EQUILIBRIUM MODELING OF Cu (II) BIOSORPTION ONTO UNTREATED AND TREATED FOREST MACRO-FUNGUS FOMES FASCIATUS
Discharge of heavy metal laden wastewaters into the aquatic environment continues to inspire research into the development of low-cost treatment technologies. The identification of low-cost biosorbents and their subsequent optimization particularly through surface modification has been reported to improve the efficiency of biosorption process. This study investigates the biosorptive performance of treated and untreated forest macro-fungus Fomes fasciatus for the uptake of Cu (II) ions (a model cation) from aqueous solution. Batch equilibrium experiments at room temperature were conducted to assess removal as a function of solution concentration and biosorbent mass. An improvement of 17.5 per cent increase in sorption capacity as well as an accompanying increase in affinity was observed as a result of hot-alkali treatment of the biosorbent. Primary equilibrium data was analyzed by linear and non-linear regression using the Langmuir and Freundlich two-parameter models as well as the Redlich-Peterson and Sips threeparameter models. The goodness of fit was assessed using the coefficient of determination, r2, the Relative Percent Error, RPE, Marquardt’s Percent Standard Deviation, MPSD and Hybrid Error Function, HYBRID. The two-parameter Langmuir model exhibited a high correlation to the experimental data and was successful in providing some insight into the biosorptive process. The three-parameter models produced the highest correlation to the equilibrium data, sufficient to enable the future development of predictive models.