[Show abstract][Hide abstract] ABSTRACT: Natural antioxidants derived from plant sources attract considerable scientific interest. While classic extraction methods consume high volumes of toxic organic solvents, cloud point extraction requires surfactant not exceeding 15% of the waste volume. In preliminary tests, the suitability of various low hazard surfactants (Span 20, PEG 400, Tween 80 and 20) was explored for separation of phenols and carotenoids from olive mill wastewater and red-flesh orange juice. Tween 80 showed the highest recovery and further applied to the next experiments. The most appropriate surfactant concentrations were 5% (for olive mill wastewater) and 7% (for orange juice) as indicated by recovery % and the rest cloud point extraction parameters (analyte concentration, concentration factor, and phase volume ratio). A double step CPE with 5% + 5% of Tween 80 recovered up to 94.4% of the total phenols from olive mill wastewater, while a 7% + 7% of Tween 80 recovered up to 72.4% of the total carotenoids from orange juice. Evaluation of the final effects and extraction efficiency of single and double step cloud point extraction shows that double step scheme seems to be preferable in both cases. Finally, phenols and carotenoids recovered by Tween 80 maintained high antiradical activity (DPPH test).
Journal of Separation Science 08/2012; 35(19):2665-2670. · 2.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cloud point extraction (CPE), a promising and simple technique for the separation of organic compounds using surfactants (Genapol X-080 [oligoethylene glycol monoalkyl ether] and PEG 8000 [polyethylene glycol with molecular weight of 8000]), was used to recover polyphenols from wine sludge (wine production waste). The effect of various parameters such as surfactant concentration, temperature, and pH on the percentage of phenol recovery and phase volume ratio during phenol separation from wine sludge was investigated, and the derived optimum parameters were used as the basis for the selection of CPE conditions. When a two-step CPE with a total of 4% v/v of Genapol X-080 (pH = 3.5, temperature = 55 degrees C, and time = 30 min) or 10% v/v of PEG 8000 (pH = 2.5, temperature = 55 degrees C, and time = 30 min) was applied the phenol recovery values achieved were 75.8 or 98.5%, respectively. Phenols recovered from wine sludge using the above surfactants maintained high antiradical activity as determined by the 1,1-diphenyl-2-picrylhydrazyl method.
Journal of the Air & Waste Management Association (1995) 04/2010; 60(4):454-9. · 1.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In order to evaluate the mixing effect of NaCl and surfactant on the remediation of TCB contaminated soil, column experiments
were performed. Selected soils for this study were two Iowa field soils (Fruitfield, and Webster) and one Korea field soil
(Pyeongtaek). We used four nontoxic, water-soluble anionic (DOSL, SLS) and nonionic surfactants (POE20, POE4). 1, 2, 4-trichlorobenzene
(TCB) was chosen as the model contaminant. Selected electrolyte for this study was NaCl. The TCB contaminated soils were leached
with surfactant solution of 4% (v/v) or 4% (w/v) with or without 5% (w/v) and 10% (w/v) NaCl. As controls, TCB contaminated
soils were also leached with deionized water. For the nonionic surfactants (POE20, POE4), the mixing effect of NaCl on the
solubilization of contaminant was insignificant. However, much greater mixing effectiveness was observed using anionic surfactant
(SLS, single head structure) solutions containing electrolyte (NaCl) from two Iowa soils and one Korea soil. In contrast,
another anionic surfactant (DOSL, double head structure) had little mixing effectiveness on the solubilization of TCB from
three soils. However, the NaCl mixing effect of DOSL anionic surfactant was found after leaching of 2500 ml solution with
Pyeongtaek soil. The effect of NaCl in changing effectiveness was due to Na+ (counterion) effects. The maximum recovery of added TCB in column tests was 97% for 4% (w/v) aqueous SLS anionic surfactant
+ 10% (w/v) NaCl. A little effectiveness of 4% (v/v) DOSL (anionic surfactant) with electrolytes may be due to small adsorption
of the double-head sulfate polar heads onto soil particles. Therefore, these results showed that the key factor in the variation
of TCB removal effect due to surfactant + NaCl leaching was not surfactant types but surfactant structure. Also, results of
this study suggest that the anionic surfactant (SLS) solutions containing electrolyte (NaCl) is a good candidate for surfactant-assisted
remediation of TCB contaminated soil.
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