Environmental Engineering Reference
In-Depth Information
Table 5. Assumed input parameters for Triangular model
Rapidly biodegradable
fractions
Moderately biodegradable
fractions
Slowly biodegradable
fractions
t
0
[year]
0
0
0
t
max
[year]
1,92
4,62
9,90
t
end
[year]
9,63
23,10
49,51
Q
LFG,max
[Nm
3
/t] 2,78
2,55
1,19
1,2E+07
1,0E+07
8,0E+06
6,0E+06
4,0E+06
2,0E+06
0,0E+00
1
6
11
16
21
26
31
36
41
46
51
56
61
66
71
76
81
Year
Rapidly biodegradable fractions
Moderately biodegradable fractions
Slowly biodegradable fractions
Figure 4. Results of LFG production, for each group of waste components with different biodegradation
velocity, obtained by the application of Scholl Canyon model.
Results obtained from the different models have been compared with the data of collected
LFG at the landfill site during three years of operation, which are reported in Table 6. For the
analysed landfill site, the estimation escaped LFG from the landfill surface, is available from
a measuring campaign previously carried out, by means of the accumulation chamber method
(Cardellini et al., 2003) (Börjesson et al., 2000) (Raco et al., 2005) during the sixth year of
operation. The specific carbon dioxide emission resulting from those previous measurements
is 350 g/(m
2
· day). Assuming a composition of LFG of 50% CH
4
and 50% CO
2
and an
overall landfill surface of about 90.000 m
2
(at sixth year), the amount escaped LFG is about
11.713.862 Nm
3
in the sixth year. This allows the estimation of the LFG collection efficiency,
as shown in Table 6.
Table 6. Collected LFG data, estimated escaped LFG at the studied landfill site
and estimated collection efficiency
Year
Collected LFG [Nm
3
]
Escaped LFG [Nm
3
]
Estimated collection efficiency [%]
5
7.500.000
-
-
6
7.707.818
11.713.862
40
7
11.500.000
-
-
