Removal of Crystal violet and Methyl orange dyes from aqueous solutions using Green- Synthesized Activated Carbon prepared from plastic (PET) wastes

One easy way to remove synthetic colors from aqueous solutions is to adsorb them on inexpensive solid sorbents. Utilizing activated carbon from polymer waste has been the focus of recent sorption process initiatives, therefore it offers a more appealing and affordable option than commercial activated carbon, which is often more costly. This study seeks to investigate the equilibrium and sorption kinetics of two artificial cationic and Ionic dyes from aqueous media which are respectively crystal violet and methylene orange utilizing Polyethylene Terephthalate PET waste to produce activated carbon. Based on FTIR analysis, the adsorbent possesses an OH functional group in C6H8O7 modified carbon-2 and KOH modified carbon-2 of a ratio preparation of 1:2, C-H , C=O and C-O. SEM analysis indicated the presence of pores of different sizes and shapes in micrometer diameter.  Additionally, XRD images detected  C6H8O7 modified carbon-2/C-500 had small sharp peaks revealed in 2θ = 29°, 2θ = 41°and 2θ = 51°. The results suggest that these peaks reflect the condensed aromatic carbonized planes. Batch adsorption studies were performed to investigate the a effect of initial PH, contact time, initial CV and MO concentration, adsorbent dosage and temperature on adsorption. The Langmuir and Freundlich isotherm models provided the explanation for experimental data with the highest correlation coefficient with CV dye, whereas the Freundlich isotherm model is suitable to describe the adsorption reaction of the MO dye. Sorption thermodynamic data show that the adsorption process is spontaneous in all samples except (C6H8O7modified carbon-1) was  nonspontaneous. Moreover endothermic in all the samples  except (C6H8O7modified carbon-2) was exothermic sample and the clearing PET waste obtained after surface modification by C6H8O7  treatment showed a higher adsorption capacity from  KOH.