Preparation of pyrolytic coke/uio-66 composite and its effectiveness for removing mono-ethylene glycol (MEG) from aqueous environments.

In the present study, the potential of pyrolytic coke (PC) and PC modified with UiO-66 nanoparticles as adsorbents for removing mono-ethylene glycol (MEG) from aqueous solutions was studied. Different experimental techniques were used to investigate the properties of adsorbents. The modification of the PC surface (6.91 m/g) with UiO-66 significantly enhanced the specific surface area of the PC/UiO-66 composites, increasing it to 379.31 m/g. Maximum MEG adsorption using PC (84.21%) and PC/UiO-66 (96.75%) was recorded at pH equal to 5 and 7, MEG quantity of 100 mg/L, temperature of 25 °C, adsorbent dosage of 1 g/L, and treatment time of 120 min, respectively. The Langmuir isotherm adsorption capacities for MEG removal using PC and PC/UiO-66 were determined to be 265 mg/g and 291 mg/g, respectively. The K and A values for the MEG adsorption were obtained at 128.1 mg/g (L/mg) and 11.05 L/g, indicating the more pronounced affinity of the PC/UiO-66 towards MEG than the PC sample. The enthalpy, entropy, and Gibbs free energy were determined to be negative; thus, the MEG adsorption was exothermic and spontaneous in the range of 25-50 °C. The results demonstrated that the experimental data adheres to a pseudo-first-order kinetic. The adsorbents were recycled up to five stages, and the results showed that after five cycles, no significant decrease in the adsorption efficiency occurred, making them suitable for repeated utilization in the adsorption process.