Flotation of metal-loaded clay anion exchangers. Part II: the case of arsenates.
Hydrotalcite-like materials, or otherwise termed layered double hydroxides, are clays with an ability to remove anions. As they usually are in powder form, these sorbents often present appreciable problems in the solid/liquid separation process following the sorption stage. Sorptive flotation of metal-loaded particles was investigated in this paper, as an alternative two-stage process. In the sorption process, satisfactory removals of arsenic(V) were obtained onto synthetic hydrotalcite particles from water. The effect of some parameters, like the solution ionic strength, concentrations, temperature, etc. was examined. During the second stage of the process, hydrotalcite fine particles were removed from the liquid phase by dispersed-air flotation; various surfactants were tested in relation to the ionic strength of the solution. The combined process of sorptive flotation provides promising results for arsenic removal.
Lazaridis
N K
NK
Chemical Technology Division, Department of Chemistry, Aristotle University of Thessaloniki, Greece. nlazarid@chem.auth.gr
Hourzemanoglou
A
A
Matis
K A
KA
D000327:Adsorption; D000536:Aluminum Hydroxide / Q000737:chemistry; D000538:Aluminum Silicates / Q000737:chemistry*; D000863:Antacids / Q000737:chemistry; D001149:Arsenates / Q000737:chemistry*; D000077215:Clay; D007474:Ion Exchange; D008276:Magnesium Hydroxide / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry*; D013696:Temperature
D000538:Aluminum Silicates; D000863:Antacids; D001149:Arsenates; D019216:Metals, Heavy; C010467:hydrotalcite; D000536:Aluminum Hydroxide; D008276:Magnesium Hydroxide; D000077215:Clay