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Sample records for surfactant enhanced aquifer

  1. Surfactant-enhanced aquifer remediation at the Portsmouth Gaseous Diffusion Plant

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, R.E.; Londergan, J.T.; Pickens, J.F. [INTERA Inc., Austin, TX (United States)

    1995-10-01

    Many DOE facilities are situated in areas of sand and gravel which have become polluted with dense, non-aqueous phase liquids or DNAPLs, such as chlorinated solvents, from the various industrial operations at these facilities. The presence of such DNAPLs in sand and gravel aquifers is now recognized as the principal factor in the failure of standard ground-water remediation methods. The principal objective of this study, as stated in the Statement of Work of the contract (DE-AC21-92MC29111), is to demonstrate that multi-component DNAPLs can be readily solubilized in sand and gravel aquifers by dilute surfactant solutions. The specific objectives of the contract are: to identify dilute surfactants or blends of surfactants in the laboratory that will efficiently extract multi-component DNAPLs from sand and gravel aquifers by micellar solubilization (Phase 1); 2. to test the efficacy of the identified surfactants or blends of surfactants to solubilize in situ perchloroethylene (PCE) and trichloroethylene (TCE) DNAPLs by the injection and the subsequent extraction through an existing well or wells at a government-owned contaminated site (Phase 1); and 3. to demonstrate the full-scale operation of this remedial technology at a government-owned contaminated site (Phase 2). Specific objective number 1 has been completed and reported to DOE. However, the results of the test referred to in specific objective number 2, conducted at Paducah Gaseous Diffusion Plant in 1994, were inconclusive. Following this first test, it was decided by DOE and INTERA to move the test site elsewhere due to difficulties with obtaining core samples of the sand and gravel aquifer containing the DNAPL and with ascertaining the location of the DNAPL relative to the injection well. The solubilization test at the Portsmouth Gaseous Diffusion Plant (PORTS) will constitute the second test of Phase 1 of this contract.

  2. DEMONSTRATION OF PILOT-SCALE PERVAPORATION SYSTEMS FOR VOLATILE ORGANIC COMPOUND REMOVAL FROM A SURFACTANT ENHANCED AQUIFER REMEDIATION FLUID. II. HOLLOW FIBER MEMBRANE MODULES

    Science.gov (United States)

    Pilot-scale demonstration of pervaporation-based removal of volatile organic compounds from a surfactant enhanced aquifer remediation (SEAR) fluid has been conducted at USEPA's Test & Evaluation Facility using hollow fiber membrane modules. The membranes consisted of microporous...

  3. Surfactant-enhanced remediation of a trichloroethene-contaminated aquifer. 2. Transport of TCE

    Science.gov (United States)

    Sahoo, D.; Smith, J.A.; Imbrigiotta, T.E.; Mclellan, H.M.

    1998-01-01

    Field studies were conducted under an induced gradient in a trichloroethene (TCE)-contaminated aquifer at Picatinny Arsenal, NJ, to study (a) the rate-limited desorption of TCE from aquifer sediments to water and (b) the effect of a surfactant (Triton X-100) on the desorption and transport of TCE. Clean water was injected into the contaminated aquifer for 206 day. Triton X-100 was added for a 36-day period (days 36-71 from the start of clean water injection). The effect of Triton X-100 on the desorption and transport of TCE in the field was examined by observing the concentrations of these two solutes in four monitoring wells 3-9 m from the injection wells. These data show a small but discernible increase in the TCE concentration in two of the wells corresponding approximately to the time when surfactant reaches the wells; in the other two monitoring wells, the increase in TCE concentration is negligible. A solute transport model that assumes local sorption equilibrium and used a laboratory-derived distribution coefficient could not adequately describe TCE desorption and transport observed in the aquifer. Two model formulations that accounted for rate-limited sorption - two-site and multisite models - fit the data well. TCE concentrations after surfactant injection were underpredicted by the models unless mass transfer rate was increased to account for the effect of surfactant on the rate of TCE desorption. The concentration data from the two wells and the model analysis suggest that the rate of TCE desorption is increased (by approximately 30%) as a result of Triton X-100 injection.Field studies were conducted under an induced gradient in a trichloroethene (TCE)-contaminated aquifer at Picatinny Arsenal, NJ, to study (a) the rate-limited desorption of TCE from aquifer sediments to water and (b) the effect of a surfactant (Triton X-100) on the desorption and transport of TCE. Clean water was injected into the contaminated aquifer for 206 day. Triton X-100 was added

  4. Surfactant-enhanced remediation of a trichloroethene-contaminated aquifer. 1. Transport of triton X-100

    Science.gov (United States)

    Smith, J.A.; Sahoo, D.; Mclellan, H.M.; Imbrigiotta, T.E.

    1997-01-01

    Transport of a nonionic surfactant (Triton X-100) at aqueous concentrations less than 400 mg/L through a trichloroethene-contaminated sand-and-gravel aquifer at Picatinny Arsenal, NJ, has been studied through a series of laboratory and field experiments. In the laboratory, batch and column experiments were conducted to quantify the rate and amount of Triton X-100 sorption to the aquifer sediments. In the field, a 400 mg/L aqueous Triton X-100 solution was injected into the aquifer at a rate of 26.5 L/min for a 35-d period. The transport of Triton X-100 was monitored by sampling and analysis of groundwater at six locations surrounding the injection well. Equilibrium batch sorption experiments showed that Triton X-100 sorbs strongly and nonlinearly to the field soil with the sharpest inflection point of the isotherm occurring at an equilibrium aqueous Triton X-100 concentration close to critical micelle concentration. Batch, soil column, and field experimental data were analyzed with zero-, one-, and two- dimensional (respectively) transient solute transport models with either equilibrium or rate-limited sorption. These analyses reveal that Triton X- 100 sorption to the aquifer solids is slow relative to advective and dispersive transport and that an equilibrium sorption model cannot simulate accurately the observed soil column and field data. Comparison of kinetic sorption parameters from batch, column, and field transport data indicate that both physical heterogeneities and Triton X-100 mass transfer between water and soil contribute to the kinetic transport effects.Transport of a nonionic surfactant (Triton X-100) at aqueous concentrations less than 400 mg/L through a trichloroethene-contaminated sand-and-gravel aquifer was studied. Equilibrium batch sorption experiments showed that Triton X-100 sorbs strongly and nonlinearly to the field soil with the sharpest inflection point of the isotherm occurring at an equilibrium aqueous Triton X-100 concentration close to

