managementEngineers 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 other processes are utilized to remove


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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.

Lecture # 02 Environmental Pollution

As the sciences have evolved, so has environmental engineering; today, environmental engineers

work in a wide variety of settings to improve the condition of the environment. Preventative

measures include things like waste management, pollution controls, and resource allocations

which are designed to ensure that supplies of clean water endure.

Environmental issues were first pushed to the forefront of the collective consciousness in the late

1900s, when people realized that their activities were having a negative impact on the

environment. Pollution, rampant use of natural resources, and other activities were questioned in

light of information about how these activities hurt the environment, and people began to look

into more eco-friendly ways of living and doing business.

Environmental Pollution

The environment is made up of systems, cycles, and specialized relationships between living and

non-living elements. When everythings working the way it should be, all the living organisms

within the environment, including humans, are healthy and thriving.

But when something harmful is introduced to the cycle, or part of the cycle is disrupted

somehow, it can cause a chain reaction of problems right through the rest of the system. These

changes can really hurt the health and well-being of living organisms. One of these negative

changes is pollution, which is the result of unnatural elements entering the environment.

Unfortunately, humans are usually at fault.

Anything thats harmful to the environment is pollution. Litter, car exhaust, motor oil, used tires,

smoke, and chemicalsall of these can have an instant or a gradual impact on the health of our

earth.


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But even though theres been a lot of damage done to the environment by pollutants, that dont

mean its game over for Earth. There are two ways to tackle the problem. First, clean up what

we can. And second, take action to prevent further pollution.

1. Land Pollution:Most of the pollution on land comes from litter. People toss away garbage instead of disposing of

it properly, which clogs up the land, attracts pests such as insects and rodents, and even harms

the soil and the critters that live there if it contains chemicals. If garbage kills the plants in an

area by covering them up, it affects the food chain, since green plants are the start of every chain.

It also affects the air quality, since plants help clean the air.

2. Air Pollution:Dust and sand form storms. While there are some natural sources of air pollution, the majority of

air pollutants come from things we do ourselvesor things people have invented, such as the

combustion engine.

Airborne pollutants make it tough to breathe and can even cause diseases like cancer. One

problem is the way winds cross-across the globe, picking up pollutants and carrying them all

over the world. This is how areas far away from where the actual pollution is created can become

affected, too. Air pollution is not just a local concern.

Some pollutants that enter the air come from natural sources. For example, when a volcano

erupts, volcanic ash blasts into the air and can remain there for years. Other natural sources of air

pollution include smoke from forest fires, and

3. Water Pollution:Definition:

Water pollution refers to the changesin the physical, biological, and chemical conditions of any

body of water which detrimentally disrupts the balance of the ecosystem.

Explanation:

Like any type of pollution, water pollution results when an overpowering amount of waste

coming from different sources of pollutants can no longer be accommodated by the natural

ecosystem. Consequently, when the wastes are non-ruined as fast as they are produced, they

make it unfavorable to humans and many other organisms. But thats not all. Learn more about

what causes water pollution.


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There are really many particular reasons behind what causes water pollution. However, it is

important to acquaint yourself with the two main categories of water pollution. Some pollution

comes directly from ones particular location. This type of pollution is called point source

pollution such as sewerage pipes that empty polluted water into the river and farmland.

Meanwhile, non-point source pollution is pollution that comes from large areas like gasoline and

other dirt from highways that go into the lakes and rivers.

One major cause of water pollution that has caused serious environmental and wellnessproblems are the pollutants coming from chemical and industrial processes. When factories

and manufacturers pour their chemicals and stock wastes directly into streams and rivers, the

water becomes poisonous and oxygen levels are low causation many aquatic organisms to

die. These wastes include solvents and toxic substances. Most of the wastes are non-

biodegradable. Power plants, paper mills, refineries, automobile factories dispose waste

into the rivers.

