• 한국지하수토양환경학회지:지하수토양환경
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• 제21권5호
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• pp.1-7
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• 2016

The removal of non-aqueous phase liquids (NAPLs) from groundwater using pure water, via pump and treat, is quite ineffective due to their low solubility and hydrophobicity. Therefore, the objectives of pilot tests were to select potentially suitable surfactants that solubilize tetrachloroethylene (PCE) and trichloroethylene (TCE) present as contaminants and to evaluate the optimal range of process parameters that can increase the removal efficiency in surfactant-enhanced soil flushing (SESF). Used experimental method for surfactant selection was batch experiments. The surfactant solution parameters for SESF pilot tests were surfactant solution concentration, surfactant solution pH, and the flow rate of surfactant solution in the SESF pilot system. Based on the batch experiments for surfactant selection, DOSL (an anionic surfactant) was selected as a suitable surfactant that solubilizes PCE and TCE present as contaminants. The highest recovery (95%) of the contaminants was obtained using a DOSL surfactant in the batch experiments. The pilot test results revealed that the optimum conditions were achieved with a surfactant solution concentration of 4% (v/v), a surfactant solution pH of 7.5, and a flow rate of 30 L/min of surfactant solution (Lee and Woo, 2015). The maximum removal of contaminants (89%) was obtained when optimum conditions were simultaneously met in pilot-scale SESF operations. These results confirm the viability of SESF for treating PCE and TCE-contaminated groundwater.

• 자원환경지질
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• 제34권4호
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• pp.417-422
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• 2001

계면활성제는 소수성 화합물로 오염된 토양과 대수층을 복원하는데 사용할 수 있다. 본 연구의 목적은 톨루엔으로 오염된 사질토양을 복원하는데 사용될 수 있는 적당한 계면활성제들의 선택과 선택된 계면활성제들이 얼마나 효과적으로 톨루엔을 제거하는가를 연구하는데 있다. 사용된 토양은 Ottawa 사질 토양이며, 이용된 유기오염물질은 톨루엔이었다. 6종의 계면활성제의 선택은 독성도, 용해도 등에 따라 이루어졌으며, 이들을 이용한 계면활성제들의 선택실험 방법은 separatory funnel 실험과 shaker table agitation and centrifugation 실험이다. HLB 및 표면장력과 본 연구의 실험 결과에 의하여 6종의 계면활성제 중 가장 효율적인 종으로 Sandopan JA36(an anionic surfactant)과 Pluronic L44(a nonionic surfactant)가 선택되었다. 최고의 톨루엔 회수율 96%는 Sandopan JA36를 사용한 shaker table agitation and centrifugation 실험에서 얻었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 INTERNATIONAL SYMPOSIUM ON SOIL & GROUNDWATER ENVIRONMENT
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• pp.131-132
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• 2005

• 한국물환경학회지
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• 제22권5호
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• pp.824-830
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• 2006

Several tests were conducted to optimize the design parameters of ln-situ soil flushing processes for diesel contaminated soil. According to the batch extraction test for three anionic surfactants evaluation, Calgonit limiting bubble occurrence was selected for its higher oil cleaning efficiency. After optimum surfactant selection, there were many sets of column flushing test. Over 70% of BTEX was removed in this surfactant dose with 400% of soil volume. In the case of no surfactant addition flushing in column, so called "blank flushing test", BTEX removal rate was 64%. But when we reused the effluent for the cleaning solution, the removal rate was decreased to 46.9%. This result showed reabsorption of oil occurred on the soil. With the addition of Calgonit solution to the diesel contaminated column, BTEX was removed up to 98.9% during the first flushing and 99.4% for the second recirculation flushing. In microcosm tests, diesel contaminated soils were cleaned by both surfactant flushing and biological activities. In anoxic condition, nitrate was used as an electron acceptor while the surfactant and the oil were used an electron donor. BTEX removal efficiency could be achieved up to 80% by biological degradation.

• Clinical and Experimental Pediatrics
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• 제60권9호
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• pp.273-281
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• 2017

