Performance Of Abr : Case Study Using Glycerin Pitch As Substrate
PERFORMANCE OF ABR :
CASE STUDY USING GLYCERIN PITCH AS SUBSTRATE
*)
Maya Sarah*)
Staf Pengajar Departemen Teknik Kimia, Fakultas Teknik USU
Abstract
The wastes of oleo chemical industry is categorize as wastewater and glycerin pitch. Treatment of waste water of
oleo chemical industry which contains glycerin pitch using Anaerobic Baffled Reactor (ABR) was proven to be
effective in treating medium level concentration (influent COD of 15.000 mg/l) with COD removal efficiency of
72%. For overall, ABR performance in reducing organic compound, influence significantly only with the feed
concentration and biomass losses. Increasing of feed concentration from COD of 15.000 mg/l to COD of 18.000
mg/l followed with the increasing of biomass losess of 27%.
Key words: Anaerobic baffled reactor, Bioreactor anaerobic, Fatty acid, Fatty alcohol, Glycerin pitch, Methyl
esther, β-oxidation
1. Introduction
The oleo chemical industry mainly problem is
the treatment and disposal of their wastes. The
wastes of oleo chemical industry is categorize as
wastewater and glycerin pitch. Glycerin pitch is a
viscous liquid coloring brown to dark brown with
organic compound in average 1 to 2 million mg
COD per liter. Glycerin pitch disposal become
serious problem since it is high organic compound
lead to the difficulties of biological degradation.
However the dilution of glycerin pitch with the
wastewater has reduced the COD less than 27,000
mg per liter.
Study on the degradation of glycerin pitch in the
batch condition using anaerobic bioreactor has been
conducted resulting low COD removal efficiency
(35% to max 47%) [a]. Meanwhile the Anaerobic
Baffled Reactor (ABR) has been proven to be
effective in treating palm oil mill effluent [b] with
COD removal efficiency of 90%. As oleo chemical
industry is the derivation of palm oil industry, the
ABR was used to treat wastewater of oleo chemical
industry. The operation is in the batch condition
and effluent was recycling back to the influent
using a peristaltic pump.
The ABR design uses a series of baffles to force
the wastewater to flow under and over (or through)
the baffles as it passes from the inlet to the outlet.
Bacteria within the reactor gently rise and settle due
to flow characteristics and gas production, but
move down the reactor at a slow rate. The most
significant advantage of the ABR is its ability to
separate
acidogenesis
and
methanogenesis
longitudinally down the reactor, allowing the
reactor to behave as a two-phase system without the
associated control problems and high cost. Twophase operation can increase acidogenic and
methanogenic activity by a factor of up to four as
acidogenic bacteria within the first stage and
different bacterial groups can develop under more
favorable conditions.
Wastewater contains several organic substrate
such as glycerin (C6-C12); methyl esters (C6-C12);
fatty acid (C6-C12); esters of glycerin (C6-C12) and
fatty alcohol (C6-C12). Except glycerin, the others
organic substances were degraded by anaerobic
microorganism via β-oxidation pathway to form
acetate acid as an intermediate product and
resulting product such as methanol and glycerin.
Meanwhile glycerin is degraded by EmbdenMeyerhof-Parnas (EMP) pathway to form pyruvate
acid [c]. The anaerobic degradation were mediated
by hydrolytic microorganism, acidogens and
metanogens to form methane gas as final product
[d].
2. Materials and Methods
2.1 Materials
a. Glycerin pitch
b. Wastewater of fatty alcohol industry
c. Inoculums: Mixed culture (have been acclimated
well with substrate of fatty alcohol industry)
2.2 Equipments
Anaerobic Baffled Reactor (ABR)
Analytical equipments: GC and glassware
Analytical methods to determine experiment’s
parameters were: COD with close reflux
distillation; TVA and biogas were with
chromatography gas. TVA analysis conducted with
GC 14B Shimadzu, FID detector, SE-30 column
(column temperature was 185 oC and injector
temperature was 230oC).
