Biosorption potentials of activated carbons from pentaclethra Macrophylla (PMAC) seed shells for the
removal of Pb(II) from aqueous solution were investigated. The physicochemical properties of pentaclethra Macrophylla (PMAC) seed shells were characterized through ASTM standards for adsorbents tests. The functional groups of the pentaclethra Macrophylla (PMAC) were investigated using Fourier transform infrared (FTIR) spectroscopy, morphology measured with scanning electron microscopy (SEM),oxides investigated by X-ray fluorescence (XRF) and diffraction pattern observed by x-ray diffraction (XRD). Influence of key parameters such as contact time, pH of Pb(II) solution, temperature of Pb(II) solution, adsorbent dosage, adsorbent particle size and initial concentration of Pb(II)solution were studied by batch mode. These process parameters were optimized using response surface methodology (RSM) and analysis of variance (ANOVA). The significance of the different process parameters and their combined effects on the adsorption efficiency were established through a full factorial central composite design. The results obtained are in good agreement with published data for other activated carbons as well as various international standards for water treatment.
An optimal yield of 94.83% was obtained with optimal conditions of solution temperature, 30oC; contact time, 120minutes; adsorbent dosage, 1.50 g; and pH, 7. The optimization was performed using the numerical method of the Design Expert version 8.7.1.0 by State Ease U.S.A. This investigation has shown that Pentaclethra Macrophylla (PMAC) seed shells from Nigeria can be used for industries as activated carbon for waste water treatment.