  5. Correlation between DNAPL distribution area and dissolved concentration in surfactant enhanced aquifer remediation effluent: a two-dimensional flow cell study

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Bin; Li, Huiying; Du, Xiaoming; Zhong, Lirong; Yang, Bin; Du, Ping; Gu, Qingbao; Li, Fasheng

    2016-02-01

    During the process of surfactant enhanced aquifer remediation (SEAR), free phase dense non-aqueous phase liquid (DNAPL) may be mobilized and spread. The understanding of the impact of DNAPL spreading on the SEAR remediation is not sufficient with its positive effect infrequently mentioned. To evaluate the correlation between DNAPL spreading and remediation efficiency, a two-dimensional sandbox apparatus was used to simulate the migration and dissolution process of 1,2-DCA (1,2-dichloroethane) DNAPL in SEAR. Distribution area of DNAPL in the sandbox was determined by digital image analysis and correlated with effluent DNAPL concentration. The results showed that the effluent DNAPL concentration has significant positive linear correlation with the DNAPL distribution area, indicating the mobilization of DNAPL could improve remediation efficiency by enlarging total NAPL-water interfacial area for mass transfer. Meanwhile, the vertical migration of 1,2-DCA was limited within the boundary of aquifer in all experiments, implying that by manipulating injection parameters in SEAR, optimal remediation efficiency can be reached while the risk of DNAPL vertical migration is minimized. This study provides a convenient visible and quantitative method for the optimization of parameters for SEAR project, and an approach of rapid predicting the extent of DNAPL contaminant distribution based on the dissolved DNAPL concentration in the extraction well.

  6. Correlation between DNAPL distribution area and dissolved concentration in surfactant enhanced aquifer remediation effluent: A two-dimensional flow cell study.

    Science.gov (United States)

    Wu, Bin; Li, Huiying; Du, Xiaoming; Zhong, Lirong; Yang, Bin; Du, Ping; Gu, Qingbao; Li, Fasheng

    2016-02-01

    During the process of surfactant enhanced aquifer remediation (SEAR), free phase dense non-aqueous phase liquid (DNAPL) may be mobilized and spread. The understanding of the impact of DNAPL spreading on the SEAR remediation is not sufficient with its positive effect infrequently mentioned. To evaluate the correlation between DNAPL spreading and remediation efficiency, a two-dimensional sandbox apparatus was used to simulate the migration and dissolution process of 1,2-DCA (1,2-dichloroethane) DNAPL in SEAR. Distribution area of DNAPL in the sandbox was determined by digital image analysis and correlated with effluent DNAPL concentration. The results showed that the effluent DNAPL concentration has significant positive linear correlation with the DNAPL distribution area, indicating the mobilization of DNAPL could improve remediation efficiency by enlarging total NAPL-water interfacial area for mass transfer. Meanwhile, the vertical migration of 1,2-DCA was limited within the boundary of aquifer in all experiments, implying that by manipulating injection parameters in SEAR, optimal remediation efficiency can be reached while the risk of DNAPL vertical migration is minimized. This study provides a convenient visible and quantitative method for the optimization of parameters for SEAR project, and an approach of rapid predicting the extent of DNAPL contaminant distribution based on the dissolved DNAPL concentration in the extraction well.

  7. The in-situ decontamination of sand and gravel aquifers by chemically enhanced solubilization of multiple-component DNAPLS with surfactant solutions. Topical report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-01-01

    Laboratory, numerical simulation, and field studies have been conducted to assess the potential use of micellar-surfactant solutions to solubilize chlorinated solvents contaminating sand and gravel aquifers. Laboratory studies were conducted at the State University of New York at Buffalo (SUNY) while numerical simulation and field work were undertaken by INTERA Inc. in collaboration with Martin Marietta Energy Systems Inc. at the Paducah Gaseous Diffusion Plant (PGDP) in Kentucky. Ninety-nine surfactants were screened for their ability to solubilize trichloroethene (TCE), perchloroethylene (PCE), and carbon tetrachloride (CTET). Ten of these were capable of solubilizing TCE to concentrations greater than 15,000 mg/L, compared to its aqueous solubility of 1,100 mg/L. Four surfactants were identified as good solubilizers of all three chlorinated solvents. Of these, a secondary alcohol ethoxylate was the first choice for in situ testing because of its excellent solubilizing ability and its low propensity to sorb. However, this surfactant did not meet the Commonwealth of Kentucky`s acceptance criteria. Consequently, it was decided to use a surfactant approved for use by the Food and Drug Administration as a food-grade additive. As a 1% micellar-surfactant solution, this sorbitan monooleate has a solubilization capacity of 16,000 mg TCE/L, but has a higher propensity to sorb to clays than has the alcohol ethoxylate.