Jurnal Teknik SIMETRIKA Vol. 4 No. 1 – April 2005: 271 – 274
271
e
k
g
f
j
dd
h
i
c
1.
2.
3.
4.
5.
Anaerobic Baffled Reactor
Baffle
Gas Outlet
Influent
Effluent
6.
7.
8.
9.
Peristaltic pump
Gas measurement
Sampling ports
Thermometer
Figure 1: Equipment for the experiment
2.3 Methods
Glycerin pitch dilutes with the wastewater of
fatty alcohol industry and fed into the ABR.
Inoculums used was anaerobic microorganism
(25% volume of bioreactor) which had been
acclimated well using the same substrate. Variable
of the experiment was the treatment using feed
concentration of 15,000 mg/l and 18.000 mg/l in
batch condition. Most effluent was recycle back to
the influent using a peristaltic pump, and the rest
was drained through sampling port.The parameters
of the experiment were COD, TKN, MLSS, pH and
TVA. Experiment conducted in the temperature of
35oC in which the mesophilic microorganism
worked at their optimum condition.
concentration. Nitrogen concentration for both
treatments was relatively the same (average of 200
mg/l).
3.2 ABR Performance in Maintaining System’s
Alkalinity
Correlation between pH and alkalinity of ABR
is illustrated in figure 3. Increasing of organic
compound was follow with the increasing of
alkalinity value, but had no effect to pH liquid in
the ABR (6.8–7 in average). Balance pH was
achieved as the waste water containing several
Mineral sucs as NaCl, Na2SO4 and also
Na2CO3. Alkalinity and volatile acids (intermediate
product in anaerobic degradation) were forming
acid-base equilibrium system which is reconstruct
as follow:
3. Results and Discussion
CH4 ↑
3.1 Influence of Nitrogen Concentration to
Organic Removal
Influence of nitrogen concentration to organic
removal is illustrated in figure 2. The increasing of
fed concentration has no effect to the increasing of
nitrogen concentration (as TKN) within the system.
No intermediate metabolite produced from nitrogen
during anaerobic degradation was believed as the
reason of the stabilization of nitrogen
272
CHO + H2O
Performance of ABR: … (Maya Sarah)
CO2 ↑
↔
H2CO3 ↔
H+ + HCO3 - ↔ H+ + CO3 =
RCOOH
↔ H+ +
RCOO-
(b) COD 18.000 mg/l
TKN (m g/l)
(a) COD 15.000 mg/l
1000
20000
800
15000
1000
20000
800
15000
600
600
10000
5000
200
5000
200
0
0
10000
400
400
0
0
0 32 39 41 45 52 55 59 66 69 72 76 79 83 86 90
0 32 39 41 45 52 55 59 66 69 72 76 79 83 86 90
Time(Days)
TKN
COD
TKN
Time (Days)
TKN
COD
COD
COD
TKN
Figure 2: Correlation between nitrogen concentration and COD removal
2500
14
2500
2000
12
10
2000
1500
8
6
1000
4
2
500
0
0
pH
pH
12
10
Alk alinitas (m g/l)
14
1500
8
6
1000
4
2
500
0
0
0 25 32 39 41 45 52 55 59 66 69 72 76 79 83 86 90
0 25 32 39 41 45 52 55 59 66 69 72 76 79 83 86 90
Time (days)
Tim e (days)
pH
Alkalinitas
pH
Alkalinitas
Alk alinitas (m g/l)
(b) COD 18.000 m g/l
(b) COD 18.000 m g/l
pH
Alkalinitas
pH
Alkalinitas
Figure 3: Correlation between pH and Alkalinity
The new acid-base equilibrium was buffering the
pH system to the neutral condition. However the
alkalinity of both treatments slightly increases as
the concentration of organic compound increasing.
3.3 Influence of Feed Concentration and
Biomass Losses to Organic Removal Process
The effect of feed concentration and biomass
losses to ABR performance is illustrated in figure 4.
