Comparative Characterization of Derived <i>Vignasubterranea (L.) verdc.</i> Adsorbents, Using Chemical and Steam Activation Methods

Abstract

Low-cost adsorbents were produced from Bambara nut (Vignasubterranea (L.) verdc.) shells via chemical and physical activation using phosphoric acid  and steam respectively. Acid activated Bambara nut shells (ABBNSAC) and steam activated Bambara nut shells (S-BBNSAC) were characterized using  Fourier Transform infrared (FTIR), Brunauer–Emmet–Teller (BET), Scanning electron microscope (SEM), Energy dispersive Xray (EDX), Transmission electron  microscope (TEM) and other physico-chemical properties. FTIR analysis indicated the presence of functional groups on both surfaces and the  surface morphology showed the presence of well developed pores that are uniformly distributed over the surfaces and the elemental analysis revealed  that carbon and oxygen were the major constituents in both adsorbents and the carbon contents were found to be 64.70 and 45.20 % for A-BBNSAC and  S-BBNSAC respectively while the BET surface area for A-BBNSAC and S-BBNSAC were determined to be 580.42 and 1442.67 m² /g respectively. The study  concluded that SBBNSAC could be used as adsorbent for removal of pollutants from aqueous solution.