Treatment of benzene vapors from contaminated air stream in a laboratory-scale compost biofilter
DOI:
https://doi.org/10.20450/mjcce.2009.227Keywords:
compost biofilter, benzene, performance, removal efficiency, elimination capacityAbstract
Biofiltration of process waste–gas streams using microorganisms attached to porous support matrix, at low concentrations and high gas flow rates, has gained importance as a versatile treatment technology ever since the Clean Air Act Amendments (1990), by the US – EPA came into existence. In this study, we evaluated the potential of a laboratory–scale biofilter, inoculated with mixed culture, to remove gas–phase benzene from a synthetic waste gas stream. Experiments were conducted in three different phases, after the acclimatization step, corresponding to empty bed residence times (EBRT) varying between 0.81–2.45 min and benzene concentrations up to 1.7 g/m3. At high concentrations, significant reduction in removal efficiency was observed, which may be due to insufficient biomass in the filter bed to utilize the substrate, or due to substrate inhibition at high concentrations. Removal efficiencies higher than 90% were achieved for inlet benzene loading rates lesser than 40 g/m3hr.
References
WHO, Occupational Diseases, Macmillan Publishers, Singapore, 1986.
S. P. P. Ottengraf, Exhaust Gas Purification, In: Biotechnology, H. J. Rehm and G. Reed. (eds.), 425–452, VCH Verlagsgesellschraft, Weinham, Germany (1986).
J. S. Devinny, M. A. Deshusses, T. S. Webster, Biofiltration for Air Pollution Control, Lewis Publishers, Boca Raton (1999).
D. Arulneyan, T. Swaminathan, Biodegradation of ethanol vapors in a biofilter, Bioproc. Eng., 22, 63– 67 (2000).
E. R. Rene, D. V. S. Murthy, T. Swaminathan, Performance evaluation of a compost biofilter treating toluene vapors, Proc. Biochem., 40, 2771-2779 (2005).
J-H. Kim, S-H. Park, C-H. Park, H-S. Park, Removal characteristics of NH3 and H2S in biofilter packed with biomedia encapsulated by organic polymer, J. Korea Soc. Waste. Mgmt., 21, 288–295 (2004).
H. Jorio, L. Bibeau, G. Viel, M. Heitz, M, Effects of gas flow rate and inlet concentration on xylene vapors biofiltration performance, Chem. Eng. Sci., 76, 209–221 (2000).
E. R. Rene, M. C. Veiga, C. Kennes, Performance of a biofilter for the removal of high concentrations of styrene under steady and non-steady state conditions, J. Hazard. Mat. (2009) In Press.
M. Zilli, C. Guarino, D. Daffonchio, S. Borin, A. Converti, Laboratory-scale experiments with a powdered compost biofilter treating benzene-polluted air. Proc. Biochem., 40, 2035 – 2043 (2005).
