Formation of tooeleite and the role of direct removal of As(III) from high-arsenic acid wastewater

• Published in: Journal of hazardous materials Vol. 320; pp. 620 - 627
• Main Authors: Chai, Liyuan, Yue, Mengqing, Yang, Jinqin, Wang, Qingwei, Li, Qingzhu, Liu, Hui
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.12.2016
• Subjects: Acid wastewater; Arsenite; Efficiency; Ferrihydrite; Formations; Hazardous wastes; Precipitates; Precipitation; Precursors; Stability; Tooeleite; Wastewater treatment; Ferrihydrite; Acid wastewater; Tooeleite; Arsenite
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2016.07.069

[Display omitted] ⿢A novel method for direct removal of As(III) by forming tooeleite is developed.⿢Arsenic removal efficiency can reach 99% for high As(III) concentration of 7.5g/L.⿢Ferrihydrite contributes to the formation of tooeleite and the removal of As(III). In this study, an earth-mimetic method was proposed for the direct removal of As(III) by the formation of tooeleite, a ferric arsenite sulfate mineral. A series of batch experiments was used to study the relationship between the formation of tooeleite and the removal of As(III). The results indicate that As(III) removal efficiency reached up to 99% under the treatment condition of pH 1.8⿿4.5, initial As(III) concentration higher than 0.75g/L, and Fe/As ranged from 0.8 to 2 at room temperature. Various characterizations confirm that the precipitate obtained by this treatment was tooeleite with relatively high stability. In addition, it is assumed that ferrihydrite exists as a precursor, which is vital to the formation of tooeleite and the removal of As(III). This study suggests that tooeleite formation may be an alternative method in the direct removal of As(III) from high-arsenic acid wastewater.