title: Adsorption of toxic carbamate pesticide oxamyl from liquid phase by newly synthesized and characterized graphene quantum dots nanomaterials.
abstract: Graphene quantum dots have been synthesized using the microwave-assisted hydrothermal route. The surface textural and morphological structure of synthesized adsorbent i.e. graphene quantum dots was analyzed using various analytical techniques such as X-ray diffraction, Transmission electron Microscopy, Atomic Force Microscopy and N2 adsorption-desorption instrumental techniques. The application of graphene quantum dots as an adsorbent for the removal of noxious pesticide compound i.e. oxamyl from aqueous solutions was well investigated and elucidated. The impact of several effective parameters such as effect of agitation speed, pH, adsorbent dose, contact time, temperature and initial concentration on sorption efficiency was studied and optimized using batch adsorption experiments. The optimized pH for maximum oxamyl adsorption was found to be 8.0 and for the maximum adsorption rates the adsorbent dose of 0.6g was found to be optimum to carry out the adsorption with in less than 25min of contact time. From the results obtained, it is clear that for all contact times, an increase in oxamyl concentration resulted in increase in the percent oxamyl removal. The adsorption equilibrium and kinetic data were well fitted and found to be in good agreement with the Langmuir isotherm and pseudo-second-order kinetic model.
authors.affiliation: Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa.
authors.forename: Shilpi
authors.initials: S
authors.lastname: Agarwal
authors.affiliation: Department of Environmental Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Nima
authors.initials: N
authors.lastname: Sadeghi
authors.affiliation: Department of Chemistry, Indian Institute of Technology Roorkee, 247667, India.
authors.forename: Inderjeet
authors.initials: I
authors.lastname: Tyagi
authors.affiliation: Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa; Department of Chemistry, Indian Institute of Technology Roorkee, 247667, India. Electronic address: vinodfcy@iitr.ac.in.
authors.forename: Vinod Kumar
authors.initials: VK
authors.lastname: Gupta
authors.affiliation: Young Researchers and Elites Club, Science and Research Branch, Islamic Azad University, Tehran, Iran. Electronic address: ali.fakhri88@yahoo.com.
authors.forename: Ali
authors.initials: A
authors.lastname: Fakhri
keywords: Adsorption; Isotherms; Kinetic models; Oxamyl; Thermodynamic study