The heated water from the power plants is called thermal pollution. This kills aquaticanimals and plants by reducing the oxygen content of the water. Power plants use water to

cool their machineries, thus changing the temperature of the water.

Aside from thermal pollution, there are also organic and inorganic pollutants.o The organic wastes admit refuse from slaughter houses, fish and meat canning

factories, and leather tanning companies, manufacturing plants, pesticides and crudeoil companies. Since organic wastes are decomposed by microorganisms, much of the

dissolved in water is used up and the waster begins to stink.

o Inorganic wastes admit toxic and corrosive substances like acids, heavy metals,mercury, cadmium and lead which can impair the normal body processes. Battery

manufacturers, mining, paper mills increase the concentration of mercury making the

water dangerous and poisonous for most living things.

Another cause of water pollution is from pesticides. Farm pesticides poison aquatic plantsand animals. Animal manure, chemical fertilizers, orthophosphate detergent foul water

by provision excess nutrients. This pollution is known as eutrophication. This greatly

increases the growth of algae in water thereby decreasing the amount of oxygen level in

water causation the death of many aquatic organisms.


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Water is also being polluted by garbage specifically plastics and other plastic-likesubstances. Some plastic like nylon can entangle fishes and other marine animals. Plastics

that have broken down into tiny pieces can be eaten by sea creatures which may cause their

death. Since plastic is non-biodegradable, it will continue to kill more fishes.

One more cause of water pollution is sewage coming from households. Since no one wants tolive in a contaminated area, near a dumpsite or landfill, the wastewater and untreated sewage

are carried away from the home polluting unlike bodies of water. Most development

countries practice this type of sewage disposal. Even modern countries carry poorly treated

sewerage to canals leading to major bodies of water. The peril is when the sewage pipes gets

broken and waste contaminates the drinking water. When this happens, the break will open a

wide array of water borne diseases that will surely pose peril to consumers.

Last among the causes of water pollution are personal care and household products.Shampoo, lotion, moisturizer, hair dye, bleach, laundry detergent, fabric softener, and many

others contribute to water pollution. Human waste is not the only thing that goes to sewage.

These products also join the wastewater to contaminate the streams, rivers, and lakes.

Although the world abounds with water, only three percent of it is potable . Included in the

3% source of potable water are the streams, spring, rivers, lakes, and waterfalls that are

continuously being threatened and contaminated by the unlike factors that cause of water

pollution. If the sources of water pollution are not controlled, this basic necessity will eventuallybecome a rare good only a few can afford to have.

Lecture # 03: Water Pollution Control Parameter:

Control of pollution:

1. Domestic sewage:Domestic sewage is typically 99.9 percent water with 0.1 percent pollutants. Although found in

low concentrations, these pollutants pose risk on a large scale. In urban areas, domestic sewage is

typically treated by centralized sewage treatment plants. Well-designed and operated systems

(i.e., secondary treatment or better) can remove 90 percent or more of these pollutants. Some

plants have additional systems to remove nutrients and pathogens. Most municipal plants are not

specifically designed to treat toxic pollutants found in industrial wastewater.


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Cities with sanitary sewer overflows or combined sewer overflows employ one or more

engineering approaches to reduce discharges of untreated sewage, including:

utilizing a green infrastructure approach to improve storm water management capacitythroughout the system, and reduce the hydraulic overloading of the treatment plant

repair and replacement of leaking and malfunctioning equipment Increasing overall hydraulic capacity of the sewage collection system (often a very

expensive option).

A household or business not served by a municipal treatment plant may have an individual septic

tank, which treats the wastewater on site and discharges into the soil. Alternatively, domestic

wastewater may be sent to a nearby privately owned treatment system (e.g. in a rural

community).

