A Comparative Study of Modified Magnetic Nano-Particles Grafted to β-yclodextrin/Thermosensitive Polymer for Removal of Diazinon and Fenitrothion from Aqueous Solution

Abstract

Organophosphate pesticides such as diazinon and fenitrotion are fat-soluble, so delayed toxicity occurs if significant amounts of them are stored in adipose tissues. These insecticides have been classified by the World Health Organization (WHO) as class II, having a moderate hazard. Therefore the preparation and use of grafted β-cyclodextrin/thermo-sensitive polymer/modified Fe3O4/SiO2 nano-particles was investigated for the removal of fenitrothion and diazinon from aqueous solution. Modified MNPs were synthesized due to increase of removal efficiency and applicability in different condition. MNPs were synthesized and characterized by using FTIR, SEM, CHN, TGA, and TEM. The effect of some operational parameters, such as pH, adsorption isotherms, sorption kinetics, concentration, reusability, adsorption/desorption temperature, and ultrasound effect on desorption were examined. The results showed that the best sorption of pesticides on the MNPs-AGENVC-CD took place at 20 °C and optimum pH of 6. The initial concentration and nano-sorbent dosage were 100 mg/L and 0.01 g, respectively. The kinetic study showed that the best time for the pesticides sorption was 90 min. Also, the Pseudo-Second-Order model used fitted the adsorption kinetics well, thus exhibiting high correlation coefficients. Pesticides sorption capacity was found to be 34 and 29 mg/g. The equilibrium data of pesticides modified by the MNPs-sorbent were correctly shown by Langmuir, Freundlich, Redlich-Peterson, and Temkin models. The data was well-fitted to Langmuir equation. The findings showed that the proposed method was very impressive, providing a significant adsorption capacity, appropriate reusability and control functions along with temperature variations.

Keywords

• mnps
• diazinon
• fenitrothion
• β-cyclodextrin
• smart polymer