Phosphate Adsorption from Membrane Bioreactor Effluent Using Dowex 21K XLT and Recovery as Struvite and Hydroxyapatite

Tanjina Nur, Paripurnanda Loganathan, Jaya Kandasamy and Saravanamuthu Vigneswaran
Additional contact information
Tanjina Nur: Centre for Technology in Water and Wastewater, Faculty of Engineering and Information Technology, University of Technology Sydney, Broadway, Sydney NSW 2007, Australia
Paripurnanda Loganathan: Centre for Technology in Water and Wastewater, Faculty of Engineering and Information Technology, University of Technology Sydney, Broadway, Sydney NSW 2007, Australia
Jaya Kandasamy: Centre for Technology in Water and Wastewater, Faculty of Engineering and Information Technology, University of Technology Sydney, Broadway, Sydney NSW 2007, Australia
Saravanamuthu Vigneswaran: Centre for Technology in Water and Wastewater, Faculty of Engineering and Information Technology, University of Technology Sydney, Broadway, Sydney NSW 2007, Australia

IJERPH, 2016, vol. 13, issue 3, 1-12

Abstract: Discharging phosphate through wastewaters into waterways poses a danger to the natural environment due to the serious risks of eutrophication and health of aquatic organisms. However, this phosphate, if economically recovered, can partly overcome the anticipated future scarcity of phosphorus (P) resulting from exhaustion of natural phosphate rock reserves. An experiment was conducted to determine the efficiency of removing phosphate from a membrane bioreactor effluent (pH 7.0–7.5, 20, 35 mg phosphate/L) produced in a water reclamation plant by adsorption onto Dowex 21K XLT ion exchange resin and recover the phosphate as fertilisers. The data satisfactorily fitted to Langmuir adsorption isotherm with a maximum adsorption capacity of 38.6 mg·P/g. The adsorbed phosphate was quantitatively desorbed by leaching the column with 0.1 M NaCl solution. The desorbed phosphate was recovered as struvite when ammonium and magnesium were added at the molar ratio of phosphate, ammonium and magnesium of 1:1:1 at pH 9.5. Phosphate was also recovered from the desorbed solution as hydroxyapatite precipitate by adding calcium hydroxide to the solution at a phosphate to calcium molar ratio of 1:2 at pH 7.0. The P contents of struvite and hydroxyapatite produced were close to those of the respective commercial phosphate fertilisers.

Keywords: phosphate; adsorption; struvite; hydroxyapatite; wastewater; fertiliser (search for similar items in EconPapers)
JEL-codes: I I1 I3 Q Q5 (search for similar items in EconPapers)
Date: 2016
References: View complete reference list from CitEc
Citations: View citations in EconPapers (2)

Downloads: (external link)
https://www.mdpi.com/1660-4601/13/3/277/pdf (application/pdf)
https://www.mdpi.com/1660-4601/13/3/277/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jijerp:v:13:y:2016:i:3:p:277-:d:64985

Access Statistics for this article

IJERPH is currently edited by Ms. Jenna Liu

More articles in IJERPH from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().