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The Effect Of An Oil Water Separator's Shape On It's Effectiveness |
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Researched by The purpose of this experiment was to determine if the shape of an oil-water separator affected how effectively it separated oil from water
I became interested in this idea when Mr. Norm Hepner, a department of ecology professional engineer, informed me that some oil-water separators could be more effective than others.
The information gained from this experiment will affect us all because if oil mixes with wastewater it is a danger to everyone. It is people who own or manage parking lots or carwashes who have the legal responsibility to make their wastewater cleaner, but all of us are affected.
My hypothesis was that the circular shaped oil water separator would work better because it has less dead space (places where the water sits in one spot) so the oil would have less setting time in the primary chamber
I based my hypothesis on my understanding of fluid dynamic principles and oil water chemistry (stoke’s law). Fluid dynamics are the characteristics of how a fluid will act, this is also known as Fluid mechanics. Oil water chemistry depends on something’s density and its viscosity. The density is a measure of a quantity such as mass per unit volume, and the viscosity is how thick or sticky something is. Stokes law is the formula showing the velocity at which a less dense liquid will rise through a more dense liquid.
The constants in this study were:
- Size of buckets
- Temperature of water
- Amount of water
- Amount of oil
- Type of oil
- Rate at which mixture was poured in
- Size of polypropylene pads
- Polypropylene Pad absorbency
The manipulated variable was the shape of the oil-water separators.
The responding variable was how much oil was in the polypropylene at the end of the experiment.
To measure the responding variable I used a scale to measure the change in mass of the polypropylene pad after it had absorbed the oil.
| QUANTITY | ITEM DESCRIPTION |
| 1 |
rectangular 7.5 liter bucket |
| 1 |
rounded 7.5 liter bucket |
| 4 |
gallons of water |
| 1 | gallon of oil |
| 6 |
pads of polypropylene |
| 2 |
nozzle |
| 3 |
separate buckets to mix oil and water in |
| 1 | drill |
| 1 | paint stirring rod |
| 1 | caulking gun |
| 2 |
tubes of Epoxy |
1. Build two separators
a) Find measurements of separators
b) Cut separator to required lengths
c) Put divider in bucket
d) Use epoxy to keep in bucket
e) Wait for epoxy to dry
f) Drill hole in side of bucket
g) Place plastic nozzle in separator
h) Put epoxy on nozzle to secure
i) Wait for epoxy to dry
j) Repeat steps A-I using other separator
2. Fill Separator with clean waterb) Cut separator to required lengths
c) Put divider in bucket
d) Use epoxy to keep in bucket
e) Wait for epoxy to dry
f) Drill hole in side of bucket
g) Place plastic nozzle in separator
h) Put epoxy on nozzle to secure
i) Wait for epoxy to dry
j) Repeat steps A-I using other separator
3. Cut 6 polypropylene pads
4. Weigh all polypropylene pads
5. Weigh all Ziploc bags
6. Place 1 pad in each of the six bags
7. Weigh all bags containing pads
8. Pour .5 liters of oil into solution bucket
9. Pour 7 liters of water into solution bucket
10. Pour 7.5 liters of water into separator
11. Use paint stirring rod to mix solution
12. Open solution bucket valve
13. Open separator nozzle
14. Wait for solution bucket to empty
15. Close separator nozzle
16. Let it sit for 5 minutes
17. Place polypropylene pad in collection bucket
18. Stir around for 5 minutes
19. Take pad out of bucket
20. Hang up to dry
21. Wait 45 minutes
22. Place in Ziploc bag
23. Put rubber band around bag
24. Place on scale
25. Measure weight
26. Clean out all buckets and separators
27. Repeat steps 2-26 for trials 2 and 3
28. Repeat steps 2-27 using other separator
The original purpose of this experiment was to find if an oil water separator’s shape affected the separator’s ability to do its job.
The results of the experiment were that the square separator worked better than the circular separator, I know this because the square had an average weight gain of 42.13 grams, where as the circular separator had an average weight gain of 50.37. I think this was because the circular did not have as much surface area causing the oil to go down deeper and letting it pass through the separator.
See the table and graph below.
My hypothesis was that the circular separator would work better because there would be less dead spaces.
The results indicate that this hypothesis should be rejected because the square separator was more effective than the circular.
