Valorisation of plastic waste from the beverage industry through its transformation into adsorbent and solid fuel materials

Abstract

In the present study, char and activated carbon (AC) materials were prepared from water bottles, recuperated from the waste collection point in Mourouj, Ben Arous, Tunisia, by using a rotative horizontal tubular furnace, on a lab/pilot scale and through chemical and physical activation. Different samples were characterized by $\text{N}_2$ adsorption isotherms, SEM-EDX, XRD, EA as well as by the determination of the $\text{pH}_{\mathrm{zpc}}$. The efficiency of the ACs to remove (2-methyl-4-chlorophenoxyacetic acid (MCPA) and 2,4-dichlorophenoxyacetic acid (2,4-D)) herbicides from aqueous solutions was also investigated. The results demonstrated that a maximum adsorption capacity of $192~\text{mg}{\cdot }\text{g}^{-1}$, for MCPA, and $290~\text{mg}{\cdot }\text{g}^{-1}$ for 2,4-D had been attained. The adsorption kinetics was fitted to pseudo first, second order and Elovich model, while the adsorption isotherms were fitted applying the Langmuir and Freundlich isotherm models. The potential use as solid fuel materials was evaluated using elemental analysis and numerical high calorific value (HCV). The experimental results were compared to the conventional solid fuels classified in the Van Krevelen graph. The essays performed showed that the HCV was in the range of 10.2–11.9 MJ/kg.

Keywords

• Waste PET
• Activated carbon
• Chemical and physical activation
• Adsorption
• Solid fuel materials
• Herbicides removal