DOI: 10.1016/j.watres.2017.12.038
Scopus记录号: 2-s2.0-85040012229
论文题名: Arsenate co-precipitation with Fe(II) oxidation products and retention or release during precipitate aging
作者: Senn A.-C. ; Hug S.J. ; Kaegi R. ; Hering J.G. ; Voegelin A.
刊名: Water Research
ISSN: 431354
出版年: 2018
卷: 131 起始页码: 334
结束页码: 345
语种: 英语
英文关键词: Arsenic removal
; Iron precipitates
; Phosphate removal
; Precipitate aging
; Water treatment
Scopus关键词: Calcium
; Calcium compounds
; Chemicals removal (water treatment)
; Coprecipitation
; Dissolution
; Electrolytes
; Iron oxides
; Pollution control
; Precipitates
; Silicates
; Silicon
; Water treatment
; Arsenic removal
; Buffered solutions
; Critical ratio
; Dissolved phosphates
; Environmental systems
; Free electrolytes
; Hydrous ferric oxides
; Phosphate removal
; Iron compounds
; arsenic acid
; buffer
; calcium phosphate
; crystallin
; electrolyte
; ferric hydroxide
; ferric oxide
; ferrous ion
; phosphate
; silicate
; arsenate
; concentration (composition)
; dissolved load
; electrolyte
; ferrihydrite
; iron
; lepidocrocite
; oxidation
; phosphate
; pollutant removal
; precipitation (chemistry)
; remobilization
; water treatment
; aging
; Article
; comparative study
; environmental factor
; oxidation
; pH
; precipitation
; priority journal
; water treatment
英文摘要: The co-precipitation of arsenate (As(V)) with Fe(III)-precipitates is of great importance in water treatment and critically affects the fate of As in environmental systems. We studied the effects of dissolved phosphate (P; 0-1 mM), silicate (Si; 0 or 0.5 mM) and Ca (0, 0.5 and 4 mM) on the sequestration of 7 μM As(V) by Fe(III)-precipitates formed by the oxidation of 0.5 mM Fe(II) in aerated bicarbonate-buffered solutions with an initial pH of 7.0 as well as the retention or release of As(V) after precipitate aging for 30 d at 40 °C. Dissolved As(V) concentrations in fresh precipitate suspensions greatly varied as a function of the initial dissolved P/Fe ratio ((P/Fe)init) and the concentrations of Ca and Si. Limited As(V) removal was observed at (P/Fe)init that exceeded the critical ratio (P/Fe)crit above which exclusively (Ca-)Fe(III)-phosphate forms. Effective As(V) removal was observed at (P/Fe)init < (P/Fe)crit, where initial formation of (Ca-)Fe(III)-phosphate is followed by the formation of Si-ferrihydrite in Si-containing electrolytes and of poorly-crystalline lepidocrocite and hydrous ferric oxide in the Si-free electrolytes. The retention of As(V) and P by fresh Fe(III)-precipitates was most effective in systems containing both Ca and Si. In the Si- and Ca-free electrolytes at (P/Fe)init of ∼0.2–0.6, the rapid onset of precipitate aging with conversion of Fe(III)-phosphate to ferrihydrite resulted in a substantial remobilization of As(V) (up to 55% of initially precipitated As(V)). Ca reduced As remobilization during aging by stabilizing Ca-Fe(III)-phosphate and promoting Ca-phosphate formation, and Si by stabilizing Si-ferrihydrite against transformation. Consequently, also after aging, the lowest dissolved As(V) and P fractions were observed in precipitate suspensions containing both Ca and Si. © 2017 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113009
Appears in Collections: 气候减缓与适应
There are no files associated with this item.
作者单位: Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, Duebendorf, CH-8600, Switzerland; Department of Environmental Sciences, Institute of Biogeochemistry and Pollutant Dynamics, ETH, Swiss Federal Institute of Technology, Zurich, Switzerland; School of Architecture Civil and Environmental Engineering, EPFL, École Polytechnique Féderale de Lausanne, Switzerland
Recommended Citation:
Senn A.-C.,Hug S.J.,Kaegi R.,et al. Arsenate co-precipitation with Fe(II) oxidation products and retention or release during precipitate aging[J]. Water Research,2018-01-01,131