Understanding the sorption behavior of tributyltin (TBT) is important for predicting its fate and effects in the aquatic environment. Equilibrium sorption coefficients ranging from 0.11 × 103 to 350 × 103 1 kg-1 have been measured in laboratory experiments using a wide variety of sorbent types, but the majority of the sorption coefficients are on the order of 103 1 kg-1. Apparent sorption coefficients calculated from TBT concentrations measured in environmental sediments and overlying waters generally agree with laboratory measurements and are on the order of 103 1 kg-1. Higher apparent sorption coefficients near boat maintenance facilities are probably the result of TBT-containing paint chips that are incorporated into sediments. Laboratory studies measuring the rate of TBT sorption or desorption show that the time required to reach equilibrium is relatively fast (hours) and that sorption is reversible. Longer-term (weeks to months) sorption kinetics for TBT have not been reported. For environments where mixing and water mass circulation times are slower than the equilibration process, laboratory-determined sorption coefficients may be reasonable estimates of TBT partitioning in the environment. Changes in salinity over the range encountered in estuaries can alter sorption coefficients, but these reported changes are varied and may depend on the particular system studied. Salinity effects may depend on sorbent-to-solution mass ratios used in equilibration experiments, and could arise from both the ionic and the hydrophobic components of the TBT molecule.
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- Sorption Behavior of Tributyltin
M. A. Unger
R. J. Huggett
W. G. MacIntyre
- Springer Netherlands
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