Application of Live, Dead and Dried Biomasses of Aspergillus Versicolor for Cadmium Biotreatment

Various industries produce and discharge wastes containing different heavy metals into the environment. Apart from using living biomass, dead and dried biomasses have been introduced as a new field of biotreatment technology.
The cadmium (Cd) (II) removal characteristics of live (growing), dead (autoclaved), and oven-dried biomasses of Aspergillus versicolor were examined as a function of initial pH, contact time, and initial Cd concentration.
Maximum bioaccumulation of Cd for live biomass [11.63 (mg g−¹)] occurred at an optimal pH of 4 and incubation time of 4 days. Themaximum biosorption of 27.56 (mg g−¹) for dead biomass occurred at 1.5 h and at a pH of 4. The maximum biosorption [18.08 (mg g−¹)] with dried biomass was reached at an equilibrium time of 3 h at a pH of 6.
The present study confirmed that heat treatment promoted the removal capacity of fungi. Cd removal was increased by decreasing the pH in live and dead-mode experiments. Inversely, Cd removal was increased with increasing pH for the dried biomass of A. versicolor. Varying responses to environmental conditions (pH and contact time) clearly proved the different removal mechanisms used by three biomasses of A. versicolor. Higher Cd concentration increased the removal ability of three types of biomasses. The results indicated that all biomasses of A. versicolor used in this study, particularly dead biomass, are a suitable biosorbent for the removal of Cd (II) ions from aqueous solution.