Filtragem de águas residuais de lavanderia por adsorção de surfactante aniônico em óxido de grafite

Abstract

Laundry wastewater when discharged directly into water bodies is an environmental problem due to the high load of pollutants where surfactant compounds that are difficult to treat by conventional processes stand out. In this work, we developed a process for treating wastewater from laundry with four stages of filtration: acrylic wool, cationic resin, granular activated carbon (GAC) and the graphite oxide (GO) synthesized by the Hummer method for adsorption retention of surfactant compounds. The applicability of GO to adsorption of anionic surfactant was evaluated by adsorption kinetics and physicochemical characterization, before and after adsorption, using sensitive techniques such as XRD, SEM, AFM, Raman spectroscopy and MIR-FTIR. The results showed that the adsorption kinetics of was well represented by the pseudo-second order model, with 𝑞𝑒,𝑐𝑎𝑙𝑐 (238.09 mg g-1) close to 𝑞𝑒,𝑒𝑥𝑝 (227.96 mg g-1) and suggest that a pre-filtering decrease competition for adsorption sites. The global filtration process reduced the pollutant load in terms of pH (24±2%), conductivity (23±5%), turbidity (69±26%), total solids (28±12%) and surfactants (93±3%) A highlight is given to the fourth stage with GO where removal of 78±11% anionic surfactants. This result is promising because anionic surfactants are the main pollutants in the wastewater of the laundry