Kayombo S, Mbwette T S A, Katima J H Y, Jorgensen S E
Faculty of Engineering, University of Dar es Salaam, PO Box 35131, Dar es Salaam, Tanzania.
Water Res. 2003 Jul;37(12):2937-43. doi: 10.1016/S0043-1354(03)00014-9.
This paper presents the effect of substrate concentration on the growth of a mixed culture of algae and heterotrophic bacteria in secondary facultative ponds (SFPs) utilizing settled domestic sewage as a sole source of organic carbon. The growth of the mixed culture was studied at the concentrations ranging between 200 and 800 mg COD/l in a series of batch chemostat reactors. From the laboratory data, the specific growth rate (micro) was determined using the modified Gompertz model. The maximum specific growth rate ( micro(max)) and half saturation coefficients (K(s)) were calculated using the Monod kinetic equation. The maximum observed growth rate ( micro(max)) for heterotrophic bacteria was 3.8 day(-1) with K(s) of 200 mg COD/l. The micro(max) for algal biomass based on suspended volatile solids was 2.7 day(-1) with K(s) of 110 mg COD/l. The micro(max) of algae based on the chlorophyll-a was 3.5 day(-1) at K(s) of 50mg COD/l. The observed specific substrate removal by heterotrophic bacteria varied between the concentrations of substrate used and the average value was 0.82 (mg COD/mg biomass). The specific substrate utilization rate in the bioreactors was direct proportional to the specific growth rate. Hence, the determined Monod kinetic parameters are useful for the definition of the operation of SFPs.
本文介绍了底物浓度对利用沉淀后的生活污水作为唯一有机碳源的二级兼性塘（SFP）中藻类和异养细菌混合培养物生长的影响。在一系列间歇式恒化器反应器中，研究了混合培养物在200至800mg COD/l浓度范围内的生长情况。根据实验室数据，使用修正的Gompertz模型确定比生长速率（μ）。使用Monod动力学方程计算最大比生长速率（μmax）和半饱和系数（Ks）。异养细菌的最大观察生长速率（μmax）为3.8 d⁻¹，Ks为200mg COD/l。基于悬浮挥发性固体的藻类生物量的μmax为2.7 d⁻¹，Ks为110mg COD/l。基于叶绿素a的藻类的μmax在Ks为50mg COD/l时为3.5 d⁻¹。观察到的异养细菌对底物的去除率因所用底物浓度而异，平均值为0.82（mg COD/mg生物量）。生物反应器中的比底物利用率与比生长速率成正比。因此，所确定的Monod动力学参数有助于定义二级兼性塘的运行。
