Separation Science and Technology, Vol.50, No.14, 2177-2189, 2015
Lactic Acid Production in a Membrane Bioreactor System with Thermophilic Bacillus coagulans: Fouling Analysis of the Used Ceramic Membranes
In lactic acid fermentation broth systems, membrane fouling is characterized as the crucial factor in limiting ceramic membrane life-time and efficiency. This study aimed to find the limiting factor of this process and seek an effective solution. By quantitative analysis using resistance-in-series model, the cake layer resistance is demonstrated to be the dominant factor in a steady state. A cake compressibility index was measured as high as 2.09. Within the low transmembrane pressure range, the cake resistance was manipulated through crossflow velocity regulation to achieve a better membrane performance. A new correlation between flux and cell density was also introduced.
Keywords:lactic acid;Bacillus coagulans;micro-;ultrafiltration;ceramic membrane;resistance-in-series model