Adsorption and desorption of tributyltin in sediments of San Diego Bay and Pearl Harbor

Adsorption and desorption of butyltin compounds from sediment under simulated estuarine conditions depends upon the characteristics of the sediment including grain size distribution, percentage of organic carbon, clay mineralogy and aqueous butyltin concentration in the overlying water column. Sediments from Pearl Harbor, Hawaii, USA, primarily consisting of calcium carbonate mud and 18–28% organic carbon by weight, have generally abundant adsorption sites and display tributyltin partition coefficients (Kp) ranging from 1000 to 5000 μg kg−1 per μdm−3. Adsorption and desorption of butyltin from San Diego Bay, California, USA, sediments is linearly dependent upon the characteristics of each sediment and the range in Kp values is from approximately 20 to 2500 μg kg−1 per μg dm−3. Sandy, low‐organic carbon sediments have low Kp while fine‐grained, relatively organic‐rich sediments have high Kp values. Similarly, samples containing significant amounts of high cation exchange capacity (CEC) clay minerals have relatively higher adsorption potentials than those consisting of low CEC minerals.