Capacity of Isolates of Six Genera of Filamentous Fungi to Remove Lead, Nickel and Cadmium from Refinery Effluent

Abstract

Laboratory experiments were carried out to determine the capacity of isolates of six genera of filamentous fungi to remove Lead (Pb), Nickel (Ni), and Cadmium (Cd) from broth cultures charged with raw refinery effluents. The concentrations of the three metals in the raw refinery effluents and tissues of the test fungi were determined both before and after the mycoremediation studies using Atomic Absorption Spectrophotometer (AA240FS). Both the percentage removal as well as the potential of the test isolates to bioaccumulate the metals in their tissues were calculated following standard procedures. It was observed that, the six isolates tested could remove from 36 to 64% of Pb, 30 to 58% of Ni and 0 to 50% of Cd. Trichoderma sp proved to be the most efficient in the removal of the three metals while Nigrospora sp and Chaetophoma sp were consistently the least efficient . It was also noted that, Trichoderma sp and Microsporum sp had the highest potential to bioaccumulation the metals than the other fungal species tested. It was therefore concluded that, Trichoderma sp, and Microsporum sp could be employed in the removal of Pb, Ni and Cd from heavy metal polluted effluents generated by petroleum refineries and other petro-chemical industries.

Keywords: Refinery effluents, Heavy metals, Pollution, Fungi, Mycoremediation, Biosorption, Bioaccumulation