‘High-pH softening pretreatment’ for boron removal in inland desalination systems

Rioyo, Javier and Aravinthan, Vasantha and Bundschuh, Jochen and Lynch, Mark (2018) ‘High-pH softening pretreatment’ for boron removal in inland desalination systems. Separation and Purification Technology, 205. pp. 308-316. ISSN 1383-5866

Abstract

Boron removal from water remains a challenge. In fact, it is largely unclear whether softening pretreatments
enhance boron removal in groundwater desalination systems. We therefore investigated the feasibility of a high-pH softening pretreatment for boron removal from magnesium dominated groundwater samples obtained from
an existing desalination facility. Different alkaline reagents were trialled with brackish groundwater initially containing 5 mg/L of boron. The results indicated that the lime and soda ash softening treatment was a better option than the caustic soda alternative, achieving 33% boron removal by sorption of hydroxyborate ions onto precipitated magnesium silicates. The process could be further optimized by the addition of MgCl2·6H2O before the softening process. In addition, a secondary polishing treatment by means of adsorption with MgO was investigated. A total of 9% extra boron removal was achieved in both cases. This ‘high-pH softening pretreatment’ could enhance compliance with strict boron standards in inland facilities using reverse osmosis or electrodialysis technology.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to published version, in accordance with the copyright policy of the publisher.
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying
Date Deposited: 31 May 2018 23:57
Last Modified: 25 Jun 2018 04:22
Uncontrolled Keywords: reverse osmosis, brackish groundwater, boron removal, softening, adsorption
Fields of Research : 09 Engineering > 0907 Environmental Engineering > 090703 Environmental Technologies
Socio-Economic Objective: D Environment > 96 Environment > 9611 Physical and Chemical Conditions of Water > 961103 Physical and Chemical Conditions of Water in Fresh, Ground and Surface Water Environments (excl. Urban and Industrial Use)
Identification Number or DOI: 10.1016/j.seppur.2018.05.030
URI: http://eprints.usq.edu.au/id/eprint/34216

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