1:45 PM - 3:15 PM
[O11-P65] Let's make degradable fibers! -Rice bran helps to decompose clothes.
Keywords:fiber, decomposition, rice bran
Background
"Fast fashion," in which fashion trends are quickly commercialized and distributed in large quantities at low cost, is expanding worldwide. This business model is said to be exacerbating environmental pollution as it leads to the mass production, mass consumption, and mass disposal of clothing. On the other hand, in recent years, there has been progress in the development of biodegradable plastics and efforts to activate microbial decomposition using rice bran. Since I am interested in working in the fashion industry in the future, I decided to study this subject in the hope that it will help prevent environmental degradation caused by mass distribution of clothing.
Purpose
In order to be useful in creating biodegradable clothing, we will investigate the conditions under which materials commonly used in clothing are decomposed by microorganisms.
Materials and Methods
・Fabric A (100% cotton) and Fabric B (40% cotton, 60% polyester)
・Potting soil
・Petri dish
・Airtight container
・Rice bran
・CO2 concentration sensor
Culture soil is placed on petri dishes, and Fabrics A (with/without rice bran coating) and B (with/without rice bran coating) are respectively buried in the soil. These petri dishes and a CO2 concentration sensor are placed in an airtight container, and changes in CO2 concentration are observed. An increase in CO2 concentration is evaluated as the progress of decomposition. In addition, at the end of the experimental period, the degree of decomposition of the cloth is visually confirmed.
Results
Experiment 1 (Summer: July 24 to August 21, 2024)
・For Fabrics A, decomposition was observed when rice bran was applied, but not when it was not applied.
・No decomposition was observed in Fabrics B, regardless of whether rice bran was applied or not.
Experiment 2 (Winter: November 19, 2024 to January 13, 2025)
・For Fabrics A, decomposition was observed when rice bran was applied, while slight decomposition was observed when it was not applied .
・No decomposition was observed in Fabrics B, regardless of whether rice bran was applied or not .
Disscussion
1. It was observed that 100% cotton fabric was partially decomposed by microorganisms in the soil, and that this was facilitated by applying rice bran to the fabric. This is thought to be because rice bran promotes the growth and activity of microorganisms, and cotton is used as a substrate.
2. The fabric made of 40 % cotton and 60 % polyester was difficult to get decomposed by microorganisms, which is thought to be because general microorganisms in soil are not using polyester as a substrate.
3. Since no clear differences were found when comparing the results for summer and winter, this experiment did not reveal the effects of temperature and humidity on decomposition.
Future Outlook
In order to identify the appropriate decomposition conditions, we would like to conduct experiments on the following three points: (1) Conduct experiments using substances other than rice bran , such as compost or leaf mold , as substances that activate microorganisms . ( 2 ) Use a culture device that can appropriately set conditions such as temperature and humidity . ( 3 ) Conduct experiments using natural materials other than cotton .
Acknowledgements
I am deeply grateful to Kei Kurita, Professor Emeritus of the Earthquake Research Institute, University of Tokyo, for his guidance and advice on this experiment . Thank you very much.
References
Chibanian Part-Time Agricultural School, "The amazing benefits of rice bran in agriculture and how to use it," https://chibanian.info/komenuka_nogyo2024/ , (Accessed April 13, 2025)
"Fast fashion," in which fashion trends are quickly commercialized and distributed in large quantities at low cost, is expanding worldwide. This business model is said to be exacerbating environmental pollution as it leads to the mass production, mass consumption, and mass disposal of clothing. On the other hand, in recent years, there has been progress in the development of biodegradable plastics and efforts to activate microbial decomposition using rice bran. Since I am interested in working in the fashion industry in the future, I decided to study this subject in the hope that it will help prevent environmental degradation caused by mass distribution of clothing.
Purpose
In order to be useful in creating biodegradable clothing, we will investigate the conditions under which materials commonly used in clothing are decomposed by microorganisms.
Materials and Methods
・Fabric A (100% cotton) and Fabric B (40% cotton, 60% polyester)
・Potting soil
・Petri dish
・Airtight container
・Rice bran
・CO2 concentration sensor
Culture soil is placed on petri dishes, and Fabrics A (with/without rice bran coating) and B (with/without rice bran coating) are respectively buried in the soil. These petri dishes and a CO2 concentration sensor are placed in an airtight container, and changes in CO2 concentration are observed. An increase in CO2 concentration is evaluated as the progress of decomposition. In addition, at the end of the experimental period, the degree of decomposition of the cloth is visually confirmed.
Results
Experiment 1 (Summer: July 24 to August 21, 2024)
・For Fabrics A, decomposition was observed when rice bran was applied, but not when it was not applied.
・No decomposition was observed in Fabrics B, regardless of whether rice bran was applied or not.
Experiment 2 (Winter: November 19, 2024 to January 13, 2025)
・For Fabrics A, decomposition was observed when rice bran was applied, while slight decomposition was observed when it was not applied .
・No decomposition was observed in Fabrics B, regardless of whether rice bran was applied or not .
Disscussion
1. It was observed that 100% cotton fabric was partially decomposed by microorganisms in the soil, and that this was facilitated by applying rice bran to the fabric. This is thought to be because rice bran promotes the growth and activity of microorganisms, and cotton is used as a substrate.
2. The fabric made of 40 % cotton and 60 % polyester was difficult to get decomposed by microorganisms, which is thought to be because general microorganisms in soil are not using polyester as a substrate.
3. Since no clear differences were found when comparing the results for summer and winter, this experiment did not reveal the effects of temperature and humidity on decomposition.
Future Outlook
In order to identify the appropriate decomposition conditions, we would like to conduct experiments on the following three points: (1) Conduct experiments using substances other than rice bran , such as compost or leaf mold , as substances that activate microorganisms . ( 2 ) Use a culture device that can appropriately set conditions such as temperature and humidity . ( 3 ) Conduct experiments using natural materials other than cotton .
Acknowledgements
I am deeply grateful to Kei Kurita, Professor Emeritus of the Earthquake Research Institute, University of Tokyo, for his guidance and advice on this experiment . Thank you very much.
References
Chibanian Part-Time Agricultural School, "The amazing benefits of rice bran in agriculture and how to use it," https://chibanian.info/komenuka_nogyo2024/ , (Accessed April 13, 2025)