The effect of pH on the sorption of Pb
2+ and Cu
2+ ion onto
Nypa fruticans Wurmb
biomass
was investigated. Initial pH value of 2, 5, 7, 9, and 12 were used for this study with varying initial
concentrations of metal ions. The experimental results were analyzed in terms of Langmuir, Freundlich and
Flory-Huggins isotherms. The data showed that the maximum pH (pH
max) for the efficient sorption of Pb
2+
and Cu
2+ is 5.0. Evaluation using the Langmuir equation gave the monolayer sorption capacity as 91.0mg/g
for Pb
2+ and about 61.0mg/g for Cu
2+. The sorption of Pb
2+ and Cu
2+ ion is pH dependent and the data
showed that Nypa
fruticans wurmb biomass is a successful biosorbent for treating heavy metal contaminated
wastewater. The thermodynamic assessment of the metal ions on Nypa
fruticans wurmb gave negative ΔG0
values, which confirms the feasibility of the process and the spontaneous nature of the sorption.
