chapter 4: temperature inside the landfill

4.6 Volume of Waste Wetted
Estimating the volume of the waste wetted from a liquid injection was another objective
of this study. The assumptions required were: (1) the injected water or leachate was at ambient
temperature, (2) the injected liquid mixes instantly with the moisture present in the waste, and
(3) initial moisture content and bulk density of the waste were assumed to be 0.23
(Jonnalagadda, 2004) and 710 kg/m 3 (Jain, 2005) respectively.
The liquid injected (leachate or groundwater) is assumed to be at ambient temperature T1
while the volume injected is V1. The volume of moisture already present in the waste which is
affected by the injection is V2 at temperature T2. The resulting temperature after mixing of V1
and V2 is T3.
The value of T3 can be found by the mixing equation 4-7:
T
V T + V T
1 1 2 2
3 = (4-7)
V1
+ V2
By rearranging Equation 4-7, we get the equation 4-8 to calculate the value of V2, i.e.
volume of moisture already present in the waste,
V
V ( T −T
)
1 3 1
2 = (4-8)
T2
−T3
Now, moisture content of the waste can be represented by the equation for moisture
content of the waste, i.e.
MC
i
50
ρV2
=
ρV
+ M
2
s
(4-9)