The influence of lignite fly ash on reproduction of species Eisenia fetida (a microcosm experiment)

Abstract

The aim of the study was to distinguish the effect of the lignite fly ash on several biological indicators of earthworms Eisenia fetida (Savigny, 1826) like reproduction parameters (prolificacy expressed through the number of cocoons, the hatching capacity) and mortality. Within the experiment was used fly ash resulted from the combustion of a solid fuel, the lignite, in a thermal power plant, in laboratory conditions. The content of heavy metal has been established for the soil of each experimental variant: zinc, copper, manganese, iron, and nickel. The earthworm mortality increased with the increase of concentration of heavy metals. The highest hatching capacity was at the lowest amount of lignite ash and at the lowest concentration of heavy metals. Generally, the hatching capacity was much inferior related to the potential of this species. There was noticed a decrease of cocoon number at higher concentrations of heavy metals. No abnormalities regarding the locomotion behaviour were noticed.