Aplicação de carvão pulverizado e óxido de grafeno na remoção de bisfenol A da água

Abstract

The presence of bisphenol A (BPA) in natural waters causes concern, as this compound is an endocrine disruptor with potential health effects even in low concentrations. Evidence that water treatment systems are not capable of removing this compound already exists, and it generates a necessity of more efficient ways to remove it from water. The aim of this work is to apply one pulverized activated carbon (PAC) and graphene oxide (GO) to remove BPA by the adsorption process. The adsorption of BPA in PAC was evaluated using 10 mg of adsorbent and 100 mg L-1 BPA solution. PAC was also evaluated through the influence of mass (10-40 mg) and pH (2-12) over the adsorption capacity (qe) of the material, in addition to an isotherm prepared using different solution concentrations (50-175 mg L-1) of BPA. Equilibrium was reached in 120 minutes, and adsorption capacity increased with the use of 10 mg at pH 9. Adsorption in PAC was favorable, with a good fit to Langmuir model and a maximum monolayer adsorption capacity (qmax) of 364.96 mg g-1. GO was prepared in laboratory, according to Hummers method. Adsorption in GO was evaluated through a kinetic study using the same conditions applied to PAC, in addition to a study of the influence of adsorbent mass (10-40 mg) and pH (2-12) over the adsorption capacity of the material. Equilibrium was reached in 360 minutes, and the larger qe (35.50 mg g-1) was obtained with 10 mg and pH 7. Results indicate that PAC is more interesting than GO to remove BPA from water, in the conditions applied in this study, since a lower equilibrium time and a higher qmax were obtained with this material.