Because of the results of this experiment, I wonder if varying the depth of the separator would have any effect on how the oil water separator performs.
If I were to conduct this project again I would make the separators have the same surface area to eliminate the possibility of that having an effect on the experiment. I would also have more trials, and test lighter and heavier types of oil.
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Introduction
Water is an essential part of our lives. Without it
we could not
live. People need water, but they can’t just drink any
water. We need
clean water. Everyday people contaminate water whether they mean
to or
not. The water will be altered in some way. When cars leak
oil at a
car wash or parking lot the motor oil has to go somewhere, and it
eventually goes down a storm drain. An oil water separator’s job is to
separate dirt, oil, and other contaminants that mix with our
water.
Though oil water separators are expensive to keep in good condition
they can be damaging to the environment if they are not taken care of
properly.Oil
Petroleum is the crude oil that can be found in underground deposits. Crude oil or petroleum is mostly made up of hydrocarbons, but there are some types of oil that contain sulfur or oxygen. Although there is sulfur in petroleum there is not much there, usually only .1%-.5%. Oil is anything that does not dissolve in water and is greasy. It is possible to obtain oil from animals, minerals, or vegetables. Oil is commonly used to make medicines, fertilizers, foodstuffs, plastics, and building materials. Oil is usually a liquid at room temperature and will always rise above water when the two fluids come into contact, this is because oil is not as dense as water so the oil droplets will gather and then rise above the water and sit on the top. Oil can be dissolved if it is placed in ether and is most commonly found as a liquid but can be a solid such as lard or butter fat. Many Uses of
Oil
Everybody uses petroleum directly or indirectly, whether they use it to transport themselves on land, water, or in the air. Many people own cars and those cars require motor oil to work to their full potential. Since there is a high demand for oil in our everyday lives the amount of oil is slowly decreasing and scientist predict that we will run out of petroleum by the middle of the 21st century. Characteristics
of Oil
Petroleum can be as thin as a gas or so thick that it is very hard to be pour. Small amounts of things full of gas usually are dissolved in petroleum, and whenever larger amounts of petroleum come into contact with each other they mix and will form one large liquid. Types
of Petroleum
The three types of petroleum are paraffin, asphaltic, and mixed base. Paraffin types contain molecules in which there are twice as many hydrogen atoms as the number of carbon atoms. Naphthenes in asphaltic types of petroleum have twice as many hydrogen atoms as carbon atoms. Mixed Base petroleum is a mix of both paraffin hydrocarbon and naphthenes. How
Petroleum is Made
Petroleum is made by decomposing living organisms under the surface of the earth. Whatever is left of small marine organisms and some land organisms are carried to the sea by rivers and covered in the sands and silts at the bottom of the sea. This process began millions of years ago. Once the petroleum is formed it flows up to the earth’s crust because the crust has less density than the brines that soak up in the inner wall of the shales, sands, and carbonate rocks that make up the crust of the earth. The oil and natural gas then rise into the microscopic pores of the rougher sediments above. Often the rising material hits a dense layer of rock that cannot be passed so the migration stops, then it is trapped and a reservoir of petroleum is created. Much of the natural gas and crude oil migrate all the way to the earth’s surface or under the ocean floor. Surface deposits are things like bituminous lakes and escaping natural gas. History Of
Petroleum
People have known about crude oil for thousands of years. In the places where oil appeared on the surface it was used for limited thing for a long time such as caulking boats, water proofing cloth and fueling torches. In the 14th century during the Renaissance surface deposits were used for making medicine products, and lubricants. In the 19th century people began searching for new fuels, this was called the industrial revolution. Many people wanted cheap but efficient oil for lamps because whale oil was so expensive. The search for a better lamp oil led to a huge demand for “rock-oil” which is actually crude oil. Then British entrepreneurs such as James Young along with others began to make many different products using crude oil. In 1852 a Canadian physician and geologist named Abraham Gesner received a patent for kerosene the relatively clean burning crude oil. Three years later an American chemist, Benjamin Stillman published a report showing the many useful products that can be made by distillation of petroleum. After that the demand for crude oil greatly increased. Water
