Essay/Term paper: Water pollution: is it as big of a problem as we think?

Essay, term paper, research paper:  Society Term Papers

Water Pollution: Is it as big of a problem as we think?


The following essay will be looking at the factors that cause pollution, and
the effect that pollution has on our world today. It will also investigate what
it has in store for the future if things do not improve. It will also explore
some of the methods used to treat and clean-up wastewater, and oil spills.
Today, the industrialization of Canada is severely affecting this nations
lakes, streams, and rivers. If something is not done to improve the situation
it is going to have some severe environmental problems in its future.
Today pollution is very high in both inland and marine waters. All
different types of water pollution are contributing factors in this problem.
Here are some things that are associated with pollution: Pathogens: Pathogens
are disease causing bacteria, viruses, and protozoa. They usually come from
human sewage. As pathogen numbers increase, so does the risk of human health.
Biochemical Oxygen Demand: Organic wastes that decay in a body of water.
decrease the amount of oxygen found in it. The living things in the lake need
oxygen to survive. If the oxygen level is depressed to zero, all fish in the
lake die. Any decomposition that does not contain oxygen starts to generate
noxious gases such as Hydrogen Sulfide. Pulp and paper mills, and municipal
sewage causes BOD. Nutrients: Nutrients, particularly nitrogen and phosphorus,
enrich waters and accelerate the aging of lakes and streams. Also, the result
of this is rich plant life which prohibits recreational activities. Plankton
blooms depress oxygen levels (as mentioned before) and therefore, endanger
living organisms. Major sources of nutrients are municipal sewage and
agricultural runoff. Toxic Materials: Can affect the health of aquatic organisms
and their consumers, and the people who drink the contaminated water. The
toxicants include lead, mercury, DDT, PCB, benzopyrene, oil, and dibutyl
phthalate. These chemicals enter the lake through dumping by the factories.
Temperature Changes: Temperature changes from waste heat discharges (like from a
nuclear power plant) can cause pollution. This happens if their elevation
reduces dissolved-oxygen levels, and accelerates eustrophication, which in turn
affects the ecological processes and blocks the migration path of fishes.
Acidification: Acidification (acid rain etc.) Is caused by sulfur and nitrogen
oxide in the rain, which is caused by automobiles and large industries.
Temperature Changes: The temperature of a body of water is changed by waste heat
discharges, like that of a nuclear power plant. It affects ecological processes
and blocks the migration paths of fish. Because of these pollutants Southern
Saskatchewan and Alberta are threatened by water shortages, and the great lakes
face problems in serious pollution. Rivers and streams are also greatly affected
by these pollutants. The noticeable outcomes of these pollutants are these:
Nitrates in drinking water can cause disease in infants that may sometimes end
in death. Crops in a field can absorb sludge-derived fertilizer containing
cadium, and when humans eat the crop it may result in acute liver and kidney
damage. Sometimes lakes become artificially enriched with nutrients from the
chemical fertilizers that run off cultivated fields into the water. This causes
water that is unpleasant to drink due to bad odor, taste, and algae. Also, acid
rain has left many lakes in Canada totally devoid of life.
There are three major sources of water pollution, they are municipal,
industrial and agricultural. Municipal: This type of water pollution comes from
the wastewater found only in homes and commercial establishments For many years
people have been placing importance on treating the waste to remove harmful
bacteria, etc. from it. Recently we are coming aware of the fact that we have to
improve the ways in which we dispose of the waste. Industrial: Industrial waste
is wastewater from industrial areas, and companies. There are many different
types of chemicals, and they all have different affects. Some are not as severe
as others, but all are harmful. They vary due to the amount they contain of
specific substances. Agricultural: Agricultural waste is a form of pollution
that is the source of many organic and inorganic pollutants in waters in the
ground and on the surface. Wastes from commercial feeders, animal wastes,
chemicals, etc. Run of into the land through leaching and runoff.
What is the typical wastewater from these categories made up of? Wastes from
toilets, sinks, industrial processes, and agricultural chemicals and leftovers.
Treatment of such sewage's as these is required before it may be buried, reused,
or sent back into the water system safely. In a treatment plant, the polluted
water is passed through a series of chambers, screens, and chemical processes to
reduce its bulk and toxic level severity. There are three general steps to water
treatment. They are usually classified as being part of primary, secondary, or
tertiary treatment. Primary Treatment: During this level, a large percentage of
the suspended solids and in organic material is removed from the sewage waste.
