Sensitized photolysis as pretreatment to biological degradation of trichlorobenzenes

Thesis/Dissertation · Tue Jan 01 04:00:00 UTC 1991

OSTI ID:5086006

Kim, Jae Hyoun

The role of photolysis as pretreatment process was examined for the biological degradation of trichlorobenzenes (TCBs), namely 1,2,3-, 1,2,4- and 1,3,5-trichlorobenzenes. Initially, direct and indirect photolysis experiments were conducted using aqueous solutions with 1% acetonitrile of the three isomers of trichlorobenzenes with and without sensitizers. The sensitizers used were Fenton's reagent, nitrite, triethylamine, humic acid and TiO{sub 2}. The photochemical experiments were performed using laboratory simulated sunlight and the kinetic rates for these processes were calculated. The effect of photolysis on the biological degradation chlorobenzenes were examined using a chemical activation system (CAS) which consists of EDTA, ferrous sulfate, ascorbic acid, catalase and H{sub 2}O{sub 2} in potassium phosphate buffer (monobasic) and a primary sewage effluent. Initially, kinetic rates by CAS biodegradation and primary sewage were obtained and compared. In general, the rates of biodegradation were greater in the test media with catalase. The rate of transformation in CAS was enhanced in the order: monoCB < 1,2,3-TCB < 1,2,4-TCB < 1,3,5-TCB; whereas, when CAS was used as a control, the kinetic rates in the presence of catalase increased in the sequence: 1,2,3-TCB, 1,3,5-TCB < 1,2,4-TCB < MonoCB. Photolysis studied in concert with the biological systems showed significant enhancement of the degradation rate of trichlorobenzenes. The photolysis rates were higher for those with sensitized photolysis. This study shows that photolysis can be used as a pretreatment of enhancing biodegradation of trichlorobenzenes in aqueous systems.

• Research Organization: Michigan Univ., Ann Arbor, MI (United States)
• OSTI ID: 5086006
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism &amp; Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINO ACIDS
AQUEOUS SOLUTIONS
AROMATICS
ASCORBIC ACID
BIODEGRADATION
CARBOXYLIC ACIDS
CATALASE
CHELATING AGENTS
CHEMICAL REACTIONS
CHLORINATED AROMATIC HYDROCARBONS
DECOMPOSITION
DISPERSIONS
EDTA
ENZYMES
HALOGENATED AROMATIC HYDROCARBONS
IRON COMPOUNDS
IRON SULFATES
MIXTURES
ORGANIC ACIDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PEROXIDASES
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PROTEINS
SOLUTIONS
SULFATES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
VITAMINS