Anaerobic biodegradation tests of poly(lactic acid) under mesophilic and thermophilic conditions using a new evaluation system for methane fermentation in anaerobic sludge.
Anaerobic biodegradation tests of poly(lactic acid) (PLA) powder were done at the thermophilic (55 degrees C) and mesophilic temperature (35 degrees C) under aquatic conditions [total solid concentrations of the used sludge were 2.07% (at 55 degrees C) and 2.24% (at 35 degrees C)] using a newly developed evaluation system. With this system, the evolved biogas is collected in a gas sampling bag at atmospheric pressure. This method is more convenient than using a pressure transducer or inverted graduated cylinder submerged in water. PLA was degraded about 60% in 30 days, about 80% in 40 days and about 90% in 60 days at 55 degrees C. On the other hand, the PLA degradation started in 55 days at 35 degrees C and degradation rate was much slower than at 55 degrees C.
National Institute of Advanced Industrial Science and Technology, Higashi, Tsukuba, Ibaraki, Japan. h.yagi@aist.go.jp
Hisaaki
H
Yagi
Fumi
F
Ninomiya
Masahiro
M
Funabashi
Masao
M
Kunioka
D000693:Anaerobiosis; D063566:Biodegradable Plastics / Q000737:chemistry / Q000378:metabolism; D001673:Biodegradation, Environmental; D019149:Bioreactors; D005069:Evaluation Studies as Topic; D005285:Fermentation; D019344:Lactic Acid / Q000737:chemistry / Q000378:metabolism*; D008697:Methane / Q000378:metabolism*; D011091:Polyesters; D011108:Polymers / Q000737:chemistry / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology
D063566:Biodegradable Plastics; D011091:Polyesters; D011108:Polymers; D012722:Sewage; D019344:Lactic Acid; C033616:poly(lactide); D008697:Methane