Secondary Treatment: The focus of secondary treatment is to reduce the organic
material content. They do this by accelerating the natural biological processes.
Tertiary Treatment: This group of treatment is necessary when the water will be
reused. At this time 99% of the solids in the water are removed and various
chemical processes are used to ensure the water is as free from as many
impurities as possible.
After the water treatment process has been broken into three categories, it
can be further broken down into a number of smaller headings. Here is a summary
of some of the steps: Grit Chamber: The wastewater that enters a treatment plant
contains debris that might clog or damage the pumps and machinery. So the sewage
is passed through the grit chamber. These are long, and narrow settling tanks,
that is used to remove such inorganic, and mineral matter such as sand, silt,
gravel, and cinders. They made all particles 0.2mm or larger to settle at the
bottom. Sedimentation Tank: When grit is removed, it passes into the
sedimentation tank. In this step all organic materials settle on the bottom, and
are drawn off for disposal. This procedure can remove about 20 to 40 percent of
BOD5 and 40 to 60 percent of suspended solids Digester: This is a complicated
step. The object of it is to make the chemically complex organic sludge to
methane, carbon dioxide, and an inoffensive humus type material. First the
matter is made soluble by enzymes, then the substance is fermented by a group of
acid-producing bacteria, reducing it to simple organic acids such as acetic acid.
The organic acids are than converted to methane and carbon dioxide by bacteria.
Thickened sludge is heated and added as continuously as possible to the digester,
where it remains for 10 to 30 days and is decomposed. Digestion reduces organic
matter by 45 to 60 percent. Drying Beds: Digested sludge is placed on sand beds
for air drying. Percolation into the sand and air drying are the main processes
involved in the dewatering process. Air drying requires dry, relatively warm
weather for greatest efficiency, and some treatment plants have a greenhouse-
like structure to shelter the sand beds. Dried sludge is used in most cases as a
soil conditioner; sometimes it is used as a soil fertilizer because of its two
percent nitrogen and 1 percent phosphorous content. Trickling Filter: In this
process, a waste stream is distributed intermittently over a bed or column. A
gelatinous film of microorganisms coats the bed, and functions as the removal
agent. The organic matter in the waste stream is absorbed by the microbial film
and converted to aerobic products. The reduction of the amount of BOD5 is about
85 percent. Activated Sludge: This a process where the sludge particles are
suspended in an aeration tank and supplied with oxygen. The organic matter is
absorbed by the activated sludge particles and converted to aerobic products.
The reduction of BOD5 fluctuates between 60 and 85 percent.
There are a few other remaining steps but they are pretty straightforward,
such as disposing of the waste.
Sometimes the sewage is not cleaned or treated and is dumped directly into
the river. This results in lakes and rivers that look very brown and dirty not
clean and clear. The pollution of rivers and streams with chemical contaminants
has become among the most critical environmental problems of the century. It is
estimated that 10 million people die each year from drinking contaminated water!
Another big problem are Oil spills. These large scale accidental discharges of
liquid petroleum products are an important factor of the pollution along shore
lines. The most spectacular spills involve the supertankers that are used to
transport the product, but offshore drilling contribute to a large share of the
pollution. One estimate is that for every million ton of oil that is shipped,
one ton is spilled. Some of the largest spills recorded are from the tanker
Amoco Cadiz off the French coast in 1978 (1.6 million barrels of crude oil).
The Ixtoc I oil well in the gulf of Mexico in 1979 (3.3 million barrels). The
largest spill in the US (240,000 barrels) was that of the tanker Exxon Valdez in
Prince William Sound, Gulf of Alaska, in march 1989. Within a week, under high
winds, this spill had become a 6700-sq.-km., slick that endangered wildlife
and fisheries in the entire gulf area. The oil spills in the Persian Gulf in
1983, during the Iran-Iraq conflict, and in 1991, during the Persian Gulf War,
resulted in enormous damage to the entire area, especially to the marine life.
One of the methods used to clean up oil spills is a long sponge that they drag
along the surface of the water that soaks up all the oil. It is a long and
tedious job, but it works quite well. if you would like to see them you could
look back on FIG 1-2.
