Caşcaval Dan, Blaga Alexandra Cristina, Galaction Anca-Irina
a Department of Organic, Biochemical and Food Engineering , 'Gheorghe Asachi' Technical University of Iasi , Iasi , Romania.
b Faculty of Medical Bioengineering, Department of Biomedical Science , 'Grigore T. Popa' University of Medicine and Pharmacy of Iasi , Iasi , Romania.
Environ Technol. 2018 Jan;39(2):240-252. doi: 10.1080/09593330.2017.1298675. Epub 2017 Mar 8.
The effects of external and internal diffusions of pyridine on its biodegradation rate in a bioreactor with a stationary basket bed of immobilized Bacillus spp. cells have been investigated for various biocatalyst diameters and thicknesses of the basket bed, considering the adapted Haldane kinetic model for substrate inhibition. Due to the very low values of pyridine mass flow inside the biocatalyst particles, the 'biological inactive region' appeared mainly near the particles' centre. This region is extended up to 38.5% from the overall volume of each studied size of the biocatalysts, increasing at higher biocatalyst size and basket bed width. Compared to the system containing free Bacillus spp. cells, the basket configuration of packed bed led to the reduction of biodegradation rate up to 82 times, similar to the mobile bed or column packed bed. The cumulated analysis of the influences of the studied factors allowed concluding that the optimum diameter of biocatalysts is 3 mm.
考虑到适用于底物抑制的哈代动力学模型，针对固定化芽孢杆菌属细胞的固定床生物反应器中，不同生物催化剂直径和固定床厚度的情况，研究了吡啶的外部和内部扩散对其生物降解速率的影响。由于生物催化剂颗粒内部吡啶质量流的值非常低，“生物非活性区域”主要出现在颗粒中心附近。该区域从每个研究尺寸的生物催化剂总体积延伸至38.5%，随着生物催化剂尺寸和固定床宽度的增加而增大。与含有游离芽孢杆菌属细胞的系统相比，填充床的固定床配置导致生物降解速率降低多达82倍，类似于移动床或柱填充床。对研究因素影响的累积分析得出结论，生物催化剂的最佳直径为3毫米。
