hemprichi in the microcosm using river water sampled on the day when herbicidal
dispersion was completed at the farm. However, a decrease was observed in the
abundance of Lecane sp. and a bacterium, and an increase was observed in the
abundance of Cyclidium glaucoma. Additionally, the decrease in the abundance of
Lecane sp. and in bacteria were remarkable, and the presence of Lecane sp. was not
able to be confirmed by the 21st day of the experiment.
No difference was observed after culturing began in the upper reaches or in the
downstream area of the farm until the seventh day, when a difference between these
areas became noticeable. A decrease was seen in the downstream abundance of
Lecane sp. and in a bacterium in comparison with the upper reaches on the 14th day
after culturing began, and an increase in abundance was observed in Cyclidium
glaucoma. Additionally, at the location of inflow, where it was assumed that there
was no influence from the dispersion of pesticide because there was no control
system, remarkable differences in the species composition of the microcosm were
confirmed.
9.3.7 Golf Course Effluent
The investigation of golf course effluent was conducted for underdrainage after
pesticide dispersion at a golf course in Narita City, Chiba. The pesticides used
were all herbicides, namely, Double Up DG, Scoly Tex (SDS), Ajiran, Mecoprop
(MCPP), and Dictran. Additionally, field measurements of water temperature, pH,
and DO and laboratory measurements of T-N, NO 2 -N, NO 3 -N, NH 4 -N, T-P, PO 4 -P,
COD, BOD, and SS were taken. The ratios of the test drainage water were set as 0%
(control/no-addition system), 25%, 50%, 75%, and 100%. After 16 days of microcosm cultivation, test drainage water, which was suction filtered using a 0.45 μm
diameter membrane (ADVANTEC, GS-45), was added to the microcosm.
As the addition ratio of the environmental water increased to 25%, 50%, and
100%, the structural parameters (abundance) of Chlorella sp. (a producer),
Scenedesmus quadricauda (a producer), and Aeolosoma hemprichi (a top predator)
were influenced. In the 100% addition system, Aeolosoma hemprichi perished. From
these results, the m-NOEC of the structural parameter was estimated as less than
25% because some influence was observed at all addition ratios of in the golf course
effluent. As shown in Fig. 9.8, system bioactivity increased in the 25% addition
system for the functional parameter (P/R ratio); it then decreased before rising again
in the 50% addition system. Furthermore, bioactivity decreased remarkably and
immediately in the 100% addition system. From these results, the m-NOEC of the
functional parameter was estimated as 25% of the golf course effluent. Dilution of
more than four times was considered necessary to discharge this drainage safely
(Fig. 9.8).
9 Application to the Whole Effluent Toxicity Test
179
dispersion was completed at the farm. However, a decrease was observed in the
abundance of Lecane sp. and a bacterium, and an increase was observed in the
abundance of Cyclidium glaucoma. Additionally, the decrease in the abundance of
Lecane sp. and in bacteria were remarkable, and the presence of Lecane sp. was not
able to be confirmed by the 21st day of the experiment.
No difference was observed after culturing began in the upper reaches or in the
downstream area of the farm until the seventh day, when a difference between these
areas became noticeable. A decrease was seen in the downstream abundance of
Lecane sp. and in a bacterium in comparison with the upper reaches on the 14th day
after culturing began, and an increase in abundance was observed in Cyclidium
glaucoma. Additionally, at the location of inflow, where it was assumed that there
was no influence from the dispersion of pesticide because there was no control
system, remarkable differences in the species composition of the microcosm were
confirmed.
9.3.7 Golf Course Effluent
The investigation of golf course effluent was conducted for underdrainage after
pesticide dispersion at a golf course in Narita City, Chiba. The pesticides used
were all herbicides, namely, Double Up DG, Scoly Tex (SDS), Ajiran, Mecoprop
(MCPP), and Dictran. Additionally, field measurements of water temperature, pH,
and DO and laboratory measurements of T-N, NO 2 -N, NO 3 -N, NH 4 -N, T-P, PO 4 -P,
COD, BOD, and SS were taken. The ratios of the test drainage water were set as 0%
(control/no-addition system), 25%, 50%, 75%, and 100%. After 16 days of microcosm cultivation, test drainage water, which was suction filtered using a 0.45 μm
diameter membrane (ADVANTEC, GS-45), was added to the microcosm.
As the addition ratio of the environmental water increased to 25%, 50%, and
100%, the structural parameters (abundance) of Chlorella sp. (a producer),
Scenedesmus quadricauda (a producer), and Aeolosoma hemprichi (a top predator)
were influenced. In the 100% addition system, Aeolosoma hemprichi perished. From
these results, the m-NOEC of the structural parameter was estimated as less than
25% because some influence was observed at all addition ratios of in the golf course
effluent. As shown in Fig. 9.8, system bioactivity increased in the 25% addition
system for the functional parameter (P/R ratio); it then decreased before rising again
in the 50% addition system. Furthermore, bioactivity decreased remarkably and
immediately in the 100% addition system. From these results, the m-NOEC of the
functional parameter was estimated as 25% of the golf course effluent. Dilution of
more than four times was considered necessary to discharge this drainage safely
(Fig. 9.8).
9 Application to the Whole Effluent Toxicity Test
179