  8. Coupled Transport of PAH and Surfactants in Natural Aquifer Material

    Science.gov (United States)

    Danzer, J.; Grathwohl, P.

    1998-03-01

    Surfactants in aqueous solution adsorb onto mineral surfaces and form micelles above the critical micelle concentration (CMC) due to their physico-chemical properties. Hydrophobic organic compounds such as polycyclic aromatic hydrocarbons (PAHs) have a high affinity for the adsorbed surfactant layers (monomers, hemimicelles and admicelles) and to the micelles in the mobile aqueous phase. The transport of PAHs is controlled by the concentration of the surfactant and the partition coefficients, of the PAHs between water and admicelles (adsolubilization: K adm) and water and micelles (solubilization: K mic), respectively. These partition coefficients were measured in laboratory batch and column experiments using phenanthrene as a chemical probe for the PAHs, a non-ionic surfactant (Terrasurf G50), natural aquifer sand (River Neckar Alluvium: RNA) and its petrographic subcomponents. The sorption of the surfactant can be described by a linear isotherm for concentrations below the CMC and a sorption maximum above the CMC, which both depend on the grain size and the surfactant accessible internal surface area of the particles. K adm was found to be higher than K mic. Both depend on the surfactant's properties, such as alkyl chain length, polar headgroup or ethoxylation. In column experiments an increasing retardation of phenanthrene was observed up to the CMC followed by a facilitated transport at surfactant concentration several times the CMC.

  9. Surfactant enhanced volumetric sweep efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Harwell, J.H.; Scamehorn, J.F.

    1989-10-01

    Surfactant-enhanced waterflooding is a novel EOR method aimed to improve the volumetric sweep efficiencies in reservoirs. The technique depends upon the ability to induce phase changes in surfactant solutions by mixing with surfactants of opposite charge or with salts of appropriate type. One surfactant or salt solution is injected into the reservoir. It is followed later by injection of another surfactant or salt solution. The sequence of injections is arranged so that the two solutions do not mix until they are into the permeable regions well away from the well bore. When they mix at this point, by design they form a precipitate or gel-like coacervate phase, plugging this permeable region, forcing flow through less permeable regions of the reservoir, improving sweep efficiency. The selectivity of the plugging process is demonstrated by achieving permeability reductions in the high permeable regions of Berea sandstone cores. Strategies were set to obtain a better control over the plug placement and the stability of plugs. A numerical simulator has been developed to investigate the potential increases in oil production of model systems. Furthermore, the hardness tolerance of anionic surfactant solutions is shown to be enhanced by addition of monovalent electrolyte or nonionic surfactants. 34 refs., 32 figs., 8 tabs.

  10. Effects of pH and cationic and nonionic surfactants on the adsorption of pharmaceuticals to a natural aquifer material.

    Science.gov (United States)

    Hari, Ajai C; Paruchuri, Rajiv A; Sabatini, David A; Kibbey, Tohren C G

    2005-04-15

    A wide range of pharmaceutical compounds have been identified in the environment, and their presence is a topic of growing concern, both for human and ecological health. Adsorption to aquifer materials and sediments is an important factor influencing the fate and transport of pharmaceutical compounds in the environment. Surfactants and other amphiphiles are known to influence the adsorption of many compounds and may be present in the environment from wastewaters or other sources. The work described here examines the adsorption of four pharmaceutical compounds, acetaminophen, carbamazepine, nalidixic acid, and norfloxacin, in the presence of a natural aquifer material. Adsorption was studied as a function of pH and in the presence and absence of two surfactants, cetylpyridinium chloride (CPC), a cationic surfactant, and Tergitol NP9, an ethoxylated nonionic surfactant. In the absence of surfactants, results indicate a 1-2 orders of magnitude variation in adsorption affinity with changing pH for each of the two quinolone pharmaceuticals (nalidixic acid and norfloxacin) but no measurable adsorption for carbamazepine or acetaminophen. In the presence of surfactants, adsorption of acetaminophen and carbamazepine was enhanced to extents consistent with compound hydrophobicity, while adsorption of nalidixic acid and norfloxacin was not. At high pH values, the anionic species of nalidixic acid exhibited enhanced adsorption in the presence of the cationic surfactant, CPC.

  11. Surfactant Enhanced Electroremediation of Phenanthrene

    Institute of Scientific and Technical Information of China (English)

    佘鹏; 杨建刚; 等

    2003-01-01

    Removal of hydrophobic organic contaminants(HOCs) form soil of low permeability by electroremediation was investigated by using phenanthrene and kaolinite as a model system.Tween 80 was added into the purging solution in order to enhance the solubility of phenanthrene.The effects of pH on the adsorption of phenanthrene and Tween 80 on kaolinite and the magnitude of ζ-potential of kaolinite were examined,respectively.The effects of electric field strength indicated by electric current on the electroremediation behavior,including the pH of purging solution,the conductivity,phenanthrene concentration and flow rate of effluent,were experimentally investigated,repectively,In case of an electric field of 25mA applied for 72 hours,over 90% of phenanthrene was removed from 424g(dry mass)of kaolinite at an energy consumption of 0.148kW.h.The experimental results described in present study show that the addition of surfactant into purging solution greatly enhances the removel of HOCs by electroremediation.

  12. Evaluation of trichloroethene recovery processes in heterogeneous aquifer cells flushed with biodegradable surfactants

    Science.gov (United States)

    Suchomel, Eric J.; Ramsburg, C. Andrew; Pennell, Kurt D.

