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Trublet, M., Scukins, E., Carabante, I. & Rusanova-Naydenova, D. (2019). Competitive Sorption of Metal Ions on Titanium Phosphate Sorbent(TiP1) in Fixed-Bed Columns: A Closed-Mine Waters Study. ACS Sustainable Chemistry & Engineering, 7(9), 8145-8154
Open this publication in new window or tab >>Competitive Sorption of Metal Ions on Titanium Phosphate Sorbent(TiP1) in Fixed-Bed Columns: A Closed-Mine Waters Study
2019 (English)In: ACS Sustainable Chemistry & Engineering, ISSN 2168-0485, Vol. 7, no 9, p. 8145-8154Article in journal (Refereed) Published
Abstract [en]

Sorptionfixed-bed column experiments were performed using atitanium phosphate ion-exchanger composed of−H2PO4units [TiO(OH)(H2PO4)·H2O]. Model mine water containingfive divalent metal ions (Cu2+,Zn2+,Mn2+,Ni2+,and Co2+) and a few closed-mine water samples were treated to evaluate the sorptionpreference of the material. For thefirst time, dynamic ion-exchange capacities(estimated to be between 3.2 and 4.2 mequiv g−1) and static ion-exchange uptakes(calculated to be between 3.1 and 3.5 mequiv g−1) were obtained for the same TiP1sorbent and data were discussed in terms of sorption behavior. It was found thatsorption processes on TiP1 in model and closed-mine waters during a columnexperiment could be accurately predicted from the corresponding batch experiment(including the sorbent’s capacities in different types of waters). A competitivesorption phenomenon in favor of Cu2+on TiP1 was established for all cases, pointingtoward the possibility of isolating pure copper concentrate from closed-mine waters.The relatively high amounts of calcium and magnesium ions present in mine waters did not appear to considerably affect theselectivity of TiP1 material. Exploratory experiments for sorbent regeneration and desorption using a low concentration of nitricacid were demonstrated.

Keywords
Titanium phosphate, Water treatment, Heavy metals, Column, Sorption
National Category
Other Environmental Engineering Physical Chemistry
Research subject
Waste Science and Technology; Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-74044 (URN)10.1021/acssuschemeng.8b05971 (DOI)000467351200017 ()2-s2.0-85065065701 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-05-27 (oliekm)

Available from: 2019-05-27 Created: 2019-05-27 Last updated: 2019-08-19Bibliographically approved
Trublet, M. & Rusanova-Naydenova, D. (2018). Complete Column Trials for Water Refinement Using Titanium(IV) Phosphate Sorbents. ACS Sustainable Chemistry & Engineering, 6(5), 6157-6165
Open this publication in new window or tab >>Complete Column Trials for Water Refinement Using Titanium(IV) Phosphate Sorbents
2018 (English)In: ACS Sustainable Chemistry & Engineering, E-ISSN 2168-0485, Vol. 6, no 5, p. 6157-6165Article in journal (Refereed) Published
Abstract [en]

A titanium phosphate sorbent with linked active units (LTP) is synthesized. XRD, 31P MAS NMR, and TGA techniques are used to disclose the relation between the ion-exchange units of −HPO4 (crystalline α-TiP) and of −H2PO4 (amorphous TiP1) type. The reported kinetics data of TiP1 sorbent in batch mode have been reprocessed according to the nonlinear approach in order to explore further the sorption mechanism. It was found that the data could be well described by the pseudo-second-order model in the case of Ni2+ ions. Consequently, fixed-bed column sorption experiments of Ni2+ ions on LTP were designed, and the effects of both the amount of nickel(II) ions in the feed solution and the flow rates on the sorption equilibrium were studied. The ion-exchange capacity is estimated to be 1.6 meq·g–1 during the first four cycles before decreasing to 1.2 meq·g–1 for cycles five and six. The experimental data were simulated following the Thomas model, and desorption experiments with HCl were performed. Observations show that regeneration and reutilization of the LTP ion-exchanger are possible through at least six cycles. It is revealed that the sorption performances in column conditions could be undoubtedly predicted from the corresponding batch sorption data.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
Keywords
Column, Ion-exchanger, Nickel, Sorption, Titanium phosphate
National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-68298 (URN)10.1021/acssuschemeng.7b04823 (DOI)000431927500054 ()2-s2.0-85046747198 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-05-23 (andbra)

