• Journal of Korean Society for Atmospheric Environment
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• v.13 no.1
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• pp.31-40
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• 1997

This study was conducted to investigate the biodegradation of gaseous trichloroethylene (TCE) and tetrachloroethylene (PCE) in an activated carbon biofilter inoculated with phenol-oxidizing microorganisms and to study the effect of surfactant concentration below its critical micelle concentration (CMC) on the re-moval efficiency of TCE or PCE. The investigation was conducted using two specially built stainless steel biofilters, one for TCE and the other for PCE, at residence times of 1.5~7 min. The removal efficiency of gaseous TCE was 100％ at a residence time of 7 min and its average inlet concentration of 85 ppm. For gaseous PCE, 100％ removal efficiency was obtained at residence times of 4~7 min and its average concentrations of 47~84 ppm. It was found that adsorption by GAC was a minor mechanism for TCE and PCE removal in the activated carbon biofilters. Transformation yields of gaseous TCE and PCE were about 8~48 g of TCE/g of phenol and 6~25g of PCE/g of phenol, according to residence times. This values showed one or two orders of magnitude less than aqueous TCE degradation. The TCE and PCE activated carbon biofilter performances were observed to be a little enhanced but not significantly, when the surfactant was introduced at concentrations of 5~50 mg/L.

• Microbiology and Biotechnology Letters
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• v.39 no.1
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• pp.86-92
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• 2011

Three bioremediation methods, natural attenuation (NA), biostimulation (BS) and bioaugmentation (BA) were applied to remediate diesel-contaminated soil, with their remediation efficiencies and soil microbial activities compared both with and without surfactant (Tween 80). BA treatment employing Rhodococcus sp. EH831 was the most effective for the remediation of diesel-contaminated soil at initial remediation stage. On the addition of surfactant, no significant effect on the remediation performance was observed. A negative correlation was found between the dehydrogenase activity (DHA) and residual concentration of total petroleum hydrocarbons (TPHs) at below 20,000 mg-$TPHs{\cdot}kg$-dry $soil^{-1}$, as follows: DHA (${\mu}g$-TPF(Triphenylformazan)${\cdot}g$-dry $soil^{-1}\;d^{-1}$) = -0.02 ${\times}$ TPHs concentration (mg-$TPHs{\cdot}kg$-dry $soil^{-1}$) + 425.76 (2500 ${\leq}$ TPHs concentration ${\leq}$ 20000, p < 0.01).

• Journal of the Korean Applied Science and Technology
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• v.30 no.4
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• pp.679-687
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• 2013

The critical micelle concentration (CMC) and counter-ion binding constant (B) of the pure cationic surfactants (DTAB, TTAB, CTAB), nonionic surfactants (Tween-20, Tween-40, Tween-80), and their mixed surfactants (TTAB/Tween-20, TTAB/Tween-40, TTAB/Tween-80) in aqueous solutions of 4-chlorobenzoic acid were determined by using the UV/Vis absorbance method and the conductivity method from 284 K to 312 K. Thermodynamic parameters (${\Delta}G^o{_m}$, ${\Delta}H^o{_m}$, and ${\Delta}S^o{_m}$), associated with the micelle formation of those surfactant systems, have been estimated from the dependence of CMC and B values on the temperature and carbon length of surfactant molecules. The calculated values of ${\Delta}G^o{_m}$ are all negative within the measured range but the values of ${\Delta}H^o{_m}$ and ${\Delta}S^o{_m}$ are positive or negative, depending on the length of the carbon chain and surfactant.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.740-747
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• 2015

This research was performed to evaluate the feasibility of in situ soil flushing for TPH-contaminated soil remediation. It was conducted in batch test as fundamental research for in situ soil flushing. The 30% of initial TPH concentration was removed by shaking only in batch test. The removal efficiency of TPH in case of groundwater as surfactant dilution solution was approximate 2~6% lower than that of distilled water. Mixing ratio of soil to surfactant solution did not practically effect on the TPH removal efficiency. In the experiment of using single or mixed surfactant solution with 0.1~4.0 wt%, Tween-80, SWA-1503, SWA-1503+SDS showed averagely over 80%. It was determined that the optimum surfactant concentration was 0.1 wt% because there was no significant difference between concentrations of 0.1~4.0 wt%.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.53-59
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• 2005

