Using Sorghum Waste and Biomass Components to Remove Pollutants from Aquatic Environments (a Literature Review)

The review briefly summarizes literature information on the use of sorghum biomass components (stems, leaves, roots) and waste (husks, bagasse) as sorption materials to remove the ions of various metals (As(V), Cd2+, Cr(III), Cr(VI), Cu2+, Fe3+, Mn(II), Ni2+, Pb2+, Tl+, Zn2+), dyes and other organic compounds from aqueous media. Brief information is provided on how sorghum biomass components and waste are used in various industries. The review presents the parameters of the above pollutants' adsorption process by sorghum biomass components and waste. It is shown that treating the latter with various chemicals improves their sorption characteristics for various pollutants. It was found that adsorption isotherms are described by various models, most often by those of Langmuir and Freundlich. In most cases, the process kinetics follows the pseudo-second-order model. It has also been shown that sorghum biomass components and waste are good precursors for activated carbons and carbonized production, which are also used to remove organic and inorganic pollutants from aquatic environments.