FTIR and kinetic modelling of fungal biosorbent Trichoderma asperellum for the removal of Pb(II), Cu(ii), Zn(II) and Cd(II) from multi-metal solutions

Metal biosorption potential of Pb(II), Cu(II), Zn(II) and Cd(II) by Trichoderma asperellum in multi-metal solutions was compared against single-metal solutions to mimic occurrence in natural wastewater. Significantly lower metal removal was observed in multi-metal solutions compared to single-metal solutions. Antagonistic metal interaction may have led to poor metal removal in multi-metal solution (equilibrium achieved after 360 min) although biosorption occurred more rapidly in single-metal solution (equilibrium detected as early as 120 min). Preference for metals was consistent in both metal solutions, preferring Pb(II) > Cu(II) > Zn(II) ≥ Cd(II), albeit lower levels removed in multi-metal solutions. Binding of metals involved functional groups such as amino (–NH₂), carbonyl (C=O) and sulphur (–S) discovered from ATR-FTIR analysis. Metal biosorption by T. asperellum in both metal solutions was mainly via a rate-limiting chemisorption, with compliance to pseudo-second order kinetic.