HW2
1)
Given:
Waste production ppl: 4 lb/person/day
Waste production industrial facility: 100 tons/day
Town: 1500 ppl
Town landfill: estimated 4 years (with no industrial waste), or 1460 days
Total town waste = 4 lbs*1500ppl /2000 = 3 tons per day
Capacity of landfill = 1460 days*3 tons/day = 4380 tons of space remaining
Town + Facility = 100 +3 = 103 tons waste/day
Time for landfill with ind. Waste = 4380 tons / 103 tons/day = 42.5 days left
At 42 days, at 100 tons per day, the industrial facility will contribute 4,200 tons of waste. At
$10/ton, this will cost the town an additional $42,000 over the course of 42 days.
2)
Based on info from staff who orders paper, approximately:
30 reams per week of 8.5x11
1 ream 11x17
3 rolls plotter paper (36x500)
3)based on page 253, maximum compaction is appx. 1250 lb/yd^3
4) Response to Chapel Hill News: Although the heat value of trash will vary based upon the
composition (trash with more paper waste will have a higher heating value than one containing
more yard trimmings), oil will continue to have a higher heating value. In addition, trash can
retain moisture. A significant amount of energy is spent to overcome the moisture content (an
issue not found with oil). In addition, derivatives of oil can be used in places where trash cant
(such as in personal vehicles).
5) Trash can either absorb or evaporate moisture in between generation and ultimate disposal
(landfill or incineration). Rain events or food waste can transfer moisture to absorbent waste
such as paper products. If weather conditions are dry and arid, waste has the potential to
evaporate moisture content prior to ultimate disposal.
6) Office waste content:
Paper 80%
Garbage 10% (food waste, bathroom waste)
Glass <1
Aluminum <1
Steel <1
Plastics 10% (packaging, including food packaging)
Other <1
7) code and switch
8) Public relations campaigns. According to the Ecology Center (accessed 2/9/2014 at
http://ecologycenter.org/plastics/ptf/report2/), a plastics industry group spent $18 million in a
national advertising campaign called “Take Another Look At Plasctics” citing the large number
of plastics recycled (but did not mention that the quantity recycled was miniscule compared to
the amount of virgin product produced)
9)
100,000 ppl * 4 lb waste/day = 400,000 lb/day
Assume when placed compacted to density of 1000 lb/cy
So 400 CY of waste placed per day
Assume 20% cover
So total 480 CY per day
It will take
375 days to fill 180,000 CY (a little over 1 year)
10)
As-received = conditions of waste when tipped at disposal facility. Determined as-is.
Moisture free heat value = heat value assuming no water contained in waste. Determined by
removing water content.
Moisture and ash free = heat value assuming no water contained in waste and only accounting
for content of waste that will volatlized (instead of turning to ash).
11) Objective = extend landfill space. However, consequence is more can be incinerated (instead
or reducing / reusing / recycling) and that will meet same goal). To encourage community
recycling, place large taxes on incineration / landfills and publicize the huge costs to make
recycling the more economical choice.
12) yes – it goes in the universal waste recycling bin.
13) Loose refuse = 200 lb/cy
Baled refures = 1200 lb/cy
Loose refuse 6x as bulky as baled.
14)
food
paper
cardboard
plastics
textile
rubber
moisture
Wt of
content % by wt moisure
70
10
7
6
33
1.98
5
8
0.4
2
5
0.1
10
4
0.4
2
3
0.06
yard waste
metals
misc
assume 100 lbs of
waste
60
3
6
18
10
9
10.8
0.3
0.54
lbs of
21.58 moisture
21% moisture content
15) Assuming 21 lbs moisture, 79 lbs dry
So 26.5% moisture content on dry basis
The first (21% moisture content) makes more sense to me – more clear what each number is.
16) If no yard waste, 11 lbs of moisture per 82 lbs of waste (13.4% moisture content)
Separating yard waste would significantly decrease moisture content
17)
food
paper
cardboard
plastics
textile
rubber
yard
waste
metals
misc
btu/lb
% wt
2000
7200
7000
14000
7500
10000
2800
300
3000
10
33
8
5
3
4
18
10
9
total
btus
200
2376
560
700
225
400
504
30
270
5265 btu/lb
18)
total
btu/lb
% wt
btus
food
2000
10
200
paper
7200
16.5
1188
cardboard
7000
8
560
plastics
14000
3.75
525
textile
7500
3
225
rubber
yard
waste
metals
misc
10000
4
2520
300
3000
18
6.6
9
400
453.6
19.8
270
3841.4 btu/lb
Energy content would go down, recycling in the manner which the problem states
19)10 ft/lb (see figure 2-13 of book)
20) 2008: 250 million tons MSW in US, 33% diverted
(http://teamster.org/sites/teamster.org/files/22411RecyclingJobsReportExecutiveSummary.pdf)
2012: 251 million tons MSW, 34.5% diverted
(http://www.epa.gov/waste/nonhaz/municipal/pubs/2012_msw_fs.pdf)
Basically no change in waste generation or diversion rates since 2008