Efficacy of Single-Walled Carbon Nanotubes and Titanium Dioxide Nanoparticles as Remediators of the Aquatic Environment from Pendimethalin Residues

Abstract

Pesticides are useful in increasing the quantity and quality of agricultural products. However, over-application or misuse would accumulate their residues in the environments, which might pose threats to non-target organisms and humans. Therefore, this study investigated the sorption of herbicide, pendimethalin (PD) onto titanium dioxide nanoparticles (TiO2 NPs) and single-walled carbon nanotubes (SWCNTs) surfaces in aqueous solutions. Several experiments were conducted to study the contact time of the nanoparticles with different concentrations of PD under laboratory conditions. The experiments were done at 25 ºC and pH values 7.0. Sorption results were then fitted using Langmuir and Freundlich isotherm models. Quantities of 0.5 to 2.5 µg/ml of TiO2 NPs and 50.0 µg/ml of SWCNTs exhibited 100.0% and 99.8% removal of PD, respectively. Small amounts of PD (0.5-2.5 µg/ml) were completely removed (100%) by TiO2NPs and SWCNTs particles. Isotherms displayed adsorption capacities of 1.850 and 2.304 µg/g for TiO2NPs and SWCNTs, respectively, which highlight the elevated potential of cleaning the environment from pendimethalin residues.