Available from: 2018-04-11 Created: 2018-04-11 Last updated: 2018-08-10Bibliographically approved
Persson, I., Trublet, M. & Klysubun, W. (2018). Structure Determination of Phosphoric Acid and Phosphate Ions in Aqueous Solution Using EXAFS Spectroscopy and Large Angle X-ray Scattering. Journal of Physical Chemistry A, 122(37), 7413-7420
Open this publication in new window or tab >>Structure Determination of Phosphoric Acid and Phosphate Ions in Aqueous Solution Using EXAFS Spectroscopy and Large Angle X-ray Scattering
2018 (English)In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 122, no 37, p. 7413-7420Article in journal (Refereed) Published
Abstract [en]

The structures of hydrated phosphoric acid and phosphate ions (H2PO4-, HPO42- and PO43-) in aqueous solution have been determined by P K-edge EXAFS and large angle X-ray scattering (LAXS). The P-O bond distance in all phosphate species studied is close to 1.53 Å. The P-(O)⋅⋅⋅Oaq distances have been refined to ca. 3.6 Å from the LAXS data giving a P-O⋅⋅⋅Oaq bond angle close to tetrahedral suggesting that each oxygen or OH group of phosphoric acid and dihydrogenphosphate, on average, hydrogen bind three water molecules. The (P-)O(-H)···Oaq and (P-)O···(H-)Oaq hydrogen bonds in hydrated phos-phoric acid and the H2PO4- ion are shorter than the hydrogen bonds in neat water. This supports previous infrared spectro-scopic studies claiming that the hydrogen bonds in hydrated phosphoric acid and phosphate ions are stronger than the hy-drogen bonds in neat water. Phosphoric acid and phosphate ions can therefore be regarded as structure making solutes. This is the first study applying transmission mode X-ray absorption spectroscopy (XAS) data collection on the P K-edge. It shows that XAS spectra collected in transmission mode have a much better S/N ratio than data collected in fluorescence mode, allowing accurate determination of P-O bond distances. Furthermore, P K-edge EXAFS data collected in fluorescence mode display a higher amplitude at high k than expected due to increasing radiated volume of the sample with increasing energy as the total absorption decreases sharply with increasing energy of the X-rays. As a result, the fluorescence signal becomes non-proportional to the intensity of the X-ray beam over the EXAFS spectrum. This results in an increasing amplitude of the EXAFS function with increasing energy of the X-ray beam resulting in too small Debye-Waller coefficients.

Place, publisher, year, edition, pages
Washington: American Chemical Society (ACS), 2018
National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-70697 (URN)10.1021/acs.jpca.8b05641 (DOI)000445711900017 ()30156411 (PubMedID)2-s2.0-85053767264 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-09-26 (inah)

Available from: 2018-08-31 Created: 2018-08-31 Last updated: 2019-04-24Bibliographically approved
Trublet, M. (2018). Titanium(IV) Phosphates: The Next Generation of Wastewater Sorbents. (Doctoral dissertation). Luleå: Luleå University of Technology
Open this publication in new window or tab >>Titanium(IV) Phosphates: The Next Generation of Wastewater Sorbents
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Treatment of industrial waters containing heavy metal ions is essential before being discharged into the environment. Consequently, European regulations have been established to control and limit the amount of heavy metals released. There is a need to develop efficient water treatment techniques that can remove contaminants with respect to these EU regulations.

