ABSTRACT

The conversion of renewable resources into value-added products such as bioenergy is one of the growing concerns of bioeconomy strategy. Within this concept, assessing the proper combination of local wastes has major importance. This study set out to assess the feasibility of using spent tea waste as a single and co-substrate on anaerobic digestion and to explore the influence of the amount of microorganisms on the digester performance. For this purpose, biomethane potentials tests were conducted for seven different mixing ratios of spent tea waste and cow manure on a mass basis. The reactors operated under mesophilic conditions for 20 days with two inoculum/substrate ratios. The results revealed that using spent tea waste as a co-substrate did not reveal a significant effect on biomethane production in the reactors. Contrarily, the amount of inoculum had a remarkable effect on biomethane production, resulted in an increase in methane production between 28 and 32%. While the biomethane yields were in the range of 129–138 mL_N CH₄ g_VS⁻¹ for the co-digesters operated with inoculum/substrate ratio of 1, the range was 165–181 mL_N CH₄ g_VS⁻¹ for the co-digesters operated with inoculum/substrate ratio of 2. These findings represent the potential usage of the spent tea waste as a co-substrate within the sustainable waste management approach and are relevant to plant operators.

摘要

将可再生资源转化为生物能源等增值产品是生物经济战略日益关注的问题之一。在这个概念中，评估当地废物的适当组合非常重要。本研究旨在评估将废茶废物用作厌氧消化的单一和共底物的可行性，并探讨微生物数量对消化器性能的影响。为此，对废茶废物和牛粪的七种不同混合比例按质量进行了生物甲烷潜力测试。反应器在中温条件下以两种接种物/底物比率运行 20 天。结果表明，使用废茶废物作为共底物对反应器中的生物甲烷生产没有显着影响。相反，接种量对生物甲烷产量有显着影响，导致甲烷产量增加 28% 至 32%。而生物甲烷产量在 129–138 mL 范围内_N CH ₄ g _VS ^-1对于以接种物/底物比为 1 操作的共消化器，范围为 165–181 mL _N CH ₄ g _VS ^-1对于以接种物/底物比为 2 操作的共消化器。这些调查结果代表了废茶废物作为可持续废物管理方法中的共同底物的潜在用途，并且与工厂运营商相关。