X-ray Absorption (XRA): A New Technique for the Characterization of Granular Activated Carbons.

Jeamichel Puente Torres,Robert Carleer,Ángel Brito Sauvanell,Peter Adriaensens,Thayset Mariño Peacok,Jan Yperman,Harold Crespo Sariol

doi:10.3390/ma14010091

Jeamichel Puente Torres, Robert Carleer + Show 5 more

Open Access

https://doi.org/10.3390/ma14010091

Copy DOI

Journal: Materials	Publication Date: Dec 28, 2020
Citations: 2	License type: CC BY 4.0

Affiliation: University of Santiago de Cuba, Hasselt University

Abstract

The X-ray absorption (XRA) method using digital image processing techniques is a reliable technique to determine the exhaustion degree of granular activated carbons (GACs). Using an innovative digital image processing technique, the identification of individual adsorbed molecules or ions in a GAC was possible. Adsorption isotherm models (Langmuir and Freundlich) were used to simulate the adsorption equilibrium data of Methylene Blue (MB), nickel, cobalt and iodine. Freundlich equation was found to have the highest value of R2 compared with Langmuir. The identification of distinctive patterns applying XRA for different adsorbed ions and molecules onto GAC was explored. It is demonstrated that unique XRA configurations for each adsorbed ion or molecule are found, as well as a proportional relationship between its incident energy (needed to achieve maximum photon attenuation) and the (effective) atomic number, the adsorbate mass and the molar or atomic mass of adsorbed molecule or ion. XRA method in combination with image histogram modifications was used to obtain a digital signature of adsorbed ions/molecules, giving distinct GSI values for each one in the used energy range. Probabilistic models prove that XRA results are within relationships between effective atomic number and photonic interaction probability, reinforcing the potentialities of XRA for monitoring (multi-)ion and/or molecule combinations on GAC using advanced digital image processing techniques. It was proved that the proposed approach could assess different adsorbed ions/molecules onto GACs in water purification systems.

Highlights

X-ray were discovered by the German physicist Wilhelm K
The adsorption process of nickel, cobalt, Methylene Blue and iodine onto granular activated carbons (GACs) was best described by the Freundlich isotherm
A proportional dependency was found between incident energy to achieve maximum photon attenuation and adsorbed mass, effective atomic number or atomic number and molar or atomic mass on GAC loaded with nickel, cobalt, Methylene Blue (MB) and iodine

Summary

Introduction

X-ray were discovered by the German physicist Wilhelm K. In 1913, Henry G.J. Moseley (1887–1915) found a linear relation between the square root of the frequency of X-rays corresponding with the K line transitions in an X-ray spectrum (K-alpha lines) and the atomic number (Z) of 40 elements. Moseley (1887–1915) found a linear relation between the square root of the frequency of X-rays corresponding with the K line transitions in an X-ray spectrum (K-alpha lines) and the atomic number (Z) of 40 elements He was credited with the revision of the periodic table based on Z rather than the atomic mass (A). He later laid the foundation for identifying elements in X-ray spectroscopy by establishing a relationship between frequency (energy) and the atomic number, a basis of X-ray spectrometry [1]. Orbital energy is determined mainly by the principal quantum number [2]

Objectives

Methods

Results

Conclusion