Chlorinated Aliphatics

2019 ◽  
pp. 150-151
Keyword(s):  
Chlorinated Aliphatics

The Effect of Mixtures of Xenobiotics and Primary Electron Donor on the Anaerobic Biotransformation of High Concentrations of Chlorinated Aliphatics

1992 ◽  
Vol 26 (1-2) ◽  
pp. 117-126 ◽  
Author(s):  
J. B. Hughes ◽  
G. F. Parkin
Keyword(s):  
Electron Donor ◽  
Mixed Effects ◽  
Primary Electron ◽  
Primary Electron Donor ◽  
Loading Rates ◽  
Chlorinated Aliphatics ◽  
Anaerobic Biotransformation ◽  
Transformation Rates ◽  
High Concentrations ◽  
Effect Of Feeding

Results are presented from experiments addressing the anaerobic biotransfoimation of high concentrations of three chlorinated aliphatics, dichloromethane (DCM), chloroform (CF), and 1,1,1-trichloroethane (TCA), when fed alone and in mixtures. Experiments were conducted to address the effect of feeding mixtures of these compounds on the transformation rates of individual components in the mixture, and to assess the effect of acetate loading rates on the extent of transformation of the chlorinated aliphatics. Feeding mixtures of chlorinated aliphatics caused decreased transformation of TCA, increased the transformation of DCM, and had mixed effects on CF transformation. The systems fed higher acetate loading rates demonstrated an increased ability to transform the chlorinated aliphatics.

Development and application of bacterial cultures for the removal of chlorinated aliphatics

1995 ◽  
Vol 31 (1) ◽  
pp. 237-247 ◽  
Author(s):  
Dick B. Janssen ◽  
Wim de Koning
Keyword(s):  
Waste Streams ◽  
Synthetic Compound ◽  
Catabolic Enzymes ◽  
Treatment Processes ◽  
Cometabolic Degradation ◽  
Chlorinated Aliphatics ◽  
Biological Remediation ◽  
Related Compounds ◽  
Remediation Process ◽  
Selection Of

The possibility of obtaining microbial cultures for the degradation of halogenated aliphatic hydrocarbons is mainly determined by the diversity and activity of catabolic enzymes that exist in nature. If a suitable organism is available, applications for the treatment of different waste streams can be developed. The relation between the kinetic parameters of the key enzymes and the properties of the organisms relevant for such applications is discussed, both for growth supporting and cometabolic degradation. When growth on a chlorinated aliphatic compound is possible, development of a biological remediation process is likely to be relatively easy. This is illustrated with the degradation of 1,2-dichloroethane, a synthetic compound that can be mineralized by specific cultures. Closely related compounds may be recalcitrant, which can be understood from an examination of the degradative pathways. The development of biological treatment processes based on cometabolic degradation is more demanding because selection of the proper organisms and maintaining them in the process are not straightforward. The range of compounds that can be degraded cometabolically is significantly larger. The potential of obtaining improved degradation by genetic adaptation and the use of biofilms is discussed.

Differences in Rat Liver Enzyme-Altered Foci Produced By Chlorinated Aliphatics and Phenobarbital

1986 ◽  
Vol 2 (4) ◽  
pp. 351-362 ◽  
Author(s):  
David L. Story ◽  
Earl F. Meierhenry ◽  
Charles A. Tyson ◽  
Harry A. Milman
Keyword(s):  
Body Weight ◽  
Rat Liver ◽  
Corn Oil ◽  
Maximum Tolerated Dose ◽  
The Other ◽  
Peptidase Activity ◽  
Oral Gavage ◽  
Cytotoxic Potential ◽  
Chlorinated Aliphatics ◽  
Preneoplastic Foci

Nine chlorinated aliphatics (CAs)—1,1-dichloroethane, 1,2-dichloro ethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, trichloro ethylene, tetrachloroethylene, 1,1,1,2-tetrachloroethane, 1,1,2,2- tetrachloroethane, and hexachloroethane—were examined in a rat liver foci assay for evidence of initiating and promoting potential. Young adult male Osborne-Mendel rats (ten/group) were given partial hepa tectomies, followed 24 hr later by a single i.p. dose of either diethyl nitrosamine (30 mg/kg body weight) or CA, 1 wk later either a diet containing 0.05% (w/w) phenobarbital or daily oral gavage (5 × /wk) of CA in corn oil for 7 weeks, and sacrificed 1 wk later. Putative preneo plastic markers monitored were foci with increased γ-glutamyltrans peptidase activity [GGT( + )]. CAs were without significant effect in the initiation protocol at the maximum tolerated dose. In the promotion protocol, 1,1-dichloroethane, 1,1,2-trichloroethane, tetrachloro ethylene, 1,1,2,2-tetrachloroethane, and hexachloroethane induced significant increases in GGT( + ) foci above control levels. Two variants of GGT( + ) foci were distinguishable, one associated predominantly with phenobarbital promotion, resembling preneoplastic foci in other models, and the other associated with CA promotion, which was less intensely stained and exhibited branching, resemblingfoci undergoing redifferentiation. The marked differences in response may relate to differences in cytotoxic potential or mechanism of action of the two types of agents.

Correlation between in vivo and in vitro toxicity of some chlorinated aliphatics

1989 ◽  
Vol 3 (2) ◽  
pp. 145-150 ◽  
Author(s):  
C.A. Tyson ◽  
S.J. Gee ◽  
K. Hawk-Prather ◽  
D.L. Story ◽  
H.A. Milman
Keyword(s):  
In Vitro Toxicity ◽  
Chlorinated Aliphatics

scholarly journals REDUCTIVE DECHLORINATION REACTION OF CHLORINATED ALIPHATICS BY ZERO-VALENT IRONS AND ITS DURABILITY OF REACTION RATE

2006 ◽  
Vol 62 (2) ◽  
pp. 268-277
Author(s):  
Masanori NEGISHI ◽  
Masanori SHIMOMURA ◽  
Yuichi HIGUCHI ◽  
Masaki TAKAOKA ◽  
Nobuo TAKEDA
Keyword(s):  
Reductive Dechlorination ◽  
Reaction Rate ◽  
Chlorinated Aliphatics ◽  
Dechlorination Reaction
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