Extending granular activated carbon (GAC) bed life: A column study of in-situ chemical regeneration of pesticide loaded activated carbon for water treatment.
File(s)
Author(s)
Larasati, Amanda
Fowler, Geoffrey D
Graham, Nigel JD
Type
Journal Article
Abstract
In-situ chemical regeneration of granular activated carbon (GAC) may represent an advantageous alternative to conventional off-site thermal regeneration in water treatment applications. The performance of chemical regeneration of carbon exhausted by metaldehyde and isoproturon was investigated using rapid small-scale column tests, performed using a sequence of pesticide adsorption and chemical regeneration cycles with a novel alkaline-organic regenerant solution. A fresh regenerant solution was able to achieve 82% and 45% regeneration of carbon exhausted by metaldehyde and isoproturon, respectively. After the first regeneration, the performance declined slightly to 79%, and to 36% after the fourth regeneration. A comparison using a thermally regenerated (operational) carbon suggested that chemical regeneration was more beneficial for carbon exhausted by metaldehyde. The regenerant solution has a potential to be re-used multiple times, thereby minimizing the amount of waste chemicals generated. A series of carbon characterization tests showed that chemical regeneration did not alter the surface area, pore size distribution and surface chemistry of the carbon. As part of the evaluation, the adsorption thermodynamics of virgin and chemically regenerated carbons were determined using isothermal titration calorimetry to evaluate the adsorption behaviour of the pesticides on the carbon samples. The relatively high regeneration efficiency achieved by chemical regeneration, and minimal deleterious effect to the physico-chemical properties of the carbon, demonstrated the beneficial potential of this process as an alternative to conventional thermal regeneration of GAC.
Date Issued
2021-08-16
Date Acceptance
2021-08-11
Citation
Chemosphere, 2021, 286 (Pt 3), pp.1-10
ISSN
0045-6535
Publisher
Elsevier
Start Page
1
End Page
10
Journal / Book Title
Chemosphere
Volume
286
Issue
Pt 3
Copyright Statement
© 2021 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
Northumbrian Water
Anglian Water Services Ltd
Severn Trent Water Ltd
Thames Water Utilities Ltd
Yorkshire Water Plc
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/34418652
PII: S0045-6535(21)02360-2
Grant Number
TBC
4504762231
RWD15-002 - PhD Studentship
TBC
T0802/2/1/1
Subjects
Activated carbon
Adsorption
In-situ chemical regeneration
Pesticides
Water treatment
Publication Status
Published
Coverage Spatial
England
Date Publish Online
2021-08-16