Effects of sediment organic carbon content on the elimination rates of neutral lipophilic compounds in the midge (Chironomus Riparius)

Publisher Website
Google Scholar
Abstract
The effects of varying sediment conditions on elimination rates for four neutral lipophilic compounds were investigated in midge larvae, Chironomus riparius. Four treatments were used: water only (no sediment present) (WO); midges screened from 3% organic carbon (OC) sediment (screened); water and 3% OC sediment (3% OC); and water and 15% OC sediment (15% OC). In general, elimination rates were larger in the 3 and 15% OC sediment systems compared to the WO and screened treatments. The largest elimination rates were found in the 15% OC treatments. The mechanism that accounts for increased elimination rates noted in the high‐OC‐content sediment systems is unknown; however, several possible mechanisms are discussed. A predictive relationship has been established between the elimination rate constant (Kd), the octanol/water partition coefficient (Kow), and sediment OC content. These results further emphasize the importance of sediment characteristics in determining the environmental fate of xenobiotics.