1:45 PM - 3:15 PM
[O08-P98] Why doesn’t “silent sand” make sound?
Keywords:Kotogahama Beach, squeaky sand (singing sand), pack test, ammonium nitrogen
1 Purpose of the research
To investigate "why the sand that does not squeak does not squeak" through experiments. Since we learned from a previous study conducted at Hamada High School that the beach sand in Shimane Prefecture does sound when washed, we searched for the pollutants that prevent the sand from singing.
2 Experiments and results
(1) Fieldwork
Sand samples were collected from three locations in Ohda City, and the condition of the beaches was examined.(Figure 1)
1 Nima Town: Kotogahama Beach 2 Kute Town: Kute Beach 3 Hane Town: Hane Beach
(Kotogahama Beach and Hane Beach are squeaky sand beaches)
(2) Observation
･Percentage of transparent grains (quartz)
Low Kute ･Percentage of black grains
Low Kotogahama
(3) Pack test (a water quality test kit used for testing wastewater and drinking water)
Added water to sand, and examined each category using a pack test.
Kute and Hane beaches are more polluted, while Kotogahama beach is less polluted.(Table 1)
Ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen are the most abundant on Hane Beach, but because Hane Beach is a singing sand beach, it is thought that they do not affect sound level.
(4) The relationship between pollutants and singing
Add various substances to the sand of Kotogahama, which is singing sand, and examine changes in sound and pack-test values.The value of the pack test is compared with the value of unprocessed Kotogahama sand to see if there is more contamination. The singing is rated on three levels: well, a little, and not.
COD values were low for all substances added. Beef tallow, which had higher ammonium nitrogen than the sand at Kotogahama beach, sounded. Sand with higher values of ammonium nitrogen other than beef tallow than the sand at Kotogahama did not sound. For nitrite nitrogen, nitrate nitrogen, and phosphate nitrogen, some sands sounded with high values and some sands did not sound with low values. (Table 2)
The sand with ammonium chloride added sand did not sing and the concentration of ammonium nitrogen in the pack test of this sand was very high. This suggests that ammonium nitrogen may have an effect on the sound level. Considering the results and consideration of experiment (3)pack test, we hypothesized that up to a certain value, ammonium nitrogen has no effect on whether or not the sand sings, but too much ammonium nitrogen will cause the sand to stop squeaking.
(5) The relationship between the amount of ammonium nitrogen and singing
To confirm the above hypothesis, we investigated the relationship between the amount of ammonium nitrogen and changes in sound.
Make aqueous ammonium chloride solutions with five different concentrations and soak each solution in the sand of Kotogahama beach. After drying, examine changes in sound and pack test values. The pack test is also conducted with sand from Hane, which contains high levels of ammonium-form nitrogen, and sounds well.Thwen, the values are compared.
The higher the concentration of ammonium chloride solution, the darker the color of the pack test. The molar concentration of the aqueous solution also made a difference in the way the sand squeaked. Sand with a molar concentration greater than 0.25 mol/L did not squeak, while sand with a molar concentration less than 0.25 mol/L squeaked well. The regular waveforms characteristic of squeaking sand could be confirmed on the computer graph. (Table 3)
From the pack test and the sound experiment, it can be said that the more ammonium-form nitrogen is contained, the less squeaking occurs. Ammonium nitrogen may be one of the pollutants that cause the squeaking sand to stop singing.
3 Conclusion
This experiment was conducted with ammonium nitrogen, but we believe that more accurate data can be obtained by conducting similar experiments with other pollutants. Ammonium-form nitrogen increases when the fertilizer content from domestic wastewater and fields flows into rivers and waterways. Therefore, it is understandable that Kotogahama, where the river basin area flows into the sandy beach and the population of the surrounding area is small, makes the most sound.
4 References
(1)San'in Chuo Shimpo, August 5, 2023
(2)Report on the investigation of "Narigasuna" sand at Kiyogahama Beach
(3)Narisuna Notebook Kunio Kawamura, Technical Research Institute, Magara Construction Co.