The wastes treated are the ones that flow into the sewer system and enters the
treatment plant. But some wastes are discharged directly into the Marine Waters.
In fact, in the U.S. it is estimated that 45 million metric tons of sewage each
year ends up in the marine waters. About 80 percent of this amount of waste is
produced by dredging, 10 percent is industrial waste, and 9 percent is sewage
sludge.
The U.S. alone produces 4,036,300,000 metric tons of sewage per YEAR! The
following elements combined have very serious consequences: The presence of
toxic substances, the rapid uptake of contaminants by marine organisms, heavy
deposits of materials on the seabed near the shore, and the excessive growth of
undesirable organisms.
A person living in a wealthy, industrialized nation may produce as much a 875
kg ( more than 1900 ponds! ) of garbage per year! that means that by the time
they are seventy years old they will have produced 61250 kg! ( 133000 pounds! )
These numbers are pretty scary, especially when multiplied by millions to find
out the whole country's kilograms per year. The average person needs to pay
attention to the amount of waste they produce, and try to cut back a little.
But what exactly needs to be improved? Well, domestic, or household waste
includes a wide variety of items, But it is often a mix of potentially reusable
or recyclable items, ( such as newspaper and cans.), and largely non-recyclable
material ( such as broken, worn out devices, and plastic wrappings). Due to
dwindling space for landfills, many cities have adopted widespread recycling
programs in which people separate the recyclable things apart from the non-
recyclable garbage. And the recyclable goes to a recycling plant to be reused,
and the remaining garbage goes to a landfill. What is the composition of
wastewater, and how do we discover it? Well, the composition is what it is made
up of as in, how many parts of water does it have and what the parts are made
up of. To find out scientists analyze it. This is done by using several physical,
chemical, and biological measurements. The most common analyses include the
measurements of solids, biochemical oxygen demand ( BOD5 ) chemical oxygen
demand ( COD ) , and pH. the solid wastes include dissolved and suspended
solids. the suspended solids are further divided into settleable and
nonsettleable solids. All of THESE solids can be divided into volatile or fixed
solids being inorganic or mineral matter. The concentration of organic matter
is measured by the BOD5 or COD analyses. to see a typical chart of the
breakdown, concentration, and composition.
After the water is treated where does it Go? Most often a direct discharge
into a receiving lake or stream is the answer. But in some areas of the United
States that are faced with worsening shortages of water for both domestic and
industrial use, some places are turning to reuse of appropriately treated
wastewater for groundwater recharge, irrigation of non edible crops, industrial
processing, recreation, and other uses.
Where does the wastewater originate from? Mainly form domestic, industrial,
groundwater, and meteorological sources. And these are most commonly known as
Domestic Sewage, Industrial Waste, Infiltration, and Storm-Water Drainage.
Domestic Sewage: This type of wastewater results from peoples day to day
activities, such as bathing, body elimination, food preparation, and recreation,
averaging about 227 liters ( about 60 gallons ) per person per day! Industrial
Wastewater: The quantity and character of industrial wastewater is highly
varied, depending on the type of industry, the management of it's water usage,
and the amount of treatment the water receives before it is discharged. But to
give you an idea of the amount I have a figure for a steel mill. One steel mill
may discharge anywhere from 5,700 to 151,000 liters ( about 1,500 to 40,000
gallons) per ton of steel manufactured. A typical metropolitan area discharges a
volume of wastewater equal to about 60 to 80 percent of its total daily
requirements! The rest is being used for washing cars, watering lawns, and for
manufacturing processes such as food canning and bottling. Infiltration: This
occurs when sewer lines are placed below the water table or when rainfall goes
down through the earth to the pipe. We do not like it because it means that the
piping system and the treatment plant have to work extra hard Storm Water
Drainage: This is simply the water from rain, melted snow, etc. draining into
our pipelines and sewers where it goes to a treatment plant to be treated, but
there is nothing wrong with it.
In conclusion, From all the points I have brought up it is easy to see that
the more people there are in the world the more water pollution there is going
to be. That doesn't mean that we have to stop having children, what it means is
that we have to start watching where we drain our polluted water, and start to
use our resources more wisely. We should also be more careful with hazardous
chemicals , and things like oil drilling, etc.