To date, preterm infants with respiratory distress syndrome (RDS) after birth have been managed with a combination of endotracheal intubation, surfactant instillation, and mechanical ventilation. It is now recognized that noninvasive ventilation (NIV) such as nasal continuous positive airway pressure (CPAP) in preterm infants is a reasonable alternative to elective intubation after birth. Recently, a meta-analysis of large controlled trials comparing conventional methods and nasal CPAP suggested that CPAP decreased the risk of the combined outcome of bronchopulmonary dysplasia or death. Since then, the use of NIV as primary therapy for preterm infants has increased, but when and how to give exogenous surfactant remains unclear. Overcoming this problem, minimally invasive surfactant therapy (MIST) allows spontaneously breathing neonates to remain on CPAP in the first week after birth. MIST has included administration of exogenous surfactant by intrapharyngeal instillation, nebulization, a laryngeal mask, and a thin catheter. In recent clinical trials, surfactant delivery via a thin catheter was found to reduce the need for subsequent endotracheal intubation and mechanical ventilation, and improves short-term respiratory outcomes. There is also growing evidence for MIST as an alternative to the INSURE (intubation-surfactant-extubation) procedure in spontaneously breathing preterm infants with RDS. In conclusion, MIST is gentle, safe, feasible, and effective in preterm infants, and is widely used for surfactant administration with noninvasive respiratory support by neonatologists. However, further studies are needed to resolve uncertainties in the MIST method, including infant selection, optimal surfactant dosage and administration method, and need for sedation.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권1호
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• pp.13-21
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• 2012

This study reports a surfactant-enhanced in-situ remediation treatment at a test site which is located in a hilly terrain. The leakage oils from a storage tank situated on the top of the hill contaminated soils and groundwater in the lower elevation. Sixteen vertical injection wells (11 m deep) were installed at the top of the hill to introduce 0.1-0.5 vol.% of non-ionic Tween-80 surfactant. The contaminated area that required remediation treatment was about $1,650\;m^2$. Two cycles of injecting surfactant solution followed by water were repeated over approximately 7.5 months: first cycle with 0.5 month of surfactant injection followed by 3 months of water injection, and second cycle with 1 month of surfactant followed by 3 months of water injection. The seasonal fluctuation in groundwater table was also considered in the selection of periods for surfactant and water injection. The results showed that the initial Total Petroleum Hydrocarbon (TPH) concentration of 1,041 mg/kg (maximum 3,605 mg/kg) was reduced significantly down to 76.6 mg/kg in average. After 2nd surfactant injection process finished, average TPH concentration of soils was reduced to 7.5% compared to initial concentration. Also, average BTEX concentration of soils was reduced to 10.8%. This resultes show that the surfactant enhanced in-situ remediation processes can be applicable to LNAPL contaminated site in field scale.

• Membrane and Water Treatment
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• 제13권4호
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• pp.201-208
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• 2022

Emulsion Liquid Membrane (ELM) is a prominent technique for the separation of heavy metal ions from wastewater due to the fast extraction and is a single-stage operation of stripping-extraction. The selection of the components (Surfactant and Carrier) of ELM is a very significant step for its preparation. In the ELM technique, the primary water- in-oil (W/O) emulsion is emulsified in water to produce water-in-oil-in-water (W/O/W) emulsion. The water in oil emulsion was prepared by mixing the membrane phase and internal phase. To prepare the membrane phase, the extractant D2EHPA (di-2-ethylhexylphosphoric acid) was used as a mobile carrier, Span-80 as a surfactant, and Paraffin as a diluent. Moreover, the internal (receiving) phase was prepared by dissolving sulphuric acid in water. Di-(2- ethylhexyl) phosphoric acid such as surfactant concentration, carrier concentration, sulphuric acid concentration in the receiving (internal) phase, agitation time (emulsion phase and feed phase), the volume ratio of the membrane phase to the receiving phase, the volume ratio of the external feed phase to the primary water-in-oil emulsion and pH of feed were studied on the percentage extraction of metal ions at 20℃. The results show that it is possible to remove 78% for As(V), 98% for Cd(II), and 99% for Pb(II). Emulsion Liquid Membrane (ELM) is a well-known technique for separating heavy metal ions from wastewater due to the fast extraction and is a single-stage operation of stripping-extraction. The selection of ELM components (Surfactant and Carrier) is a very significant step in its preparation. In the ELM technique, the primary water-in-oil (W/O) emulsion is emulsified to produce water-in-oil-in-water (W/O/W) emulsion. The water in the oil emulsion was prepared by mixing the membrane and internal phases. The extractant D2EHPA (di-2-ethylhexylphosphoric acid) was used as a mobile carrier, Span-80 as a surfactant, and Paraffin as a diluent. Moreover, the internal (receiving) phase was prepared by dissolving sulphuric acid in water. Di-(2-ethylhexyl) phosphoric acid such as surfactant concentration, carrier concentration, sulphuric acid concentration in the receiving (internal) phase, agitation time (emulsion phase and feed phase), the volume ratio of the membrane phase to the receiving phase, the volume ratio of the external feed phase to the primary water-in-oil emulsion and pH of feed were studied on the percentage extraction of metal ions at 20℃. The results show that it is possible to remove 78% for As(V), 98% for Cd(II), and 99% for Pb(II).

