Centre for Rural Development and Technology, Indian Institute of Technology Delhi, India.
Centre for Rural Development and Technology, Indian Institute of Technology Delhi, India.
Sci Total Environ. 2023 Dec 20;905:167250. doi: 10.1016/j.scitotenv.2023.167250. Epub 2023 Sep 21.
Anaerobic digestion (AD) of agricultural wastes is a promising approach for energy recovery and crop residue management. However, its recalcitrant chemical structure hinders microbial hydrolysis and reduces biomethane production under AD. Biochar supplementation has been proven to promote the digestibility and biomethanation of lignocellulosic substrates. Therefore, this study investigated the influence of different pyrolysis temperatures (450 °C, 550 °C, and 650 °C) on the physicochemical properties of biochar. Furthermore, the impact of ruminal content biochar supplementation (1 %, 2 %, and 3 %) on the AD of rice straw with rumen fluid as inoculum has been investigated. The ruminal content biochar (RUCB) supplemented reactors showed an increment in biomethane yield and the highest cumulative biomethane yield 243.11 mL/g volatile solids (VS)) was recorded at 2 % RUCB supplementation, followed by 227.12 mL/g VS at 1 % RUCB supplementation and 162.86 mL/g VS at 3 % RUCB supplementation (P > 0.05). Compared to the control reactors (128.68 mL/g VS), RUCB supplemented reactors exhibited 1.88-fold, 1.76-fold, and 1.26-fold increments in biomethane yield due to pH stabilization and facilitation of microbial biofilm formation on the biochar. The correlation analysis showed that biomethane production is positively correlated with VS reduction (R = 0.9852). This study proposed a potential strategy to utilize ruminal content waste as a feedstock for biochar production and its application in AD for accelerating the biomethanation of rice straw.
农业废弃物的厌氧消化（AD）是一种有前途的能源回收和作物残体管理方法。然而，其顽固的化学结构阻碍了微生物水解，降低了 AD 下的生物甲烷产量。生物炭的添加已被证明可以促进木质纤维素底物的可消化性和生物甲烷化。因此，本研究调查了不同热解温度（450°C、550°C 和 650°C）对生物炭理化性质的影响。此外，还研究了瘤胃液作为接种物的水稻秸秆 AD 中添加不同比例（1%、2%和 3%）的瘤胃内容物生物炭的影响。添加瘤胃内容物生物炭（RUCB）的反应器表现出生物甲烷产量增加，在 2%RUCB 补充下记录到最高累积生物甲烷产量 243.11 mL/g 挥发性固体（VS），在 1%RUCB 补充下为 227.12 mL/g VS，在 3%RUCB 补充下为 162.86 mL/g VS（P>0.05）。与对照反应器（128.68 mL/g VS）相比，RUCB 补充的反应器由于 pH 稳定和促进生物炭上微生物生物膜形成，生物甲烷产量增加了 1.88 倍、1.76 倍和 1.26 倍。相关性分析表明，生物甲烷产量与 VS 减少呈正相关（R=0.9852）。本研究提出了一种利用瘤胃液作为生物炭生产原料并将其应用于 AD 以加速水稻秸秆生物甲烷化的潜在策略。
