Acid modification of lignocellulosic derived material for dye and heavy metals removal: A review

Abstract

Researchers have tested Lignocellulose derived material (LDMs) from different sources ranging from agricultural to wood in order to facilitate the adsorption of chemical contaminants, such as heavy metals and dyes from water bodies, to eradicate water contamination. However, different methods have been employed to modify the nature of the LDMs to enable their suitability for contaminants removal. Among all these methods, acid modification of LDMs has gained a lot of attention. This review focused on the use of acid modification LDMs for the removal of anionic and cationic dyes, and heavy metals in water. The characteracerization techniques employed in studying the morphology and functional groups of the LDMs were discussed. The adsorption dynamics and mechanisms of reported studies were extensively summarized. The reported adsorption capacity of unmodified LDMs in the available liturature is in the range of 4.44–156.00 mg/g while for the modified is between 80.05–250.01 mg/g for dye removal. The adsorption capacity of modified LDMs reported was 1.60–18.03 times higher than the unmodified because of additional functional groups such as -SO3 from sulphuric acid modification. Finally, the future outlook and challenges of this method were pulled together.