Professor Mitsuo Yamashita of the Department of Applied Science, Faculty of Engineering, Shibaura Institute of Technology has succeeded in developing a disposal process that incorporates biodegradation by degrading microorganisms by replacing petroleum-derived absorbents with naturally-derived materials.
Normally, used disposable diapers are incinerated, but incinerating used disposable diapers that contain the same amount of water as food waste reduces incineration efficiency, promotes carbon dioxide emissions, and is one of the causes of deterioration of the incinerator. ing.In addition, due to rising demand due to the aging society, disposable diaper emissions are on the rise.
Therefore, Professor Yamashita proposed a paper diaper in which the absorbent is replaced with a biodegradable cellulosic material derived from petroleum, and 7% of all diapers are made by the synthetic microorganism "Cerulomonas gelida" that biodegrades cellulose. Succeeded in making it biodegradable.By adding Cellulomonas gelida to make a solution, it was confirmed that 50 g of the cellulosic absorbent containing water became 12 g after 1.5 hours.
Furthermore, it was confirmed that the cellulosic absorbent synthesized by Professor Yamashita from CMC (carboxymethyl cellulose) and the cross-linking agent EGDE (ethylene glycol diglycidyl ether) has a maximum absorption of 210 g, exceeding the absorption of 260 g of commercially available disposable diapers. rice field.
It can be said that a "carbon-neutral" disposal process that reduces the incineration load has been realized because the diapers that have been made into a solution by biodegradation and the water absorbed by the absorbent can be treated as wastewater.In future research, Professor Yamashita says that he will promote research to acquire microorganisms that can decompose non-biodegradable plastics that make up the remaining 3% of paper diaper constituents, or to replace those parts with biodegradable materials. If this is realized, it is expected that paper diapers can be completely biodegraded.
