Odor Problems in Lake Biwa

In 1969 a musty odor was first found in the southern basin of Lake Biwa. Since then we have been investigating the causes of the problem. In the 1970's musty odor problems commonly occurred from May to early June due to the metabolites produced by Phormidiumtenue. However, the problem which took place in the summer of 1981 was found to be caused by an algal bloom of Anabaenamacrospora. The analyses of the water taken in the lake as well as of the laboratory cultures of the blue-green algae led to the conclusion that 2-methylisoborneol is produced by Phormidiumtenue, whereas geosmin by Anabaenamacrospora. Purge and trap concentration followed by mass fragmentography was developed and applied as a measurement method for these two odorous compounds. The method was found to be rapid, reproducible and sensitive enough to detect them at a nanogram per liter concentration level or beneath their threshold odors, requiring only a small sample (100 ml). Slow sand filtration was found to be effective in removing odor, where the odorous compounds were reduced to less than 10 ng/l in the effluents.

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Blue-Green Algae in Lake Biwa Which Produce Earthy-Musty Odors

Water Science & Technology ◽

10.2166/wst.1988.0232 ◽

1988 ◽

Vol 20 (8-9) ◽

pp. 117-123 ◽

Cited By ~ 19

Author(s):

T. Negoro ◽

M. Ando ◽

N. Ichikawa

Keyword(s):

Water Supply ◽

Green Algae ◽

Lake Biwa ◽

Supply System ◽

Surrounding Water ◽

Blue Green Algae ◽

Kyoto City ◽

Off Flavors ◽

Musty Odor ◽

Odorous Compounds

Since 1969, earthy-musty odor problems have frequently occurred in the water supply system of Kyoto City. Though the causes of these off-flavors were identified as 2-methylisoborneol (MIB) and geosmln, the causative organisms were not identified until recently. Now three species of planktonic blue-green algae from Lake Biwa have been identified as playing important roles in such problems. From the unlalgal culture of each alga, Anabaenamacrospora Klebahn was shown to produce geosmln, and both Phormidiumtenue (Meneghini) Gomont and Oscillatoriatenuis Agardh to produce MIB. These odorous compounds were found to be mainly stored in trlchomes, although it was once thought that they were dissolved in the surrounding water. Therefore, most of the odorous compounds can be removed from the water when the causative algae are removed.

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The relationship between musty-odor-causing organisms and water quality in Lake Biwa

Water Science & Technology ◽

10.2166/wst.1995.0426 ◽

1995 ◽

Vol 31 (11) ◽

pp. 153-158 ◽

Cited By ~ 3

Author(s):

M. Kajino ◽

K. Sakamoto

Keyword(s):

Water Quality ◽

Data Analysis ◽

Green Algae ◽

Analytical Methods ◽

Lake Biwa ◽

Blue Green Algae ◽

Odor Compounds ◽

Musty Odor ◽

The Relationship

Musty odor has occurred annually in Lake Biwa since 1969. Osaka municipal waterworks, which is located downstream of Lake Biwa, has made many efforts to treat musty-odor compounds produced in Lake Biwa from spring through autumn. With the development of analytical methods for the determination of musty-odor compounds, we have been able to confirm that planktonic blue-green algae are the major causes of the musty-odor occurrences. The relationship between the growth of blue-green algae and the water quality was not so apparent. However, through our data analysis focusing on the relationship between musty-odor occurrences due to Phormidium tenue or Oscillatoria tenuis and some nutrients in Lake Biwa, we found that the concentration of nitrate in water may be an important parameter for the estimation of growth of the algae and the musty-odor behavior.

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Removal of Musty-Odorous Compounds in Water and Retained in Algal Cells through Water Purification Processes

Water Science & Technology ◽

10.2166/wst.1992.0065 ◽

1992 ◽

Vol 25 (2) ◽

pp. 299-306 ◽

Cited By ~ 20

Author(s):

A. Ando ◽

M. Miwa ◽

M. Kajino ◽

S. Tatsumi

Keyword(s):

Activated Carbon ◽

Solid Phase ◽

Large Fraction ◽

Algal Cell ◽

Surrounding Water ◽

Blue Green Algae ◽

Musty Odor ◽

Odorous Compounds ◽

High Concentrations ◽

Metabolite Content

Musty-odorous compounds, metabolites of some species of blue-green algae, are usually contained in both the water and algal cell bodies. The compounds in the latter solid phase were found to be easily removed by coagulation and sedimentation without breakpoint prechlorination (intermediate chlorination used instead). Chlorination of the algae results in an artificial release of the metabolite content into the surrounding water. When a large fraction of the compounds was present in the algal cell bodies, more than 60% of these compounds were removed in the intermediate-chlorination treatment. Powdered activated carbon treatment is effective in removing the compounds in the aqueous phase. However, the effectivness was usually limited in practical treatment to high concentrations of musty odor. On the other hand, the ozonation and granular activated carbon (GAC) treatment was found to be an effective method for removal. It was observed that the musty-odorous compounds were completely removed through the ozonation and GAC treatment system, which included coagulation and sedimentation without prechlorination.

