Title: Ammonia removal from landfill leachate by struvite precipitation/coated silica sand filtration

Authors: Matthew Hendrix; Peter Grasel; Lee Martin; Kamal Tawfiq; Gang Chen

Addresses: Department of Civil and Environmental Engineering, FAMU-FSU College of Engineering, 2525 Pottsdamer Street, Tallahassee, FL 32310, USA ' Florida Department of Environmental Protection, 3900 Commonwealth Boulevard M.S. 49, Tallahassee, Florida 32399, USA ' Florida Department of Environmental Protection, 3900 Commonwealth Boulevard M.S. 49, Tallahassee, Florida 32399, USA ' Department of Civil and Environmental Engineering, FAMU-FSU College of Engineering, 2525 Pottsdamer Street, Tallahassee, FL 32310, USA ' Department of Civil and Environmental Engineering, FAMU-FSU College of Engineering, 2525 Pottsdamer Street, Tallahassee, FL 32310, USA

Abstract: The objective of this study was to investigate onsite physicochemical systems for the treatment of landfill leachate with high ammonia content. A laboratory scale magnesium ammonium phosphate (struvite or MAP) precipitation system was tested and ammonia removal under various operational conditions was evaluated. For landfill leachate treatment by MAP precipitation, magnesium salts are a major economic constraint. It was demonstrated in this research that Mg²⁺, NH⁴⁺ and PO₄ ³⁻ stoichiometry and pH impacted MAP precipitation and subsequent ammonia removal. With the application of filtration in goethite-coated silica, ammonia removal can be dramatically improved. From this research, it was also discovered that goethite-coated silica sand can be used to remove excess phosphorous for the treatment of landfill leachate by struvite precipitation.

Keywords: struvite precipitation; ammonia removal; phosphorous removal; landfill leachate; goethite-coated silica sand; sand filtration; magnesium salts.

DOI: 10.1504/IJEWM.2015.069130

International Journal of Environment and Waste Management, 2015 Vol.15 No.3, pp.201 - 216

Received: 26 Dec 2012
Accepted: 27 May 2013
Published online: 30 Apr 2015 *

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