Groundnut plant ash: Characterisation and adsorption efficacy study for removal of paraquat dichloride

For the first time combustion residue of agricultural waste i.e. groundnut plant is characterized in detail and explored as an adsorbent for removal of chlorinated herbicide, paraquat. The study investigates the chemical, physical, mineralogical, and morphological characteristics of GPA (Groundnut Plant Ash) adsorbent produced using groundnut plant. GPA has been characterized using the Fourier Transform Infrared (FTIR) spectroscopy to determine the functional groups, and Scanning Electron Microscopy (SEM) to examine the surface morphology of the carbon. Batch adsorption is performed by varying adsorbent dosage, initial concentration and contact time. Result shows that the kinetic models mainly the pseudo-second order and Elovich model had the best fit. The equilibrium data are analyzed using different isotherm models. The adsorption capacity of GPA for paraquat removal is found 265.71 mg/m2 which is the highest reported value.