Department of Food, Agricultural and Biological Engineering, The Ohio State University, Wooster, OH 44691, USA.
Waste Manag Res. 2011 Nov;29(11):1117-23. doi: 10.1177/0734242X11417985. Epub 2011 Sep 2.
In this study, the organic loading rate (OLR) of a high-solids anaerobic digestion (HSAD) system was increased from 3.4 to 5.0 gVS L(-1) day(-1) and reactor stability, performance and microbial community structure were determined. Laboratory simulations (3.5 L) of the full-scale process (500 dry ton year(-1)) were conducted using continuously stirred-tank mesophilic reactors. OLRs of 3.4 gVS L(-1)day(-1) (equal to the full-scale HSAD), 4.0, 4.5 and 5.0 gVS L(-1)day(-1) were evaluated. Biochemical parameters and archaeal community dynamics were measured over 42 days of steady state operation. Results showed that increasing OLR increased the amount of organic matter conversion and resulted in higher organic matter removal and volumetric methane (CH₄) production (VMP) rates. The highest volatile solids (VS) removal and VMP results of 54 ± 2% and 1.4 ± 0.1 L CH₄ L(-1)day(-1) were observed for 5.0 gVS L(-1) day(-1). The efficiency of reactor conversion of organic matter to CH(4) was found to be similar in all the treatments with an average value of 0.57 ± 0.07 LCH(4) gVS(-1) (removed). 16S rRNA gene terminal restriction fragment polymorphism (T-RFLP) analyses revealed that archaeal TRFs remained stable during the experiment accounting for an average relative abundance (RA) of 81 ± 1%. Archaea consistent with multiple terminal restriction fragments (TRFs) included members of the Euryarchaeota and Crenarchaeota phyla, including acetoclastic and hydrogenotrophic groups. In conclusion, this laboratory-scale study suggests that performance and stability as well as the archaeal community structure in this HSAD system was unaffected by increasing the OLR by nearly 50% and that this increase resulted in a similar increase in the amount of CH(4) gas generated.
在这项研究中，高固体厌氧消化（HSAD）系统的有机负荷率（OLR）从 3.4 增加到 5.0 gVS/L/d，并确定了反应器的稳定性、性能和微生物群落结构。使用连续搅拌罐中温反应器对全规模过程（500 干吨/年）进行实验室模拟（3.5 L）。评估了 3.4 gVS/L/d（等于全规模 HSAD）、4.0、4.5 和 5.0 gVS/L/d 的 OLR。在 42 天的稳定运行期间测量了生物化学参数和古菌群落动态。结果表明，增加 OLR 增加了有机物的转化量，导致更高的有机物去除率和体积甲烷（CH₄）产率（VMP）。在 5.0 gVS/L/d 时，观察到最高的挥发性固体（VS）去除率和 VMP 分别为 54±2%和 1.4±0.1 L CH₄/L/d。发现所有处理中有机物转化为 CH(4)的反应器效率相似，平均值为 0.57±0.07 LCH(4)/gVS（去除）。16S rRNA 基因末端限制性片段多态性（T-RFLP）分析显示，古菌 TRFs 在实验过程中保持稳定，平均相对丰度（RA）为 81±1%。与多个末端限制性片段（TRFs）一致的古菌包括广古菌和泉古菌门的成员，包括产乙酸菌和产氢菌。总之，这项实验室规模的研究表明，通过将 OLR 增加近 50%，HSAD 系统的性能和稳定性以及古菌群落结构不受影响，并且这种增加导致 CH(4)气体生成量的相似增加。
