Heavy metal retention in copper mine soil treated with mussel shells: Batch and column experiments

► Mussel shell amendment on mine soil raises pH proportionally to the shell dose used. ► Shell amendment clearly increased Cu, Cd, Ni and Zn retention in soil/shell mixtures. ► Retention decreases when increasing amounts of metal are added to un-amended soil. ► Shell amendment would favour remediation and restoration of contaminated acid soils.