TY - JOUR
T1 - Dynamic micellar enhanced ultrafiltration
T2 - Use of anionic (SDS)-nonionic(NPE) system to remove Cr3+ at low surfactant concentration
AU - Aoudia, Mohamed
AU - Allal, Nora
AU - Djennet, Ahcene
AU - Toumi, Leila
N1 - Funding Information:
The authors thank the University of Blida and The Ministry of Higher Education and Scientific Research, Algeria.
PY - 2003/6/1
Y1 - 2003/6/1
N2 - Ultrafiltration experiments were carried out with tangential cell system. The permeate flux and rejection characteristics of SDS and nonylphenol ethoxylated C9H19C6H4(CH2CH 2O)5CH2CH2OH (NPE) micellar solutions for a ceramic tubular membrane (zirconium oxide-Titanium oxide) were investigated. For both surfactants, micelle rejection increased with pressure and reached an asymptotic value at ΔP=250kPa beyond which micellar rejection remained unchanged (∼+99%). This was explained in terms of concentration polarization occurring in the vicinity of the membrane-solution interface. Time dependence of the permeate surfactant concentration was also investigated. During the first 2h of ultrafiltration, the surfactant concentration changed with time. Then a steady-state condition was reached and the permeate concentration remained invariant. This trend was attributed to a time-dependent gradual change of the state of packing of the micelles over the membrane surface. Cr3+ rejection by SDS-NPE mixed micelles yielded high Cr3+ rejection (+99.5%) at NPE molar fraction up to 0.2. Within this optimum composition and ΔP=250kPa, unexpectedly high rejection (33.50%) was measured below the critical micellar concentration (cmc). This was considered as due to a high surfactant concentration in the vicinity of the membrane surface where micelles are present, although the retentate surfactant concentration is below the cmc. Above the cmc, high Cr3+ rejections (+99%) were obtained. Interestingly, this rejection was found to be independent of the feed surfactant concentration within the range investigated in this study (3×cmc-30×cmc), suggesting that Cr3+ rejection is not a function of the surfactant concentration in the bulk retentate solution but a function of the surfactant concentration nearby the membrane surface. The presence of NaCl in the feed surfactant solution showed a drastic adverse effect on Cr3+ rejection by SDS-NPE micelles.
AB - Ultrafiltration experiments were carried out with tangential cell system. The permeate flux and rejection characteristics of SDS and nonylphenol ethoxylated C9H19C6H4(CH2CH 2O)5CH2CH2OH (NPE) micellar solutions for a ceramic tubular membrane (zirconium oxide-Titanium oxide) were investigated. For both surfactants, micelle rejection increased with pressure and reached an asymptotic value at ΔP=250kPa beyond which micellar rejection remained unchanged (∼+99%). This was explained in terms of concentration polarization occurring in the vicinity of the membrane-solution interface. Time dependence of the permeate surfactant concentration was also investigated. During the first 2h of ultrafiltration, the surfactant concentration changed with time. Then a steady-state condition was reached and the permeate concentration remained invariant. This trend was attributed to a time-dependent gradual change of the state of packing of the micelles over the membrane surface. Cr3+ rejection by SDS-NPE mixed micelles yielded high Cr3+ rejection (+99.5%) at NPE molar fraction up to 0.2. Within this optimum composition and ΔP=250kPa, unexpectedly high rejection (33.50%) was measured below the critical micellar concentration (cmc). This was considered as due to a high surfactant concentration in the vicinity of the membrane surface where micelles are present, although the retentate surfactant concentration is below the cmc. Above the cmc, high Cr3+ rejections (+99%) were obtained. Interestingly, this rejection was found to be independent of the feed surfactant concentration within the range investigated in this study (3×cmc-30×cmc), suggesting that Cr3+ rejection is not a function of the surfactant concentration in the bulk retentate solution but a function of the surfactant concentration nearby the membrane surface. The presence of NaCl in the feed surfactant solution showed a drastic adverse effect on Cr3+ rejection by SDS-NPE micelles.
KW - Concentration polarization
KW - MEUF
KW - Micelle rejection
KW - Permeate flux
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U2 - 10.1016/S0376-7388(03)00128-5
DO - 10.1016/S0376-7388(03)00128-5
M3 - Article
AN - SCOPUS:0038412767
SN - 0376-7388
VL - 217
SP - 181
EP - 192
JO - Journal of Membrane Science
JF - Journal of Membrane Science
IS - 1-2
ER -