CARBARYL REMOVAL FROM WATER USING A LAYERED DOUBLE HYDROXIDE MODIFIED WITH A NATURAL SURFACTANT

Abstract

Carbaryl is a widely used insecticide in the agricultural industry worldwide. Accumulation of this compound in the environment poses serious risks to both human health and ecosystems, particularly by impacting essential pollinators such as bees. The adsorption of carbaryl onto layered double hydroxides (LDH) has not been previously studied. In this work, a surfactant-modified LDH was synthesized via the co-precipitation method and evaluated as an adsorbent for carbaryl removal from water. The material, denoted as CaAl-PS-HDL, contains Ca and Al in the main layers, with sodium palmitate (PS) as the interlayer anion. This combination of cations and a natural, food-grade surfactant minimizes toxicity risks associated with the adsorbent. The aim of this work was to characterize the material using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FT-IR). As well as to evaluate its adsorption capacity for carbaryl and the effects of contact time, initial pesticide concentration, adsorbent dose, pH, and temperature on the adsorption process. A significant increase in the LDH basal spacing was observed after modification with PS. The adsorption capacity of CaAl-PS-LDH was significantly higher than that of the unmodified inorganic LDH, involving both hydrophobic and polar interactions between the contaminant and the adsorbent. Comparison with other clay- and mineral-type adsorbents indicates that CaAl-PS-LDH is suitable for potential application in the treatment of pesticide-contaminated water.