Title
Extraction and characterization of α-cellulose-rich residue from maize (Zea mays L.) husk
Authors
ALICHO JAMES, MODISE SEKOMENG JOHANNES, MTUNZI FAKS FANYANA, FRANCIS OJO and OKOLI JOSEPH BAMIDELE

Received June 7, 2023
Published Volume 57 Issue 9-10 September-December
Keywords Zea mays husk, cellulose, hydrolysis, lignin, hemicelluloses, characterization

Abstract
Agricultural waste leads to a number of environmental issues, including pollution and environmental degradation. In Nigeria, Zea mays husk is one of the most prevalent agricultural wastes, and it can be turned into a valuable resource of quality cellulose. The goal of this study was to establish a low-cost and sustainable chemical treatment method for isolating cellulose from Z. mays husk feedstock. A series of alkaline delignification, digesting, and bleaching techniques were used to extract and purify cellulose. TAPPI T203 OS-74, TAPPI T222 OS-83 and TAPPI T222 OM 02 methods were used to determine the cellulose, hemicellulose and lignin contents, respectively. The samples were also characterised by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), and CHNS/O analyses. The resulting product was found to contain 97.95% α-cellulose, 0.19% β-cellulose, and 1.86% γ-cellulose. The presence of 40.95% carbon, 2.98% hydrogen, 0.72% nitrogen, 0.07% sulphur, and 55.28% oxygen was found by the CHNS/O analysis of cellulose. The untreated husk microscopy displayed an uneven, flake-like, and non uniform surface, whereas the delignified husk, digested husk, and pure cellulose (ZMH-C) micrographs revealed, respectively, a smooth non-uniform surface, an irregular porous surface, and a smooth wool-like surface. The FTIR spectra of the treated samples demonstrated an increase in the intensity of the polar property of the OH group, as well as the elimination of the hemiacetal group and β-1,4-glycosidic linkages. The ZMH-C diffractogram verified the existence of characteristic 2θ peaks of cellulose at 220, 240, and 300, as well as a 4.7% crystallinity index. The comparatively low-temperature sequential alkaline delignification, digesting, and bleaching method adopted extracted low-lignin crystalline cellulose material from Z. mays husk. The flexibility, biodegradability, and availability of husk make it a viable source of high-quality cellulose with several possible applications. Z. mays cellulose has been thus demonstrated to be an appealing material for a wide variety of industries seeking environmentally acceptable and sustainable solutions.