Metal extraction in water/micelle systems: Complex formation, stripping and recovery of Cd(II)

Adsorption of surfactant micelles and Cd2+/Zn2+ in micellar-enhanced ultrafiltration

“…7 shows the second-order Lagergren adsorption kinetics curve for the effect of SDS micelles on Cd 2+ /Zn 2+ in MEUF. The adsorption kinetics equations are expressed as: Zn 2+ t = 0.0338t + 0.0424t (6) where is the adsorption capacity (mg/g), and t is the adsorption time (min). The second-order Lagergren adsorption kinetics constant and the equilibrium adsorption capacity are 0.117 g/(mg min), 29.67 mg/g for Cd 2+ , and 0.027 g/(mg min), 29.59 mg/g for Zn 2+ .…”

“…MEUF was first used in the treatment of heavy metals in wastewater in the 1970s [5], and it has since been found that MEUF can be used to separate almost all heavy metal ions, including Cd 2+ , Ni 2+ , Zn 2+ , Cr 3+ , Mn 2+ , Pb 2+ , CrO 4 3− , Fe 3+ , Cu 2+ , and Fe(CN) 6 3− [6][7][8][9][10][11][12][13][14][15][16][17][18][19]. The surfactants used in MEUF range from single ionic surfactants, such as sodium dodecyl sulfate (SDS), cetyltriethylammnonium bromide (CTAB), dichloroacetic acid (DCA), trichloroacetic acid (TCA), sodium salt of 2-(2-carboxyethyl)-3-decyl maleic anhydride (DCMA-3Na), tetradecyl trimethyl ammonium bromide (TTAB), and polyoxyethylene nonyl phenyl ether (PONPE) [20][21][22][23][24][25][26], to mixed surfactants, such as SDS and polyoxyethylene octyl phenyl ether (Tritonx-100), SDS and polyoxyethyleneglycol dodecyl ether (Brij35), and SDS and nonylphenol ethoxylated (NPE) [27,28].…”

Metal ion extraction in microheterogeneous systems

“…Copper(II) reduction was not possible in a CTAB/BuOH/HQ microemulsion [45]. The effects of Mg 2+ , Na + and H + were investigated for the recovery of Cd 2+ from PADA-SDS micelles [31].…”

“…96% of 100 mg/kg of Cr 3+ ions were extracted in SDS micelles [30]. Anionic micelles solubilising PADA were successfully used to extract 10 −4 M of Cd(II) [31]. SDS micelles solubilising D2EHPA gave no selectivity between Co(II) and…”

Recovery and reuse of surfactant SDS from a MEUF retentate containing Cd2+ or Zn2+ by ultrafiltration

“…MEUF is a viable alternative technique which is economical and effective for removing heavy metal ions from wastewater compared with conventional techniques since membranes can be added as a retrofit of existing plants. Moreover, removal efficiency of 99.0% can be almost easily obtained [12,13]. Sodium dodecyl sulfate (SDS), an anionic surfactant, which is often selected for the effective removal of heavy metal ions such as cadmium [14,15], chromium [16], cobalt [17], cesium [17], nickel [18], zinc [19], plumbum [20] and copper [21,22] in MEUF.…”