Liquid purification or separation – Processes – Treatment by living organism
Patent
1998-09-11
2000-08-08
Upton, Christopher
Liquid purification or separation
Processes
Treatment by living organism
210610, 210625, 210626, 2101952, 2101953, 210202, C02F 302
Patent
active
060997311
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process and an apparatus for treating a water containing chlorinated organic compounds. Particularly, it relates to a treatment process and an apparatus for purifying groundwater, wastewater or the like containing aliphatic chlorinated organic compounds such as trichloroethylene, dichloroethylene, vinyl chloride, or aromatic chlorinated organic compounds such as chlorobenzene.
2. Description of Related Art
In recent years, there have been cases that aliphatic chlorinated organic compounds such as trichloroethylene, which are often used as cleaning agents in semiconductor factories or metal processing factories, leak from storage facilities or from wastewater, resulting contamination of soil and groundwater. Such leakage poses serious environmental problems. Contaminated groundwater has been conventionally treated mainly by pumping the contaminated groundwater, stripping the contaminant by air in an aeration column and then releasing it into the atmosphere or adsorbing it into activated carbon. If the contaminant is directly released into the atmosphere, treatment can be accomplished at low cost involving only aeration costs. However, this is an insufficient treatment process since it merely transfers the contaminant from water to the atmosphere thus giving rise to air pollution. If the contaminant is adsorbed into activated carbon, however, regeneration costs are incurred for regenerating spent activated carbon, and recovered chlorinated organic compounds must be disposed of. Wastewater containing chlorinated organic compounds have also been treated in the same manner or combined with other wastewater and treated by an activated sludge process or similar treatment process using an aerobic organism. However, problems also exist in these treatments since the compounds concerned are readily vaporizable with the result that they may be immediately diffused into the air by aeration.
Various techniques for biologically degrading such chlorinated organic compounds by biologically treating them with methanotrophs, phenol-degrading bacteria, toluene-degrading bacteria or the like have been proposed, but no practically feasible technique has yet been established. For example, a treatment technique using a bioreactor containing a methanotroph immobilized in gel has been proposed (JPB No. 67314/94). However, degrading bacteria which have once degraded chlorinated organic compounds such as trichloroethylene (TCE) rapidly decrease their trichloroethylene degradation activity, and many problems still remain for achieving a continuous and stable treatment on a practical level.
A bioreactor system for biodegrading trichloroethylene with a methanotroph has also been proposed (MIPR Nos. N91-84, N92-63: Herbes, S. E., Palumbo, A. V., Strong-Gunderson, J. L., Donaldson, T. L., Sayler, G. S., Bienkowski, P. R., Bowman, J. L., and Tschantz, M. F., "Innovative Bioreactor Development for Methanotrophic Biodegradation of Trichloroethylene", report number AL/EQ-TR-1994-0007, January 1994).
As shown in FIG. 5, this bioreactor system 20 comprises a continuous stirred tank reactor 22, four plug-flow reactor columns 24 and a dewatering column 26. Methane and oxygen are supplied to the tank reactor 22 via a flow controller not shown and a methanotroph is cultivated in the tank reactor 22.
Then, a liquid containing the methanotroph is introduced into one of the reactor columns 24 from the tank reactor 22. This reactor column 24 is fed with trichloroethylene. In this reactor column 24, the methanotroph biodegrades trichloroethylene. A formate is supplied between the second and third stage reactor columns.
The liquid having passed through the reactor columns 24 is reintroduced into the tank reactor 22.
The liquid in the tank reactor 22 is introduced to the dewatering column 26. The dewatering column 26 contains a porous metal filter covered with a TEFLON.RTM. layer having a pore diameter of 0.22 .mu.m. Wastewater having permeated the metal filter is di
REFERENCES:
patent: 2658034 (1953-11-01), Hood
patent: 3557954 (1971-01-01), Welch
patent: 4705633 (1987-11-01), Bogusch
patent: 5037551 (1991-08-01), Barkley et al.
patent: 5057221 (1991-10-01), Bryant et al.
patent: 5151187 (1992-09-01), Behmann
patent: 5196121 (1993-03-01), Moore et al.
patent: 5254253 (1993-10-01), Behmann
patent: 5302286 (1994-04-01), Semprini et al.
patent: 5384048 (1995-01-01), Hazen et al.
patent: 5868934 (1999-02-01), Yamasaki et al.
S.E. Herbes, et al. "Innovative Bioreactor Development for Methanotrophic Biodegradation of Trichloroethylene", Jan. (1994), pp. iii-xvii and 1-105.
Hiroo Uchiyama, et al., "Areobic Degradation of Trichloroethylene by a New Type II Methane-Utilizing Bacterium, Strain M", Chem. 53, Apr. 28, 1989, pp. 2903-2907.
Hiroo Uchiyama, et al., Aerobic Degradation of Trichloroethylene at High Concentration by a Methane-Utilizing Mixed Culture, Chem. 53, Oct. 20, 1988, pp. 1019-1024.
Gregory A. Brusseau, et al., "Optimization of trichloroethylene oxidation by methanotrophs and the use of a colorimetric assay to detect soluble methane monooxygenase activity", Jun. 21, 1990, pp. 19-29.
Hasegawa Takeshi
Kitagawa Masayoshi
Shimomura Tatsuo
Uchiyama Hiroo
Yagi Osami
Ebara Research Co. Ltd.
Japan as represented by Director General of Agency of National I
Upton Christopher
LandOfFree
Method and apparatus for treating water does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for treating water, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for treating water will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1147006