**2.4 Characterization of carbon residues**

Spectroscopic, microscopic and structural characterization methods were applied to determine the qualitative and structural properties of the carbonaceous materials in this study. The analytical methods employed have been chosen as the most suitable ones considering the instrument, material availability, and cost. The selected methods and techniques will then be adapted to enhance the accuracy and precision of analysis of the material as far as possible. The as-prepared activated carbons were characterized using Fourier transform infrared spectroscopy (Perkin Elmer, System 2000 FT-IR, USA), scanning electron microscopy/energy dispersive X-ray spectroscopy (Jeol, JSM-6390 LV SEM with Noran system Six software, USA), powder X-ray diffraction (Brker X8 Proteum pXRD), and Brunnauer Emmett–Teller methods.
