3 Citationer (Scopus)

Resumé

Phosphate, which contains the essential element phosphorous (P), is a necessary fertilizer for agriculture, but the current phosphate deposits are running out and alternative sources are needed. Sludge obtained from wastewater treatment plants contains high concentrations of phosphorus and represents an alternative, sustainable source. In this study, sludge obtained from a wastewater treatment plant with biological and chemical phosphorus removal was acidified (pH = 3, 4, 5 and 6) to release orthophosphate followed by sequestration of the orthophosphate by a zinc aluminum layered double hydroxide (Zn 2 Al-LDH). Sulfuric acid (H 2 SO 4 ), nitric acid (HNO 3 ), and hydrochloric acid (HCl) was tested, which showed that only sulfate anions compete with phosphate and results in reduced phosphate recovery (25–35%). The orthophosphate concentration in the liquid phase increased from 20% (raw sludge) to 75% of the total phosphorus concentration at a pH of 3, which enhanced the phosphate uptake by the ZnAl-LDH from 1.7 ± 0.2% to 60.3 ± 0.6%. During acidification, the competing anion carbonate is degassed as CO 2 , which further improved the phosphate uptake. PXRD showed the intercalation of carbonate in the LDH in the raw sludge at pH = 8, whereas orthophosphate was intercalated at lower pH values. 27 Al MAS NMR spectroscopy and powder X-ray diffraction (PXRD) proved preservation of the LDH at all pH values. Furthermore, about a fourth of the Al is present as an amorphous aluminum phosphate (AlPO 4 ) upon exposure to phosphate at low pH (pH = 3 and 5) based on 27 Al MAS NMR spectroscopy. At a pH of 6 about a third of the P is present as brushite (CaHPO 4 ·2H 2 O).

OriginalsprogEngelsk
Artikelnummer153
TidsskriftWater Research
Vol/bind153
Sider (fra-til)208-216
Antal sider9
ISSN0043-1354
DOI
StatusUdgivet - 15 apr. 2019

Fingerprint

hydroxide
Phosphorus
Phosphates
sludge
phosphate
phosphorus
Recovery
orthophosphate
MAS
Wastewater treatment
X ray powder diffraction
Nuclear magnetic resonance spectroscopy
Carbonates
Phosphate deposits
Negative ions
nuclear magnetic resonance
anion
aluminum
Aluminum
spectroscopy

Citer dette

@article{98c558ef405c4059887603bfe97d9496,
title = "Layered Double Hydroxides for phosphorus recovery from acidified and non-acidified dewatered sludge",
abstract = "Phosphate, which contains the essential element phosphorous (P), is a necessary fertilizer for agriculture, but the current phosphate deposits are running out and alternative sources are needed. Sludge obtained from wastewater treatment plants contains high concentrations of phosphorus and represents an alternative, sustainable source. In this study, sludge obtained from a wastewater treatment plant with biological and chemical phosphorus removal was acidified (pH = 3, 4, 5 and 6) to release orthophosphate followed by sequestration of the orthophosphate by a zinc aluminum layered double hydroxide (Zn 2 Al-LDH). Sulfuric acid (H 2 SO 4 ), nitric acid (HNO 3 ), and hydrochloric acid (HCl) was tested, which showed that only sulfate anions compete with phosphate and results in reduced phosphate recovery (25–35{\%}). The orthophosphate concentration in the liquid phase increased from 20{\%} (raw sludge) to 75{\%} of the total phosphorus concentration at a pH of 3, which enhanced the phosphate uptake by the ZnAl-LDH from 1.7 ± 0.2{\%} to 60.3 ± 0.6{\%}. During acidification, the competing anion carbonate is degassed as CO 2 , which further improved the phosphate uptake. PXRD showed the intercalation of carbonate in the LDH in the raw sludge at pH = 8, whereas orthophosphate was intercalated at lower pH values. 27 Al MAS NMR spectroscopy and powder X-ray diffraction (PXRD) proved preservation of the LDH at all pH values. Furthermore, about a fourth of the Al is present as an amorphous aluminum phosphate (AlPO 4 ) upon exposure to phosphate at low pH (pH = 3 and 5) based on 27 Al MAS NMR spectroscopy. At a pH of 6 about a third of the P is present as brushite (CaHPO 4 ·2H 2 O).",
keywords = "Ion exchange, Layered double hydroxides (LDH), Phosphate recovery, Sludge acidification, Solid state NMR spectroscopy, Wastewater",
author = "Laura Lundeh{\o}j and Jensen, {Henriette Casper} and Lisbeth Wybrandt and Nielsen, {Ulla Gro} and Christensen, {Morten Lykkegaard} and Quist-Jensen, {Cejna Anna}",
year = "2019",
month = "4",
day = "15",
doi = "10.1016/j.watres.2019.01.004",
language = "English",
volume = "153",
pages = "208--216",
journal = "Water Research",
issn = "0043-1354",
publisher = "I W A Publishing",

}

Layered Double Hydroxides for phosphorus recovery from acidified and non-acidified dewatered sludge. / Lundehøj, Laura; Jensen, Henriette Casper; Wybrandt, Lisbeth; Nielsen, Ulla Gro; Christensen, Morten Lykkegaard; Quist-Jensen, Cejna Anna.

