Application of the OECD 301F respirometric test for the biodegradability assessment of various potential endocrine disrupting chemicals.
The biodegradability of several potential endocrine disrupting compounds, namely 4-n-nonylphenol (4-n-NP), nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO), bisphenol A (BPA), triclosan (TCS), di-(2-ethylhexyl)-phthalate (DEHP), perfluorooctanoate (PFOA) and perfluorononanoate (PFNA) was evaluated in this study, using OECD method 301F (manometric respirometry test) and activated sludge as inoculum. According to the results, 4-n-NP and BPA meet the strict definition of ready biodegradability and they are not expected to be persistent during the activated sludge process. Partial biodegradation was observed for DEHP (58.7+/-5.7%, n=3), TCS (52.1+/-8.5%, n=3) and NP1EO (25.9+/-8.1%, n=3), indicating their possible biodegradation in wastewater treatment systems, while no biodegradation was observed for NP2EO, PFOA and PFNA. Experiments in the co-presence of a readily biodegradable compound showed the absence of co-metabolic phenomena during 4-n-NP, BPA and TCS biodegradation. Using first order kinetics to describe biodegradation of the target compounds, half-lives of 4.3+/-0.6, 1.3+/-0.2, 1.8+/-0.5, 6.9+/-2.6 days were calculated for 4-n-NP, BPA, TCS and DEHP, respectively. Toxicity tests using marine bacterium Vibrio fischeri showed that biodegradation of 4-n-NP, NP1EO, BPA and TCS is a simultaneous detoxification process, while possible abiotic or biotic transformations of NP2EO, DEHP, PFOA and PFNA during respirometric test resulted to significant increase of their toxicities.
Stasinakis
Athanasios S
AS
Department of Environment, Water and Air Quality Laboratory, University of the Aegean, University Hill, Mytilene 81 100, Greece. astas@env.aegean.gr
Petalas
Anastasios V
AV
Mamais
Daniel
D
Thomaidis
Nikolaos S
NS
D000332:Aerobiosis / Q000187:drug effects; D048908:Aliivibrio fischeri / Q000187:drug effects; D001559:Benzhydryl Compounds; D001673:Biodegradation, Environmental / Q000187:drug effects; D002210:Caprylates / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D004051:Diethylhexyl Phthalate / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D052244:Endocrine Disruptors / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005466:Fluorocarbons / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D010636:Phenols / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D015203:Reproducibility of Results; D018675:Toxicity Tests; D014260:Triclosan / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D000098826:Bisphenol A Compounds
D001559:Benzhydryl Compounds; D002210:Caprylates; D004051:Diethylhexyl Phthalate; D052244:Endocrine Disruptors; D005466:Fluorocarbons; D010636:Phenols; D014260:Triclosan; C025256:nonylphenol; C023036:perfluorooctanoic acid; C006780:bisphenol A; D000098826:Bisphenol A Compounds