Capacidad de adsorción de diuron en medio acuoso utilizando carbón activado obtenido de la cáscara de coco

Abstract

The objective of this study was to remove diuron in an aqueous medium using activated charcoal. The adsorbent was obtained by chemical activation with phosphoric acid. The surface area was determined using an iodine value, surface groups were identified with the help of an infrared spectrophotometer, the adsorption tests were carried out with three levels of temperature, pH and dose of adsorbent; the residual diuron concentration was determined using a UV-VIS spectrophotometer at a wavelength of 245 nm. The iodine index was 637.85 mg I2 /g which complies with the provisions of the INEN standard, which indicates that it has a good surface area, has an acid character due to the presence of carboxylic groups, acid anhydrides, lactones. Through adsorption tests it was determined that the highest amount of adsorption is obtained at 35 °C at pH 5 with 0.166 g of activated carbon for 120 minutes, removing more than 98% of the herbicide. The adsorption of diuron in an aqueous medium on activated carbon is efficient, having a removal capacity greater than 5 mg / g. It is recommended to use activated charcoal from coconut shells in the study of the adsorption of other phenyl urea herbicides.