Increasing of feed concentration in general will
increase the microorganism growth. In this ABR
experiment, treatment with organic concentration of
15,000 mg/l resulting better organic removal
compare with other treatment (concentration of
18,000 mg/l).
ABR performance is depending to its ability to
keep biomass formation retained in the bioreactor.
ABR with higher feed concentration was found
more difficult to keep the biomass formation. A
small number of biomass were suspended and leave
the ABR, and detected as BOD. However compare
with the baseline condition, both treatments show
significant parameters of organic reduction as COD
of both decreasing.
274
4. Conclusion
Treatment of waste water of oleo chemical
industry which contains glycerin pitch using ABR
was proven to be effective in treating medium level
concentration (influent COD of 15.000 mg/l) with
COD removal efficiency of 72%. ABR
performance influence significantly only with the
feed concentration and biomass losses.
Notation
COD : Chemical Oxygen Demand
MLSS : Mixed Liquor Suspended Solid
TKN
: Total Kjedahl Nitrogen
Performance of ABR: … (Maya Sarah)
References
Maya Sarah, 2000. Pengolahan Limbah Cair
Industri Fatty Alcohol Secara Anaerobik, Thesis
of Magister ITB, Bandung, page 51-100.
Setiadi,T., Husaini, Djajadiningrat, A., 1996, Palm
Oil Mill Effluent Treatment by Anaerobic
Baffled Reactors: Recycle Effects and
Biokinetic Parameters, Water Science and
Technology, Vol 34, No 11, page 59-66.
Gaudy, A.F., Gaudy, E.T., 1981. Microbiology for
Environmental Scientist and Engineers,
McGraw Hill
International Book Co, Tokyo, page 519- 551.
Speece, R.E., 1996. Anaerobic Biotechnology
for Industrial Wastewaters, Archae Press,
Nashville, Tennessee, USA, page 3 – 6.
Jurnal Teknik SIMETRIKA Vol. 4 No. 1 – April 2005: 271 – 274
275
CASE STUDY USING GLYCERIN PITCH AS SUBSTRATE
*)
Maya Sarah*)
Staf Pengajar Departemen Teknik Kimia, Fakultas Teknik USU
Abstract
The wastes of oleo chemical industry is categorize as wastewater and glycerin pitch. Treatment of waste water of
oleo chemical industry which contains glycerin pitch using Anaerobic Baffled Reactor (ABR) was proven to be
effective in treating medium level concentration (influent COD of 15.000 mg/l) with COD removal efficiency of
72%. For overall, ABR performance in reducing organic compound, influence significantly only with the feed
concentration and biomass losses. Increasing of feed concentration from COD of 15.000 mg/l to COD of 18.000
mg/l followed with the increasing of biomass losess of 27%.
Key words: Anaerobic baffled reactor, Bioreactor anaerobic, Fatty acid, Fatty alcohol, Glycerin pitch, Methyl
esther, β-oxidation
1. Introduction
The oleo chemical industry mainly problem is
the treatment and disposal of their wastes. The
wastes of oleo chemical industry is categorize as
wastewater and glycerin pitch. Glycerin pitch is a
viscous liquid coloring brown to dark brown with
organic compound in average 1 to 2 million mg
COD per liter. Glycerin pitch disposal become
serious problem since it is high organic compound
lead to the difficulties of biological degradation.
However the dilution of glycerin pitch with the
wastewater has reduced the COD less than 27,000
mg per liter.
Study on the degradation of glycerin pitch in the
batch condition using anaerobic bioreactor has been
conducted resulting low COD removal efficiency
(35% to max 47%) [a]. Meanwhile the Anaerobic
Baffled Reactor (ABR) has been proven to be
effective in treating palm oil mill effluent [b] with
COD removal efficiency of 90%. As oleo chemical
industry is the derivation of palm oil industry, the
ABR was used to treat wastewater of oleo chemical
industry. The operation is in the batch condition
and effluent was recycling back to the influent
using a peristaltic pump.
