In dye-removal
studies, two different aspects can be distinguished, namely, dyeremoval
rate, and chemical and physical processes involved. Removal
processes are monitored by measuring analytical indices
{e.g., total organic carbon (TOC), chemical oxygen demand (COD),
and absorbance in UV-vis at the wavelength of maximum absorption
[43–46]}. Also, less common processes are coagulation methods
and a conductivity technique [22,47].