Geoscience Reference
In-Depth Information
Table 16.10
Degradation rates and half-lives determined from batch incubation experiments at pH 5.33-5.95
Data
a
Degradation rate, k (day
-1
)
b
Half-life, t
1/2
(day)
b
Description
Alrazine
Hexazinone
Procymidone
Atrazine
Hexazinone
Procymidone
(1) Degradation in the liquid phase
Total degradation in
groundwater
A
0.00E+00
5.18E-03
3.32E-02
Infinite
134
20.8
(0.00E+00-1.09E-03)
(0.00E+00-1.22E-02)
(2.61E-02-4.37E-02)
(636-infinite)
(56.8-infinite)
(15.9-27.6)
Chemical
degradation in
groundwater
B
0.00E+00
8.95E-03
5.72E-03
Infinite
77
121
(0.00E+00-8.23E-04)
(3.23E-03 02)-1.60E-02)
(3.07E-03-8.38E-03)
(842-infinite)
(43.3-215)
(82.7-226)
Biodegradation in
groundwater
A-B
0.00E+00
-
2.75E-02
Infinite
-
25.2
(0.00E+00-2.67E-04)
-
(2.20E-02-3.53E-02)
(2596-infinite)
-
(19.6-31.5)
(2) Reduction in the mixture of liquid and solid phases
Total degradation in
groundwater and
sand
C
1.95E-02
8.30E-03
1.28E-02
36.5
83.5
54.1
(1.72E-02-2.21E-02)
(2.67E-03-1.50E-02)
(8.99E-03-1.72E-02)
(31.4-40.3)
(46.2-260)
(40.3-77.1)
Chemical
degradation in
groundwater and
sand
D
9.26E-03
5.09E-03
2.20E-02
74.8
196
31.5
(7.75E-03-1.18E-02)
(5.15E-04-9.68E-03)
(1.84E-02-2.56E-02)
(64.2-89.4)
(71.6-1346)
(27.1-37.7)
Biodegradation in
groundwater and
sand
C-D
1.02E-02
3.21E-03
-
67.7
216
-
(9.45E-03-1.13E-02)
(2.16E-03-5.32E-03)
-
(61.3-73.3)
(130-322)
-
Reproduced with permission. Pang et al. (
2005
), Copyright Society of Chemical Industry. Permission granted by John Wiley & Sons Ltd. on behalf of the
SCI
a
A = nonsterilized groundwater. B = sterilized groundwater. C = nonsterilized groundwater with nonsterilized aquifer sand. D = sterilized groundwater
with sterilized aquifer sand. Estimations for C and D were based on date of days 3-120. Sorption onto the glass bottle was not considered so the results of
isothermal tests show that sorption of the pesticides onto the glass bottles is negligible
b
Values in parentheses give the possible range based on analysis errors