Ion-exchange is one of the processes that is being investigated due to fast kinetics, high treatment capacity and its ability to remove heavy metal ions present in trace amounts. Titanium phosphates (TiP) are a group of inorganic ion-exchangers that have demonstrated to be particularly selective towards transition metal ions in aqueous solutions. Two types of ion-exchange units are present in TiP material, which are –HPO4 and –H2PO4 groups. Their structural characteristic is highly dependent on the synthesis conditions, which include the source of titanium, temperature, reaction time and P2O5:TiO2 ratio. Most of the studies have been performed on amorphous TiP containing a mixture of both exchange units, with –HPO4 groups being predominant; as crystalline TiP and –H2PO4 based TiP  are often obtained in difficult conditions, high temperature (up to 250 °C) and/or long reaction time (up to 30 days) and/or using autoclave. Despite promising properties depicted in batch conditions, very few data in continuous flow systems (fixed-bed columns) have been reported.

In this work, amorphous TiP composed of entirely –H2PO4 ion-exchange units (TiP1) was synthesized at mild conditions using a TiOSO4 solution and HCl/deionized water as post-synthesis treatments. The sorbent was characterized using a range of techniques (solid-state 31P MAS NMR, Raman, XRD, TGA, BET, Elemental analysis, EXAFS and XANES,) and tested in batch and column set-ups towards single and multi-component waters. The chemical formula of TiP1 was established as TiO(OH)(H2PO4)·H2O and it was found that the synthesis of TiP1 was also dependent on the TiO2/H2SO4 content in the primary titanium solution.

The material displayed a high maximum exchange capacity of ca. 6.4 meq.g-1, expressed as the sodium uptake. The actual ion-exchange capacity towards divalent metal ions was calculated to be ca. 3.4 meq.g-1 in batch condition and up to 4.1 meq.g-1 in fixed-bed column, which is to date the highest recorded for TiP materials. Kinetics of the exchange processes have been studied and the equilibrium was reached within 5-20 minutes. Modeling of the breakthrough curves was achieved using the Thomas model, indicating that the rate driving forces of the processes follow second-order reversible kinetics. The TiP1 sorbent has shown to maintain a high selectivity towards heavy metal ions in multi-component systems (including closed-mine waters) when column studies were performed. The sorption behavior of TiP1 in batch experiments correlates very well with data obtained in fixed-bed column conditions, confirming that prediction of the sorption behavior on the basis of batch data is conceivable.

Another important aspect of this work also involves the mild syntheses of crystalline α-TiP, Ti(HPO4)·H2O, and LTP (Linked Titanium Phosphate) composed of α-TiP and TiP1, where the structural characteristics of these materials were investigated using solid-state NMR, XRD, TGA, EXAFS and XANES.

Place, publisher, year, edition, pages
Luleå: Luleå University of Technology, 2018
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
National Category
Chemical Engineering Chemical Sciences Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-70326 (URN)978-91-7790-178-5 (ISBN)978-91-7790-179-2 (ISBN)
Public defence
2018-09-14, E632, Luleå, 09:00 (English)
Opponent
Supervisors
Available from: 2018-08-13 Created: 2018-08-10 Last updated: 2018-08-28Bibliographically approved
Trublet, M., Maslova, M. V., Rusanova-Naydenova, D. & Antzutkin, O. (2017). Sorption performances of TiO(OH)(H2PO4)·H2O in synthetic and mine waters. RSC Advances, 7(4), 1989-2001
Open this publication in new window or tab >>Sorption performances of TiO(OH)(H2PO4)·H2O in synthetic and mine waters
2017 (English)In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 7, no 4, p. 1989-2001Article in journal (Refereed) Published
Abstract [en]

