New Perspectives on the Interactions between Adsorption and Degradation of Organic Micropollutants in Granular Activated Carbon Filters
Betsholtz, Alexander LU ; Falås, Per LU ; Svahn, Ola ; Cimbritz, Michael LU and Davidsson, Åsa LU
(2024)
In Environmental Science and Technology
58(26).
p.11771-11780
- Abstract
The removal of organic micropollutants in granular activated carbon (GAC) filters can be attributed to adsorption and biological degradation. These two processes can interact with each other or proceed independently. To illustrate the differences in their interaction, three 14C-labeled organic micropollutants with varying potentials for adsorption and biodegradation were selected to study their adsorption and biodegradation in columns with adsorbing (GAC) and non-adsorbing (sand) filter media. Using 14CO2 formation as a marker for biodegradation, we demonstrated that the biodegradation of poorly adsorbing N-nitrosodimethylamine (NDMA) was more sensitive to changes in the empty bed contact time (EBCT)... (More)
The removal of organic micropollutants in granular activated carbon (GAC) filters can be attributed to adsorption and biological degradation. These two processes can interact with each other or proceed independently. To illustrate the differences in their interaction, three 14C-labeled organic micropollutants with varying potentials for adsorption and biodegradation were selected to study their adsorption and biodegradation in columns with adsorbing (GAC) and non-adsorbing (sand) filter media. Using 14CO2 formation as a marker for biodegradation, we demonstrated that the biodegradation of poorly adsorbing N-nitrosodimethylamine (NDMA) was more sensitive to changes in the empty bed contact time (EBCT) compared with that of moderately adsorbing diclofenac. Further, diclofenac that had adsorbed under anoxic conditions could be degraded when molecular oxygen became available, and substantial biodegradation (≥60%) of diclofenac could be achieved with a 15 min EBCT in the GAC filter. These findings suggest that the retention of micropollutants in GAC filters, by prolonging the micropollutant residence time through adsorption, can enable longer time periods for degradations than what the hydraulic retention time would allow for. For the biologically recalcitrant compound carbamazepine, differences in breakthrough between the 14C-labeled and nonradiolabeled compounds revealed a substantial retention via successive adsorption-desorption, which could pose a potential challenge in the interpretation of GAC filter performance.
(Less)
- author
- Betsholtz, Alexander
LU
; Falås, Per
LU
; Svahn, Ola
; Cimbritz, Michael
LU
and Davidsson, Åsa
LU
- organization
- publishing date
- 2024-07-02
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- biological degradation, pharmaceuticals, retention
- in
- Environmental Science and Technology
- volume
- 58
- issue
- 26
- pages
- 10 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- pmid:38889182
- scopus:85196549068
- ISSN
- 0013-936X
- DOI
- 10.1021/acs.est.4c00815
- language
- English
- LU publication?
- yes
- id
- 30bb522e-2bf1-4e73-bf51-a9c4cd7d5600
- date added to LUP
- 2024-08-30 13:11:32
- date last changed
- 2024-09-04 12:32:47
@article{30bb522e-2bf1-4e73-bf51-a9c4cd7d5600,
abstract = {{<p>The removal of organic micropollutants in granular activated carbon (GAC) filters can be attributed to adsorption and biological degradation. These two processes can interact with each other or proceed independently. To illustrate the differences in their interaction, three <sup>14</sup>C-labeled organic micropollutants with varying potentials for adsorption and biodegradation were selected to study their adsorption and biodegradation in columns with adsorbing (GAC) and non-adsorbing (sand) filter media. Using <sup>14</sup>CO<sub>2</sub> formation as a marker for biodegradation, we demonstrated that the biodegradation of poorly adsorbing N-nitrosodimethylamine (NDMA) was more sensitive to changes in the empty bed contact time (EBCT) compared with that of moderately adsorbing diclofenac. Further, diclofenac that had adsorbed under anoxic conditions could be degraded when molecular oxygen became available, and substantial biodegradation (≥60%) of diclofenac could be achieved with a 15 min EBCT in the GAC filter. These findings suggest that the retention of micropollutants in GAC filters, by prolonging the micropollutant residence time through adsorption, can enable longer time periods for degradations than what the hydraulic retention time would allow for. For the biologically recalcitrant compound carbamazepine, differences in breakthrough between the <sup>14</sup>C-labeled and nonradiolabeled compounds revealed a substantial retention via successive adsorption-desorption, which could pose a potential challenge in the interpretation of GAC filter performance.</p>}},
author = {{Betsholtz, Alexander and Falås, Per and Svahn, Ola and Cimbritz, Michael and Davidsson, Åsa}},
issn = {{0013-936X}},
keywords = {{biological degradation; pharmaceuticals; retention}},
language = {{eng}},
month = {{07}},
number = {{26}},
pages = {{11771--11780}},
publisher = {{The American Chemical Society (ACS)}},
series = {{Environmental Science and Technology}},
title = {{New Perspectives on the Interactions between Adsorption and Degradation of Organic Micropollutants in Granular Activated Carbon Filters}},
url = {{http://dx.doi.org/10.1021/acs.est.4c00815}},
doi = {{10.1021/acs.est.4c00815}},
volume = {{58}},
year = {{2024}},
}