Page 165 - Materials Chemistry, Second Edition

148 Practical Design Calculations for Groundwater and Soil Remediation

Use Equation (4.24) to find the final effluent concentration:

C out C out − (0.1)(100) − 10
= = e = e
C in 1,800

C = 0.082 mg/kg (It is below the cleanup level.)
out
(b) For the two 2-m reactors,
3
the residence time = V/Q = 2 m /(0.02 m /min) = 100 min each
3
3
Q/2, C 0 Q/2, C 1
2 m 3
Q, C 0 Q, C f
Q/2, C 0 Q/2, C 2
2 m 3

Use Equation (4.24) to find the effluent concentration for each
reactor:

= = e = e
C out C out − (0.1)(100) − 10
C in 1,800

C = 0.082 mg/kg for both reactors (The combined final effluent
out
is below the cleanup level.)
3
(c) The residence time of the first reactor = 1 m /(0.02 m /min)
3
= 50 min
The residence time of the second reactor
= 3 m /(0.02 m /min) = 150 min
3
3
Q/2, C 0 Q/2, C 1
1 m 3
Q, C 0 Q, C f
Q/2, C 0 Q/2, C 2
3 m 3

Use Equation (4.24) to find the effluent concentration from each
reactor:

C 1 − (0.1)(50) − 5
Reactor 1: = e = e
1,800