flow. As for the analytical prediction model, a one-dimensional semi-infinite porous
medium cylinder is selected with a fixed concentration boundary model at one end;
C
C 0
¼
1
2
erfc
x À ut
2
ffiffiffiffiffiffiffi
D L t
p
þ
1
2
e
ux
D L erfc
x þ ut
2
ffiffiffiffiffiffiffi
D L t
p
where:
t
time;
C
concentration of pollutants at x at t, mg/L;
C0 concentration of leaked pollutant;
X
distance from the injection point;
U
actual concentration of groundwater;
DL longitudinal dispersion coefficient;
erfc complementary error function, according to Hydrogeological Handbook and
related data.
(2) Leachate quality
According to the Proposal and Feasibility Study Report for Phase II Extension
Project of a Landfill in A City of a Province in Southeast China, the quality of
leachate is shown in Table 5.79.
(3) Hydrogeological parameter selection
According to the investigation and data collected, the permeability coefficient is
taken as 1.56 Â 10
−5 cm/s for clinosol, 6.29 Â 10
−4 cm/s for strongly weathered
rock, and 7.29 Â 10
−5 cm/s for moderately weathered rock. The hydraulic gradient
J of the plant site area is 0.029, and the effective porosity ne is 0.015. According to
Darcy’s Law: v = KJ, where v is the seepage velocity of groundwater, wet get the
actual velocity of groundwater:
U ¼ v=ne ¼ KJ=ne ¼ 0:543 Ã 0:029=0:015 ¼ 1:05 m=d
Table 5.79 Water quality
indexes of landfill leachate of
phase II extension project
S/N
Control of pollutants
Concentration
1
CODcr
1000 mg/L
2
N H 3 –N
800 mg/L
3
TN
1200 mg/L
4
SS
1500 mg/L
5
TP
20 mg/L
6
p H
7 –8
252
5 Application Cases
medium cylinder is selected with a fixed concentration boundary model at one end;
C
C 0
¼
1
2
erfc
x À ut
2
ffiffiffiffiffiffiffi
D L t
p
þ
1
2
e
ux
D L erfc
x þ ut
2
ffiffiffiffiffiffiffi
D L t
p
where:
t
time;
C
concentration of pollutants at x at t, mg/L;
C0 concentration of leaked pollutant;
X
distance from the injection point;
U
actual concentration of groundwater;
DL longitudinal dispersion coefficient;
erfc complementary error function, according to Hydrogeological Handbook and
related data.
(2) Leachate quality
According to the Proposal and Feasibility Study Report for Phase II Extension
Project of a Landfill in A City of a Province in Southeast China, the quality of
leachate is shown in Table 5.79.
(3) Hydrogeological parameter selection
According to the investigation and data collected, the permeability coefficient is
taken as 1.56 Â 10
−5 cm/s for clinosol, 6.29 Â 10
−4 cm/s for strongly weathered
rock, and 7.29 Â 10
−5 cm/s for moderately weathered rock. The hydraulic gradient
J of the plant site area is 0.029, and the effective porosity ne is 0.015. According to
Darcy’s Law: v = KJ, where v is the seepage velocity of groundwater, wet get the
actual velocity of groundwater:
U ¼ v=ne ¼ KJ=ne ¼ 0:543 Ã 0:029=0:015 ¼ 1:05 m=d
Table 5.79 Water quality
indexes of landfill leachate of
phase II extension project
S/N
Control of pollutants
Concentration
1
CODcr
1000 mg/L
2
N H 3 –N
800 mg/L
3
TN
1200 mg/L
4
SS
1500 mg/L
5
TP
20 mg/L
6
p H
7 –8
252
5 Application Cases