The ABR design uses a series of baffles to force
the wastewater to flow under and over (or through)
the baffles as it passes from the inlet to the outlet.
Bacteria within the reactor gently rise and settle due
to flow characteristics and gas production, but
move down the reactor at a slow rate. The most
significant advantage of the ABR is its ability to
separate
acidogenesis
and
methanogenesis
longitudinally down the reactor, allowing the
reactor to behave as a two-phase system without the
associated control problems and high cost. Twophase operation can increase acidogenic and
methanogenic activity by a factor of up to four as
acidogenic bacteria within the first stage and
different bacterial groups can develop under more
favorable conditions.
Wastewater contains several organic substrate
such as glycerin (C6-C12); methyl esters (C6-C12);
fatty acid (C6-C12); esters of glycerin (C6-C12) and
fatty alcohol (C6-C12). Except glycerin, the others
organic substances were degraded by anaerobic
microorganism via β-oxidation pathway to form
acetate acid as an intermediate product and
resulting product such as methanol and glycerin.
Meanwhile glycerin is degraded by EmbdenMeyerhof-Parnas (EMP) pathway to form pyruvate
acid [c]. The anaerobic degradation were mediated
by hydrolytic microorganism, acidogens and
metanogens to form methane gas as final product
[d].
2. Materials and Methods
2.1 Materials
a. Glycerin pitch
b. Wastewater of fatty alcohol industry
c. Inoculums: Mixed culture (have been acclimated
well with substrate of fatty alcohol industry)
2.2 Equipments
Anaerobic Baffled Reactor (ABR)
Analytical equipments: GC and glassware
Analytical methods to determine experiment’s
parameters were: COD with close reflux
distillation; TVA and biogas were with
chromatography gas. TVA analysis conducted with
GC 14B Shimadzu, FID detector, SE-30 column
(column temperature was 185 oC and injector
temperature was 230oC).
Jurnal Teknik SIMETRIKA Vol. 4 No. 1 – April 2005: 271 – 274
271
e
k
g
f
j
dd
h
i
c
1.
2.
3.
4.
5.
Anaerobic Baffled Reactor
Baffle
Gas Outlet
Influent
Effluent
6.
7.
8.
9.
Peristaltic pump
Gas measurement
Sampling ports
Thermometer
Figure 1: Equipment for the experiment
2.3 Methods
Glycerin pitch dilutes with the wastewater of
fatty alcohol industry and fed into the ABR.
Inoculums used was anaerobic microorganism
(25% volume of bioreactor) which had been
acclimated well using the same substrate. Variable
of the experiment was the treatment using feed
concentration of 15,000 mg/l and 18.000 mg/l in
batch condition. Most effluent was recycle back to
the influent using a peristaltic pump, and the rest
was drained through sampling port.The parameters
of the experiment were COD, TKN, MLSS, pH and
TVA. Experiment conducted in the temperature of
35oC in which the mesophilic microorganism
worked at their optimum condition.
concentration. Nitrogen concentration for both
treatments was relatively the same (average of 200
mg/l).
3.2 ABR Performance in Maintaining System’s
Alkalinity
Correlation between pH and alkalinity of ABR
is illustrated in figure 3. Increasing of organic
compound was follow with the increasing of
alkalinity value, but had no effect to pH liquid in
the ABR (6.8–7 in average). Balance pH was
achieved as the waste water containing several
Mineral sucs as NaCl, Na2SO4 and also
Na2CO3. Alkalinity and volatile acids (intermediate
product in anaerobic degradation) were forming
acid-base equilibrium system which is reconstruct
as follow:
3. Results and Discussion
CH4 ↑
3.1 Influence of Nitrogen Concentration to
Organic Removal
Influence of nitrogen concentration to organic
removal is illustrated in figure 2. The increasing of
fed concentration has no effect to the increasing of
nitrogen concentration (as TKN) within the system.
