Tsuno Hiroshi

A biologically activated carbon anaerobic reactor was applied for treatment of two types of food industry wastewater : low soluble COD concentration wastewater of 1000-1500㎎/L with high suspended solid of 300㎎/L, and bean paste production process wastewater. Mean total COD removal efficiency of 86% and 89% were obtained for both wastewaters under the fluidized-bed-volume organic loading rate of 0.5-33㎏ COD/(m³・d) and 1.6-29㎏ COD/(m³・d) respectively. It was indicated that conversion efficiency of removed soluble COD to solid COD was 0.12㎏ COD/㎏ COD-removed and the solubilization ratio of solid-COD was 95% for the low soluble COD concentration wastewater.

Batch and semi-continuous thermophilic l-lactate fermentation experiments were performed using Bacillus coagulans and glucose as a substrate. Reactor performance and biomass concentrations were assessed using two methods: turbidity as a traditional biomass index and real-time polymerase chain reaction (PCR) quantification of 16S rRNA genes. In the batch experiment, although the relationship between turbidity and real-time PCR assay differed depending on the growth phase, a correlation was observed between both assay methods. In the semi-continuous experiment, real-time PCR measurement was well suited for use as an index for evaluating bacterial mass under different organic loading conditions. A mathematical model was applied to evaluate the real-time PCR quantification to long-term, semi-continuous lactate fermentation. Lactate fermentation was well suited since only B. coagulans was involved in the reactions. The results obtained revealed a fundamental relationship between real-time PCR and traditional biomass analyses.