Environmental Engineering Reference

In-Depth Information

Figure 3.. Graphical representation of LFG production over a five-year period from the rapidly and

slowly decomposable organic materials in landfill (Tchobanoglous et al., 1993).

Analytically, the LFG production rate in the Triangular model can be described as a

function of time as it follows:

Q

=

0

t

≤

t

LFG

,

t

,

i

i

0

,

i

t

−

t

i

0

,

i

growing

phase

:

Q

=

Q

,

t

≤

t

≤

t

LFG

,

t

,

i

LFG

,

max,

i

0

,

i

i

max,

i

t

−

t

max,

i

0

,

i

t

−

t

(2)

max,

i

i

decreasing

phase

:

Q

=

Q

,

t

≤

t

≤

t

LFG

,

t

,

i

LFG

,

max,

i

max,

i

i

end

,

i

t

−

t

end

,

i

max,

i

Q

=

0

t

≥

t

LFG

,

t

,

i

i

end

,

i

where:

Q
LFG,t,i
= LFG production rate at year t for waste placed at year i [m
3
/(t · year)]

t
max,i
= time at which LFG production reaches the peak for waste placed at year i [year]

In order to estimate the current emissions from waste placed in all years, Equation 1 and

Equation 2 can be solved for all values of R
i
and the results summed:

(3)

t

∑

Q

=

Q

LFG

,

t

LFG

,

t

,

i

i

=

initial

year