Development and characterization of new ecological adsorbents based on cardoon wastes: Application to brilliant green adsorption

This study aimed to develop four adsorbents, neat and activated, from the cardoon leaves and stems. The developed adsorbents were first analyzed to determine the surface acid–base properties using Boehm’s method, pH at zero charge point, iodine and methylene blue values, and moisture, ash, and fixed carbon contents. They were also characterized by scanning electron microscopy coupled with energy-dispersive X-ray analysis, X-ray diffraction, Fourier transform infrared absorption spectroscopy, thermogravimetric analysis, and inductively coupled plasma atomic emission spectroscopy. After that, these adsorbents were applied for adsorption of an organic dye “brilliant green” (BG), and the effect of various parameters on the adsorption efficiency was evaluated. The obtained results revealed the differences between the adsorbents derived from the neat cardoon leaves and stems and their activated carbon in terms of properties and BG adsorption efficiency.