In vitro removal of electronic and electrical wastes by fungi isolated from soil At Annaba area in northeast of Algeria

Abstract

Electronic and electrical wastes (EEW) have increased exponentially in recent years due to technological progress. The uncontrolled incineration of these wastes causes pollution of air, soil, and water that has dangerous effects on health of human beings and other living organisms. This work isolated fungi that are capable of degrading some of these electroni c wastes. In this study, fungi isolated from soil polluted by EEW were grown on potatoes dextrose agar (PDA) medium. The estimation of the biodegradation was achieved by inoculation of both rechargeable batteries and printed circuit boards on a minimum solid and liquid medium with selected fungal strains. During the process of biodegradation on solid medium, microscopic observation was done, and on liquid medium the production of keratinolytic enzymes was evaluated using a colorimetric method after incubation with keratine powder. After 30 days, the obtained results showed that Geotrichum candidum is capable of degrading battery and circuit boards with rates of 23% and 71%, respectively, while Rhizopus stolonifer reduced battery weight by 7% and printed circuit boards by 60%. Microscopic observations showed no morphological modification in Geotrichum candidum, while there was sporocyst formation in Rhizopus stolonifer. The detection of enzymatic production indicated that there is a relation between the biodegradation process of electronic wastes and keratinolytic enzymes in Geotrichum candidum.