• 펄프종이기술
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• 제47권6호
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• pp.164-169
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• 2015

Nowadays blending ratio of OMG (old magazine) in recovered paper used for manufacturing newspaper have been increased. When large amount of OMG is consumed in newsprint mill, brightness can be improved by inorganic pigments of coating layer. On the other hand decrease in yield of deinking process will be encountered because the pigments can be removed as reject of froth flotation process. Therefore selection of the optimal deinking agent is an important. Non-ionic surfactant have been used widely in newsprint mill. Non-ionic surfactant has amphoteric characteristics. Hydrophilic group is ethylene and propylene oxide that can induce hydrogen bonding with water molecules. In this regard, cloud point is an important parameter in order to control efficiency of deinking process because hydration of the hydrophobic group can be varied according to temperature of a system. In this study, deinking properties of ONP at high blending ratio of OMG was analyzed according to cloud points of non-ionic surfactants. $L^*$, $a^*$, $b^*$, brightness and effective residual ink concentration did not affected by the change of cloud points. Especially, flotation reject decreased significantly according to increase in cloud point of the non-ionic surfactant. Consequently, when a nonionic surfactant having a cloud point higher than the temperature of the system is used, properties of the deinked pulp can be maintained and yield of deinking process can be improved.

• 한국지하수토양환경학회지:지하수토양환경
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• 제10권4호
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• pp.26-32
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• 2005

계면활성제는 소수성 물질(톨루엔)의 물질전달율을 증가시켜 미생물이 있는 액상으로 잘 녹아들어가게 함으로써 미생물에 의한 분해를 증가시킨다. 본 연구에서는 여러 종류의 계면활성제가 존재할 때 톨루엔의 물질전달율과 미생물에 의한 분해가 어떻게 이루어지는지에 대해 알아보았다. 사용한 계면활성제는 다음과 같다: Sodium Oodecyl Sulfate (SOS), TritonX-100, Tween 80, BYK-345 (silicone 계면활성제). 실험결과에 따르면 BYK-345는 critical micelle concentration (CMC)에서 톨루엔의 용해도를 증가시켰다. 하지만, SDS와 TritonX-100는 CMC에서 톨루엔의 용해도를 증가시키지 못했다. 증류수에 계면활성제를 첨가하면 증류수만 있는 경우보다 톨루엔의 물질전달율$(K_La)$이 증가했다. 톨루엔 분해 미생물을 이용한 회분식 실험에서 SOS는 톨루엔의 분해를 감소시켰다. 그 이유는 SDS가 미생물에 독성을 미쳤기 때문일 수도 있고, 기질로서 이용되어서 톨루엔과 경쟁관계에 놓였기 때문일 수도 있다. BYK-345를 계면활성제로 사용한 실험에서도 톨루엔의 분해가 감소했는데 이것은 BYK-345가 미생물의 활성도에 심각한 영향을 미쳤기 때문이다. 하지만, TritonX-100 와 Tween 80의 경우에는 톨루엔의 분해가 크게 감소하지 않았다. 낮은 농도의 TritonX-100의 경우에 오히려 톨루엔의 분해는 증가했다. 이와 같은 결과들을 통해 톨루엔의 생물학적 분해를 위해 가장 적절한 계면활성제는 TritonX-100임을 알 수 있었다.

• 대한화학회지
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• 제57권6호
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• pp.703-711
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• 2013

In the present investigation, kinetic studies of oxidation of formic acid with and without catalyst and promoter in aqueous acid media were studied under the pseudo-first order conditions [formic acid]T ${\gg}[Cr(VI)]_T$ at room temperature. In the 1,10-phenanthroline (phen) promoted path, the cationic Cr(VI) phen complex is the main active oxidant species undergoes a nucleophilic attack by the substrate to form a ternary complex which subsequently experiences a redox decomposition through several steps leading to the products $CO_2$ and $H_2$ along with the Cr(III) phen complex. The anionic surfactant (i.e., sodium dodecyl sulfate, SDS) and neutral surfactant (i.e., Triton X-100, TX-100) act as catalyst and the reaction undergo simultaneously in both aqueous and micellar phase with an enhanced rate of oxidation in the micellar phase. Whereas the cationic surfactant (i.e., N-cetyl pyridinium chloride, CPC) acts as an inhibitor restricts the reaction to aqueous phase. The observed net enhancement of rate effects has been explained by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. The neutral surfactant TX-100 has been observed as the suitable micellar catalyst for the phen promoted chromic acid oxidation of formic acid.