90
6 Performance Evaluation of Fixed-Bed Hybrid Bioreactor …
Table 6.1 Composition of
synthetic carbonaceous
wastewater with COD
concentration 1000 mg/l
(approx.)
Compound
Concentration (mg/l)
Dextrose (C 6 H 12 O 6 )
940
NH 4 NO 3
260
KH 2 P0 4
82.67
CaCl 2
27.5
MgSO 4 .7H 2 0
22.5
FeCl 3
0.25
was also measured time to time in this semi-batch study. Finally, semi-batch study
gives the optimum operating conditions like optimum HRT and initial MLSS values,
which are required for running the continuous operation of the reactor in the selected
mode. Ammonium and nitrate-nitrogen of the influent and effluent sample were also
measured to check any occurrence of nitrification/denitrification in the reactor.
6.2.2 Procedure of Semi-batch Study
Semi-batch study was conducted in the laboratory-scale fixed-bed hybrid reactor at
an interval of 2 h for the batch period of maximum 8 h. The study was conducted
for total 7(seven) days. The influent substrate concentration was varied from 100 to
250 mg/l with an increment of 50 mg/l at each time in accordance with the tentative
COD concentration in the municipal wastewater. Different biomass concentration
(MLSS) was set out at the initial stage of batch study, which varied from 2000 to
2500 mg/l. During this semi-batch study, at each batch interval effluent sample was
collected and the relevant parameters including MLSS and COD (substrate) were
measured. In addition, biomass sample was extracted from the attached surface to
measure the density of the attached biomass. Biomass density in the attached surface
was determined by washing the biofilm surface with 25 ml 0.1 (N) NaOH and thereafter heating the solution at 80 degree Celsius [1] followed by spectrometric observation as per Lowry’s method. The total biomass in the biofilm surface bioreactor
(X attached ) was determined from the principle of Lowry’s method. Apart from COD,
effluent soluble sample was also analyzed for finding out the ammonium-nitrogen
concentration (NH 4
+ –N) and nitrate-nitrogen concentration (NO 3
− N) with the help
of ion meter. The purpose of the analysis was to check the occurrence of nitrification
and denitrification in the fixed-bed hybrid reactor. The results of semi-batch study
with synthetic wastewater are shown in Table 6.2.
6 Performance Evaluation of Fixed-Bed Hybrid Bioreactor …
Table 6.1 Composition of
synthetic carbonaceous
wastewater with COD
concentration 1000 mg/l
(approx.)
Compound
Concentration (mg/l)
Dextrose (C 6 H 12 O 6 )
940
NH 4 NO 3
260
KH 2 P0 4
82.67
CaCl 2
27.5
MgSO 4 .7H 2 0
22.5
FeCl 3
0.25
was also measured time to time in this semi-batch study. Finally, semi-batch study
gives the optimum operating conditions like optimum HRT and initial MLSS values,
which are required for running the continuous operation of the reactor in the selected
mode. Ammonium and nitrate-nitrogen of the influent and effluent sample were also
measured to check any occurrence of nitrification/denitrification in the reactor.
6.2.2 Procedure of Semi-batch Study
Semi-batch study was conducted in the laboratory-scale fixed-bed hybrid reactor at
an interval of 2 h for the batch period of maximum 8 h. The study was conducted
for total 7(seven) days. The influent substrate concentration was varied from 100 to
250 mg/l with an increment of 50 mg/l at each time in accordance with the tentative
COD concentration in the municipal wastewater. Different biomass concentration
(MLSS) was set out at the initial stage of batch study, which varied from 2000 to
2500 mg/l. During this semi-batch study, at each batch interval effluent sample was
collected and the relevant parameters including MLSS and COD (substrate) were
measured. In addition, biomass sample was extracted from the attached surface to
measure the density of the attached biomass. Biomass density in the attached surface
was determined by washing the biofilm surface with 25 ml 0.1 (N) NaOH and thereafter heating the solution at 80 degree Celsius [1] followed by spectrometric observation as per Lowry’s method. The total biomass in the biofilm surface bioreactor
(X attached ) was determined from the principle of Lowry’s method. Apart from COD,
effluent soluble sample was also analyzed for finding out the ammonium-nitrogen
concentration (NH 4
+ –N) and nitrate-nitrogen concentration (NO 3
− N) with the help
of ion meter. The purpose of the analysis was to check the occurrence of nitrification
and denitrification in the fixed-bed hybrid reactor. The results of semi-batch study
with synthetic wastewater are shown in Table 6.2.