Removal of Heavy Metals from Aqueous Solution Using Oil Palm Biomass

This research intends to investigate the performance of oil palm biomass as biosorbent to different metals from aqueous solution with different parameters. The influence of physic-chemical parameters such as pH and metal ion concentration towards percentage of heavy metal removal were investigated. Behaviour of biosorption in mixed metal ion system and desorption of metal ion from oil palm biomass were also studied to research the feasibility of oil palm biomass to be used as biosorbent. In order to understand the metal-binding capacity and compare the performance of biosorbents as a function of aforesaid parameters, biosorption isotherm models such as Langmuir, Freundlich and Dubinin-Radushkevich were used. The results showed that equilibrium data of Cu and Pb fitted well to all isotherm models except for Zn metal ion. The percentage removal of metal ions is strongly affected by pH of metal ions concentration. The adsorption capacity increase sharply at pH values 6.0 to 7.0 while the pH values below 3.0 inhibit the biosorption of metal ions. The maximum adsorption uptake was found at 31.11 mg/g at pH 7.0. The uptake capacity, qₑ of Cu and Pb was increased at 50 mg/L to 200 mg/L, while uptake capacity of Zn is increase at 50 mg/L to 150 mg/L. The results of this study indicate that oil palm biomass is suitable biomass for removal of Cu, Zn and Pb metal ion from aqueous solution.
Key words: Oil palm root biomass, biosorption isotherm models, Langmuir, Freundlich, Dubinin-Radushkevich, desorption, biosorption, metal-binding capacity.