    2007-12-01

    The ability of two biodegradable surfactants, polyoxyethylene (20) sorbitan monooleate (Tween® 80) and sodium dihexyl sulfosuccinate (Aerosol® MA), to recover a representative dense non-aqueous-phase liquid (DNAPL), trichloroethene (TCE), from heterogeneous porous media was evaluated through a combination of batch and aquifer cell experiments. An aqueous solution containing 3.3% Aerosol MA, 8% 2-propanol and 6 g/l CaCl 2 yielded a weight solubilization ratio (WSR) of 1.21 g TCE/g surfactant, with a corresponding liquid-liquid interfacial tension (IFT) of 0.19 dyn/cm. Flushing of aquifer cells containing a TCE-DNAPL source zone with approximately two pore volumes of the AMA formulation resulted in substantial (> 30%) mobilization of TCE-DNAPL. However, a TCE mass recovery of 81% was achieved when the aqueous-phase flow rate was sufficient to displace the mobile TCE-DNAPL toward the effluent well. Aqueous solutions of Tween 80 exhibited a greater capacity to solubilize TCE (WSR = 1.74 g TCE/g surfactant) and exerted markedly less reduction in IFT (10.4 dyn/cm). These data contradict an accepted empirical correlation used to estimate IFT values from solubilization capacity, and indicate a unique capacity of T80 to form concentrated TCE emulsions. Flushing of aquifer cells with less than 2.5 pore volumes of a 4% T80 solution achieved TCE mass recoveries ranging from 66 to 85%, with only slight TCE-DNAPL mobilization (Tween 80 and Aerosol MA solutions to efficiently recover TCE from a heterogeneous DNAPL source zone, and the utility of the total trapping number as a design parameter for a priori prediction of DNAPL mobilization and bank angle formation when flushing with low-IFT solutions. Given their potential to stimulate microbial reductive dechlorination at low concentrations, these surfactants are well-suited for remedial action plans that couple aggressive mass removal followed by enhanced bioremediation to treat chlorinated solvent source zones.

  13. Enhanced Oil Recovery with Surfactant Flooding

    DEFF Research Database (Denmark)

    Sandersen, Sara Bülow

    Enhanced oil recovery (EOR) is being increasingly applied in the oil industry and several different technologies have emerged during, the last decades in order to optimize oil recovery after conventional recovery methods have been applied. Surfactant flooding is an EOR technique in which the phase...... both for complex surfactant systems as well as for oil and brine systems. It is widely accepted that an increase in oil recovery can be obtained through flooding, whether it is simple waterflooding, waterflooding where the salinity has been modified by the addition or removal of specific ions (socalled...... “smart” waterflooding) or surfactant flooding. High pressure experiments have been carried out in this work on a surfactant system (surfactant/ oil/ brine) and on oil/ seawater systems (oil/ brine). The high pressure experiments were carried out on a DBR JEFRI PVT cell, where a glass window allows...

  14. Visualization of surfactant enhanced NAPL mobilization and solubilization in a two-dimensional micromodel

    Energy Technology Data Exchange (ETDEWEB)

    ZHONG,LIRONG; MAYER,ALEX; GLASS JR.,ROBERT J.

    2000-03-08

    Surfactant-enhanced aquifer remediation is an emerging technology for aquifers contaminated with nonaqueous phase liquids (NAPLs). A two-dimensional micromodel and image capture system were applied to observe NAPL mobilization and solubilization phenomena. In each experiment, a common residual NAPL field was established, followed by a series of mobilization and solubilization experiments. Mobilization floods included pure water floods with variable flow rates and surfactant floods with variations in surfactant formulations. At relatively low capillary numbers (N{sub ca}<10{sup {minus}3}), the surfactant mobilization floods resulted in higher NAPL saturations than for the pure water flood, for similar N{sub ca}.These differences in macroscopic saturations are explained by differences in micro-scale mobilization processes. Solubilization of the residual NAPL remaining after the mobilization stage was dominated by the formation of dissolution fingers, which produced nonequilibrium NAPL solubilization. A macroemulsion phase also as observed to form spontaneously and persist during the solubilization stage of the experiments.

  15. Silicone antifoam performance enhancement by nonionic surfactants in potato medium.

    Science.gov (United States)

    Christiano, Steven P; Fey, Kenneth C

    2003-01-01

    The ability of a silicone antifoam to retard foaming in a liquor prepared from potatoes is enhanced by the addition of ethoxylated nonionic surfactants. The enhancement is non-linear for surfactant concentration, with all 12 surfactants tested possessing a concentration at which foam heights strongly diminish, referred to as the surfactant critical antifoaming concentration (SCAFC). SCAFCs vary between surfactants, with lower values indicating better mass efficiency of antifoaming enhancement. SCAFCs decrease with degree of ethoxylation and decrease with the hydrophilic-lipophilic balance for ethoxylated nonionic surfactants. Surfactant addition produces a mixed water-surface layer containing surfactant and surface-active components in the potato medium. Surface tension reduction does not correlate well with antifoam performance enhancement. A model is proposed where surfactant adsorption promotes desorption of surface-active potato medium components from the water surface. At the SCAFC, desorption is not complete, yet the rate of bubble rupture is sufficiently enhanced to provide excellent foam control.

