Recycling
Recycling is the process of producing new products from used material in order to protect
our environment. Following are various numbers of recyclable materials:
1. Plastic
2. Glass
3. Waste water
4. Metal Food and Beverage Containers
5. Paper
There are various number of recycling systems which can be implemented on island in
order to collect recyclable material from the general waste stream such as "drop-off centers",
"buy-back centers" and "curbside collection".[1] Let’s suppose that to establish the composition
of recyclable material in the waste stream on island, a waste was estimated and given as follow:
S#
Percentage Generated
1
2
Recyclable
Material
Plastic
Glass
3
Waste
50%
4
Metal containers
7%
5
Paper
15%
3%
25%
1. Plastic Recycling
http://www.youtube.com/watch?v=0THzy4d67SQ&feature=related
Conveyer
Washing Type
Crushing
U-shape screw
Conveyer
Washing and
Impurities
seperation
Squeez type
De-watering
Washing and
Impurities
seperation
Squeez type
De-watering
Screw Conveyer
Crushing
Blowing
Cyclone
Side Feeding
Main Extruding
Sub-Extruding
Cooling
Dehumidifying
Cutting
Storing
Fig: 1
2. Glass Recycling
Glass is sorted at material recycling facility into various colors, mainly Flint (clear glass), Green
glass, and Brown / Amber glass. Glass is then sold to glass processors to be cleaned and crushed.
The glass that has been processed is now known as cullet and is ready to be used in producing
new glass.
(http://www.youtube.com/watch?v=G1yaoeWtWJY)
http://www.youtube.com/watch?v=6R8YObQbE88&feature=related
Glass
Containers
Collection
Mixing with
Raw
materials(Sand)
Melted in
Furnace at
1000 F˚
Delivered to
Re-Processing
Sent to Glass
Factory
Moulding/
mechanically
blown
Screening
Crushing
Packaging
Contamination
Seperation
according to
colors
Fig: 2
3. Waste Water Treatment
The waste water can be treated by number of following steps:
Coagulation/flocculation- Raw water from terminal reservoirs is drawn into mixing basins at
treatment plants where alum, polymer and sometimes lime and carbon dioxide are added. This
process causes small particles to stick to one another, forming larger particles.
Sedimentation- Over time, the now-larger particles become heavy enough to settle to the bottom
of a basin from which sediment is removed.
Filtration- The water is then filtered through layers of fine, granulated materials — either sand,
or sand and coal, depending on the treatment plant. As smaller, suspended particles are removed,
turbidity diminishes and clear water emerges.
Disinfection- To protect against any bacteria, viruses and other microbes that might remain,
disinfectant is added before the water flows into underground reservoirs throughout the
distribution system.
Corrosion control- pH is maintained by adding alkaline substances to reduce corrosion in the
distribution system. <http://www.youtube.com/watch?v=9z14l51ISwg&feature=related>
Stored
Raw
Water
Home
Coagulation
Finihed Water
Storage
Sedimentation
Disinfection
Filteration
Fig: 3
4. Metal Food and Beverage Containers
Today it is cheaper, faster and more energy-efficient to recycle aluminum than ever before. The
process of recycling aluminum cans is described below;
Step#01
Aluminum cans are collected at residential drop-offs and by municipal pick-ups. Once cans
arrive at the MRF (Material Recovery Facility) they will be sorted using a device called an eddy
current. The eddy current briefly electrically charges they can cause it to repel from the device
off a sorting line into an awaiting bin. After, they condense the cans into highly dense, 30-pound
briquettes or 1,200-pound bales and ship them off to aluminum companies for melting.
Step#02
At the aluminum companies, the condensed cans are shredded, crushed and stripped of their
inside and outside decorations via a burning process. Then, the potato chip-sized pieces of
aluminum are loaded into melting furnaces, where the recycled metal is blended with new, virgin
aluminum.
Step#03
The molten aluminum is then poured into 25-foot long ingots that weigh over 30,000 pounds.
The ingots are fed into rolling mills that reduce the thickness of the metal from 20-plus inches to
a sheet that is about 10/1,000 of an inch thick.