Water is the most common thing on earth. About 70% of our planet is covered in water. Water can be found in many places. You can find it in the oceans, rivers, lakes, and even on the very ground we stand on. Without water people could not exist. On earth there are 326 million cubic miles of water. Every cubic mile contains over a million gallons of water. Everybody takes in nutrients (food), but you need water to put the nutrients to use. Water causes the nutrients to have a chemical reaction turning the nutrients into energy and becoming capable of healing bodily wounds. Not only do we need water for nutrients, but we also need it to carry out our bodily wastes. Without water all that waste would build up inside us. Humans need water to exist. A person can live a little longer than two months without food, but can only live without water for about a week. If a person loses more than 20% of their water they will die a painful death. Everybody needs to take in at least 2 1/2 quarts of water each day whether it comes from a beverage, or the water in food. The average person will take in 16,000 gallons of water in their life. A human body contains about 65% water, a chicken contains about 75%, and a tomato consists of 95% water. Erosion
Water has been reforming our earth forever, for example when a wave hits a beach or a river flows through a canyon it will slowly erode that area until it has been completely reformed. This process has been going on since the beginning of time. Water keeps parts of the world from getting too hot or too cold. The sun puts out energy quickly, but the ocean absorbs and releases that energy slowly, bringing warm winds in the winter and cold winds in the summer. Effects of
Water On Earth
Water is vital to our lives. Many great civilizations have fallen because they had a lack of water. When water falls to earth it is very important, many people consider it so important they worship rain gods. People would pray for a good amount of rain, if they got too much there would be a flood killing many people and ruining the crops, where as if there wasn’t enough there would be a drought also killing many and destroying the crops. We are not the only living things on earth that need water to live, all humans, animals, and plants need water to live. Daily uses of
Water
People use water every day, we use it to take baths, wash dishes, clean clothes, irrigate farmland, and we use waterfalls and rivers to generate electricity for use in our every day lives. The average person will use 100 gallons of water on a daily basis. Most of the earth’s usable water is put to use by industry, for example people use 80 gallons of water to make all the papers on a Sunday or it takes 20 gallons per pound of steel manufactured. Everybody uses water and we always have enough, Unusable Water
Most of the world’s water is unusable, 97% of the earth’s water is in the ocean meaning that it can’t be used for many of our needs. We can’t use the oceans water because it contains a lot of salt, making it not useful for drinking, farming (irrigation), or manufacturing. Most of the usable water is frozen in glaciers and icecaps so we don’t use that large abundance of water. To be exact there is 3/4 of our usable water frozen in the icecaps that is more than the total of all the water that has flown through rivers and streams in the last 1,000 years. Today we only use 3% of the world’s water and still have plenty to go around. The Water Cycle
Water is the only thing on earth that can be a liquid, a solid (ice), and a gas (water vapor) at normal living temperatures. We will never use up our water resources because water will always find it’s way to the ocean, where it then evaporates and becomes a gas (water vapor) and then rises into the sky where condensation occurs. Once the water has gathered it falls back to earth as clean usable water (precipitation). This is a never-ending process that has been going forever. Shortages of
Water
Just because there is enough water to go around doesn’t mean everybody has enough, some places have more than enough whereas there are still places that do not have very much clean water. There are places that don’t receive enough rain causing them to have a dry spell. If they get too much rain the rivers will overflow often resulting in flood damage. Many times shortages occur because the usable water is poorly managed. If a factory dumps waste into a lake or a river they make it harder to get usable water from that particular lake. Oil/Water
Separators
Separators are designed to remove oils, fuels, and hydraulic fluids from water. The two main uses for an oil water separator are rainwater runoff, and equipment wash-down. Oil water separators are used in airports, vehicle maintenance facilities, railroads, military installations, parking lots, and utilities. How It Works
The mixture of oils, solids and water flow into the separator and spread out horizontally. The oils will join together and rise to the top of the water because the oil is not as dense as the water or the solids, because the solids (trash and sludge) are denser than any of the other substances causing it to sink to the bottom. Stoke’s law is a way to determine how rapidly a fluid will rise. If somebody wanted to speed up the process you could use baffles, coalescing units, and or oil skimmers. Stokes law is the formula showing the velocity at which a viscous fluid will rise, it states V=(2gr?)(d1d2)/9 Where V=velocity of rise (cm sec-?), g=acceleration of gravity (cm sec-?), r=”equivalent” radius of particle (cm), d1=density of particle (g cm-?). d2=density of medium (g cm-?), and ?=viscosity of medium (dyne sec cm-?). The Chambers
