Removal of Reactive Dyes from a Real Bichromatic Textile Effluent Employing Bio-Based Nanomagnetic Adsorbents

Effluents containing reactive dyes are globally generated in significant quantities as result of dyeing process applied to cellulosic fibers, frequently exhibiting elevates levels of dyes and inorganic salts. These textile effluents pose a substantial environmental concern due to their potential to induce eutrophication, impede photosynthesis, and even possess carcinogenic proprieties. This research endeavor aimed to address the treatment of intricate bichromatic effluents derived from an industrial dyeing process, which encompassed reactive dyes such as blue 19 (B-19), red 198 (R-198), and yellow 15 (Y-15) using two bio-based adsorbents: (1) yeast waste obtained from the ethanol industry after β-glucan removal from yeast biomass (YW), and (2) a nanomagnetic composite produced with YW and magnetite nanoparticles (YW-MNP). The concentrations of dyes in each binary mixture were quantified through the utilization of UV–Vis spectrophotometry and multivariate calibration, both prior and following the adsorption process. To evaluated the predictive capability partial least squares (PLS) and multivariate linear regression with variable selection via a successive projection algorithm (SPA-MLR), were employed, with PLS demonstrating the best predictive capacity. Langmuir isotherms yielded the best fit for YW and YW-MNP, respectively. Generally, YW exhibited higher dye removal compared to YW-MNP, attaining a maximum of 32% dye removal for bichromatic effluents under the physical–chemical conditions characteristic of effluent production. Graphical abstract