I: Water Research, Bind 153, 153, 15.04.2019, s. 208-216.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Layered Double Hydroxides for phosphorus recovery from acidified and non-acidified dewatered sludge

AU - Lundehøj, Laura

AU - Jensen, Henriette Casper

AU - Wybrandt, Lisbeth

AU - Nielsen, Ulla Gro

AU - Christensen, Morten Lykkegaard

AU - Quist-Jensen, Cejna Anna

PY - 2019/4/15

Y1 - 2019/4/15

N2 - Phosphate, which contains the essential element phosphorous (P), is a necessary fertilizer for agriculture, but the current phosphate deposits are running out and alternative sources are needed. Sludge obtained from wastewater treatment plants contains high concentrations of phosphorus and represents an alternative, sustainable source. In this study, sludge obtained from a wastewater treatment plant with biological and chemical phosphorus removal was acidified (pH = 3, 4, 5 and 6) to release orthophosphate followed by sequestration of the orthophosphate by a zinc aluminum layered double hydroxide (Zn 2 Al-LDH). Sulfuric acid (H 2 SO 4 ), nitric acid (HNO 3 ), and hydrochloric acid (HCl) was tested, which showed that only sulfate anions compete with phosphate and results in reduced phosphate recovery (25–35%). The orthophosphate concentration in the liquid phase increased from 20% (raw sludge) to 75% of the total phosphorus concentration at a pH of 3, which enhanced the phosphate uptake by the ZnAl-LDH from 1.7 ± 0.2% to 60.3 ± 0.6%. During acidification, the competing anion carbonate is degassed as CO 2 , which further improved the phosphate uptake. PXRD showed the intercalation of carbonate in the LDH in the raw sludge at pH = 8, whereas orthophosphate was intercalated at lower pH values. 27 Al MAS NMR spectroscopy and powder X-ray diffraction (PXRD) proved preservation of the LDH at all pH values. Furthermore, about a fourth of the Al is present as an amorphous aluminum phosphate (AlPO 4 ) upon exposure to phosphate at low pH (pH = 3 and 5) based on 27 Al MAS NMR spectroscopy. At a pH of 6 about a third of the P is present as brushite (CaHPO 4 ·2H 2 O).

AB - Phosphate, which contains the essential element phosphorous (P), is a necessary fertilizer for agriculture, but the current phosphate deposits are running out and alternative sources are needed. Sludge obtained from wastewater treatment plants contains high concentrations of phosphorus and represents an alternative, sustainable source. In this study, sludge obtained from a wastewater treatment plant with biological and chemical phosphorus removal was acidified (pH = 3, 4, 5 and 6) to release orthophosphate followed by sequestration of the orthophosphate by a zinc aluminum layered double hydroxide (Zn 2 Al-LDH). Sulfuric acid (H 2 SO 4 ), nitric acid (HNO 3 ), and hydrochloric acid (HCl) was tested, which showed that only sulfate anions compete with phosphate and results in reduced phosphate recovery (25–35%). The orthophosphate concentration in the liquid phase increased from 20% (raw sludge) to 75% of the total phosphorus concentration at a pH of 3, which enhanced the phosphate uptake by the ZnAl-LDH from 1.7 ± 0.2% to 60.3 ± 0.6%. During acidification, the competing anion carbonate is degassed as CO 2 , which further improved the phosphate uptake. PXRD showed the intercalation of carbonate in the LDH in the raw sludge at pH = 8, whereas orthophosphate was intercalated at lower pH values. 27 Al MAS NMR spectroscopy and powder X-ray diffraction (PXRD) proved preservation of the LDH at all pH values. Furthermore, about a fourth of the Al is present as an amorphous aluminum phosphate (AlPO 4 ) upon exposure to phosphate at low pH (pH = 3 and 5) based on 27 Al MAS NMR spectroscopy. At a pH of 6 about a third of the P is present as brushite (CaHPO 4 ·2H 2 O).

KW - Ion exchange

KW - Layered double hydroxides (LDH)

KW - Phosphate recovery

KW - Sludge acidification

KW - Solid state NMR spectroscopy

KW - Wastewater

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U2 - 10.1016/j.watres.2019.01.004

DO - 10.1016/j.watres.2019.01.004

M3 - Journal article

VL - 153

SP - 208

EP - 216

JO - Water Research

JF - Water Research

SN - 0043-1354

M1 - 153

ER -