30
2 Advantages of Hybrid Bioreactor
substrate removal partitions (i.e., substrate consumed by each of the two growth) and
specific substrate utilization rate evaluate the competitiveness among suspendedand attached-growth biomass for a single substrate in an integrated fixed-film activated process [90]. In this regard, specific substrate utilization rate of both the
suspended and the attached biomass must be determined to get rid of their individual
performance.
Most of the hybrid bioreactor models already developed appeared to be complex
and tedious in calculation requiring significant time for analysis. In this context,
the simplified model for hybrid bioreactor may be conceptualized in future research
work for predicting the relevant outputs rationally. The future scope in innovative
simplified modeling of fixed-bed hybrid bioreactor also lies in extending the same
for different kinds of substrate like carbonaceous, nitrogenous and phosphorus by
incorporating growth kinetics of respective microorganisms. The influence of various
process parameters like pH, dissolved oxygen (DO), etc. may also be catered by
introducing all the concerned kinetic expressions.
Process design of the fixed-bed hybrid bioreactor using the rational model can
also be optimized to make it cost-effective. In that case, configuration of the hybrid
bioreactor in the field can be modified to get it accommodated in a small footprint.
Another special aspect regarding the hybrid bioreactor system is that innovations of
newer attached media with a view to enhance the specific surface area. Apart from
that, the kinetic coefficients for different types of wastewater in a hybrid bioreactor
system must be determined precisely. Any rational and simplified model can be used
judiciously for this purpose so that the prototype design is possible in case of other
flow characteristics. Indeed, the design rationales need to be established by operating
the hybrid bioreactor under wide fluctuations of the process parameters, before going
to such design.
The sensitivity, i.e., influence of any parameter on the overall performance is an
important issue also in case of hybrid bioreactor model. The profile of performance
variation on account of change in a specific process can be derived, provided the
model equations are accurate and dependable. Hence, out of several variables, the
most sensitive one can be detected and thereby its optimal range can be ascertained.
2.8 Mathematical Modeling of Aerobic Hybrid Bioreactor
System
In most existing models of hybrid bioreactor, the biofilm liquid interface has not been
considered properly. Mass transfer at this surface is decisive for the supply of the
active biomass with all types of soluble substrates. It is quite reasonable to assume
that the biofilm surface is separated from bulk liquid by a transition zone, where the
classical biofilm theory can be applied. In several models of biofilm, the thickness of
this transition layer was considered as 100 µm (Wanner and Gujer 1986, Suidan et al.
2 Advantages of Hybrid Bioreactor
substrate removal partitions (i.e., substrate consumed by each of the two growth) and
specific substrate utilization rate evaluate the competitiveness among suspendedand attached-growth biomass for a single substrate in an integrated fixed-film activated process [90]. In this regard, specific substrate utilization rate of both the
suspended and the attached biomass must be determined to get rid of their individual
performance.
Most of the hybrid bioreactor models already developed appeared to be complex
and tedious in calculation requiring significant time for analysis. In this context,
the simplified model for hybrid bioreactor may be conceptualized in future research
work for predicting the relevant outputs rationally. The future scope in innovative
simplified modeling of fixed-bed hybrid bioreactor also lies in extending the same
for different kinds of substrate like carbonaceous, nitrogenous and phosphorus by
incorporating growth kinetics of respective microorganisms. The influence of various
process parameters like pH, dissolved oxygen (DO), etc. may also be catered by
introducing all the concerned kinetic expressions.
Process design of the fixed-bed hybrid bioreactor using the rational model can
also be optimized to make it cost-effective. In that case, configuration of the hybrid
bioreactor in the field can be modified to get it accommodated in a small footprint.
Another special aspect regarding the hybrid bioreactor system is that innovations of
newer attached media with a view to enhance the specific surface area. Apart from
that, the kinetic coefficients for different types of wastewater in a hybrid bioreactor
system must be determined precisely. Any rational and simplified model can be used
judiciously for this purpose so that the prototype design is possible in case of other
flow characteristics. Indeed, the design rationales need to be established by operating
the hybrid bioreactor under wide fluctuations of the process parameters, before going
to such design.
The sensitivity, i.e., influence of any parameter on the overall performance is an
important issue also in case of hybrid bioreactor model. The profile of performance
variation on account of change in a specific process can be derived, provided the
model equations are accurate and dependable. Hence, out of several variables, the
most sensitive one can be detected and thereby its optimal range can be ascertained.
2.8 Mathematical Modeling of Aerobic Hybrid Bioreactor
System
In most existing models of hybrid bioreactor, the biofilm liquid interface has not been
considered properly. Mass transfer at this surface is decisive for the supply of the
active biomass with all types of soluble substrates. It is quite reasonable to assume
that the biofilm surface is separated from bulk liquid by a transition zone, where the
classical biofilm theory can be applied. In several models of biofilm, the thickness of
this transition layer was considered as 100 µm (Wanner and Gujer 1986, Suidan et al.