There is few data in the literature on Eisenia fetida bimass concentrations of such elements as phosphorus, abundant in municipal sewage sludge or sodium which in considerable amounts is found in tannery sludge. The paper aimed to determine the contents of selected elements (Ca, Mg, Na, K, P and Cr) in Eisenia fetida redworm kept in sewage sludge composts. The studied composts were characterised by diversified contents of the analysed elements. Their concentrations in the redworm biomass depended on their contents in composts. Bigger concentrations of calcium, sodium and chromium in the redworm biomass were found in specimens feeding in composts with added tannery sludge. Redworm originating from composts prepared from municipal sludge contained more phosphorus. Magnesium and potassium contents in the redworm biomass from different composts were comparable, which resulted from their similar contents in composts.

3-9