Enhancement of anaerobic fermentation performance of polylactic acid by 60Co-γ ray irradiation pretreatment

ZHOU Chao; LI Zhen; LI Lingxi; JIA Wenbao; LING Yongsheng

doi:10.11889/j.1000-3436.2023-0115

Fushe yanjiu yu fushe gongyi xuebao (Aug 2024)

Enhancement of anaerobic fermentation performance of polylactic acid by 60Co-γ ray irradiation pretreatment

ZHOU Chao,
LI Zhen,
LI Lingxi,
JIA Wenbao,
LING Yongsheng

Affiliations

ZHOU Chao: Institute of Nuclear Analysis Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China
LI Zhen: Institute of Nuclear Analysis Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China
LI Lingxi: Institute of Nuclear Analysis Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China
JIA Wenbao: Institute of Nuclear Analysis Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China
LING Yongsheng: Institute of Nuclear Analysis Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China

DOI: https://doi.org/10.11889/j.1000-3436.2023-0115
Journal volume & issue: Vol. 42, no. 4
pp. 89 – 97

Abstract

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Polylactic acid (PLA) plastic waste has significant potential for methane production in anaerobic digestion, but its slow degradation rate hinders efficient fermentation. Pre-treatment of PLA plastic waste can enhance anaerobic fermentation efficiency, promoting resource utilization. PLA plastic cup sample was pre-treated by irradiation with 60Co-γ ray to study the changes of PLA molecular structure and soluble substance content under the irradiation with absorbed doses of 0, 20, 40 and 60 kGy. And the effect of ionizing irradiation on the anaerobic fermentation performance of PLA samples was investigated by the proteolytic enzyme enzymatic digestion experiments and the changes of anaerobic fermentation gas production. The results showed that the lactic acid content in the supernatant of PLA samples irradiated by 60Co-γ ray increased slightly with the increase of absorbed dose in the range of 0~60 kGy. The molecular structure of the samples did not change significantly, but their crystallinity and molecular weight decreased significantly. The lactate concentration and mass loss of the irradiated samples increased significantly during the enzymatic digestion process compared to the unirradiated samples. Specifically, The PLA sample with an absorbed dose of 60 kGy reached its maximum lactate concentration on the 4th day, which was 17.4% higher than that of non irradiated samples. The mass loss increased over time, which was 68.7% higher than that of non irradiated samples on the 7th day. The irradiated samples took significantly less time to reach gas production equilibrium in anaerobic fermentation, and the total gas production increased by 3.0%. The results indicate that γ-ray irradiation has potential application as a pretreatment technology for PLA plastics, and this study can provide a theoretical reference for the resourceful disposal of PLA plastics.

Published in Fushe yanjiu yu fushe gongyi xuebao

ISSN: 1000-3436 (Print)
Publisher: Science Press
Country of publisher: China
LCC subjects: Science: Physics: Nuclear and particle physics. Atomic energy. Radioactivity; Medicine: Medicine (General): Medical physics. Medical radiology. Nuclear medicine
Website: https://www.fs.sinap.ac.cn/

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