Temperature impact on the sorption of selenium(VI) onto anatase

Jordan, Norbert; Müller, K.; Franzen, Carola; Brendler, Vinzenz

doi:10.1016/j.jcis.2012.09.021

Cited by 13 publications

(6 citation statements)

References 45 publications

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“…where ΔH o M and ΔH o sorb are the mean sorption site energy and change in site enthalpy, respectively; R is the universal gas constant; T is the thermodynamic temperature; and r is a proportionality constant. As evident from Equation 3.1, temperature affects the sorption energy and could lead to formation of less thermodynamically stable complexes, different adsorption capacity and faster adsorption kinetic (Ambe, 1987;Banerjee et al, 2008;Jordan et al, 2013b).…”

Section: Influence Of Sorbent Properties On Sorption Thermodynamicsmentioning

confidence: 99%

“…The extent of this speciation at a given pH is governed by the weak-acid oxyanions' pKa values and pH of the environment. However, the increase in total concentration of negative charges, increases with the water matrix pH as a result of oxyanions' deprotonation (Fuller et al, 1993;Jordan et al, 2013b;Su et al, 2010). To a greater or lesser extent, pH induced deprotonation affects all weak-acid oxyanions in an aqueous solution.…”

Section: Influence Of Water Matrix Properties On Sorption Thermodynamicmentioning

confidence: 99%

See 1 more Smart Citation

Engineering metal (hydr)oxide sorbents for removal of arsenate and similar weak-acid oxyanion contaminants: A critical review with emphasis on factors governing sorption processes

Hristovski

Markovski

2017

Science of The Total Environment

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To create an integrative foundation for engineering of the next generation inexpensive sorbent systems, this critical review addresses the existing knowledge gap in factor/performance relationships between weak-acid oxyanion contaminants and metal (hydr)oxide sorbents. In-depth understanding of fundamental thermodynamics and kinetics mechanisms, material fabrication, and analytical and characterization techniques, is necessary to engineer sorbent that exhibit high capacity, selectivity, stability, durability and mass transport of contaminants under a wide range of operating and water matrix conditions requirements. From the perspective of thermodynamics and kinetics, this critical review examines the factors affecting sorbent performances and analyzes the existing research to elucidate future directions aimed at developing novel sorbents for removal of weak-acid oxyanion contaminants from water. Only sorbents that allow construction of simple and inexpensive water treatment systems adapted to overcome fiscal and technological barriers burdening small communities could pave the road for providing inexpensive potable water to millions of people. Novel sorbents, which exhibit (1) poor performances in realistic operating and water matrix conditions and/or (2) do not comply with the purely driven economics factors of production scalability or cost expectations, are predestined to never be commercialized.

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Section: Influence Of Sorbent Properties On Sorption Thermodynamicsmentioning

confidence: 99%

Section: Influence Of Water Matrix Properties On Sorption Thermodynamicmentioning

confidence: 99%

Engineering metal (hydr)oxide sorbents for removal of arsenate and similar weak-acid oxyanion contaminants: A critical review with emphasis on factors governing sorption processes

Hristovski

Markovski

2017

Science of The Total Environment

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“…Among these, sorption is considered as an efficient, simple, and low-cost process, particularly suitable for removing contaminated selenium at low levels and point-of-use applications . Inorganic titanium oxide, − aluminum oxide, − iron oxides, − mixed metal oxides, − and other minerals − were commonly used for this application. However, due to the limited activated sites for sorption, most of the inorganic oxide sorbents exhibit low capacity for capturing selenium.…”

Section: Introductionmentioning

confidence: 99%

Selenium Sequestration in a Cationic Layered Rare Earth Hydroxide: A Combined Batch Experiments and EXAFS Investigation

Zhu

Zhang

et al. 2017

Environ. Sci. Technol.

105

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Selenium is of great concern owing to its acutely toxic characteristic at elevated dosage and the long-term radiotoxicity of Se. The contents of selenium in industrial wastewater, agricultural runoff, and drinking water have to be constrained to a value of 50 μg/L as the maximum concentration limit. We reported here the selenium uptake using a structurally well-defined cationic layered rare earth hydroxide, Y(OH)Cl·1.5HO. The sorption kinetics, isotherms, selectivity, and desorption of selenite and selenate on Y(OH)Cl·1.5HO at pH 7 and 8.5 were systematically investigated using a batch method. The maximum sorption capacities of selenite and selenate are 207 and 124 mg/g, respectively, both representing the new records among those of inorganic sorbents. In the low concentration region, Y(OH)Cl·1.5HO is able to almost completely remove selenium from aqueous solution even in the presence of competitive anions such as NO, Cl, CO, SO, and HPO. The resulting concentration of selenium is below 10 μg/L, well meeting the strictest criterion for the drinking water. The selenate on loaded samples could be desorbed by rinsing with concentrated noncomplexing NaCl solutions whereas complexing ligands have to be employed to elute selenite for the material regeneration. After desorption, Y(OH)Cl·1.5HO could be reused to remove selenate and selenite. In addition, the sorption mechanism was unraveled by the combination of EDS, FT-IR, Raman, PXRD, and EXAFS techniques. Specifically, the selenate ions were exchanged with chloride ions in the interlayer space, forming outer-sphere complexes. In comparison, besides anion exchange mechanism, the selenite ions were directly bound to the Y center in the positively charged layer of [Y(OH)(HO)] through strong bidentate binuclear inner-sphere complexation, consistent with the observation of the higher uptake of selenite over selenate. The results presented in this work confirm that the cationic layered rare earth hydroxide is an emerging and promising material for efficient removal of selenite and selenate as well as other anionic environmental pollutants.

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“…3 References: a: Hayes et al (1987), b: Manceau and Charlet (1994), c: Schulthess (2000b), d: Peak andSparks (2002), e: Das et al (2013), f: Yue et al (2020), g: Su and Suarez (2000), h; Johnston and Chrysochoou (2016), i; Kikuchi et al (2019), j; Borsig et al (2017), k; Lounsbury et al (2019), l; Jordan et al (2013b), m;Peak (2006), n; Elzinga et al (2009), o; Jordan et al (2018), p; Jordan et al (2011), q;Jordan et al (2013a).…”

Section: Etlm Treatmentmentioning

confidence: 99%

“…For anatase, we retrieved the selenate adsorption constants from the data reported by Jordan et al (2011), Jordan et al (2013a and Yamani et al (2014) using the values of K 1 , K 2 , K C+ and K A-estimated from the ETLM fitting of anatase surface charge data (Kitadai et al, 2018) (Fig. S1), setting N s and C 1 (=C 2 ) to the values predicted by Sverjensky (2005).…”

Section: Etlm Treatmentmentioning

confidence: 99%