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Controlled release experiments with nonylphenol in aquatic microcosms
Author(s) -
Pfister Gerd,
Jüttner Ingrid,
Severin Gabriele F.,
Schramm KarlWerner,
Kettrup Antonius
Publication year - 2003
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620220124
Subject(s) - microcosm , environmental chemistry , macrophyte , chemistry , nonylphenol , sediment , zoology , biology , ecology , paleontology
A method of controlled release of technical nonylphenol (tNP) was developed to simulate realistic exposure in ecotoxicological studies on aquatic organisms. The direct addition of tNP from an aqueous stock solution into 50 ml of water led to a concentration decrease of 80 to 90% weight/volume (w/v) from nominal values within 48 h. The inclusion of tNP in semipermeable low‐density polyethylene (LDPE) lay‐flat tubing (controlled‐release devices [CRDs]) of different length allowed a continuous release into pure water at a rate of about 30 μg/cm 2 /d. Using CRDs in aquaria containing 15 L of 63‐μm‐filtered lake water, eight different concentrations with maxima between 38.1 and 326.7 μg/L were maintained for 11 d. During a second experiment in 15‐L aquaria, five replicates of three concentrations were maintained using CRDs of the same length. Concentrations after 38 d varied between 0.1 and 6.7, 26.1 and 41.9, and 49.9 and 76.0 μg/L. In aquatic microcosms containing 230 L of lake water, a natural plankton community, 50 L of sediment, and macrophytes, seven different tNP concentrations (maxima 11–120.1 μg/L) were maintained over 45 d using CRDs of different length. They were replaced after 14 and 25 d because release of tNP was slower than predicted from laboratory experiments. Concentrations in the top 1‐cm sediment layer were on average 19 times higher during the dosing period than concentrations in the water at the same time. In the sediments, different levels of applications led to concentrations that differed less distinctly than in the water. This method is suitable for exposing aquatic organisms continuously to constant, ecologically relevant concentrations of NP and represents an improvement over previous dosing methods in which exposure varied.