  16. The in-situ decontamination of sand and gravel aquifers by chemically enhanced solubilization of multiple-compound DNAPLs with surfactant solutions: Phase 1 -- Laboratory and pilot field-scale testing and Phase 2 -- Solubilization test and partitioning and interwell tracer tests. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-24

    Laboratory, numerical simulation, and field studies have been conducted to assess the potential use of micellar-surfactant solutions to solubilize chlorinated solvents contaminating sand and gravel aquifers. Ninety-nine surfactants were screened for their ability to solubilize trichloroethene (TCE), perchloroethylene (PCE), and carbon tetrachloride (CTET). The field test was conducted in the alluvial aquifer which is located 20 to 30 meters beneath a vapor degreasing operation at Paducah Gaseous Diffusion Plant. This aquifer has become contaminated with TCE due to leakage of perhaps 40,000 liters of TCE, which has generated a plume of dissolved TCE extending throughout an area of approximately 3 km{sup 2} in the aquifer. Most of the TCE is believed to be present in the overlying lacustrine deposits and in the aquifer itself as a dense, non-aqueous phase liquid, or DNAPL. The objective of the field test was to assess the efficacy of the surfactant for in situ TCE solubilization. Although the test demonstrated that sorbitan monooleate was unsuitable as a solubilizer in this aquifer, the single-well test was demonstrated to be a viable method for the in situ testing of surfactants or cosolvents prior to proceeding to full-scale remediation.

  17. ENVIRONMENTAL RESEARCH BRIEF: USE OF CATIONIC SURFACTANTS TO MODIFY AQUIFER MATERIALS TO REDUCE THE MOBILITY OF HYDROPHOBIC ORGANIC COMPOUNDS

    Science.gov (United States)

    Cationic surfactants can be used to modify surfaces of soils and subsurface materials to promote sorption of hydrophobic organic compounds (HOC) and retard their migration. For example, cationic surfactants could be injected into an aquifer downgradient from a source of HOC conta...

  18. SURFACTANT BASED ENHANCED OIL RECOVERY AND FOAM MOBILITY CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    George J. Hirasaki; Clarence A. Miller; Gary A. Pope; Richard E. Jackson

    2004-02-01

    Surfactant flooding has the potential to significantly increase recovery over that of conventional waterflooding. The availability of a large number of surfactant structures makes it possible to conduct a systematic study of the relation between surfactant structure and its efficacy for oil recovery. Also, the addition of an alkali such as sodium carbonate makes possible in situ generation of surfactant and significant reduction of surfactant adsorption. In addition to reduction of interfacial tension to ultra-low values, surfactants and alkali can be designed to alter wettability to enhance oil recovery. An alkaline surfactant process is designed to enhance spontaneous imbibition in fractured, oil-wet, carbonate formations. It is able to recover oil from dolomite core samples from which there was no oil recovery when placed in formation brine.

  19. Opportunities to enhance management of karstic aquifers

    Science.gov (United States)

    Parizek, Richard R.

    2007-01-01

    Methods exist to obtain “new sources of water.” Examples include: (1) capturing and enhancing stormwater recharge and retention within diffuse-flow portions of karst and other aquifers; (2) recycling and reuse of waste water; (3) reducing evapotranspiration and rejected recharge; and (4) ameliorating atmospheric acid deposition through use of alkaline groundwater. These little used management methods have immense potential to sustain future water demands. Full utilization of “new” and traditional water resources requires an understanding of the hydrogeologic framework of karstic aquifers. Reliable conceptual, numerical flow and transport models are needed to help evaluate, select, and design viable water management options. Three such simulation examples are provided together with a discussion of Penn State’s Wastewater reuse project where recharge approaches 3.785 × 109l/year

  20. SURFACTANT BASED ENHANCED OIL RECOVERY AND FOAM MOBILITY CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    George J. Hirasaki; Clarence A. Miller; Gary A. Pope; Richard E. Jackson

    2004-07-01

    Surfactant flooding has the potential to significantly increase recovery over that of conventional waterflooding. The availability of a large number of surfactants makes it possible to conduct a systematic study of the relation between surfactant structure and its efficacy for oil recovery. Also, the addition of an alkali such as sodium carbonate makes possible in situ generation of surfactant and significant reduction of surfactant adsorption. In addition to reduction of interfacial tension to ultra-low values, surfactants and alkali can be designed to alter wettability to enhance oil recovery. An alkaline surfactant process is designed to enhance spontaneous imbibition in fractured, oil-wet, carbonate formations. It is able to recover oil from dolomite core samples from which there was no oil recovery when placed in formation brine. Mobility control is essential for surfactant EOR. Foam is evaluted to improve the sweep efficiency of surfactant injected into fractured reservoirs. UTCHEM is a reservoir simulator specially designed for surfactant EOR. A dual-porosity version is demonstrated as a potential scale-up tool for fractured reservoirs.

  1. Surfactant-enhanced cellulose nanocrystal Pickering emulsions.

    Science.gov (United States)

    Hu, Zhen; Ballinger, Sarah; Pelton, Robert; Cranston, Emily D

    2015-02-01

    The effect of surfactants on the properties of Pickering emulsions stabilized by cellulose nanocrystals (CNCs) was investigated. Electrophoretic mobility, interfacial tension, confocal microscopy and three-phase contact angle measurements were used to elucidate the interactions between anionic CNCs and cationic alkyl ammonium surfactants didecyldimethylammonium bromide (DMAB) and cetyltrimethylammonium bromide (CTAB). Both surfactants were found to adsorb onto CNCs with concentration-dependent morphology. At low concentrations, individual surfactant molecules adsorbed with alkyl tails pointing outward leading to hydrophobic CNCs. At higher concentrations, above the surfactant's apparent critical micelle concentration, surfactant aggregate morphologies on CNCs were inferred and the hydrophobicity of CNCs decreased. DMAB, which has two alkyl tails, rendered the CNCs more hydrophobic than CTAB which has only a single alkyl tail, at all surfactant concentrations. The change in CNC wettability from surfactant adsorption was directly linked to emulsion properties; adding surfactant increased the emulsion stability, decreased the droplet size, and controlled the internal phase of CNC Pickering emulsions. More specifically, a double transitional phase inversion, from oil-in-water to water-in-oil and back to oil-in-water, was observed for emulsions with CNCs and increasing amounts of DMAB (the more hydrophobic surfactant). With CNCs and CTAB, no phase inversion was induced. This work represents the first report of CNC Pickering emulsions with surfactants as well as the first CNC Pickering emulsions that can be phase inverted. The ability to surface modify CNCs in situ and tailor emulsions by adding surfactants may extend the potential of CNCs to new liquid formulations and extruded/spray-dried materials.

