Zandvoort Marcel H, Geerts Roy, Lettinga Gatze, Lens Piet N L
Subdepartment of Environmental Technology, Agricultural University of Wageningen, Biotechnion-Bomenweg, 2, PO Box 8129, 6700 EV Wageningen, The Netherlands.
Biotechnol Prog. 2002 Nov-Dec;18(6):1233-9. doi: 10.1021/bp020078e.
The effect of the trace metal cobalt on the conversion of methanol in an upflow anaerobic sludge bed (UASB) reactor was investigated by studying the effect of cobalt deprivation from the influent on the reactor efficiency and the sludge characteristics. A UASB reactor (30 degrees C; pH 7) was operated for 261 days at a 12-h hydraulic retention time (HRT). The loading rate was increased stepwise from 2.6 g chemical oxygen demand (COD) x L reactor(-1) x d(-1) to 7.8 g COD x L reactor(-1) x d(-1). Cobalt deprivation had a strong impact on the methanogenic activity of the sludge. In batch tests, the methanogenic activity of the sludge with methanol as the substrate increased 5.3 (day 28) and 2.1 (day 257) times by addition of 840 nM of cobalt. The sludge had an apparent K(m) for cobalt of 948 nM after 28 days of operation and 442 nM at the end of the run. Cobalt deprivation during 54 days of operation led to a methanol conversion efficiency of only 55%. Continuous addition of cobalt (330 nM) for 33 days improved the methanol removal efficiency to 100%. In this period of cobalt dosing, the cobalt concentration in the sludge increased 2.7 times up to 32 microg x g TSS(-1). Upon omission of the cobalt addition, cobalt washed-out at a stable rate of 0.1 microg x g VSS(-1) x d(-1). At the end of the run, the cobalt concentration of the sludge was similar to that of the seed sludge.
通过研究进水钴缺乏对反应器效率和污泥特性的影响，考察了痕量金属钴对升流式厌氧污泥床（UASB）反应器中甲醇转化的影响。一个UASB反应器（30℃；pH 7）在12小时水力停留时间（HRT）下运行261天。负荷率从2.6 g化学需氧量（COD）×L反应器⁻¹×d⁻¹逐步提高到7.8 g COD×L反应器⁻¹×d⁻¹。钴缺乏对污泥的产甲烷活性有强烈影响。在批次试验中，以甲醇为底物时，添加840 nM钴后，污泥的产甲烷活性分别提高了5.3倍（第28天）和2.1倍（第257天）。运行28天后，污泥对钴的表观米氏常数（K(m)）为948 nM，运行结束时为442 nM。运行54天期间钴缺乏导致甲醇转化效率仅为55%。连续添加钴（330 nM）33天可将甲醇去除效率提高到100%。在该钴投加期，污泥中的钴浓度增加了2.7倍，达到32 μg×g总悬浮固体（TSS）⁻¹。停止添加钴后，钴以0.1 μg×g挥发性悬浮固体（VSS）⁻¹×d⁻¹的稳定速率被洗脱。运行结束时，污泥中的钴浓度与接种污泥相似。
