Filtration biomass measurements

Biomass Production. Biomass is usually measured by dry weight of viable cells per unit volume X. We bypass the sometimes tricky problems associated with this measurement except to say that it is the province of the microbiologist and usually involves plate cultures and filtration followed by drying. Suppose there is one limiting nutrient S, and that all other nutrients are available in excess. Then the Monod model for growth is... 

Since an on-line generated signal for biomass concentration is decisive for control purposes a series of sensors and methods that can be automated have appeared in recent decades. Many of them rely on optical measuring principles, others exploit filtration characteristics, density changes of the suspension as a consequence of cells, or (di)electrical properties of suspended cells. Some of the... 

A direct estimation of the biomass present maybe made by determining the dry weight of a sample. In breweries, however, less direct but more rapid methods are used. Examples of such techniques are the measurement of the packed cell volume of a sample after centrifugation under precisely controlled conditions, determination of wet weight after filtration, and the measurement of the optical opacity of a sample by turbidimetry or spectrophotometry. Alternatively, where pressed yeast or yeast slurry of consistent quality are available, the weight or volume of such samples may be measured. The accuracy of all of these procedures is impaired where non-yeast matter such as trub or haze is present. 

A membrane fouling simulator (MFS) provides a similar visualization method to DOTM and DVO. This technique features microscopic visualization of the surface of a spiral wound membrane and a crossflow membrane module constructed from stainless steel plate. TMP during filtration is also measured, while fouling deposition of biomass on spacer is visualized simultaneously. MFS is easy to handle, simple, robust and small, with a flow capacity of 15-25 Lh [70, 71]. 

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