Structural characterization of acid and alkali treated-corncob waste: a potential resources biosorbent

Abstract

Corncob is an agricultural scrap obtained in bulk quantities during the production of corn. This agriculture waste is a potential resource to act as a biosorbent for the removal of heavy metals. Therefore, the objective of this study is to highlight a structural and surface characterization of raw corncob, H3PO4-pretreated corncob, and KOH-pretreated corncob since modification of raw corncob with different methods may change the surface area and also the electrical nature and surface functional groups of corncob, the removal capability of corncob as adsorbent could also be affected. The biomass samples were characterized via Fourier transform infrared spectroscopy (FTIR) and Brunauer–Emmett–Teller (BET) analysis. The FTIR result shows that the major functional groups of corncob such as –OH, C–O, C–H, and C=C experienced a slight shift due to the presence of KOH and H3PO4. Treatments with KOH and H3PO4 improved the BET surface area with the values of 8.8920 and 6.7894 m2/g, respectively, compared with raw corncob (0.5011 m2/g). The results indicate that the pretreatment of corncob influenced the functional groups and surface area of the raw corncob. Improved surface area may increase the ability of the corncob as adsorbent in heavy metals removal.