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Phosphate sorption by three potential filter materials as assessed by isothermal titration calorimetry

Lyngsie, Gry LU ; Penn, Chad J.; Hansen, Hans C B and Borggaard, Ole K. (2014) In Journal of Environmental Management 143. p.26-33
Abstract

Phosphorus eutrophication of lakes and streams, coming from drained farmlands, is a serious problem in areas with intensive agriculture. Installation of phosphate (P) sorbing filters at drain outlets may be a solution. The aim of this study was to improve the understanding of reactions involved in P sorption by three commercial P sorbing materials, i.e. Ca/Mg oxide-based Filtralite-P, Fe oxide-based CFH-12 and Limestone in two particle sizes (2-1mm and 1-0.5mm), by means of isothermal titration calorimetry (ITC), sorption isotherms, sequential extractions and SEM-EDS. The results indicate that P retention by CFH is due to surface complexation by rapid formation of strong Fe-P bonds. In contrast, retention of P by Filtralite-P and... (More)

Phosphorus eutrophication of lakes and streams, coming from drained farmlands, is a serious problem in areas with intensive agriculture. Installation of phosphate (P) sorbing filters at drain outlets may be a solution. The aim of this study was to improve the understanding of reactions involved in P sorption by three commercial P sorbing materials, i.e. Ca/Mg oxide-based Filtralite-P, Fe oxide-based CFH-12 and Limestone in two particle sizes (2-1mm and 1-0.5mm), by means of isothermal titration calorimetry (ITC), sorption isotherms, sequential extractions and SEM-EDS. The results indicate that P retention by CFH is due to surface complexation by rapid formation of strong Fe-P bonds. In contrast, retention of P by Filtralite-P and Limestone strongly depends on pH and time and is interpreted due to formation of calcium phosphate precipitate(s). Consequently, CFH can unambiguously be recommended as P retention filter material in drain outlets, whereas the use of Filtralite-P and Limestone has certain (serious) limitations. Thus, Filtralite-P has high capacity to retain P but only at alkaline pH (pH≥10) and P retention by Limestone requires long-time contact and a high ratio between sorbent and sorbate.

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author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Calcium phosphates, CFH-12, Fe-oxides, Filtralite-P, Limestone, P sorbing reactions
in
Journal of Environmental Management
volume
143
pages
8 pages
publisher
Academic Press
external identifiers
  • scopus:84900018296
ISSN
0301-4797
DOI
10.1016/j.jenvman.2014.04.010
language
English
LU publication?
no
id
1688a438-6230-4256-a7be-5654e15e26c5
date added to LUP
2016-10-17 14:08:11
date last changed
2017-08-27 06:26:13
@article{1688a438-6230-4256-a7be-5654e15e26c5,
  abstract     = {<p>Phosphorus eutrophication of lakes and streams, coming from drained farmlands, is a serious problem in areas with intensive agriculture. Installation of phosphate (P) sorbing filters at drain outlets may be a solution. The aim of this study was to improve the understanding of reactions involved in P sorption by three commercial P sorbing materials, i.e. Ca/Mg oxide-based Filtralite-P, Fe oxide-based CFH-12 and Limestone in two particle sizes (2-1mm and 1-0.5mm), by means of isothermal titration calorimetry (ITC), sorption isotherms, sequential extractions and SEM-EDS. The results indicate that P retention by CFH is due to surface complexation by rapid formation of strong Fe-P bonds. In contrast, retention of P by Filtralite-P and Limestone strongly depends on pH and time and is interpreted due to formation of calcium phosphate precipitate(s). Consequently, CFH can unambiguously be recommended as P retention filter material in drain outlets, whereas the use of Filtralite-P and Limestone has certain (serious) limitations. Thus, Filtralite-P has high capacity to retain P but only at alkaline pH (pH≥10) and P retention by Limestone requires long-time contact and a high ratio between sorbent and sorbate.</p>},
  author       = {Lyngsie, Gry and Penn, Chad J. and Hansen, Hans C B and Borggaard, Ole K.},
  issn         = {0301-4797},
  keyword      = {Calcium phosphates,CFH-12,Fe-oxides,Filtralite-P,Limestone,P sorbing reactions},
  language     = {eng},
  month        = {10},
  pages        = {26--33},
  publisher    = {Academic Press},
  series       = {Journal of Environmental Management},
  title        = {Phosphate sorption by three potential filter materials as assessed by isothermal titration calorimetry},
  url          = {http://dx.doi.org/10.1016/j.jenvman.2014.04.010},
  volume       = {143},
  year         = {2014},
}