Insight to aspirin sorption behavior on carbon nanotubes from aqueous solution: Thermodynamics, kinetics, influence of functionalization and solution parameters

Mohamed R Elamin; Babiker Y Abdulkhair; Amin O Elzupir

doi:10.1038/s41598-019-49331-6

Insight to aspirin sorption behavior on carbon nanotubes from aqueous solution: Thermodynamics, kinetics, influence of functionalization and solution parameters

Sci Rep. 2019 Sep 5;9(1):12795. doi: 10.1038/s41598-019-49331-6.

Authors

Mohamed R Elamin^{1

2}, Babiker Y Abdulkhair^{3

4}, Amin O Elzupir⁵

Affiliations

¹ Imam Mohammad Ibn Saud Islamic University (IMSIU), College of Science, Chemistry Department, Riyadh, Saudi Arabia.
² Industrial research and consultancy center (IRCC), Khartoum North, Sudan.
³ Imam Mohammad Ibn Saud Islamic University (IMSIU), College of Science, Chemistry Department, Riyadh, Saudi Arabia. babiker35.by@gmail.com.
⁴ Sudan University of Science and Technology (SUST), College of Science, Chemistry Department, Khartoum, Sudan. babiker35.by@gmail.com.
⁵ Imam Mohammad Ibn Saud Islamic University (IMSIU), College of Science, Committee on Radiation and Environmental Pollution Protection, Riyadh, Saudi Arabia.

Abstract

The chronic exposure to the pharmaceuticals and personal care products contaminants in water represent a serious public health problem to man and animal. We studied the removal of aspirin (Asp) as an example to these hazardous materials from an aqueous solution using functionalized (FMCNT) and pristine multiwall carbon nanotubes (PMCNT). The characterization of synthetic sorbents was examined with scanning electron energy-dispersive microscopy and transmission electron microscopy. The effects of adsorption time, sorbent mass, solution pH, ionic strength, and temperature were optimized. The functionalization increased the surface area from 151 to 181 m² g^-1. Consequently, the adsorption capacity increased from 41 mg g^-1 to 58 mg g^-1 for PMCNT and FMCNT, respectively. The results showed that the adsorption kinetic follows the pseudo-second-order model with very good agreement. Whereas, the adsorption mechanism study showed a partial agreement with the liquid-film diffusion model on PMCNT and FMCNT at 25 °C and 35 °C, respectively, with acceptable linear regression coefficients. The adsorption isotherm results revealed that the adsorption fits the Freundlich model. The thermodynamic study revealed that, Asp adsorption on both sorbents is exothermic, spontaneous and favorable. FMCNT showed relatively high removal efficiency when compared with the PMCNT when used for most of the conditions investigated.