Gas-bubbled nano zero-valent iron process for high concentration arsenate removal.
In this study, batch experiments were performed to investigate a novel process for high concentration arsenate removal in the presence of air and/or CO(2) bubbling. The pretreatment step, CO(2) bubbling at 300 mL/min for 5 min, was taken to adjust the solution pH to an acidic environment, followed by air bubbling at 300 mL/min for 10 min to increase dissolved oxygen in the solution. In the treatment period, the nano-scale zero-valent iron was applied to remove aqueous arsenate of 3000 μg/L, while the treatment system was continuously bubbled by 300 mL/min of air. Such a process resulted in outstanding performance in arsenate removal. Furthermore, in the field groundwater application, the arsenate removal rate for the proposed process was 5 times faster than the rate measured when the system was pretreated by acidic chemical species only.
Department of Chemical Engineering, Faculty of Engineering, Thammasat University, Pathumthani, Thailand.
Visanu
V
Tanboonchuy
Jia-Chin
JC
Hsu
Nurak
N
Grisdanurak
Chih-Hsiang
CH
Liao
D000465:Algorithms; D001149:Arsenates / Q000302:isolation & purification*; D002245:Carbon Dioxide / Q000737:chemistry; D017666:Deuterium Oxide / Q000737:chemistry; D005740:Gases; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D046529:Microscopy, Electron, Transmission; D012996:Solutions; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D014881:Water Supply / Q000032:analysis
D001149:Arsenates; D005740:Gases; D012996:Solutions; D014874:Water Pollutants, Chemical; D002245:Carbon Dioxide; D007501:Iron; D017666:Deuterium Oxide; C025657:arsenic acid