Szaja Aleksandra, Montusiewicz Agnieszka, Lebiocka Magdalena, Bis Marta
Faculty of Environmental Engineering, Lublin University of Technology, Lublin, Poland.
PeerJ. 2020 Dec 22;8:e10590. doi: 10.7717/peerj.10590. eCollection 2020.
The present study examines the effect of introducing dried brewery spent grain (BSG), known as the main solid by-product of the brewery industry on biogas yields and kinetics in co-digestion with sewage sludge (SS). The experiment was conducted in semi-continuous anaerobic reactors (supplied once a day) operating under mesophilic conditions (35°C) at different hydraulic retention times (HRT) of 18 and 20 d. In co-digestion runs, the BSG mass to the feed volume ratio was constant and maintained 1:10.The results indicated that the addition of BSG did not influence the biogas production, by comparison with SS mono-digestion (control run). At HRT of 18 d, in the co-digestion run, the average methane yield was 0.27 m kg/VS, while in the control run the higher value of 0.29 m kg/VSwas observed. However, there was no difference in terms of statistical significance. At HRT of 20 d, the methane yield was 0.21 m kg/VS for both mono- and co-digestion runs. In the BSG presence, the decrease in kinetic constant values was observed. As compared to SS mono-digestion, reductions by 21 and 35% were found at HRT of 20 and 18 d, respectively. However, due to the supplementation of the feedstock with BSG rich in organic compounds, the significantly enhanced energy profits were achieved with the highest value of approx. 40% and related to the longer HRT of 20 d. Importantly, the mono- and co-digestion process proceeded in stable manner. Therefore, the anaerobic co-digestion of SS and BSG might be considered as a cost-effective solution that could contribute to the energy self-efficiency of wastewater treatment plants (WWTPs) and sustainable waste management for breweries.
本研究考察了引入啤酒厂干酒糟（BSG）这一啤酒工业主要固体副产品对其与污水污泥（SS）共消化过程中沼气产量和动力学的影响。实验在半连续厌氧反应器（每天进料一次）中进行，反应器在中温条件（35°C）下运行，水力停留时间（HRT）分别为18天和20天。在共消化运行中，BSG质量与进料体积比保持恒定，为1:10。结果表明，与SS单消化（对照运行）相比，添加BSG对沼气产量没有影响。在HRT为18天的共消化运行中，平均甲烷产量为0.27 m³/kg VS，而在对照运行中观察到较高值0.29 m³/kg VS。然而，在统计学意义上没有差异。在HRT为20天的情况下，单消化和共消化运行的甲烷产量均为0.21 m³/kg VS。在有BSG存在的情况下，观察到动力学常数的值有所下降。与SS单消化相比，在HRT为20天和18天时分别降低了21%和35%。然而，由于向原料中添加了富含有机化合物的BSG，在HRT为20天时长时实现了显著提高的能源利润，最高值约为40%。重要的是，单消化和共消化过程均稳定进行。因此，SS和BSG的厌氧共消化可被视为一种具有成本效益的解决方案，有助于污水处理厂（WWTPs）的能源自给自足以及啤酒厂的可持续废物管理。
