Comparison of the capacity of two biotic ligand models to predict chronic copper toxicity to two Daphnia magna clones and formulation of a generalized bioavailability model

摘要: Although it is increasingly recognized that biotic ligand models (BLMs) are valuable in the risk assessment of metals aquatic systems, use 2 differently structured and parameterized BLMs (1 United States another European Union) to obtain bioavailability-based chronic water quality criteria for copper worthy further investigation. In present study, authors evaluated predictive capacity these a large dataset toxicity data with Daphnia magna clones, termed K6 ARO. One BLM performed best clone data, whereas other ARO data. addition, there was an important difference between how they predicted bioavailability as function pH. These modeling results suggested effect pH on different clones considered, which confirmed additional experiments. Finally, because fundamental differences model structure made impossible create average BLM, generalized (gBAM) developed. Of 3 gBAMs developed, recommend gBAM-C(uni), combines log-linear relation 21-d median effective concentration (expressed free Cu(2+) ion activity) pH, more conventional BLM-type competition constants sodium, calcium, magnesium. This can be considered first step improving accuracy predictions chemistry (for variety clones), even beyond robustness current used regulatory applications.