High biomass retention reactor

Biodegradation of MTBE in a High Biomass Retention Reactor... 

The reactor is an aerobic, plug flow, packed-bed biofihn reactor. Reticulated polyurethane (PUR), a foam with large surface area, is used as the substrate for microorganisms. The substantial area available on the PUR for contact results in a high biomass concentration and thus high reaction rates at short retention times. Biopur can be used in conjunction with soil vapor extraction technology. 

The main reason for the popularity of the three widely used reactors lies in their ability to effectively retain a very high biomass concentration in their biofilms with a high sludge age and short hydraulic retention time. 

Lee and co-workers (Lee et al., 2007 Lee, Li, Noike, 2009) describe the continuous H2 production in a continuously stirred tank reactor coupled with a submerged hollow-fibre membrane unit. The presence of the membrane module integrated within the reaction volume allows reducing biomass washout at a high hydraulic retention time with a general improvement of the reactor performance in terms of H2 productivity and yield. 

Fixed-biofilm processes offer the advantage of high concentrations of biomass in relatively small reactors, as little biomass is lost in the effluent. The result is a long solids retention time (necessary to foster slow-growing microorganisms) and the possibility of degrading hazardous contaminants or wastes with low concentrations of organics. 

The accumulation and retention of biomass lends itself readily to the employment of continuous single pass reactors such as plug-flow or fluidized-bed reactors. When high quantities of biomass are retained, greater total quantities of nutrients may be delivered and greater quantities of waste products may be removed per unit time. Any mechanism that can be offered to retain the cells in high concentrations, deliver the nutrients rapidly, and remove waste products should offer a highly efficient reactor. 

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