Fungi have been shown to play an important role in the bioremediation of contaminated water and soils. The biosorption potential of a fungus, Penicillium notatum for chromium and copper ions in aqueous solution of their salts was investigated in this study. The effects of various parameters on the biosorption process were evaluated. These parameters which include biosorbent dose, solution pH, contact time and initial metal ion concentration were evaluated. The study showed that the maximum removal efficiency for chromium ions was recorded at pH 5 while that for copper was attained at pH 9. There was also an increase in biosorptive amount with increase in initial metal ion concentration for both ions. The equilibrium data for copper fitted better to the Langmuir isotherm compared to the Freundlich isotherm while that of chromium had a better fit for Freundlich isotherm compared to the Langmuir model. The maximum biosorption capacity, Qo, for chromium and copper obtained from the Langmuir plots are 23.15 and 4.02 (mg/g) respectively. This shows that Penicillium notatum biomass has the ability to remove these metal ions from contaminated waters under suitable conditions.
The objective of this investigation was to study the biosorption of Cd (II) onto Aspergillus fumigatus immobilized in calcium alginate and to determine the isotherms and kinetics of the adsorption reaction. The parameters investigated were effect of initial solution pH, contact time and initial metal ion concentration. The results showed that the removal efficiency increased with an increase in pH. The maximum Cd (II) biosorption of 96.39 % was achieved at pH of 8.0, contact time of 120 minutes and initial Cd (II) concentration of 2 mg/L. The values of the coefficient of determination R2 for the Langmuir and Freundlich isotherms (0.9856 and 0.9548 respectively) showed that the experimental data fitted the Langmuir better than the Freundlich isotherm. The maximum biosorption capacity Qo was 3.86 mgg-1. The kinetic plots also showed that the pseudo – second order kinetics was the rate – controlling step. These results show that the investigated biosorbent is a good low cost adsorbent for the removal of Cd (II) from wastewaters. Key words: Biosorption, Aspergillus fumigatus, Alginate, Isotherm, Langmuir, Freundlich
The objective of this study was to investigate the biosorption of Cu (II) and Ni (II) ions from aqueous solution by calcium alginate beads. The effects of solution pH, contact time and initial metal ion concentration were evaluated. The results showed that maximum Cu (II) removal (93.10%) occurred at pH of 9.0, contact time of 120 minutes and initial ion concentration of 10 mg/L while that of Ni (II) was 94.6%, which was achieved at pH of 8.0, contact time of 120 minutes and initial ion concentration of 10 mg/L. The equilibrium data fitted well to the Langmuir Isotherm indicating that the process is a monolayer adsorption. The coefficients of determination, R2, values for the Langmuir Isotherm were 0.9799 and 0.9822 respectively for Cu (II) and Ni (II) ions. The values of the maximum biosorption capacity, Qo, were 10.79 and 6.25 mgg-1 respectively. The kinetic data also revealed that the sorption process could best be described by the pseudo – second order kinetic model. The R2 values for the pseudo – second order kinetic plots for Cu (II) and Ni (II) were 0.9988 and 0.9969 respectively. These values were higher than those for the pseudo – first order plots. The values of the biosorption capacity qe obtained from the pseudo – second order plots were very close to the experimental values of qe indicating that the biosorption process follows the second order kinetics. This study has therefore shown that calcium alginate beads can be used for the removal of Cu (II) and Ni (II) ions from wastewaters.
Keywords: Keywords: Adsorption, Calcium alginate, Isotherm, Langmuir, Pseudo- first order, Pseudo-second order
The objective of this investigation was to study the biosorption of Cd (II) from aqueous solution onto Penicillium sp immobilized in calcium alginate and to determine the isotherms and kinetics of the adsorption process. The capacity for Cd (II) biosorption was investigated as a function of pH, adsorbent dose, contact time and initial metal ion concentration. The results showed that the removal efficiency increased with increase in adsorbent dosage and solution pH. For adsorbent dosage, the highest removal efficiency was 93.45% (adsorbent dosage of 200 mg). In terms of pH, the highest removal percentage was 89.75% at pH of 9.0 and Cd (II) ion concentration of 2 mg/L. The experimental data fitted the Freundlich isotherm better than the Langmuir isotherm. Their R2 values were 0.9852 and 0.8053 respectively. The calculated maximum biosorption capacity Qo was 7.12 mg g-1. The values of R2 for the pseudo – first and pseudo – second order kinetics are 0.9007 and 0.9960 respectively. The experimental value of qe, the biosorption capacity at equilibrium, for the pseudo second order model was closer to the theoretical value than that of the pseudo – first order indicating that chemisorption is the probable mechanism of the process. These results show that the investigated biosorbent is a good low cost adsorbent for the removal of Cd (II) from wastewaters.
The objective of this study was to investigate the biosorption of Zn (II) from aqueous solution by Aspergillus fumigatus immobilized in calcium alginate. The effects of adsorbent dosage, initial solution pH, contact time and initial Zn (II) concentrations were investigated. Results were fitted to the Langmuir isotherm. The results showed an increase in biosorption efficiency with increase in biosorbent dosage. The optimum pH of adsorption was 5.0 while the maximum adsorption was achieved within 10 minutes at initial Zn (II) concentration of 1 mg/L. The experimental results showed a high R2 (0.9070) value for the Langmuir isotherm. This therefore suggests that it is a monolayer adsorption. The maximum biosorption capacity was 3.55 mgg-1. These results indicate that zinc metal removal by biomass of Aspergillus fumigatus immobilized in alginate is a low cost wastewater treatment option and can be effectively used in small scale treatment plants.Keywords: Biosorption, Aspergillus fumigatus, Adsorbent, Alginate, Isotherm, Langmuir
