Cu and Zn accumulation in earthworm Lumbricus terrestris L. in sewage sludge amended soil and fractions of Cu and Zn in casts and surrounding soil

In this study, the bioaccumulation of Cu and Zn by the earthworm Lumbricus terrestris L. and Cu and Zn fractions in casts and surrounding soil of soil amended with different doses of sewage sludge have been explored. The total and fractions of Cu and Zn contents were increased by sewage sludge amendments at all doses. Thirty days after sewage sludge amendment, the soil. cast, and earthworm bodies receiving the highest dose (400 g kg(-1)) showed significantly higher Cu and Zn content than the non-amended soil. In particular exchangeable (EX)-Zn and organically complexed (OM)-Cu contents of casts and surrounding soil were hi-her than the other fractions at all sewage sludge amended soils. (C) 2004 Elsevier B.V. All rights reserved.