92
6 Performance Evaluation of Fixed-Bed Hybrid Bioreactor …
6.3 Details of Continuous Study
The performance of hybrid bioreactor was also evaluated under continuous mode of
operation using the same synthetic carbonaceous wastewater as used in the semibatch study. In order to accomplish this, flow rate was adjusted with the help of
peristaltic pump complying with desired hydraulic retention time (HRT). Apart from
HRT, other operating parameters were also varied accordingly to match with the most
possible operating regime for the municipal wastewater. Analysis of the influent
and effluent samples for soluble COD (mg/l) expressed the performance of hybrid
bioreactor.
6.3.1 Basic Approach
A continuous study was planned with synthetic carbonaceous wastewater as influent
with varying HRT ranging between 4 and 8 h, variable influent organic strength
(COD) between 150 and 250 mg/l and varying input biomass concentrations in
the range of 20,003,500 mg/l. There are 27 (twenty-seven) numbers of continuous
runs, performed on the reactor with 3 (three) variations in each of influent COD
concentrations, HRT and MLSS concentrations The reactor was run under continuous
mode, following the above-stated operating ranges with a view to find out the COD
removal efficiency as a performance indicator. The continuous study was also aimed
to validate the present mathematical model as developed earlier. Each continuous
run under a particular operating condition was monitored until the quasi-steady-state
condition reached in the reactor system.
6.3.2 Procedure for Continuous Study
The hybrid bioreactor was run under continuous mode with three variable initial
COD concentrations, viz 150, 200 and 250 mg/l and maintaining a HRT of 4, 6 and
8 h. The initial biomass concentration (both suspended and attached) was also varied
in commensurate with initial COD concentration. The reactor was allowed to run by
means of peristaltic pump until quasi-steady-state condition reached. The influent
and effluent sample was taken for measuring final COD concentration, whereas the
reactor content was taken for determining steady-state suspended biomass concentration. A portion of attached media (perspex sheet) was also washed out with 0.1 N
NaOH solution to measure the attached biomass.
All the relevant parameters except MLSS were measured as per Standard Methods
(1995). In case of MLSS, 50 mL mixed liquor sample was taken out from the reactor
and the same was filtered. The filtrate retained in the filter paper was allowed to dry
in a hot air oven at 105 °C until it attained a constant weight. Then the filter paper was
6 Performance Evaluation of Fixed-Bed Hybrid Bioreactor …
6.3 Details of Continuous Study
The performance of hybrid bioreactor was also evaluated under continuous mode of
operation using the same synthetic carbonaceous wastewater as used in the semibatch study. In order to accomplish this, flow rate was adjusted with the help of
peristaltic pump complying with desired hydraulic retention time (HRT). Apart from
HRT, other operating parameters were also varied accordingly to match with the most
possible operating regime for the municipal wastewater. Analysis of the influent
and effluent samples for soluble COD (mg/l) expressed the performance of hybrid
bioreactor.
6.3.1 Basic Approach
A continuous study was planned with synthetic carbonaceous wastewater as influent
with varying HRT ranging between 4 and 8 h, variable influent organic strength
(COD) between 150 and 250 mg/l and varying input biomass concentrations in
the range of 20,003,500 mg/l. There are 27 (twenty-seven) numbers of continuous
runs, performed on the reactor with 3 (three) variations in each of influent COD
concentrations, HRT and MLSS concentrations The reactor was run under continuous
mode, following the above-stated operating ranges with a view to find out the COD
removal efficiency as a performance indicator. The continuous study was also aimed
to validate the present mathematical model as developed earlier. Each continuous
run under a particular operating condition was monitored until the quasi-steady-state
condition reached in the reactor system.
6.3.2 Procedure for Continuous Study
The hybrid bioreactor was run under continuous mode with three variable initial
COD concentrations, viz 150, 200 and 250 mg/l and maintaining a HRT of 4, 6 and
8 h. The initial biomass concentration (both suspended and attached) was also varied
in commensurate with initial COD concentration. The reactor was allowed to run by
means of peristaltic pump until quasi-steady-state condition reached. The influent
and effluent sample was taken for measuring final COD concentration, whereas the
reactor content was taken for determining steady-state suspended biomass concentration. A portion of attached media (perspex sheet) was also washed out with 0.1 N
NaOH solution to measure the attached biomass.
All the relevant parameters except MLSS were measured as per Standard Methods
(1995). In case of MLSS, 50 mL mixed liquor sample was taken out from the reactor
and the same was filtered. The filtrate retained in the filter paper was allowed to dry
in a hot air oven at 105 °C until it attained a constant weight. Then the filter paper was