Use of Citrus grandis (L.) Osbeck (Fam. Rutaceae) Peels Waste Material as a Biosorbent for Lead Contaminated WaterUse of Citrus grandis (L.) Osbeck (Fam. Rutaceae) Peels Waste Material as a Biosorbent for Lead Contaminated Water

The ability of pomelo peels to remove lead (Pb2+) from contaminated water and how factors such as pH, contact time and initial lead concentration affect this phenomenon was investigated. Biosorption studies were carried out by batch process. Biomass was added to conical flasks containing a known amount of metal solution of desired concentration. The mixture was agitated for 3 hours, time more than sufficient to reach equilibrium. The pH of the solutions were adjusted by adding 0.1 N NaOH or 0.1N HNO3. The biomass was then removed by filtration using a vacuum filter (pore size of 45 μm) and the filtrates were analyzed for residual lead concentration by atomic absorption spectrophotometry. The results showed that biosorption was found to be optimum at pH 4. Kinetics data exhibited that biosorption followed the pseudo-second order model. Biosorption was rapid within the first 30 minutes of contact, eventually reaching equilibrium after 90 minutes. Isotherm experiments were better described by the Freundlich model than the Langmuir model.The study indicates that pomelo peels are effective low cost biosorbent for lead-contaminated water and is of potential for remediation of heavy metal contamination.