Ecotest device for estimation of environmental fate of chemicals in the laboratory

A glass vessel device with water volume of 20 L was constructed for fast testing of the fate of a chemical in freshwater watercourse environment. The dynamic system consisted of natural water with throughflow, of 4.5 mL min−1 and bottom sediment from a clean oligohumic lake in Central Finland. Duckweed (Lemna sp.) as plant material, lake mussel (Anodonta piscinalis) and crucian carp (Carassius carassius) as test animals were included in the test device. Tetrachloroguaiacol (TeCG) was dissolved at start to water to make 2 μg L−1 concentration. The same concentration of TeCG was maintained in inflow water. After static and dynamic pre-tests, a dynamic four weeks test at 15°C was run with natural water taken in winter. Then, two dynamic four weeks experiments in three parallel devices with water taken in summer (15°C) and in autumn (10°C) were done. Concentration of TeCG in outflow water and its partition between sediment and water came to an equilibrium. Contents in mussel and fish reached no equilibria during the tests. Six chlorophenolic metabolites of TeCG were identified, but most of the TeCG had reacted to nonidentified degradation products. The degradation rate of TeCG was more dependent on the time of year of water sampling than on the test temperature.