Environmental Biotechnology Group (EBiTG), Department of Civil Engineering, Indian, Institute of Technology, Roorkee, Roorkee, 247667, India.
Department of Environmental Science, Gurukul Kangri University, Haridwar, India.
Chemosphere. 2022 Mar;291(Pt 1):132682. doi: 10.1016/j.chemosphere.2021.132682. Epub 2021 Oct 26.
High-temperature thermal pretreatment alone or in conjugation with chemical pretreatment (highly acidic or alkaline) produced recalcitrant compounds, which inhibits the anaerobic digestion (AD) process performance. This study aims to develop a strategy to use carbon-based conductive materials to mitigate the recalcitrant toxicity and enhance the methane generation in the downstream AD. The formation of recalcitrant compounds, mainly the furan derivatives, i.e., furfural and 5-HydroxyMethyl furfurals (5-HMF) during thermo-chemical pretreatment of OFMSW at 150 °C, 175 °C, 200 °C with 3 g/L-NaOH dose, and the alleviation of their inhibitory effects by adding 25 g/L of each of granular activated carbon (GAC) and granular biochar (GBC) during mesophilic AD were studied. The addition of conductive materials resulted in the highest biogas yield of 462 mL/gVS (GAC) and 449 mL/gVS (GBC) for 175°C-3g/L-NaOH pretreatment, which was >45% higher over control. The highest improvement of >65% in biogas yield was observed for 200°C-3g/L-NaOH pretreatment despite the lower biogas yield. The conductive materials amended digester shows a significant decrease in the 5-HMF and furfurals concertation. The highest reduction in 5-HMF (44%) and furfural (51%) concentrations were observed for 200°C-3g/L-NaOH pretreatment, and 25 g/L GBC amended tests. The score plots from the principal component analysis (PCA) of the characterization of the digestate showed that the data were significant, whereas the loading plots depicted the correlation of different experimental parameters studied (like fate of recalcitrant, biogas yield and other parameters post AD of OFMSW when aided with conductive materials). Application of regression models in all the batch assays depicted that a lag phase of 2-4 days was observed in Modified Gompertz Model (MGM), 4-5 days in Logistic Model (LM) and a rapid hydrolysis was proven with the value of hydrolysis coefficient being between 0.003 and 0.029 from the first-order (FO) model.
高温热预处理单独或与化学预处理（高度酸性或碱性）结合会产生顽固性化合物，从而抑制厌氧消化（AD）过程的性能。本研究旨在开发一种策略，使用基于碳的导电材料来减轻顽固性毒性并提高下游 AD 中的甲烷生成量。在 150°C、175°C、200°C 下用 3 g/L-NaOH 剂量对 OFMSW 进行热化学预处理时，会形成顽固性化合物，主要是呋喃衍生物，即糠醛和 5-羟甲基糠醛（5-HMF），以及在添加 25 g/L 颗粒活性炭（GAC）和颗粒生物炭（GBC）时减轻其在中温 AD 中的抑制作用进行了研究。添加导电材料可使产气量最高，分别为 175°C-3g/L-NaOH 预处理时的 462 mL/gVS（GAC）和 449 mL/gVS（GBC），比对照高出>45%。尽管沼气产量较低，但在 200°C-3g/L-NaOH 预处理时，观察到沼气产量提高了>65%。添加导电材料的消化器中 5-HMF 和糠醛的浓度显著降低。在 200°C-3g/L-NaOH 预处理和添加 25 g/L GBC 的测试中，观察到 5-HMF（44%）和糠醛（51%）浓度的最高降低。主成分分析（PCA）对消化物特性的得分图显示数据是显著的，而加载图则描述了不同实验参数之间的相关性（例如添加导电材料后 OFMSW 的 AD 过程中的顽固性命运、沼气产量和其他参数）。在所有批次试验中应用回归模型表明，在修正的 Gompertz 模型（MGM）中观察到 2-4 天的滞后期，在 Logistic 模型（LM）中观察到 4-5 天的滞后期，并且通过水解系数的值证明了快速水解，该值在一阶（FO）模型中在 0.003 到 0.029 之间。
