Heavy Metals Bioaccumulation by Iranian and Australian Earthworms (Eisenia fetida) in the Sewage Sludge Vermicomposting

Vermicomposting of organic waste has an important part to play in an integrated waste management strategy.in this study, the possibility of heavy metals accumulation with two groups of iranian and australianearthworms in sewage sludge vermicompost was investigated. eisenia fetida was the species of earthwormsused in the vermicomposting process. the bioaccumulation of cr, cd, pb, cu, and zn as heavy metals byiranian and australian earthworms was studied. the results indicated that heavy metals concentrationdecreased with increasing vermicomposting time. comparison of the two groups of earthworms showed thatthe iranian earthworms consumed higher quantities of micronutrients such as cu and zn comparing with theaustralian earthworms, while the bioaccumulation of non-essential elements such as cr, cd, and pb by theaustralian group was higher. the significant decrease in heavy metal concentrations in the finalvermicompost indicated the capability of both iranian and australian e.fetida species in accumulating heavymetals in their body tissues.