Chen Guangyin, Cao Hainan, Tang Yaling, Ni Keye, Wang Jing, Wu Pei
Anhui Engineering Laboratory of Soil and Water Pollution Control and Remediation, Wuhu, 241002, China.
School of Ecology and Environment, Anhui Normal University, Wuhu, 241002, China.
Environ Sci Pollut Res Int. 2023 Apr;30(17):50444-50456. doi: 10.1007/s11356-023-25829-5. Epub 2023 Feb 16.
To improve the biogas yield of rice straw, an innovative cascade utilization process for biogas production was proposed using a method referred to as "the first digestion + NaOH treatment + the second digestion" (labeled FSD). Both the first digestion and the second digestion of all treatments were conducted at the initial total solid (TS) loading of straw of 6%. A series of lab-scale batch experiments were conducted to investigate the effect of first digestion time (5, 10, and 15 days) on biogas production and lignocellulose structure destruction of rice straw. The results showed that the cumulative biogas yield of rice straw using the FSD process was increased by 13.63-36.14% compared with the control (CK), and the highest biogas yield of 233.57 mL g TS was obtained when the first digestion time was 15 days (FSD-15). The removal rates of TS, volatile solids, and organic matter were increased by 12.21-18.09%, 10.62-14.38%, and 13.44-16.88%, respectively, compared with those of CK. The results of Fourier transform infrared spectroscopy analysis revealed that the skeletal structure of rice straw was not significantly destroyed after the FSD process, but the relative contents of functional groups in rice straw were changed. The FSD process accelerated the destruction of crystallinity of rice straw, and the lowest crystallinity index of 10.19% was obtained at FSD-15. The abovementioned results indicated that the FSD-15 process is recommended for cascade utilization of rice straw in biogas production.
为提高稻草的沼气产量，提出了一种创新的沼气生产级联利用工艺，即采用“一次消化+NaOH处理+二次消化”（标记为FSD）的方法。所有处理的一次消化和二次消化均在稻草初始总固体（TS）负荷为6%的条件下进行。进行了一系列实验室规模的批次实验，以研究一次消化时间（5、10和15天）对稻草沼气产量和木质纤维素结构破坏的影响。结果表明，与对照（CK）相比，采用FSD工艺的稻草累积沼气产量提高了13.63%-36.14%，当一次消化时间为15天时（FSD-15），获得了最高沼气产量233.57 mL g TS。与CK相比，TS、挥发性固体和有机物的去除率分别提高了12.21%-18.09%、10.62%-14.38%和13.44%-16.88%。傅里叶变换红外光谱分析结果表明，FSD工艺后稻草的骨架结构没有明显破坏，但稻草中官能团的相对含量发生了变化。FSD工艺加速了稻草结晶度的破坏，在FSD-15时获得了最低结晶度指数10.19%。上述结果表明，FSD-15工艺推荐用于稻草在沼气生产中的级联利用。
