Tai Mingqing, Tai Yafei
School of Civil Engineering, Nanyang Institute of Technology, Nanyang 473004, China.
State Key Laboratory of Motor Vehicle Biofuel Technology, Nanyang 473000, China.
ACS Omega. 2021 Apr 29;6(18):11832-11839. doi: 10.1021/acsomega.0c05980. eCollection 2021 May 11.
Vinasses are not only an easily biodegradable substrate but also a heat energy resource. In this study, the energy balance and kinetic model of anaerobic co-digestion of waste activated sludge (WAS) with vinasses have been investigated in semicontinuous reactor experiments at 55 °C. Herein, the maximum energy balance value, the ratio of energy to mass, and the kinetic constants μ and of anaerobic digestion of WAS were -33.44 kJ·day, -5.72 kJ·VS·day, and 0.0894 day and 0.7294, respectively, at an organic loading rate (OLR) of 1.17 VS·L·day; when the mixture ratio of WAS to vinasses was 2:1 (dry VS) for co-digestion, the maximum energy balance value, the maximum ratio of energy to mass, and the kinetic constants μ and of anaerobic co-digestion of WAS and vinasses were +39.73 kJ·day, 8.1 kJ·VS·day, and 0.2619 day and 1.9583, respectively, at an OLR of 1.73 VS·L·day. The positive energy balance was obtained for two reasons: one is for making the best use of the high-temperature heat energy resource of vinasses and the other is for enhancing the amount of biogas yield. The bottleneck of the negative energy balance of thermophilic digestion of WAS can be broken by anaerobic co-digestion of WAS and vinasses. The results indicate a promising future in the application of anaerobic thermophilic co-digestion of WAS and vinasses. Methane production from digestion and co-digestion was also predicted by the Chen-Hashimoto kinetic model.
酒糟不仅是一种易于生物降解的底物，也是一种热能资源。在本研究中，在55℃的半连续反应器实验中，研究了剩余活性污泥（WAS）与酒糟厌氧共消化的能量平衡和动力学模型。在此，在有机负荷率（OLR）为1.17 VS·L·天的条件下，WAS厌氧消化的最大能量平衡值、能量与质量比以及动力学常数μ和分别为-33.44 kJ·天、-5.72 kJ·VS·天和0.0894天以及0.7294；当WAS与酒糟的混合比例为2:1（干VS）进行共消化时，在OLR为1.73 VS·L·天的条件下，WAS与酒糟厌氧共消化的最大能量平衡值、最大能量与质量比以及动力学常数μ和分别为+39.73 kJ·天、8.1 kJ·VS·天和0.2619天以及1.9583。获得正能量平衡有两个原因：一是为了充分利用酒糟的高温热能资源，二是为了提高沼气产量。WAS高温消化负能量平衡的瓶颈可以通过WAS与酒糟的厌氧共消化来打破。结果表明，WAS与酒糟厌氧高温共消化在应用方面具有广阔的前景。消化和共消化产生的甲烷产量也通过Chen-Hashimoto动力学模型进行了预测。
