Effect of nicotine inhibition on anaerobic digestion and the co-digestion performance of tobacco stalks with different animal manures

The disposal of large quantities of tobacco stalks and animal manures generated annually is among the serious challenges faced in China, especially the former, as its toxic composition (nicotine) can induce the risk of healthy impairment during tradition treatment process. Anaerobic digestion (AD) may be an efficient technique for tobacco stalks. Nevertheless, the impact of nicotine in tobacco stalks upon AD is still unclear so far. Thus, a simulated AD experiment using glucose with different nicotine concentrations was implemented, suggesting a nicotine concentration of more than 4% (w/w) could inhibit AD. The nicotine component in tobacco stalks would not be an inhibitor on AD because its content was far below 4%. Meanwhile, in order to efficiently treat abundant tobacco stalks and manure wastes at the same time, untreated and alkaline hydrogen peroxide (AHP)-pretreated tobacco stalks were co-digested with three typical manures, including pig manure (PM), chicken manure (CM), and dairy manure (DM), to investigate their digestion performance. Co-digestion of pretreated tobacco stalks and PM at 1:4 ratio exhibited the highest methane production of 397.2 mL/g VS and had a synergistic effect. This study provides valuable guidance for simultaneously converting these two wastes in future AD applications. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

The study demonstrated that a nicotine concentration higher than 4% can inhibit anaerobic digestion, but the nicotine content in tobacco stalks is lower than this inhibitory level. Co-digestion of pretreated tobacco stalks and pig manure showed the highest methane production and exhibited a synergistic effect.