Phosphonate removal from membrane concentrate by electro-coagulation

Victor Manuel Torres Serrano; Lordina Ekua Eshun; Andreia Farinha; Geert Jan Witkamp; Szilard Bucs

doi:10.1016/j.jece.2022.109031

Phosphonate removal from membrane concentrate by electro-coagulation

Victor Manuel Torres Serrano^*, Lordina Ekua Eshun, Andreia Farinha, Geert Jan Witkamp, Szilard Bucs

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

9 Scopus citations

Abstract

In this study, the efficiency of electrocoagulation (EC) with iron electrodes was applied to remove two phosphonates, 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP) and nitrilotris(methylene) triphosphonic acid (NTMP) from concentrates. This work provides a detailed description of the experimental procedure and results on phosphonate removal and recovery from different electrolytes, including synthetic and real reverse osmosis (RO) membrane concentrates. This research showed high selectivity of EC, removing 100% and 80% of the NTMP and the HEDP respectively, confirming no competition with sulfates, nitrates, or silica. When experimenting with other electrolytes, calcium showed to be critical in enhancing the flocculation process, while calcium carbonate precipitation contributed to capturing the phosphonates from the concentrate. The produced iron oxide (sludge) was confirmed as goethite and akaganéite, and finally transformed into hematite, indicating the oxidation from Fe2+ to Fe3+ during the EC process. After the iron precipitate collection, an alkaline wash of the sludge was enough to recover 100% of the initial phosphorus from the NTMP phosphonate. However, further research is needed to optimize the recovery procedure and to improve the results with the HEDP. 70 and 140 A·m-2 current densities were optimal to bring HEDP and NTMP concentrations down to 32 μM (1 mg·L-1) in only 30 and 10 min respectively. In these conditions, the operational costs, 1.10 and 0.03 €·m-3 of treated concentrate, were estimated for HEDP and NTMP respectively. Even when EC has been widely studied for phosphate removal, this technique has been barely applied to treat concentrates containing phosphonate-based antiscalants. EC opens new possibilities for phosphonates and phosphorus to be removed and recovered respectively from membrane and other concentrates.

Original language	English (US)
Article number	109031
Journal	Journal of Environmental Chemical Engineering
Volume	10
Issue number	6
DOIs	https://doi.org/10.1016/j.jece.2022.109031
State	Published - Dec 2022

Bibliographical note

Funding Information:
The authors thank King Abdullah University of Science and Technology (KAUST) in Thuwal, Saudi Arabia for funding this research project. This work was also performed in the cooperation framework of Wetsus, European Centre of Excellence for Sustainable Water Technology (www.wetsus.eu). Wetsus is co-funded by the Dutch Ministry of Economic Affairs and Ministry of Infrastructure and Environment , the European Union Regional Development Fund , the province of Fryslân, and the Northern Netherlands Provinces . The authors want to address a special acknowledgment to Baas Rietman (Vitens) for providing the samples of real membrane concentrate and Sjoerd van Ast (AK Steel) for his advice and supplying the ARMCO material for the electrodes used during the experiments.

Publisher Copyright:
© 2022 Elsevier Ltd.

Keywords

Antiscalant
Electro-coagulation
Iron electrodes
Phosphonate recovery
Phosphonate removal
Reverse osmosis membrane concentrate

ASJC Scopus subject areas

Chemical Engineering (miscellaneous)
Waste Management and Disposal
Pollution
Process Chemistry and Technology

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10.1016/j.jece.2022.109031

Cite this

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title = "Phosphonate removal from membrane concentrate by electro-coagulation",

abstract = "In this study, the efficiency of electrocoagulation (EC) with iron electrodes was applied to remove two phosphonates, 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP) and nitrilotris(methylene) triphosphonic acid (NTMP) from concentrates. This work provides a detailed description of the experimental procedure and results on phosphonate removal and recovery from different electrolytes, including synthetic and real reverse osmosis (RO) membrane concentrates. This research showed high selectivity of EC, removing 100% and 80% of the NTMP and the HEDP respectively, confirming no competition with sulfates, nitrates, or silica. When experimenting with other electrolytes, calcium showed to be critical in enhancing the flocculation process, while calcium carbonate precipitation contributed to capturing the phosphonates from the concentrate. The produced iron oxide (sludge) was confirmed as goethite and akagan{\'e}ite, and finally transformed into hematite, indicating the oxidation from Fe2+ to Fe3+ during the EC process. After the iron precipitate collection, an alkaline wash of the sludge was enough to recover 100% of the initial phosphorus from the NTMP phosphonate. However, further research is needed to optimize the recovery procedure and to improve the results with the HEDP. 70 and 140 A·m-2 current densities were optimal to bring HEDP and NTMP concentrations down to 32 μM (1 mg·L-1) in only 30 and 10 min respectively. In these conditions, the operational costs, 1.10 and 0.03 €·m-3 of treated concentrate, were estimated for HEDP and NTMP respectively. Even when EC has been widely studied for phosphate removal, this technique has been barely applied to treat concentrates containing phosphonate-based antiscalants. EC opens new possibilities for phosphonates and phosphorus to be removed and recovered respectively from membrane and other concentrates.",

keywords = "Antiscalant, Electro-coagulation, Iron electrodes, Phosphonate recovery, Phosphonate removal, Reverse osmosis membrane concentrate",

author = "Serrano, {Victor Manuel Torres} and Eshun, {Lordina Ekua} and Andreia Farinha and Witkamp, {Geert Jan} and Szilard Bucs",

