Bacterial Nanocellulose Produced as a By-product of the Brewing Industry and Used as an Adsorbent for Synthetic Solutions of Co(II), Cu(II), Ni(II) AND Fe(III)

Abstract

An economically and environmentally viable alternative for treating waste from iron ore production in Brazil is the use of bacterial nanocellulose (BNC) as an adsorbent for the metals present in the waste composition, due to its biocompatibility and biodegradability properties. However, to reduce production costs, it is necessary to study alternative substrates, such as waste from the brewing industry, which are nutritionally rich and, therefore, excellent candidates for substrate for bacteria that produce bacterial nanocellulose. Therefore, the present work aims to statically produce BNC using waste from the brewing industry and use BNC as an adsorbent for treating waste from the mining industry. It was possible to obtain approximately 1532 mg of bacterial nanocellulose through the batch system using the hydrolyzate of residual brewing yeast at pH 7 and 5 days of incubation. When used as an adsorbent, the material obtained a maximum adsorption capacity for the metals Co (II), Ni (II), Cu (II) and Fe (III) of, respectively, 0.0739, 0.2504, 0.3945 and 0.02841 mg·g⁻¹. For the same metals, the removal rate of the synthetic solutions studied was, respectively, 62.56, 39.13, 61.64 and 24.42%. For the analysis of isotherms, the Freundlich model proved to be the most effective for describing the system. Regarding the adsorption kinetics, it was more effective in the Elovich model. This data shows that nanocellulose produced by bacteria and using agro-industrial subproducts becomes a good alternative for remediation processes in a sustainable way.