¨The sorption properties toward Cu2+, Zn2+, Ni2+, Mn2+ and Co2+ ions, in synthetic and industrial waters with pH of 3.9–7.2, and the chemical stability of a titanium phosphate ion-exchanger synthesized at mild conditions and containing solely –H2PO4 groups, TiO(OH)(H2PO4)·H2O (TiP1) are investigated. TiP1 displays the highest Na+ uptake (6.3 meq. g−1) among TiP ion-exchangers and a maximum sorption capacity of ca. 1.55 mmol g−1 (i.e. 3.1 meq. g−1) for the studied ions, which is higher than the ones reported for exchangers composed predominantly of –HPO4 groups. The sorption isotherms were best described by the Temkin model while the Langmuir and the Freundlich models appear to be insufficient in describing all data. TiP1 shows fast kinetics with an equilibrium reached within 10–20 minutes and diffusion processes play a role in the initial period of sorption that is overpowered by chemisorption reactions in the overall rate controlling step. The selectivity order of the metal ions on TiP1 is determined as: Cu2+ > Zn2+ ≫ Mn2+ > Co2+, Ni2+, following the order of stability of MOH+ complexes and the corresponding activation parameters for a water molecule exchange in [M(H2O)6]2+ ions. The surface sorption data are in good correlation with the EDS data for these systems, supporting the idea of chemical sorption with no metal hydroxide precipitation. Additional sorption studies show that the quality of industrial waters after sorption reaches the EU recommendation for drinking water. The faster kinetics and the higher exchange capacity reveal that the presence of –H2PO4 groups strongly enhances the sorption properties of titanium phosphate sorbents.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2017
National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-61629 (URN)10.1039/C6RA25410A (DOI)000393748000028 ()2-s2.0-85009723957 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-01-30 (andbra)

Available from: 2017-01-25 Created: 2017-01-25 Last updated: 2018-11-16Bibliographically approved
Trublet, M., Maslova, M. V., Rusanova-Naydenova, D. & Antzutkin, O. (2016). Mild syntheses and surface characterization of amorphous TiO(OH)(H2PO4)·H2O ion-exchanger. Materials Chemistry and Physics, 183, 467-475
Open this publication in new window or tab >>Mild syntheses and surface characterization of amorphous TiO(OH)(H2PO4)·H2O ion-exchanger
2016 (English)In: Materials Chemistry and Physics, ISSN 0254-0584, E-ISSN 1879-3312, Vol. 183, p. 467-475Article in journal (Refereed) Published
Abstract [en]

This work focuses on the synthesis of titanium phosphate (TiP1) ion-exchanger containing solely H2PO4-groups. Based on the elemental analyses, TG, 31P MAS NMR, XRD and Raman data, the formula TiO(OH)(H2PO4)·H2O is assigned to TiP1. The synthesis requires a mild heating at 70–80 °C for a short period of time, followed by filtration and HCl-washing of the TiP1 powder. The layered nature and low crystallinity of this sorbent is confirmed by powder XRD technique. The existence of micro and mesopores in the material is established using BET method. The Na+ capacity of TiP1 is determined to be 6.3 meq g−1 which is the highest value reported for H2PO4-based sorbents. The presence of H2PO4 groups is expected to considerably increase both the pH-working range of the TiP1 sorbent and its exchange capacity towards divalent metal ions. All data for TiP1 are compared to the data for amorphous TiP containing mostly HPO4 groups.

National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-59695 (URN)10.1016/j.matchemphys.2016.09.002 (DOI)000386402100057 ()2-s2.0-84994031774 (Scopus ID)
Note

Validerad; 2016; Nivå 2; 2016-10-12 (andbra)

