Hydrolysis is high in Chlorpyrifos, and the quality of soil adsorption characteristics
is also high, and it is thought that it is stabilized while adsorbed in the soil. Therefore,
it is thought that Chlorpyrifos remains behind within a system for a long term by soil
adsorption and stabilization. Chlorpyrifos is adsorbed to the bottom sediment when
Chlorpyrifos density decreases by hydrolysis detaching by chemical equilibrium,
and even one revelation being supplied to the mesocosm test where there is bottom
sediment underwater. Because there was no soil in the microcosm, the residual
property of Chlorpyrifos was low, and it was thought that it was less toxic than in
the mesocosm test in which there was soil. It is necessary to examine the analytical
methods that noted the quality of soil and bottom sediment adsorption characteristics
in the future.
7.4.2 Fenitrothion
Fenitrothion was adjusted so that acetone levels became 0.05% after addition to the
culture fluid in diluted form. The concentrations of Fenitrothion were set to 0.01, 0.10,
1.00, and 10.00 mg/L. The Fenitrothion was added 16 days after microcosm culturing
began. As a control, an acetone-only addition system and a no-addition system were
constructed to compare the influence of acetone as a solvent for pesticides.
Based on the structural parameter, there was no influence of acetone itself (i.e., in
the acetone-only system) on the populations of microorganisms, in comparison with
the no-addition system, both of which served as control systems. There was no
remarkable change observed in the populations of each species, in comparison with
these control systems, at concentrations of 0.01 mg/L of Fenitrothion, but the
population size of Aeolosoma hemprichi decreased with the addition of 0.10 mg/L
and 1.00 mg/L. There was no observed influence on the other microorganisms at
these concentrations of Fenitrothion. However, Aeolosoma hemprichi, Philodina
erythrophthalma, and Lecane sp. perished, and the population of Cyclidium
Respiration(mg O 2 /L)
Respiration(mg O 2 /L)
Respiration(mg O 2 /L)
control
1mg/L
10mg/L
Production(mg O
2 /L)
Production(mg O
2 /L)
Production(mg O
2 /L)
0
2
4
6
8
0
2
4
6
8
0
2
4
6
8
0
2
4
6
8
0
2
4
6
8
0
2
4
6
8
Fig. 7.15 Time course of P/R ratio in Chlorpyrifos-added microcosm N-system
7 Example Assessments of the Microcosm N-System
95
is also high, and it is thought that it is stabilized while adsorbed in the soil. Therefore,
it is thought that Chlorpyrifos remains behind within a system for a long term by soil
adsorption and stabilization. Chlorpyrifos is adsorbed to the bottom sediment when
Chlorpyrifos density decreases by hydrolysis detaching by chemical equilibrium,
and even one revelation being supplied to the mesocosm test where there is bottom
sediment underwater. Because there was no soil in the microcosm, the residual
property of Chlorpyrifos was low, and it was thought that it was less toxic than in
the mesocosm test in which there was soil. It is necessary to examine the analytical
methods that noted the quality of soil and bottom sediment adsorption characteristics
in the future.
7.4.2 Fenitrothion
Fenitrothion was adjusted so that acetone levels became 0.05% after addition to the
culture fluid in diluted form. The concentrations of Fenitrothion were set to 0.01, 0.10,
1.00, and 10.00 mg/L. The Fenitrothion was added 16 days after microcosm culturing
began. As a control, an acetone-only addition system and a no-addition system were
constructed to compare the influence of acetone as a solvent for pesticides.
Based on the structural parameter, there was no influence of acetone itself (i.e., in
the acetone-only system) on the populations of microorganisms, in comparison with
the no-addition system, both of which served as control systems. There was no
remarkable change observed in the populations of each species, in comparison with
these control systems, at concentrations of 0.01 mg/L of Fenitrothion, but the
population size of Aeolosoma hemprichi decreased with the addition of 0.10 mg/L
and 1.00 mg/L. There was no observed influence on the other microorganisms at
these concentrations of Fenitrothion. However, Aeolosoma hemprichi, Philodina
erythrophthalma, and Lecane sp. perished, and the population of Cyclidium
Respiration(mg O 2 /L)
Respiration(mg O 2 /L)
Respiration(mg O 2 /L)
control
1mg/L
10mg/L
Production(mg O
2 /L)
Production(mg O
2 /L)
Production(mg O
2 /L)
0
2
4
6
8
0
2
4
6
8
0
2
4
6
8
0
2
4
6
8
0
2
4
6
8
0
2
4
6
8
Fig. 7.15 Time course of P/R ratio in Chlorpyrifos-added microcosm N-system
7 Example Assessments of the Microcosm N-System
95