Co-digestion of food waste and cellulose-based bioplastic: From batch to semi-continuous scale investigation

• Published in: Waste management (Elmsford) 2023-02, Vol.156, p.272-281
• Main Authors: Kosheleva, Arina, Gadaleta, Giovanni, De Gisi, Sabino, Heerenklage, Joern, Picuno, Caterina, Notarnicola, Michele, Kuchta, Kerstin, Sorrentino, Andrea
• Format: Article
• Language: English
• Subjects: Anaerobic digestion; Biomethane potential; Cellulose acetate; Continuous stirred tank reactor; Plastic degradation
• ISSN: 0956-053X; 1879-2456
• DOI: 10.1016/j.wasman.2022.11.031

•Anaerobic co-digestion of cellulose acetate (CA) and food waste (FW) was investigated.•CA and FW produced 519 and 522 NmlCH4/g vS in batch test, with different trend.•Methane production from CA was evident only after 65 days of semi-continuous test.•CA disintegration was 98 % and 45 % in batch and semi-continuous tests, respectively. Only few studies on the behaviour of bioplastics in anaerobic co-digestion could be found in literature and most of them are conducted in batch mode. Despite the fact that continuous experiments confirm or add new insight to the findings acquired from batch ones, there is still lack of such studies. This work aims to cover this gap, carrying out a semi-continuous anaerobic co-digestion of food waste and cellulose acetate (which its behaviour under anaerobic environment is also quite unexplored). After a first evaluation of the potential methane production from each substrate at batch scale, the semi-continuous co-digestion of food waste and cellulose acetate was carried out in three configurations. During the semi-continuous process, a methane yield of 331 NmlCH4/gVS was generated from the co-digestion of food waste and cellulose acetate while bioplastics specimens achieved a weight loss of about 45 %. The results were both lower than the one obtained from batch co-digestion, although methane production rates were comparable regardless of being fed with or without bioplastics. An increase was registered after 65 days of semi-continuous process, due to the accumulation of CA specimens. This confirms the different degradation trends between bioplastics and food waste.