Effect of nano-AlO and multi-walled carbon nanotubes on the anaerobic mono-digestion of sludge and the co-digestion of tobacco waste and sludge

• Published in: RSC advances Vol. 13; no. 5; pp. 35621 - 35628
• Main Authors: Zhao, Hongmei, Cheng, Shibo, Zhao, Congqi, Ruan, Kejiang, Xu, Junju, Cheng, Xiaohong
• Format: Journal Article
• Published: 06-12-2023
• ISSN: 2046-2069
• DOI: 10.1039/d3ra07170g

Anaerobic digestion can help mitigate tobacco waste (TW) pollution. Both the mono-digestion of sludge and the co-digestion of TW and sludge were considered in this study. Additionally, the effects of nano-Al
2
O
3
and multi-walled carbon nanotubes (MWCNTs) on these two digestion systems were investigated through a 35 day digestion experiment. The microbial communities in the control reactors and the nano-Al
2
O
3
reactors were also examined. Kinetic analysis revealed that the
R
m
values for the mono- and co-digestion nano-Al
2
O
3
reactors increased by 8.88% and 13.5% compared with that of the MWCNTs reactor, respectively. Furthermore, the co-digestion system exhibited a 34.8% higher
R
m
than the mono-digestion system when nano-Al
2
O
3
was added to both systems. Nano-Al
2
O
3
was found to shorten the lag phase, while MWCNTs prolonged the lag phase time. Furthermore, 16S RNA amplicon sequencing results indicated that microbial species such as
Methanobacterium
sp.,
Hydrogenispora
sp.,
Lutispora
sp., and
Ruminiclostridium
sp. were more abundant in the nano-Al
2
O
3
reactor. These results demonstrated that biogas production in co-digestion systems was improved. Moreover, nano-Al
2
O
3
addition enhanced biogas production.
Anaerobic digestion can help mitigate tobacco waste (TW) pollution. Both the mono-digestion of sludge and the co-digestion of TW and sludge were considered in this study.