Titanium oxyhydroxide – A new effective candidate for resolving the challenging water quality issue of high alkalinity

• Published in: Journal of environmental chemical engineering 2020-10, Vol.8 (5), p.104447, Article 104447
• Main Authors: Jacobson, Andrew T., Bagley, David M., Dewey, Janet C., Fan, Maohong
• Format: Article
• Language: English
• Subjects: Adsorption mechanism; Alkalinity; ATR-FTIR analysis; Carbonate adsorption; Irrigation; Water treatment
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2020.104447

[Display omitted] •New multifunctional material developed for alkalinity removal.•Large reductions in alkalinity concentrations achieved.•Alkalinity removal mechanism proposed.•Bicarbonate/carbonate removal through transformation into respective conjugate acid.•Adsorption interfacial species occur as monodentate complexes. The use of highly alkaline water in irrigation can result in major problems for soils that have received its application. Therefore, these waters are conventionally neutralized to benign alkalinity levels through the addition of acids, which add unwanted anions, can solubilize toxic trace elements, and are dangerous to the user. Solid titanium oxyhydroxide, TiO(OH)2, has the potential to efficiently reduce alkalinity without the problems associated with acid additions. In this work, TiO(OH)2 is synthesized, characterized, and evaluated for its use in alkaline water remediation. Characterization of TiO(OH)2 was completed using inductively coupled plasma mass spectrometry (ICP-MS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area analysis. Open and closed reaction systems were used to quantify the ability of TiO(OH)2 to remove both HCO3− and CO32- anions from aqueous solutions. A reaction mechanism was proposed based on the results from these systems in conjunction with an attenuated total reflectance Fourier-transform infrared (ATR-FTIR) analysis of the aqueous interfacial species.