A novel X-ray radiography approach for the characterization of granular activated carbons used in the rum production

Abstract

Background: X-ray methods have proven to be reliable, accurate and sensitive techniques to study activated carbons in order to define its porous structure and functionality groups. Methods: For the first time, the characterization of the exhaustion level of granular activated carbon (GAC) used in rum production applying methods based on X-ray technology has been explored. In this work, the exhaustion degree of GAC from a target rum "filter" using X-ray radiography is evaluated. Digital processing techniques on X-ray radiography images from eight consecutive GAC layers of the industrial rum filter have been assessed. Results: The exhaustion profile for the rum "filter" applying X-ray radiography images processing is correlated with thermal desorptiongas chromatography/ mass spectrometry (TD-GC/MS) chromatograms. The total of pixel detected in the radiographic X-ray images (grey-scale) is related with the total amount of organic adsorbed compounds in the exhausted GAC. Conclusion: The proposed method opens possibilities for the rum producers to improve the management and economical use of the activated carbon at industrial scale. The proposed technique can be applied in the assessment of other adsorption systems such as: determining the poisoning level of catalyst material, the GAC exhaustion level in organic polluted water treatments, and the GAC regeneration degree and exhaustion studies on hemo-perfusion GAC cartridges.

Chemical Regeneration of Activated Carbon Used in A Water Treatment System for Medical Services

“…GAC samples from the first 20 cm of the adsorber (GAC-Top) were selected for the regeneration, considering the large amount of adsorbed inorganics found at the upper layers in the adsorber compared with a virgin GAC sample [3]. Samples were collected using the procedure described in [3,15,16]. The GAC-Top sample was selected using GAC samples between 0 cm and the first 20 cm of the GAC bed (see Figure S1).…”

“…XRA method [3,[15][16][17] uses digital image processing on digital X-Ray radiography. X-ray radiography experiments were conducted using a TOSHIBA Mamorez-mgu 100d X-ray equipment used for mammography studies in manual mode, according to [16].…”

“…XRA method [3,[15][16][17] uses digital image processing on digital X-Ray radiography. X-ray radiography experiments were conducted using a TOSHIBA Mamorez-mgu 100d X-ray equipment used for mammography studies in manual mode, according to [16]. The mathematical analysis of the digital X-Ray radiographic images and obtaining the image's histograms and frequency spectra were performed using dedicated software developed in MATLAB® specifically for this application [3,[15][16][17].…”

“…XRA takes advantage of the different attenuation levels of X-ray radiation by materials with different densities [3,[15][16][17]. Figure 2 depicts the original X-ray radiographic images(a), the image histograms(b) and the frequency spectra(c) of the exhausted GAC before and after the regeneration using HCl 20%(v/v) and 2 h contact time and CH 3 COOH 15%(v/v) and 4 h contact time as well as the virgin GAC sample.…”

“…The performance of both acids for regeneration has been compared using different analytical techniques such as TGA and ICP-AES, SEM and RSSCT (for obtaining breakthrough curves), as well as a new X-ray absorption method (XRA) [3,[15][16][17].…”