  2. Polymeric surfactants for enhanced oil recovery : A review

    NARCIS (Netherlands)

    Raffa, Patrizio; Broekhuis, Antonius A.; Picchioni, Francesco

    Chemical enhanced oil recovery (EOR) is surely a topic of interest, as conventional oil resources become more scarce and the necessity of exploiting heavy and unconventional oils increases. EOR methods based on polymer flooding, surfactant-polymer flooding and alkali-surfactant-polymer flooding are

  3. Polymeric surfactants for enhanced oil recovery : A review

    NARCIS (Netherlands)

    Raffa, Patrizio; Broekhuis, Antonius A.; Picchioni, Francesco

    2016-01-01

    Chemical enhanced oil recovery (EOR) is surely a topic of interest, as conventional oil resources become more scarce and the necessity of exploiting heavy and unconventional oils increases. EOR methods based on polymer flooding, surfactant-polymer flooding and alkali-surfactant-polymer flooding are

  4. Polymeric surfactants for enhanced oil recovery : A review

    NARCIS (Netherlands)

    Raffa, Patrizio; Broekhuis, Antonius A.; Picchioni, Francesco

    2016-01-01

    Chemical enhanced oil recovery (EOR) is surely a topic of interest, as conventional oil resources become more scarce and the necessity of exploiting heavy and unconventional oils increases. EOR methods based on polymer flooding, surfactant-polymer flooding and alkali-surfactant-polymer flooding are

  5. Surfactant Based Enhanced Oil Recovery and Foam Mobility Control

    Energy Technology Data Exchange (ETDEWEB)

    George J. Hirasaki; Clarence A. Miller; Gary A. Pope

    2005-07-01

    Surfactant flooding has the potential to significantly increase recovery over that of conventional waterflooding. The availability of a large number of surfactant structures makes it possible to conduct a systematic study of the relation between surfactant structure and its efficacy for oil recovery. A combination of two surfactants was found to be particularly effective for application in carbonate formations at low temperature. A formulation has been designed for a particular field application. The addition of an alkali such as sodium carbonate makes possible in situ generation of surfactant and significant reduction of surfactant adsorption. In addition to reduction of interfacial tension to ultra-low values, surfactants and alkali can be designed to alter wettability to enhance oil recovery. The design of the process to maximize the region of ultra-low IFT is more challenging since the ratio of soap to synthetic surfactant is a parameter in the conditions for optimal salinity. Compositional simulation of the displacement process demonstrates the interdependence of the various components for oil recovery. An alkaline surfactant process is designed to enhance spontaneous imbibition in fractured, oil-wet, carbonate formations. It is able to recover oil from dolomite core samples from which there was no oil recovery when placed in formation brine. Mobility control is essential for surfactant EOR. Foam is evaluated to improve the sweep efficiency of surfactant injected into fractured reservoirs. UTCHEM is a reservoir simulator specially designed for surfactant EOR. It has been modified to represent the effects of a change in wettability. Simulated case studies demonstrate the effects of wettability.

  6. Effects of permeability heterogeneity on the performance of surfactant-enhanced remediation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.S. [Kyonggi Univ., Seoul (Korea, Republic of)

    2010-07-01

    The subsurface contamination by nonaqueous phase liquids (NAPLs) is a complicated process and difficult to treat because these organic contaminants tend to adsorb onto the soil matrix. They have low water solubility and a limited rate of mass transfer for biodegradation. NAPLs may leach from the soil for a longer period of time and may eventually become a long-term continuous contamination source of the soil and groundwater. One method to enhance pump-and-treat aquifer remediation performance involves surfactant-enhanced aquifer remediation (SEAR). Because their success depends on the delivery of injected chemical and water into the subsurface to contact the organic liquids, geologic heterogeneities are likely the main factors which reduce the effectiveness of SEAR processes. This paper presented a study that involved numerical simulations to assess the effect of spatial variability of aquifer permeability on NAPL recovery and injection pressure as well as spatial and temporal distributions of NAPLs during the remediation process. The paper outlined the mathematical backgrounds, numerical model, and results and discussion. It was concluded the effectiveness of SEAR is sensitive to injection time due to dispersion of surfactant slug with the presence of a higher degree of heterogeneity. 6 refs., 3 figs.

  7. Enhanced solubilization of curcumin in mixed surfactant vesicles.

    Science.gov (United States)

    Kumar, Arun; Kaur, Gurpreet; Kansal, S K; Chaudhary, Ganga Ram; Mehta, S K

    2016-05-15

    Self-assemblies of equimolar double and single chain mixed ionic surfactants, with increasing numbers of carbon atoms of double chain surfactant, were analyzed on the basis of fluorescence and conductivity results. Attempts were also made to enhance the solubilization of curcumin in aqueous equimolar mixed surfactant systems. Mixed surfactant assembly was successful in retarding the degradation of curcumin in alkaline media (only 25-28 40% degraded in 10h at pH 13). Fluorescence spectroscopy and fluorescence quenching methods were employed to predict the binding position and mechanism of curcumin with self-assemblies. Results indicate that the interactions take place according to both dynamic and static quenching mechanisms and curcumin was distributed in a palisade layer of mixed aggregates. Antioxidant activity (using DPPH radical) and biocompatibility (using calf-thymus DNA) of curcumin-loaded mixed surfactant formulations were also evaluated. The prepared systems improved the stability, solubility and antioxidant activity of curcumin and additionally are biocompatible.