Step#04
This metal is then coiled and shipped to can makers, who produce can bodies and lids. They, in
turn, deliver cans to beverage companies for filling.
Step#05
The new cans are then ready to return to store shelves in as little as 60 days, only to go through
the entire recycling process again. (http://www.youtube.com/watch?v=1rXNdcJu-bY)
Figure: 4
5. Paper Recycling
Pulping: Adding water and applying mechanical action to separate fibers from each
other.
Screening: Using screens, with either slots or holes, to remove contaminants that are
larger than pulp fibers.
Centrifugal cleaning: Spinning the pulp slurry in cleaner cause materials that are denser
than pulp fibers to move outward and be rejected.
Flotation: Passing air bubbles through the pulp slurry, with a surfactant present, causes
ink particles to collect with the foam on the surface. By removing contaminated foam,
pulp is made brighter. This step is sometimes called de-inking.
Kneading or dispersion: Mechanical action is applied to fragment contaminant
particles.
Washing: Small particles are removed by passing water through the pulp.
Bleaching: If white paper is desired, bleaching uses peroxides or hydrosulfides to
remove color from the pulp.
Papermaking: The clean (and/or bleached) fiber is made into a "new" paper product in
the same way that virgin paper is made.
Dissolved air flotation: Process water is cleaned for reuse.
Waste disposal: The unusable material left over, mainly ink, plastics, filler and short
fibers, is called sludge. The sludge is buried in a landfill, burned to create energy at the
paper mill or used as a fertilizer by local farmers.
(http://www.youtube.com/watch?v=ETlZjOcsQIk)
Used Paper
Waste
Disposal
Sorting
Disolved Air
Flotation
Pulping
Paper
making
Screening
Centrifugal
Cleaning
Bleaching
Washing
Flotation
Dispersion
Fig: 5
References
1. World War. "Recycling." Wikipedia, the Free Encyclopedia. Wikimedia Foundation, Inc, 22 Feb. 2011.
Web. 24 Feb. 2011. <http://en.wikipedia.org/wiki/Recycling>.
2. "Treatment Process | Denver Water." Welcome to Denver Water. Web. 23 Feb. 2011.
<http://www.denverwater.org/WaterQuality/TreatmentProcess/>.
3. "Recycle These Items - Waste Management - Public Works - Region of Peel." Region of Peel Working for Citizens in Brampton, Caledon and Mississauga. Web. 23 Feb. 2011.
<http://www.peelregion.ca/pw/waste/garb-recy/recycle-items.htm>.
4. "Recyclable Materials Marketing- ReMM." Recyclable Materials Marketing - ReMM. Recyclable
Materias Marketing, 2007. Web. 23 Feb. 2011. <http://www.remm.ca/facts.html>.
5. "YouTube - Ahmedabad Paper Factory." YouTube - Broadcast Yourself. Web. 23 Feb. 2011.
<http://www.youtube.com/watch?v=ETlZjOcsQIk>.
6. "YouTube - Plastic Recycling Production Line with Shredder Recycling Equipment - Part1." YouTube Broadcast
Yourself.
Web.
23
Feb.
2011.
<http://www.youtube.com/watch?v=0THzy4d67SQ&feature=related>.
7. "YouTube - Glass Recycling." YouTube - Broadcast
<http://www.youtube.com/watch?v=G1yaoeWtWJY>.
Yourself.
Web.
23
Feb.
2011.
8. "YouTube - The Smashing Story of Recycling Glass." YouTube - Broadcast Yourself. Web. 23 Feb.
2011. <http://www.youtube.com/watch?v=6R8YObQbE88&feature=related>.
9. "YouTube - Wastewater Treatment." YouTube - Broadcast Yourself. Web. 23 Feb. 2011.
<http://www.youtube.com/watch?v=v_aJWYfm4I4>.
10. "YouTube - The Water Treatment Process." YouTube - Broadcast Yourself. Web. 23 Feb. 2011.
<http://www.youtube.com/watch?v=9z14l51ISwg&feature=related>.
11. "YouTube - Can Recycling." YouTube - Broadcast
<http://www.youtube.com/watch?v=1rXNdcJu-bY>.
Yourself.
Web.
23
Feb.
2011.