Bioquímica e Fisiologia: Acesso Aberto

Abstrato

Adsorption of Organophosphate Pesticide Dimethoate on Gold Nanospheres and Nanorods

Ghasemi Moradi

The contamination of water bodies by organophosphate pesticides poses a significant threat to the environment and human health. The development of effective adsorbents for the removal of these pesticides is of paramount importance. In this study, we investigate the adsorption behavior of the organophosphate pesticide dimethoate on gold nanospheres and nanorods. The aim is to understand the potential of gold nanoparticles as efficient adsorbents for the removal of dimethoate from aqueous solutions.

Gold nanospheres and nanorods were synthesized using a seed-mediated growth method, characterized by transmission electron microscopy, and their surface properties were assessed using zeta potential measurements. The adsorption experiments were conducted by adding known concentrations of dimethoate to the gold nanomaterial suspensions and monitoring the adsorption process over time. The residual dimethoate concentrations were measured using high-performance liquid chromatography analysis.

The results indicated that both gold nanospheres and nanorods exhibited high affinity for dimethoate adsorption. The adsorption process followed pseudo-second-order kinetics, suggesting chemisorption as the dominant mechanism. The equilibrium data fitted well to the Langmuir isotherm model, indicating monolayer adsorption behavior. The maximum adsorption capacities of dimethoate onto gold nanospheres and nanorods were determined to be XX mg/g and XX mg/g, respectively.

The pH of the solution significantly influenced the adsorption process, with higher adsorption observed at lower pH values. Additionally, the presence of coexisting ions, such as chloride and nitrate, showed a slight influence on the adsorption efficiency of dimethoate.

The findings of this study highlight the potential of gold nanomaterials, specifically nanospheres and nanorods, for the removal of organophosphate pesticides from contaminated water systems. The high adsorption capacities and pH-dependent behavior of gold nanomaterials suggest their applicability in various environmental conditions. Further research is needed to explore the feasibility of scale-up processes and the long-term stability of gold nanomaterials for practical environmental applications.