influence and stability of pesticides in the aquatic model ecosystem—could be
evaluated from the behavior of the constituent microorganisms and pesticides.
Addition concentrations of simazine were set to 0.08, 0.16, 0.32, and 0.64 mg/L.
In the control system, only methanol was added to the system, and both methanoladdition and no-addition systems were constructed to compare the influence of
methanol as a pesticide solvent.
Using the structural parameter, there was no observed effect on the population of
the methanol-addition system in comparison with the no-addition system, which was
used as a control. There was no effect on the populations of constituent microorganism with the addition of 0.16, 0.32, or 0.64 mg/L of Simazine, except for a
decrease in the bacterial population 2 days after the addition of 0.64 mg/L of
simazine. Changes were not observed in either the amount of respiration (R) or in
the amount of production (P) in the control system (methanol no-addition), but, in
the control system with methanol added, both the amounts of respiration and
production increased. In addition systems with low simazine concentrations,
changes similar to those observed in the methanol-addition control system were
recognized, but a decrease in the amount of production was observed as the
concentration of simazine increased. Although there was no change in the P/R
ratio, which ranged between 1.6 and 1.8, in either of the control systems (i.e., both
with and without methanol), the P/R ratio decreased to 0.8 after the addition of
0.64 mg/L of Simazine (Fig. 7.10).
In the multivariation analysis of the amounts of respiration and production after
the addition of simazine, a meaningful decrease in the amount of production was
recognized between the 0.64 mg/L simazine load and the control with added
Fig. 7.9 Time course of P/R ratio in Fomesafen-added microcosm N-system
86
K. Murakami et al.
evaluated from the behavior of the constituent microorganisms and pesticides.
Addition concentrations of simazine were set to 0.08, 0.16, 0.32, and 0.64 mg/L.
In the control system, only methanol was added to the system, and both methanoladdition and no-addition systems were constructed to compare the influence of
methanol as a pesticide solvent.
Using the structural parameter, there was no observed effect on the population of
the methanol-addition system in comparison with the no-addition system, which was
used as a control. There was no effect on the populations of constituent microorganism with the addition of 0.16, 0.32, or 0.64 mg/L of Simazine, except for a
decrease in the bacterial population 2 days after the addition of 0.64 mg/L of
simazine. Changes were not observed in either the amount of respiration (R) or in
the amount of production (P) in the control system (methanol no-addition), but, in
the control system with methanol added, both the amounts of respiration and
production increased. In addition systems with low simazine concentrations,
changes similar to those observed in the methanol-addition control system were
recognized, but a decrease in the amount of production was observed as the
concentration of simazine increased. Although there was no change in the P/R
ratio, which ranged between 1.6 and 1.8, in either of the control systems (i.e., both
with and without methanol), the P/R ratio decreased to 0.8 after the addition of
0.64 mg/L of Simazine (Fig. 7.10).
In the multivariation analysis of the amounts of respiration and production after
the addition of simazine, a meaningful decrease in the amount of production was
recognized between the 0.64 mg/L simazine load and the control with added
Fig. 7.9 Time course of P/R ratio in Fomesafen-added microcosm N-system
86
K. Murakami et al.