Chemical regeneration of granular activated carbon: preliminary evaluation of alternative regenerant solutions
File(s)
Published version
Author(s)
Larasati, Amanda
Fowler, Geoffrey D
Graham, Nigel JD
Type
Journal Article
Abstract
Granular activated carbon (GAC) is used in drinking water treatment plants worldwide to remove micro-pollutants such as pesticides. Early breakthrough of problematic micro-pollutants leads to frequent and costly thermal regeneration off-site. A potential alternative approach is to chemically regenerate GAC on-site (possibly in situ) with an appropriate solution capable of desorbing organic contaminants, having a range of physico-chemical properties. In this study, four types of regenerant solution were evaluated in batch tests for their ability to desorb five target contaminants. The solutions were: high purity water, sodium hydroxide, ethanol, and a mixture of sodium hydroxide and ethanol. The contaminants included: phenol and nitrobenzene, as representative aromatic compounds; clopyralid and metaldehyde, as poorly-adsorbed pesticides; and isoproturon, a well-adsorbed pesticide. Among the properties of the contaminants, their hydrophobicity and aqueous solubility had the most significant influence on the desorption efficiency. NaOH/CH3CH2OH was found to be more effective than individual solutions in desorbing the target contaminants, indicating an ability to desorb both hydrophobic and hydrophilic compounds. The NaOH/CH3CH2OH regenerant solution yielded desorption efficiencies in the range of approximately 40–90%, with the efficiency dependent on the contaminant. A thermodynamic study provided valuable fundamental information regarding the adsorption and desorption mechanisms, and the existence of two binding sites involving a weak physisorption and a stronger chemisorption-like interaction between the contaminants and the GAC.
Date Issued
2020-08-01
Date Acceptance
2020-06-12
Citation
Environmental Science: Water Research & Technology, 2020, 6 (8), pp.2043-2056
ISSN
2053-1400
Publisher
Royal Society of Chemistry
Start Page
2043
End Page
2056
Journal / Book Title
Environmental Science: Water Research & Technology
Volume
6
Issue
8
Copyright Statement
© The Royal Society of Chemistry 2020. This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence http://creativecommons.org/licenses/by-nc/3.0/.
License URL
Sponsor
Northumbrian Water
Anglian Water Services Ltd
Severn Trent Water Ltd
Thames Water Utilities Ltd
Yorkshire Water Plc
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000554046900005&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
TBC
4504762231
RWD15-002 - PhD Studentship
TBC
T0802/2/1/1
Subjects
Science & Technology
Technology
Life Sciences & Biomedicine
Physical Sciences
Engineering, Environmental
Environmental Sciences
Water Resources
Engineering
Environmental Sciences & Ecology
ISOTHERMAL TITRATION CALORIMETRY
METALDEHYDE REMOVAL
SURFACE-CHEMISTRY
AQUEOUS-SOLUTIONS
THERMAL REGENERATION
SOLVENT REGENERATION
DRINKING-WATER
ADSORPTION
PHENOL
CONTAMINANTS
Publication Status
Published
Date Publish Online
2020-06-15