High performance removal and simulation studies of diuron pesticide in water on MWCNTs

Abstract

Low-cost multi walled carbon nanotubes (MWCNTs) were made with 10.0–40.0 nm and 9.10 m2/g particle sizes and surface area, respectively. High performance removal of diuron pesticide was achieved in water on these MWCTs with optimized variables as - 100.0 μg/L diuron; 60 shacking time, 2.0 g/L MWCTs, pH 7.0 pH, and 25 °C temperature. 90.5% sorption of diuron was attained. The sorption statistics conformed Freundlich, Tempkin and Langmuir models. Diuron free energies were −11.97, −11.68, −11.65 kJ/mol. The entropy and enthalpy were −26.92 × 10−3 kJ/mol∙K and − 9.15 kJ/mol. The negative magnitude of free energy presented prompt removal of diuron on MWCNTs. The uptake was endothermic with pseudo-first order kinetics and liquid film diffusion mechanism. Supra-molecular mechanism of diuron elimination onto MWCNTs was finished by modeling readings and binding affinity and energy of diuron with MWCNTs were and 5.85 × 104 M−1, and − 6.5 kcal/mol correspondingly. The diutron-MWCNTs composite was become stable by two hydrogen bonds and sixteen hydrophobic connections. There were π-donar hydrogen bonds, π-π stacked, π-π T-shaped bonds, and π-alkyl bonds between diuron and carbon nano-tube. The binding energy of diuron with MWCNTs was 1.20 kcal/mol. These outcomes obviously shown the physical sorption of diuron.