and How They Work
Oil water separators contain many chambers one after another to create more sedimentation and to separate the oil that is gathered from storm water. Many separators have a screen to catch the larger debris that might enter the separator. A normal separator contains a sediment chamber and a discharge chamber. There are some separators that contain: and extra orifice and a chamber that can go in place for the lower pipe, the wall going all the way up to the ceiling in the second chamber, or it could have a diffusion device located at the inlet. This device is supposed to reduce the velocity and turbulence making the water flow more smoothly into the sedimentation chamber. If a “coalescing unit” is added it can increase the separator’s efficiency and can make it much more compact Coalescing units are made of oil water separating things like polypropylene. These things collect oil droplets and will rise to the top because they are less dense. When you don’t have a coalescing unit the oil and water will have to separate naturally meaning it would need more surface area for the oil and grease, which is why separators without coalescing units are larger. (found at www.epa.gov/owm/mtb/wtrqlty.pdf) Fluids can be either gas, or liquid that does not hold its own shape. The pressure is how much force is in one unit area. The deeper, the more pressure. Density is how much mass is in one unit volume. The density stays the same with depth. With depth gases will usually increase in density, fluid velocity of the molecules that form the fluid. Laminar flow
and Turbulence
Laminar flow is when layers of fluids slide smoothly over one another. When laminar flow occurs there are no vortices or cavitation. When water layers rotate back upon themselves it is known as vortices. Cavitation is when voids and bubbles are formed. Vortices and
Cavitation
When cavitation or vortices are made it is known as turbulent flow. Turbulent flow usually occurs at barriers or where the fluid flow dramatically changes. Turbulence is almost impossible to predict. As velocity increases so does turbulence. Ways to Reduce
Turbulence
There are ways to reduce turbulence. The best way to avoid turbulence is to have curves in most places were you might have sharp changes in directions, have more bends and joints as you possibly can. Another option would be to join the pipes with different diameters by using connectors made specifically for the job, this will make the transition from different diameters smoother. Polypropylene
Polypropylene is strong, durable, lightweight, heat-resistant plastic material that can be used for panels for the inside of cars, coatings for a telephone wires, or make carpet fibers. Polypropylene is a chain of monomers (links of atoms) they consist of 3 carbon and 6 hydrogen atoms, the chemical formula is (C3+H6)n. It would be best if people didn’t use detergents, these compounds mix the oil and water making it so they will never separate also causing the contaminated water to go right through the separator. When this situation occurs it is known as emulsifying. There are other ways to reduce the effectiveness of your separator here are a few. (found at http://www.epa.gov/region009/cross_pr/pr2/actofleet/separator.pdf) Summary
Oil water separators are an important part of our lives, they help
reduce pollution, purify water, and very important to our everyday
lives. Pollution is becoming a big problem in our society today
and we
need to do all we can to protect all living things on earth. |
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Carr, Stephen. “Polypropylene.” World Book Encyclopedia. 1999. Containment Solutions inc.“ Underground FRP tanks.” Containment Solutions <http://www.containmentsolutions.com/products/underground_frp/singlewallpetro/index.html Dolbear, Geoffry. “Oil.” World Book Encylopedia. 1995 Dosher, Todd. “Petroleum.” Microsoft Encarta.” 2005 edition “Fluid Dynamics” <http://wwwluvi.edu/physics/Sc13xxweb/plumbing/fluiddynamics.html Keinath, Thomas. “Water.” World Book Encyclopedia. 1998 Pan America Environmental.” Pan America Environmental Oil/Water Separator Operational Theory.”<http://www.panamenv.com/concrete -theory.html “Storm Water Technology fact sheet Water Quality Inlets” <www.epa.gov/owm/mtb/wtrqlty.pdf> |
I would like to thank the following people for helping make my project possible:
- My parents for bringing me to all of the after school classes
- My father for helping me with my experiment
- Breanna for helping me get a picture of the monomers that make up a polypropylene pad.
- Mr. Newkirk for helping me choose a project.
- Mrs. Helms for helping me find information to take notes on.
- Mr. Hepner for helping me throughout my whole project by doing things like making me interested in oil water separators.
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