  8. Surfactant enhanced recovery of tetrachloroethylene from a porous medium containing low permeability lenses. 1. Experimental studies.

    Science.gov (United States)

    Taylor, T P; Pennell, K D; Abriola, L M; Dane, J H

    2001-04-01

    A matrix of batch, column and two-dimensional (2-D) box experiments was conducted to investigate the coupled effects of rate-limited solubilization and layering on the entrapment and subsequent recovery of a representative dense NAPL, tetrachloroethylene (PCE), during surfactant flushing. Batch experiments were performed to determine the equilibrium solubilization capacity of the surfactant, polyoxyethylene (20) sorbitan monooleate (Tween 80), and to measure fluid viscosity, density and interfacial tension. Results of one-dimensional column studies indicated that micellar solubilization of residual PCE was rate-limited at Darcy velocities ranging from 0.8 to 8.2 cm/h and during periods of flow interruption. Effluent concentration data were used to develop effective mass transfer coefficient (Ke) expressions that were dependent upon the Darcy velocity and duration of flow interruption. To simulate subsurface heterogeneity, 2-D boxes were packed with layers of F-70 Ottawa sand and Wurtsmith aquifer material within 20-30 mesh Ottawa sand. A 4% Tween 80 solution was then flushed through PCE-contaminated boxes at several flow velocities, with periods of flow interruption. Effluent concentration data and visual observations indicated that both rate-limited solubilization and pooling of PCE above the fine layers reduced PCE recovery to levels below those anticipated from batch and column measurements. These experimental results demonstrate the potential impact of both mass transfer limitations and subsurface layering on the recovery of PCE during surfactant enhanced aquifer remediation.

  9. Surface-enhanced Raman spectroscopy of surfactants on silver electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Soncheng; Birke, R.L.; Lombardi, J.R. (City Univ. of New York, NY (USA))

    1990-03-08

    Surface-enhanced Raman spectroscopy (SERS) has been used to study different kinds of surfactants (cationic, anionic, and nonionic surfactants) adsorbed on a roughened Ag electrode. Spectral assignments are made for the SERS spectrum of cetylpyridinium chloride (CPC), and it is shown that the molecule is oriented with its pyridinium ring end-on at the electrode surface at potentials positive to the point of zero charge (pzc) on Ag.

  10. Surfactant Enhanced Microbial Degradation of JP-8 Contaminated Soil

    Science.gov (United States)

    1996-12-01

    Aromatics Xylenes Polycyclic Aromatics n-Alkanes Alkylbenzenes PAHs n-Alkenes Nitro-substituted Aromatics PNAs Phenols Halogenated Aliphatics Cycloalkanes...solubility has an apparent linear increase (Rosen, 1989:171). Solubilization occurs at a number of sites within a micelle (Figure 2.6): (1) the inner... Sulfonate (anionic). Each of these surfactants showed enhancement of biodegradation close to 90%, when compared to treatments without surfactant addition

  11. Intrinsic and enhanced biodegradation of benzene in strongly reduced aquifers

    NARCIS (Netherlands)

    Heiningen, W.N.M. van; Rijnaarts, H.H.M; Langenhoff, A.A.M.

    1999-01-01

    Laboratory microcosm studies were performed to examine intrinsic and enhanced benzene bioremediation using five different sediment and groundwater samples from three deeply anaerobic aquifers sited in northern Netherlands. The influence of addition of nitrate, sulfate, limited amounts of oxygen, and

  12. Monitoring of emerging contaminants (pharmaceuticals, Personal Care Products, surfactants and heavy metals) in a quaternary detritic aquifer

    Science.gov (United States)

    Candela, L.; Valdes-Abellan, J.; Jiménez-Martínez, J.

    2012-04-01

    The presence of 209 emerging compounds, surfactants, priority substances according to the 2008/105/EC Directive, 10 heavy metals and microbiological organisms in blended water and aquifer samples was investigated in a quaternary aquifer. The effects of these compounds over the environment are not clear in many cases, but many of them have been classified as endocrine disruptor compounds, EDC. Their presence in the media is controlled in one hand by their transformation and/or removal rates and, on the other hand, by their continuous release into the media, due to the broad use of these in many human activities (pharmaceuticals, personal care products, pesticides, heavy metals, LAS and others). The attention of this work focusses on the presence and fate of these substances in the vadose zone and the aquifer. The aquifer catchment (81km2) located in SE Spain presents a high natural salinity (with EC values of ~7,500 μS cm-1, and high concentrations of chloride, sulphate and sodium), making it unsuitable to be used as drinking water or irrigation. Two sampling campaigns (February and June 2011) in wells and springs have been carried out top characterize physic-chemical, microbiological and emerging contaminants presence in the aquifer. A total of 209 emerging pollutants grouped into the following classes were analysed: 125 pharmaceutical compounds (Phs), 20 polyaromatic hydrocarbons (PAHs) and Dioxins, 46 pesticides, 3 volatile priority pollutants as well as the most commonly used anionic surfactants were identified for further analysis. Heavy metals included: Cu, Cd, Pb, Hg, Ni, Zn, Sn, Pt, Pd and Tl. Results showed that 39 out of all compounds were detected: 11 pharmaceuticals, 9 PAHs, 19 pesticides, 4 surfactants and 4 heavy metals. Two of the compounds, endosulfan-α and Ni, were detected in concentrations above the allowed regulation. Although results are limited to 2 sampling campaigns, it is important to note that surfactants (LAS), pesticides PAHs and

  13. In situ, field-scale evaluation of surfactant-enhanced DNAPL recovery using a single-well, ``push-pull'' test

    Energy Technology Data Exchange (ETDEWEB)

    Istok, J.D.; Field, J.A.