note = "Funding Information: The authors thank King Abdullah University of Science and Technology (KAUST) in Thuwal, Saudi Arabia for funding this research project. This work was also performed in the cooperation framework of Wetsus, European Centre of Excellence for Sustainable Water Technology (www.wetsus.eu). Wetsus is co-funded by the Dutch Ministry of Economic Affairs and Ministry of Infrastructure and Environment , the European Union Regional Development Fund , the province of Frysl{\^a}n, and the Northern Netherlands Provinces . The authors want to address a special acknowledgment to Baas Rietman (Vitens) for providing the samples of real membrane concentrate and Sjoerd van Ast (AK Steel) for his advice and supplying the ARMCO material for the electrodes used during the experiments. Publisher Copyright: {\textcopyright} 2022 Elsevier Ltd.",

year = "2022",

month = dec,

doi = "10.1016/j.jece.2022.109031",

language = "English (US)",

volume = "10",

journal = "Journal of Environmental Chemical Engineering",

issn = "2213-2929",

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T1 - Phosphonate removal from membrane concentrate by electro-coagulation

AU - Serrano, Victor Manuel Torres

AU - Eshun, Lordina Ekua

AU - Farinha, Andreia

AU - Witkamp, Geert Jan

AU - Bucs, Szilard

N1 - Funding Information: The authors thank King Abdullah University of Science and Technology (KAUST) in Thuwal, Saudi Arabia for funding this research project. This work was also performed in the cooperation framework of Wetsus, European Centre of Excellence for Sustainable Water Technology (www.wetsus.eu). Wetsus is co-funded by the Dutch Ministry of Economic Affairs and Ministry of Infrastructure and Environment , the European Union Regional Development Fund , the province of Fryslân, and the Northern Netherlands Provinces . The authors want to address a special acknowledgment to Baas Rietman (Vitens) for providing the samples of real membrane concentrate and Sjoerd van Ast (AK Steel) for his advice and supplying the ARMCO material for the electrodes used during the experiments. Publisher Copyright: © 2022 Elsevier Ltd.

PY - 2022/12

Y1 - 2022/12

N2 - In this study, the efficiency of electrocoagulation (EC) with iron electrodes was applied to remove two phosphonates, 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP) and nitrilotris(methylene) triphosphonic acid (NTMP) from concentrates. This work provides a detailed description of the experimental procedure and results on phosphonate removal and recovery from different electrolytes, including synthetic and real reverse osmosis (RO) membrane concentrates. This research showed high selectivity of EC, removing 100% and 80% of the NTMP and the HEDP respectively, confirming no competition with sulfates, nitrates, or silica. When experimenting with other electrolytes, calcium showed to be critical in enhancing the flocculation process, while calcium carbonate precipitation contributed to capturing the phosphonates from the concentrate. The produced iron oxide (sludge) was confirmed as goethite and akaganéite, and finally transformed into hematite, indicating the oxidation from Fe2+ to Fe3+ during the EC process. After the iron precipitate collection, an alkaline wash of the sludge was enough to recover 100% of the initial phosphorus from the NTMP phosphonate. However, further research is needed to optimize the recovery procedure and to improve the results with the HEDP. 70 and 140 A·m-2 current densities were optimal to bring HEDP and NTMP concentrations down to 32 μM (1 mg·L-1) in only 30 and 10 min respectively. In these conditions, the operational costs, 1.10 and 0.03 €·m-3 of treated concentrate, were estimated for HEDP and NTMP respectively. Even when EC has been widely studied for phosphate removal, this technique has been barely applied to treat concentrates containing phosphonate-based antiscalants. EC opens new possibilities for phosphonates and phosphorus to be removed and recovered respectively from membrane and other concentrates.

AB - In this study, the efficiency of electrocoagulation (EC) with iron electrodes was applied to remove two phosphonates, 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP) and nitrilotris(methylene) triphosphonic acid (NTMP) from concentrates. This work provides a detailed description of the experimental procedure and results on phosphonate removal and recovery from different electrolytes, including synthetic and real reverse osmosis (RO) membrane concentrates. This research showed high selectivity of EC, removing 100% and 80% of the NTMP and the HEDP respectively, confirming no competition with sulfates, nitrates, or silica. When experimenting with other electrolytes, calcium showed to be critical in enhancing the flocculation process, while calcium carbonate precipitation contributed to capturing the phosphonates from the concentrate. The produced iron oxide (sludge) was confirmed as goethite and akaganéite, and finally transformed into hematite, indicating the oxidation from Fe2+ to Fe3+ during the EC process. After the iron precipitate collection, an alkaline wash of the sludge was enough to recover 100% of the initial phosphorus from the NTMP phosphonate. However, further research is needed to optimize the recovery procedure and to improve the results with the HEDP. 70 and 140 A·m-2 current densities were optimal to bring HEDP and NTMP concentrations down to 32 μM (1 mg·L-1) in only 30 and 10 min respectively. In these conditions, the operational costs, 1.10 and 0.03 €·m-3 of treated concentrate, were estimated for HEDP and NTMP respectively. Even when EC has been widely studied for phosphate removal, this technique has been barely applied to treat concentrates containing phosphonate-based antiscalants. EC opens new possibilities for phosphonates and phosphorus to be removed and recovered respectively from membrane and other concentrates.

KW - Antiscalant

KW - Electro-coagulation

KW - Iron electrodes

KW - Phosphonate recovery

KW - Phosphonate removal

KW - Reverse osmosis membrane concentrate

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DO - 10.1016/j.jece.2022.109031

M3 - Article

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SN - 2213-2929

VL - 10

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JF - Journal of Environmental Chemical Engineering

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ER -

Phosphonate removal from membrane concentrate by electro-coagulation

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

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