In this study, the supercritical electroplating was investigated by forming macroemulsion of electroplating solution using surfactant in supercritical $CO_2$. The fluorinated analogous AOT surfactant, sodium salt of bis (2,2,3,3,4,4,5,5-octafluoro-1-pentanol) sulfosuccinate which has both '$CO_2$ philic' chains and 'hydrophilic' head group was used as a surfactant, and Ni plate and Cu plate were used as the anode and the cathode, respectively. Electroplating was carried out in the conventional method and the supercritical macroemulsion and both results were compared. The supercritical electroplating was carried out in various concentration of surfactant such as 2, 4, 7 wt%, the volume ratio of Ni-plating solution to $CO_2$ was varied in the range of 10-70 vol%, and propane was used as a supercritical fluid instead of $CO_2$. According to the experimental results, the plated surface of Ni on Cu plate performed in supercritical macroemulsion was better than that, in conventional state. In the image of Ni surface plated on Cu plate in supercritical state, there were fewer pin-holes and pits comparing with that in the conventional process. The current and conductivity was increased as the volume ratio of Ni-plating solution to $CO_2$ was increased and the current and the amount of Ni plated on Cu plate were decreased as the concentration of surfactant become higher. In addition, in case of the continuous phase, using $CO_2$ was more effective than using $CO_2$.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.217-223
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• 2015

We investigated the emulsifying properties of barley octenyl succinic anhydride (OSA)-${\beta}$-glucan, such as changes in the fat globule size and zeta-potential as influenced by pH or the addition of NaCl. Additional experiments to fabricate a suitable co-surfactant system were also performed. We found that the fat globule size in OSA-${\beta}$-glucan emulsions increased upon lowering the pH (i.e., under acidic conditions) or increasing the NaCl concentration. These results were confirmed through microscopic observation. Co-surfactant hydrophilic Tween 20 was found to be suitable for the OSA-${\beta}$-glucan emulsion, which facilitated the formation of smaller fat globules and enhanced the creaming stability when it was added in >0.2 wt% concentration. From the results of the surface load of OSA-${\beta}$-glucan in emulsions, Tween 20 addition enhanced the stability probably by the co-adsorption of the two surfactants at the droplet surface.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.60-60
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• 2003

• Proceedings of the SAREK Conference
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• 2005.06a
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• pp.88-88
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• 2005

• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.379-384
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• 2011

The critical micelle concentration (CMC) and the counter ion binding constant (B) for the mixed micellizations of DBS (sodium dodecylbenzenesulfonate), SDS (sodium dodecylsulfate), and Brij 30 (polyoxyethylene(4) lauryl ether) at $25^{\circ}C$ in pure water were determined by the use of electric conductivity and surface tension measuring methods. Various thermodynamic parameters ($X_i,\;{\gamma}i,\;C_i,\;a_i^M,\;{\beta}$, and ${\Delta}H_{mix}$) were calculated and compared with each other mixed surfactant system by means of the equations derived from the nonideal mixed micellar model. The results show that the SDS molecule interacts more strongly with Brij 30 molecule than DBS molecule and that the SDS/Brij 30 mixed surfactant system has the greatest negative deviation from the ideal mixed micellar model and the SDS/DBS mixed system has followed almost the ideal mixed micellar model.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.5
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• pp.672-676
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• 2003

Effect of a surfactant Tween 80 on the bacterial growth in the rumen was examined on the in vitro pure cultures of Streptococcus bovis, Selenomonas ruminantium, Butyrivibrio fibrisolvens, Prevotella ruminicola, Megasphaera elsidenni, Fibrobacta succinogenes, Ruminanococcus albus and Ruminococcus flavefaciens. Dry matter degradability (DMD), concentrations and compositions of volatile fatty acids (VFA), and the most probable number (MPN) of cellulolytic bacteria and total number of bacteria in the presence of Tween 80 were also examined on the in vitro rumen mixed culture either with barley grain or orchardgrass hay. The growth of S. bovis, S. ruminantium, B. fibrisolvens, P. ruminicola, M. elsidenni and F. succinogenes were significantly higher (p<0.05) at over 0.05% concentrations of Tween 80 than those of the control cultures, while was not changed with R. albus and R. flavefaciens. With rumen mixed culture the DMD of barley grain and orchardgrass hay was significantly higher (p<0.05) at a 0.2% concentration of Tween 80 than the control, being reflected in the significantly higher (p<0.05) VFA production (mmol $g^{-1}$DDM) with orchardgrass hay. The higher (p<0.05) ratio of propionate to acetate at a 0.2% concentration of Tween 80 was also observed with orchardgrass hay, showing a similar trend with barley grain. No changes in the total bacterial number and MPN of cellulolytic bacteria were observed.