Available from: 2016-10-12 Created: 2016-10-12 Last updated: 2018-08-10Bibliographically approved
Trublet, M. (2015). Outline of Titanium (IV) based H2PO4 Ion-exchangers: Kinetics and Sorption models (ed.). (Licentiate dissertation). Paper presented at . : Luleå tekniska universitet
Open this publication in new window or tab >>Outline of Titanium (IV) based H2PO4 Ion-exchangers: Kinetics and Sorption models
2015 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Decontamination of industrially polluted waters has been enclosed in REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) since 2007, when it entered into force in the European Union, which emphasized the need to search for more effective sorbents. Many studies on inorganic ion-exchangers have been carried out due to the scientific interest towards their high mechanical and thermal stabilities, high resistance to oxidation and high sorption capacity regarding transition and radioactive metal ions. Titanium phosphates (TiP) in particular, have revealed very good cation-exchange properties in relation to different transition metal ions in aqueous solutions. It has been demonstrated that their physicochemical properties as well as their structural characteristics can be altered by carefully choosing the conditions of synthesis: the temperature, acidity, Ti(IV) speciation in solution and reaction time. Since the ‘classical’ crystalline TiP ionites have been divided into two main groups: alfa type; α-TiP [α-Ti(HPO4)2•H2O] and gamma type; γ-TiP [Ti(H2PO4)(PO4)•H2O] with different functional groups (–H2PO4, –HPO4 and –PO4) present, the researchers have focused on synthesis of various metastable TiP with different functional properties. In this work, three different synthetic routes for TiP ion-exchangers were explored in order to obtain a sorbent composed solely of –H2PO4 exchange units. The ─H2PO4 groups were expected to considerably increase the pH working range of the sorbents and to nearly double the theoretical exchange capacity of TiP ion-exchangers containing mostly –HPO4 functional groups. Among the synthesized ion-exchangers (TiP1, TiP2 and TiP3), TiP1 has shown very good sorption characteristics and therefore, most of the studies were performed on it. TiP1 was synthesized at mild thermal conditions using cobalt(II) ions as a modifying agent and HCl-washes as post-synthetic treatments. This sorbent was characterized by different spectroscopic techniques and its chemical formula was established to be: TiO(OH)(H2PO4)•H2O. The sorption capacity of TiP1, estimated about 4.8 meq.g-1, is higher than the reported exchange capacity for various amorphous TiP. The sorption characteristics of TiP1 towards divalent ions such as Cu2+, Zn2+, Ni2+, Mn2+ and Co2+, were investigated in this work. The results of the sorption experiments (in the 1-20 mmol.L-1 range) were fitted to the Langmuir and Temkin models with the latter one being somewhat preferred for most of the metal ions studied. This indicates that interactions between adsorbed molecules cannot be neglected. It was also found that the kinetics of the ion-exchange process was very fast and the equilibrium was reached within 10 minutes. The kinetic data were modeled using the pseudo-second order reaction rate and the obtained curves were consistent with chemisorption being the rate limiting step of the reactions. The selectivity order of the metal ions studied towards TiP1 here was found to be: Cu2+ > Zn2+ > Mn2+ > Co2+ > Ni2+. The TiP1 sorbent has also shown to be a very good cation-exchanger when batch experiments were performed using heavy metals polluted waters from closed mines, supplied by Boliden AB. These studies delineated that TiP1 has displayed exclusive sorption capacities and imminent ion-exchange kinetics. It has been distinctly shown that a modest change in the synthesis could facilitate the fabrication of titanium phosphate ion-exchangers with improved and versatile sorption properties.

Place, publisher, year, edition, pages
Luleå tekniska universitet, 2015
Series
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757
National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-17322 (URN)2d74f02d-4beb-45e5-8ac0-84b588c95734 (Local ID)978-91-7583-468-9 (ISBN)978-91-7583-469-6 (ISBN)2d74f02d-4beb-45e5-8ac0-84b588c95734 (Archive number)2d74f02d-4beb-45e5-8ac0-84b588c95734 (OAI)
Note
Godkänd; 2015; 20151102 (myltru); Nedanstående person kommer att hålla licentiatseminarium för avläggande av teknologie licentiatexamen. Namn: Myléne Trublet Ämne: Gränsytors kemi/Chemistry of Interfaces Uppsats: Outline of Titanium (IV) based H2PO4 Ion-exchangers: Kinetics and Sorption models Examinator: Professor Oleg Antzutkin, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Diskutant: Professor Ingmar Persson, Kemi och bioteknologi, Uppsala Tid: Torsdag 10 december 2015 kl 13.00 Plats: F341, Luleå tekniska universitetAvailable from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-04-16Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-4533-3920

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