Design and Modeling of a Biotechnological Nanofiltration Module Using Bacterial Cellulose Membranes for the Separation of Oily Mixtures

Abstract

The environmental impacts of the exploration and use of petroleum and derivatives in recent decades have led to increasing interest in novel materials and processes for the treatment of oily effluents. Oily emulsions are difficult to manage and, in some cases, require different types of treatment or combined methods for phase separation. Sustainable, versatile, innovative biomaterials, such as bacterial cellulose (BC), have considerable applicability potential in mixture separation methods. In the present study, a cellulose membrane produced by a symbiotic culture of bacteria and yeasts (SCOBY) was investigated with the aim of measuring the characteristics that would enable its use in the treatment of oily wastewater. BC was analyzed through physicochemical characterizations, which demonstrated its porosity (>75%), chemical structure with high cellulose content and a large quantity of intramolecular H bonds, good thermal stability with maximum degradation at temperatures close to 300 °C, high crystallinity (66%), nanofibrils of approximately 84 nm in diameter and mechanical properties that demonstrated tensile strength of up to 65.53 Mpa, stretching of approximately 18.91% and the capacity to support a compression load of around 5 kN with only the loss of free water in its structure. The characteristic data of the membranes were used for the production of a filtering module for oily mixture separation processes. This support was developed with computational fluid dynamics of finite volumes and finite element structural analysis using advanced computer-assisted engineering tools. Lastly, the conceptual, basic project of a low-cost nanofiltration module was obtained; this module could be expanded to the industrial scale, operating with several modules in parallel.