Regime de adsorção de corantes em HDL via simulação molecular

Abstract

Industrial wastewater that has high levels of dyes could cause several damage to the environment when discharged without previous treatment. To illustrate that, activated carbon is used as an adsorbent in industrial waste treatment. Nowadays, new materials have been studied to obtain new methods of wastewater treatment with lower costs and higher process efficiency. For example, Double Layered Hydroxides (DLH) are mesoporous materials that belong to the family of anionic clays. These materials have memory effect and can be regenerated for several adsorption cycles. The hydrotalcite is a DLH with a positively charged surface, therefore it is a potential adsorbent for sulfonic groups charged negatively. However, there is no predictive method to estimate the hydrotalcite’s adsorption capacity to different types of dyes. As a result, each dye must be experimentally tested to evaluate the quantity adsorbed in hydrotalcites. For a detailed understanding of the adsorption regime of these molecules on the surface of the hydrotalcite, a study by molecular simulation was done. Through Monte Carlo in the grand canonical ensemble it was possible to obtain a method to define the positioning of the molecules at the hydrotalcite surface, calculate the quantity adsorbed and the area covered by six different dye molecules.