| Popis: |
This study investigated the biosorption performance of waste yeast biomass derived from brewery for the removal of lead and nickel. Biosorption using low cost waste biomass is known to be an efficient alternative to the conventional technologies to remove heavy metals and organics from industrial effluents. In this study dried ground and protonated yeast used to investigate the removal of Lead (II) and Nickel (II) under the influence several parameters including pH, contact time, presence of co-ions, metal, and sorbent dose. The equilibrium and kinetics of the sorption process and heavy metal recovery tests were also carried out. Significant proportion of the heavy metal ion was sorbed during 5 to 10 minutes of contacting and equilibrium was reached within 60 minutes where the optimum sorption time was observed to be at 30min. Langmuir and Freundlich adsorption models were used in the equilibrium study to fit the equilibrium data after 24 hours of contacting. The kinetics of the metal uptake process was also investigated for varying metal dose in the range of 10-200mg/l and yeast dose in the range of 0.5–4 g/l. qe shows an increasing trend for increasing metals dose and is inversely related to yeast dose, similarly, k and h also showed increasing trend for increasing metal dose. Furthermore, test for ion interference effect or co-ion tests were conducted where sorption of lead decreased from 576 mg/g to 444.5 mg/g when nickel concentration was increased from 50 mg/l to 700 mg/l. Based on recovery tests, the recoverability of lead (80%) was significantly higher than that of nickel (38%). The study has proven that waste yeast industrial biomass can be used for large scale sorption applications in house or in other heavy metal waste generating industries. |