No intermediate metabolite produced from nitrogen
during anaerobic degradation was believed as the
reason of the stabilization of nitrogen
272
CHO + H2O
Performance of ABR: … (Maya Sarah)
CO2 ↑
↔
H2CO3 ↔
H+ + HCO3 - ↔ H+ + CO3 =
RCOOH
↔ H+ +
RCOO-
(b) COD 18.000 mg/l
TKN (m g/l)
(a) COD 15.000 mg/l
1000
20000
800
15000
1000
20000
800
15000
600
600
10000
5000
200
5000
200
0
0
10000
400
400
0
0
0 32 39 41 45 52 55 59 66 69 72 76 79 83 86 90
0 32 39 41 45 52 55 59 66 69 72 76 79 83 86 90
Time(Days)
TKN
COD
TKN
Time (Days)
TKN
COD
COD
COD
TKN
Figure 2: Correlation between nitrogen concentration and COD removal
2500
14
2500
2000
12
10
2000
1500
8
6
1000
4
2
500
0
0
pH
pH
12
10
Alk alinitas (m g/l)
14
1500
8
6
1000
4
2
500
0
0
0 25 32 39 41 45 52 55 59 66 69 72 76 79 83 86 90
0 25 32 39 41 45 52 55 59 66 69 72 76 79 83 86 90
Time (days)
Tim e (days)
pH
Alkalinitas
pH
Alkalinitas
Alk alinitas (m g/l)
(b) COD 18.000 m g/l
(b) COD 18.000 m g/l
pH
Alkalinitas
pH
Alkalinitas
Figure 3: Correlation between pH and Alkalinity
The new acid-base equilibrium was buffering the
pH system to the neutral condition. However the
alkalinity of both treatments slightly increases as
the concentration of organic compound increasing.
3.3 Influence of Feed Concentration and
Biomass Losses to Organic Removal Process
The effect of feed concentration and biomass
losses to ABR performance is illustrated in figure 4.
Increasing of feed concentration in general will
increase the microorganism growth. In this ABR
experiment, treatment with organic concentration of
15,000 mg/l resulting better organic removal
compare with other treatment (concentration of
18,000 mg/l).
ABR performance is depending to its ability to
keep biomass formation retained in the bioreactor.
ABR with higher feed concentration was found
more difficult to keep the biomass formation. A
small number of biomass were suspended and leave
the ABR, and detected as BOD. However compare
with the baseline condition, both treatments show
significant parameters of organic reduction as COD
of both decreasing.
274
4. Conclusion
Treatment of waste water of oleo chemical
industry which contains glycerin pitch using ABR
was proven to be effective in treating medium level
concentration (influent COD of 15.000 mg/l) with
COD removal efficiency of 72%. ABR
performance influence significantly only with the
feed concentration and biomass losses.
Notation
COD : Chemical Oxygen Demand
MLSS : Mixed Liquor Suspended Solid
TKN
: Total Kjedahl Nitrogen
Performance of ABR: … (Maya Sarah)
References
Maya Sarah, 2000. Pengolahan Limbah Cair
Industri Fatty Alcohol Secara Anaerobik, Thesis
of Magister ITB, Bandung, page 51-100.
Setiadi,T., Husaini, Djajadiningrat, A., 1996, Palm
Oil Mill Effluent Treatment by Anaerobic
Baffled Reactors: Recycle Effects and
Biokinetic Parameters, Water Science and
Technology, Vol 34, No 11, page 59-66.
Gaudy, A.F., Gaudy, E.T., 1981. Microbiology for
Environmental Scientist and Engineers,
McGraw Hill
International Book Co, Tokyo, page 519- 551.
Speece, R.E., 1996. Anaerobic Biotechnology
for Industrial Wastewaters, Archae Press,
Nashville, Tennessee, USA, page 3 – 6.
Jurnal Teknik SIMETRIKA Vol. 4 No. 1 – April 2005: 271 – 274
275