Separation of organic pesticide (insecticide): lambda-cyhalothrin from wastewater using magnetic carbon nanocomposites

Abstract

In this study, a potato wastes based magnetic carbon nanocomposite (PMCNC) was synthesized and explored for its possible applications as adsorbent in removal of lambda-cyhalothrin from synthetically contaminated water. The nanocomposites were characterized through energy-dispersive X-ray, X-ray diffraction analysis, scanning electron microscopy, Fourier-transform infrared spectrophotometry, zero-point charge (pH pzc ) and thermogravimetric/differential thermal analysis. For the demonstration of adsorption efficiency of the nanocomposite, batch adsorption experiments were carried out. Maximum removal of selected pollutant was achieved in 30 min. Several kinetic and isotherm models were applied to the sorption kinetics and isothermal data. The pseudo-sec-ond-order kinetics fitted well the data. The X max (maximum adsorption) at 50°C was recorded as 14.025 mg/g with K 2 (pseudo-second-order kinetics constant) value of 0.0162 and R 2 value of 0.99. The adsorption isotherm data fitted well the Langmuir isotherm model. The optimum pH for the removal of lambda-cyhalothrin was achieved at pH 5. 0.1 g of PMCNC was used as optimum dose in all experiments. The negative value of Gibbs free energy reveals that the removal of lambda-cyhalo-thrin is a spontaneous process. Due to the excellent adsorption capability and easy separation from slurry after use through the application of magnet the PMCNC can be effectively used as an effective sorbent alternative to activated carbon for the removal of inorganic and organic contaminants from aquatic media. This nanocomposite could compete with other adsorbents in the field of surface chemistry warranting further experimentation.