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Occurrence of Musty Odor in the Yodo River

Water Science & Technology ◽

10.2166/wst.1988.0242 ◽

1988 ◽

Vol 20 (8-9) ◽

pp. 193-196 ◽

Cited By ~ 6

Author(s):

Y. Hishida ◽

K. Ashitani ◽

K. Fujiwara

Keyword(s):

Lake Biwa ◽

Water Shortage ◽

The Body ◽

The Past ◽

Musty Odor ◽

Odorous Compounds

Geosmin and 2-methylisoborneol (MIB) for the past seven years have been responsible for the occurrence of musty odors in Lake Biwa. These odorous compounds are present in the water either in solution or in a form attached to or sited in the body of the responsible cyanobacteria. The concentration of geosmin was found to decrease during its passage through the river. However, MIB was not affected. During the water shortage period of the summer of 1985, the concentration of geosmin was found to increase downstream of the Yodo river. This was attributed to a regrowth of Anabaenamacrospora caused by stagnation of the water in this region.

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Relationship Between the Maximum Standing Crop of Musty-Odor Producing Algae and Nutrient Concentrations in the Southern Basin Water of Lake Biwa

Water Science & Technology ◽

10.2166/wst.1999.0293 ◽

1999 ◽

Vol 40 (6) ◽

pp. 179-184 ◽

Cited By ~ 1

Author(s):

M. Nakanishi ◽

T. Hoson ◽

Y. Inoue ◽

M. Yagi

Keyword(s):

Standing Crop ◽

Lake Biwa ◽

N:P Ratio ◽

Nutrient Concentrations ◽

Phosphorus Concentration ◽

Strong Positive Correlation ◽

Southern Basin ◽

Positive Correlation ◽

Soluble Phosphorus ◽

Musty Odor

In order to make clear the growth characteristics of musty-odor producing algae (Oscillatoria tenuis, Phormidium tenue and Anabaena macrospora), we examined the correlation between the maximum growth number (MGN) of each alga and nutrient concentrations, with the unialgal culture method using a 0.45μm pore size membrane-filtered lake water. We found that the MGN of Lake Biwa water was limited by soluble phosphorus concentration. In order to verify the results, we examined out the relation between the maximum standing crop (MSC) of musty-odor producing algae in the southern basin of Lake Biwa and nutrient concentrations of our 12-year (1983-1994) observation data. The MSC of P. tenue showed a positive correlation with the N:P ratio. On the other hand, The MSC of O. tenuis showed a strong positive correlation with the phosphorus concentration, and a positive correlation with the iron and soluble phosphorus concentration, but a strong negative correlation with the N:P ratio. When the phosphorus concentration is over 0.030 mg/l, O. tenuis will probably be over 10 filaments/mL. The optimum N:P ratio range was 10 to 20.

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Modelling multi-species algal bloom in a lake and inter-algal competitions

Water Science & Technology ◽

10.2166/wst.2009.632 ◽

2009 ◽

Vol 60 (10) ◽

pp. 2599-2611 ◽

Cited By ~ 15

Author(s):

Monzur Alam Imteaz ◽

Abdallah Shanableh ◽

Takashi Asaeda

Keyword(s):

Water Quality ◽

Algal Bloom ◽

Ecological Model ◽

Algal Species ◽

Dynamic Responses ◽

Bubble Plume ◽

Deep Lake ◽

Blue Green Algae ◽

Artificial Mixing ◽

Using Data

A numerical model was developed to simulate water quality and algal species composition in a deep lake. As artificial destratification is widely used in the lakes, a destratification (bubble plume) model was incorporated with the ecological model to simulate the dynamic responses of different species under artificial mixing. The ecological model predicts concentrations of PO4-P, NH4-N, NO3-N, DO and pH throughout the water column, all of which have a significant influence on the growth of different algal species. The model has been calibrated using data from Uokiri Lake (Japan) for two different species (Diatom and Cyanobacteria) with and without artificial mixing. The calibrated model was used to simulate different conditions of artificial mixing within the lake over a period of five months. The simulation results show that artificial mixing favors non-motile heavier species, such as Diatom, while preventing the growth of Blue-green algae. It is also demonstrated that intermittent operation of the artificial mixing is better for water quality amelioration than continuous operation.

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