Related Experiment Videos
Photolysis primes biodegradation of benzo[a]pyrene
R M Miller1, G M Singer, J D Rosen
1Departments of Biochemistry and Microbiology, Cook College, Rutgers University, New Brunswick, New Jersey 08903.
Applied and Environmental Microbiology
|July 1, 1988
Summary
Photolytic pretreatment transforms benzo[a]pyrene (BaP) into less harmful substances. This process aids in the detoxification and safe disposal of polycyclic aromatic hydrocarbons (PAH) in contaminated sludge and soil.
Area of Science:
- Environmental Chemistry
- Environmental Science
- Toxicology
Background:
- Polycyclic Aromatic Hydrocarbons (PAHs) like benzo[a]pyrene (BaP) are persistent environmental pollutants.
- Assessing the fate and transformation of PAHs in environmental matrices is crucial for risk assessment and remediation.
Purpose of the Study:
- To evaluate the impact of photolytic pretreatment on the subsequent biodegradation and detoxification of BaP in sewage sludge and soil.
- To investigate the transformation products of BaP following photolysis and their environmental behavior.
Main Methods:
- 14C-labeled BaP was subjected to photolysis in methanolic solution with or without hydrogen peroxide (H2O2) under UV or natural sunlight.
- Photolyzed BaP was then introduced into sewage sludge and soil test systems to assess biodegradation, mineralization, and binding.
- Mutagenicity was assessed using the Ames assay, and acute toxicity was evaluated.
Main Results:
- Photolysis, especially with H2O2, significantly enhanced BaP transformation into polar compounds.
- Intact BaP showed resistance to biodegradation, while photolysis products underwent increased mineralization and binding.
- Photolysis moderately reduced BaP mutagenicity and increased acute toxicity, but subsequent incubation in soil/sludge rapidly decreased these effects due to mineralization and binding.
Conclusions:
- Photolytic pretreatment is a promising method for detoxifying BaP and similar PAHs in contaminated matrices.
- This approach can facilitate the environmentally safe disposal of PAH-laden industrial wastes, such as petroleum refinery sludge and coal tar residues.