Immobilization microorganisms, wastewater treatment

Researchers have also combined reactor types. Guo et al. (1997), for example, designed an external loop airlift reactor that incorporates a fluidized bed within the downcomer section, shown in Figure 10.1. The fluidized bed section is used to immobilize microorganisms on carrier particles in order to protect them from damage. The design is meant for the production of enzymes, biofluidization, and wastewater treatment. Although shear rates were minimized, bubbles were not entrained within the downcomer. Furthermore, the gas-liquid mass transfer coefficient was observed to increase with gas holdup. The result was that the gas-liquid mass transfer was limited due to the fact that global gas holdup for the reactor was strictly defined by the riser gas holdup without any addition by the downcomer. 

Zhao, X., Wang, Y. M. Ye, Z. F. 2006. Oil field wastewater treatment in Biological Aerated Filter by immobilized microorganisms. Process Biochem. 41(7) 1475-1483. 

At present, the most frequently used method of biological treatment is activation of wastewaters [1,3,6, 7]. In the activation tank, water is mixed with activated sludge. Whereas in the biological columns water flows through immobile microbial growth, in this case the activated component of the treatment, i.e. microorganisms, are dispersed in water in the form of acti-... 

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