Biological and Environmental Systems Group Department of Chemical and Process Engineering, The University of Sheffield, U.K
National Council for Science and Technology, Mexico
N EW
ANAEROBIC TREATMENT OF PHENOL IN A TWO-STAGE ANAEROBIC REACTOR: A RENEWABLE SOURCE OF ENERGY Ernesto Hernández1, Robert Edyvean2 1 Sponsored by Consejo Nacional de Ciencia y Tecnología, México 2 Department of Chemical Engineering, The University of Sheffield, U.K.
[email protected]
INTRODUCTION
RESULTS
Anaerobic digestion 1:
q Performance results
q Is a natural biochemical process based on enzymatic reactions carried out by bacteria in lack of oxygen q Degrades wastes to produce biogas (fuel) and sludge (fertilizer)
54 %CO2
67 %CH4
45 % N2
32 % CO2
Lbiogas
0.3
Phenolic compounds:
0.82
L reactor×Day
Lbiogas Lreactor×Day
q Are toxic substances that can be accumulated in the environment q Broadly used in many industries including: üPlastics and resins üEtc.
üPharmaceutical üFood processing
Phenol
q Have a strong chemical structure: aromatic ring
Methanogenic
reactor
reactor
+
q Are the second largest source of carbon in nature q Cause inhibition problems to anaerobic
Acidogenic
Protein supplement
bioreactors 2,3
q Phenol is an intermediate product of the anaerobic biodegradation of protocatechuic, 4-Hydroxybenzoic acid, tyrosol, caffeic acid, catechol and gallic acid.
99.2 % Phenol degradation 42 % Phenol deg. 15 % COD deg.
CATHECHOL p-CRESOL PHLOROGLUCINOL HYDROQUINONE 3-CLOROPHENOL
ADIPIC ACID
ACETATE PROPIONATE BUTIRARATE CO2, H2
PHENOL CYCLOHEXANONE
CH4
98 % Phenol deg. 62 % COD deg.
q Monitoring results Gas production GPR1
q Consists in separating acidogenic bacteria and methanogenic bacteria to improve the biodegradation efficiency and methane production
Volume of biogas (L Biogas L reactor-1 Day -1)
CAPROIC ACID
1.2 1 0.8 0.6 0.4 0.2 0
AIMS
2
4
6
q Degrade phenol in a two phase anaerobic digester operating at 35 0C and 101 KPa q Measure:
8 10 12 14 16 18 20 22 24 26 28
ü Biomass concentration
70
CR2 1600 1400 1200 1000 800 600 400 200 0 Time (Days)
COD Degradation
Biomass concentration
%DCODdR2
%DCODdGlobal
SOCR1 SOCR2 2500 2000
60 50 40 30 20
1500 1000 500
10
ü pH evolution
CR1
%DGlobal
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
mg/L SOC
%COD degradation
ü Concentration of organic acids
%DR2
100.0 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0
80
ü Degradation of phenol and chemical oxygen demand
%DR1
Time (Days)
%DCODdR1 90
GPR2
Start
0
ü Biogas production and composition
Degradation of phenol
% Phenol degraded
Two phase anaerobic digestion:
67.8 % COD degradation
mg Phenol/L
üPetroleum üAgrochemicals
0 0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
0
15
0
Time (Days)
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15
Time (Days)
Evolution of pH
METHODS
pHR1
q Analytical methods
OAR1
v Photometrical analysis of Dr. Bruno Lange , Co. Test cuvettes:
8000
8.0
7000
7.5
6000 5000
3000
60 50 40
7.0
30 20
6.0 10
5.5
1000 0 0 1
2 3
4 5 6
7 8
9 10 11 12 13 14 15
Time (Days)
q Procedure
BR2
6.5
4000
2000
v Gas chromatography analysis, APHA 2720 4
BR1
St art
8.5
pH
üOrganic acids LYW 365, APHA 5560 4 üPhenol LCK 346, APHA 5530 4
Gas production (A)
9.0
OAR2
9000
mg Acetic Acid/L
üTotal organic carbon LCK 384, APHA 5310 4 üChemical oxygen demand LCK 014, APHA 5220 4
pHR2
5.0
ml 7.5NaOH/10NaHCO3
Organic acids concentration
0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 Time (Days)
Gas production (A)
CONCLUSIONS
400 ml
q Methane production was 3 times higher than the CO2 production at a concentration of 67%
2.5 gr phenol/L Goes into
Everyday Semi continuously
Goes into
pH = 5.5
pH = 8.5
q Phenol is highly degraded by methanogenic bacteria but not by acidogenic bacteria Methanogenic Reactor
Acidogenic Reactor
Sampling (B) Organic + H2O Matter
q 99.2% of phenol was degraded by the two phase anaerobic digester
anaerobes
Sampling (B)
CH4 + CO2 + New + NH3 + H2S + H2 + N2 + heat Biomass
q Biomass concentration was not affected by the addition of phenol
FUTURE WORK q A deep study to know if acidogenic bacteria promote changes in phenol structure q Anaerobic biodegradability by acidogenic bacteria of protocatechuic, 4Hydroxybenzoic acid, p-tyrosol, Caffeic acid, Catechol, Gallic acid and Oleuropein.
q Sample test A. Gas
REFERENCES [1] Pohland, F. G., and Ghosh, S. (1971). "Developments in anaerobic treatment process." Biotechnology and Bioengineering, 2, 85-106. Headspace
Syringe
Vial filled with N2
Gas Chromatographer
[2] Beccari, M., Bonemazzi, F., Majone, M., and Riccardi, C. (1996). "Interaction between acidogenesis and methanogenesis in the anaerobic treatment of olive oil mill effluents." Water Research, 30(1), 183-189. [3] Young, L. Y., and Rivera, M. D. (1985). "Methanogenic degradation of four phenolic compounds." Water Research, 19(10), 1325-1332.
B. Liquid
[4] APHA. (1998). Standard Methods for the Examination of Water and Wastewater, American Public Health Association, Washington.
ACKNOWLEDGEMENTS Sample
Filter
Cuvette test
Spectrophotometer
The authors want to thank the sponsorship of Consejo Nacional de Ciencia y Tecnologia, Mexico as well as R.T. Bachmann and N. B. Coutelle for their criticism.