(4)Hamada High School, work done in 2023
(5)Ohda High School, research done in 2020
To investigate "why the sand that does not squeak does not squeak" through experiments. Since we learned from a previous study conducted at Hamada High School that the beach sand in Shimane Prefecture does sound when washed, we searched for the pollutants that prevent the sand from singing.
2 Experiments and results
(1) Fieldwork
Sand samples were collected from three locations in Ohda City, and the condition of the beaches was examined.(Figure 1)
1 Nima Town: Kotogahama Beach 2 Kute Town: Kute Beach 3 Hane Town: Hane Beach
(Kotogahama Beach and Hane Beach are squeaky sand beaches)
(2) Observation
･Percentage of transparent grains (quartz)
Low Kute ･Percentage of black grains
Low Kotogahama
(3) Pack test (a water quality test kit used for testing wastewater and drinking water)
Added water to sand, and examined each category using a pack test.
Kute and Hane beaches are more polluted, while Kotogahama beach is less polluted.(Table 1)
Ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen are the most abundant on Hane Beach, but because Hane Beach is a singing sand beach, it is thought that they do not affect sound level.
(4) The relationship between pollutants and singing
Add various substances to the sand of Kotogahama, which is singing sand, and examine changes in sound and pack-test values.The value of the pack test is compared with the value of unprocessed Kotogahama sand to see if there is more contamination. The singing is rated on three levels: well, a little, and not.
COD values were low for all substances added. Beef tallow, which had higher ammonium nitrogen than the sand at Kotogahama beach, sounded. Sand with higher values of ammonium nitrogen other than beef tallow than the sand at Kotogahama did not sound. For nitrite nitrogen, nitrate nitrogen, and phosphate nitrogen, some sands sounded with high values and some sands did not sound with low values. (Table 2)
The sand with ammonium chloride added sand did not sing and the concentration of ammonium nitrogen in the pack test of this sand was very high. This suggests that ammonium nitrogen may have an effect on the sound level. Considering the results and consideration of experiment (3)pack test, we hypothesized that up to a certain value, ammonium nitrogen has no effect on whether or not the sand sings, but too much ammonium nitrogen will cause the sand to stop squeaking.
(5) The relationship between the amount of ammonium nitrogen and singing
To confirm the above hypothesis, we investigated the relationship between the amount of ammonium nitrogen and changes in sound.
Make aqueous ammonium chloride solutions with five different concentrations and soak each solution in the sand of Kotogahama beach. After drying, examine changes in sound and pack test values. The pack test is also conducted with sand from Hane, which contains high levels of ammonium-form nitrogen, and sounds well.Thwen, the values are compared.
The higher the concentration of ammonium chloride solution, the darker the color of the pack test. The molar concentration of the aqueous solution also made a difference in the way the sand squeaked. Sand with a molar concentration greater than 0.25 mol/L did not squeak, while sand with a molar concentration less than 0.25 mol/L squeaked well. The regular waveforms characteristic of squeaking sand could be confirmed on the computer graph. (Table 3)
From the pack test and the sound experiment, it can be said that the more ammonium-form nitrogen is contained, the less squeaking occurs. Ammonium nitrogen may be one of the pollutants that cause the squeaking sand to stop singing.
3 Conclusion
This experiment was conducted with ammonium nitrogen, but we believe that more accurate data can be obtained by conducting similar experiments with other pollutants. Ammonium-form nitrogen increases when the fertilizer content from domestic wastewater and fields flows into rivers and waterways. Therefore, it is understandable that Kotogahama, where the river basin area flows into the sandy beach and the population of the surrounding area is small, makes the most sound.
4 References
(1)San'in Chuo Shimpo, August 5, 2023
(2)Report on the investigation of "Narigasuna" sand at Kiyogahama Beach
(3)Narisuna Notebook Kunio Kawamura, Technical Research Institute, Magara Construction Co.
(4)Hamada High School, work done in 2023
(5)Ohda High School, research done in 2020