2. Industrial wastewaterSome industrial facilities generate ordinary domestic sewage that can be treated by municipal

facilities. Industries that generate wastewater with high concentrations of conventional pollutants

(e.g. oil and grease), toxic pollutants (e.g. heavy metals, volatile organic compounds) or other

nonconventional pollutants such as ammonia, need specialized treatment systems. Some of these

facilities can install a pre-treatment system to remove the toxic components, and then send the

partially treated wastewater to the municipal system. Industries generating large volumes of

wastewater typically operate their own complete on-site treatment systems.Some industries have been successful at redesigning their manufacturing processes to reduce or

eliminate pollutants, through a process called pollution prevention. Heated water generated by

power plants or manufacturing plants may be controlled with:

cooling ponds, man-made bodies of water designed for cooling by evaporation,convection, and radiation

cooling towers, which transfer waste heat to the atmosphere through evaporation and/orheat transfer

Co-generation, a process where waste heat is recycled for domestic and/or industrialheating purposes.

3. Agricultural wastewaterSediment (loose soil) washed off fields is the largest source of agricultural pollution in the

United States. Farmers may utilize erosion controls to reduce runoff flows and retain soil on their
http://en.wikipedia.org/wiki/Environmental_engineeringhttp://en.wikipedia.org/wiki/Green_infrastructurehttp://en.wikipedia.org/wiki/Hydraulichttp://en.wikipedia.org/wiki/Septic_tankhttp://en.wikipedia.org/wiki/Septic_tankhttp://en.wikipedia.org/wiki/Cooling_pondhttp://en.wikipedia.org/wiki/Evaporationhttp://en.wikipedia.org/wiki/Convectionhttp://en.wikipedia.org/wiki/Radiationhttp://en.wikipedia.org/wiki/Cooling_towerhttp://en.wikipedia.org/wiki/Atmospherehttp://en.wikipedia.org/wiki/Evaporationhttp://en.wikipedia.org/wiki/Heat_transferhttp://en.wikipedia.org/wiki/Cogenerationhttp://en.wikipedia.org/wiki/Sedimenthttp://en.wikipedia.org/wiki/Soilhttp://en.wikipedia.org/wiki/Erosion_controlhttp://en.wikipedia.org/wiki/Erosion_controlhttp://en.wikipedia.org/wiki/Soilhttp://en.wikipedia.org/wiki/Sedimenthttp://en.wikipedia.org/wiki/Cogenerationhttp://en.wikipedia.org/wiki/Heat_transferhttp://en.wikipedia.org/wiki/Evaporationhttp://en.wikipedia.org/wiki/Atmospherehttp://en.wikipedia.org/wiki/Cooling_towerhttp://en.wikipedia.org/wiki/Radiationhttp://en.wikipedia.org/wiki/Convectionhttp://en.wikipedia.org/wiki/Evaporationhttp://en.wikipedia.org/wiki/Cooling_pondhttp://en.wikipedia.org/wiki/Septic_tankhttp://en.wikipedia.org/wiki/Septic_tankhttp://en.wikipedia.org/wiki/Hydraulichttp://en.wikipedia.org/wiki/Green_infrastructurehttp://en.wikipedia.org/wiki/Environmental_engineering


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fields. Common techniques include contour plowing, crop mulching, crop rotation, planting

perennial crops and installing riparian buffers.

Nutrients (nitrogen andphosphorus) are typically applied to farmland as commercial fertilizer;

animal manure; or spraying of municipal or industrial wastewater (effluent) or sludge. Nutrients

may also enter runoff from crop residues, irrigation water, wildlife, and atmospheric deposition.

Farmers can develop and implement nutrient management plans to reduce excess application of

nutrientsand reduce the potential fornutrient pollution.

To minimize pesticide impacts, farmers may use Integrated Pest Management (IPM) techniques

(which can include biological pest control) to maintain control over pests, reduce reliance on

chemical pesticides, and protect water quality.

4. Urban runoff (storm water):Effective control of urban runoff involves reducing the velocity and flow of storm water, as well

as reducing pollutant discharges. Local governments use a variety of storm water management

techniques to reduce the effects of urban runoff. These techniques, called best management

practices (BMPs), may focus on water quantity control, while others focus on improving water

quality, and some perform both functions.

Pollution prevention practices include low-impact development techniques, installation ofgreen

roofs and improved chemical handling (e.g. management of motor fuels & oil, fertilizers and

pesticides). Runoff mitigation systems include infiltration basins, bio-retention systems,

constructed wetlands, retention basins and similar devices.

Thermal pollution from runoff can be controlled by storm water management facilities that

absorb the runoff or direct it into groundwater, such as bio-retention systems and infiltration

basins. Retention basins tend to be less effective at reducing temperature, as the water may be

heated by the sun before being discharged to a receiving stream.
http://en.wikipedia.org/wiki/Contour_plowinghttp://en.wikipedia.org/wiki/Mulchhttp://en.wikipedia.org/wiki/Crop_rotationhttp://en.wikipedia.org/wiki/Perennialhttp://en.wikipedia.org/wiki/Riparian_bufferhttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Phosphorushttp://en.wikipedia.org/wiki/Fertilizerhttp://en.wikipedia.org/wiki/Manurehttp://en.wikipedia.org/wiki/Crop_residuehttp://en.wikipedia.org/wiki/Irrigationhttp://en.wikipedia.org/wiki/Wildlifehttp://en.wikipedia.org/wiki/Deposition_%28Aerosol_physics%29http://en.wikipedia.org/wiki/Nutrient_managementhttp://en.wikipedia.org/wiki/Nutrient_pollutionhttp://en.wikipedia.org/wiki/Integrated_Pest_Managementhttp://en.wikipedia.org/wiki/Biological_pest_controlhttp://en.wikipedia.org/wiki/Best_management_practice_for_water_pollutionhttp://en.wikipedia.org/wiki/Best_management_practice_for_water_pollutionhttp://en.wikipedia.org/wiki/Low-impact_development_%28Canada/US%29http://en.wikipedia.org/wiki/Green_roofhttp://en.wikipedia.org/wiki/Green_roofhttp://en.wikipedia.org/wiki/Infiltration_basinhttp://en.wikipedia.org/wiki/Bioretentionhttp://en.wikipedia.org/wiki/Retention_basinhttp://en.wikipedia.org/wiki/Groundwaterhttp://en.wikipedia.org/wiki/Groundwaterhttp://en.wikipedia.org/wiki/Retention_basinhttp://en.wikipedia.org/wiki/Bioretentionhttp://en.wikipedia.org/wiki/Infiltration_basinhttp://en.wikipedia.org/wiki/Green_roofhttp://en.wikipedia.org/wiki/Green_roofhttp://en.wikipedia.org/wiki/Low-impact_development_%28Canada/US%29http://en.wikipedia.org/wiki/Best_management_practice_for_water_pollutionhttp://en.wikipedia.org/wiki/Best_management_practice_for_water_pollutionhttp://en.wikipedia.org/wiki/Biological_pest_controlhttp://en.wikipedia.org/wiki/Integrated_Pest_Managementhttp://en.wikipedia.org/wiki/Nutrient_pollutionhttp://en.wikipedia.org/wiki/Nutrient_managementhttp://en.wikipedia.org/wiki/Deposition_%28Aerosol_physics%29http://en.wikipedia.org/wiki/Wildlifehttp://en.wikipedia.org/wiki/Irrigationhttp://en.wikipedia.org/wiki/Crop_residuehttp://en.wikipedia.org/wiki/Manurehttp://en.wikipedia.org/wiki/Fertilizerhttp://en.wikipedia.org/wiki/Phosphorushttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Riparian_bufferhttp://en.wikipedia.org/wiki/Perennialhttp://en.wikipedia.org/wiki/Crop_rotationhttp://en.wikipedia.org/wiki/Mulchhttp://en.wikipedia.org/wiki/Contour_plowing

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