    1999-10-01

    The overall goal of this project was to further develop the single-well, ``push-pull'' test method as a feasibility assessment and site-characterization tool for studying the fundamental fate and transport behavior of injected surfactants and their ability to solubilize and mobilize dense nonaqueous phase liquids (DNAPLs) in the subsurface. The specific objectives were to develop a modified push-pull test for use in identifying and quantifying the effects of sorption, precipitation, and biodegradation on the fate and transport of injected surfactants, use the developed test method to quantify the effects of these processes on the ability of injected surfactants to solubilize and mobilize residual phase trichloroethane (TCE), and demonstrate the utility of the developed test method for performing site characterization and feasibility studies for surfactant-enhanced DNAPL recovery systems in the field. The results from the intermediate-scale laboratory experiments conducted for this project indicate that the single-well, push-pull test method can provide quantitative information on the effectiveness of injected surfactants in enhancing DNAPL solubilization in natural aquifer sediments. Specifically, the results of this research demonstrate the ability of the single-well, push-pull test to characterize the behavior of multi-component surfactants in the presence of natural aquifer sediment under laboratory and in-situ field conditions.

  14. Phase behavior and oil recovery investigations using mixed and alkaline-enhanced surfactant systems

    Energy Technology Data Exchange (ETDEWEB)

    Llave, F.M.; Gall, B.L.; French, T.R.; Noll, L.A.; Munden, S.A.

    1992-03-01

    The results of an evaluation of different mixed surfactant and alkaline-enhanced surfactant systems for enhanced oil recovery are described. Several mixed surfactant systems have been studies to evaluate their oil recovery potential as well as improved adaptability to different ranges of salinity, divalent ion concentrations, and temperature. Several combinations of screening methods were used to help identify potential chemical formulations and determine conditions where particular chemical systems can be applied. The effects of different parameters on the behavior of the overall surfactant system were also studied. Several commercially available surfactants were tested as primary components in the mixtures used in the study. These surfactants were formulated with different secondary as well as tertiary components, including ethoxylated and non-ethoxylated sulfonates and sulfates. Improved salinity and hardness tolerance was achieved for some of these chemical systems. The salinity tolerance of these systems were found to be dependent on the molecular weight, surfactant type, and concentration of the surfactant components.

  15. Water solubility enhancements of pyrene by single and mixed surfactant solutions

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Water solubility enhancements of pyrene by both single-surfactant and mixed-surfactant solutions were compared andevaluated. The solubility of pyrene in water was greatly enhanced by each of Triton X-100 (TX100), Triton X-405 (TX405), Brij 35 and SDS, in which the water solubility enhancements increased with increasing surfactant concentrations. The extent of solubility enhancements at surfactant concentrations below the CMC is the order of TX100 > Brij 35 > TX405 > SDS; the sequence at surfactantconcentrations above the CMC is TX100 > Brij 35 > SDS > TX405. Pyrene was solubilized synergistically by anionic-nonionic mixed surfactant solutions, especially at low surfactant concentrations. The synergistic power of the mixed surfactants is SDS-TX405 > SDS-Brij 35 > SDS-TX100. The synergism as noted is attributed to increasing Kmc and/or decreasing the CMC of the mixed surfactan solution. For SDS-TX405 and SDS-Brij 35 mixed surfactant solutions, an increase in Kmc is coupled with a decrease in the CMC; for SDS-TX100, only a decreased in the CMC value is noted. Mixed-surfactant solutions may improve the performance of the surfactant-enhanced remediation (SER) of soils by increasing the bioavailability and biodegradation of non-aqueous-phase organic pollutants and reducing the level of surfactant pollution and remediation expenses.

  16. The Effects of Surfactants on the Desorption of Organic Contaminants from Aquifer Materials

    Science.gov (United States)

    1989-08-01

    Wilmington Delaware, April 11, 1989. Cox, M. F. and K. L. Matheson. "Interactions between Linear Alkylbenzene Sulfonates and Water Hardness Ions. II. Reducing...Between Linear Alkylbenzene Sulfonates and Water Hardness Ions. I. Effect of Calcium Ion on Surfactant Solubility and Implications for Detergency...Fatty acids Sulfonate Paraffins Sulfate Olefins Carboxylate Alkylbenzenes Quaternary ammonium Long chain alcohols Protonated amine Alkyl Phenols

  17. Aquifers

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This map layer contains the shallowest principal aquifers of the conterminous United States, Hawaii, Puerto Rico, and the U.S. Virgin Islands, portrayed as polygons....

  18. Aquifers

    Data.gov (United States)

    Department of Homeland Security — This map layer contains the shallowest principal aquifers of the conterminous United States, Hawaii, Puerto Rico, and the U.S. Virgin Islands, portrayed as polygons....

  19. Surfactant Based Enhanced Oil Recovery and Foam Mobility Control

    Energy Technology Data Exchange (ETDEWEB)

    George J. Hirasaki; Clarence A. Miller

    2006-09-09

    Surfactant flooding has the potential to significantly increase recovery over that of conventional waterflooding. The availability of a large number of surfactant structures makes it possible to conduct a systematic study of the relation between surfactant structure and its efficacy for oil recovery. A mixture of two surfactants was found to be particularly effective for application in carbonate formations at low temperature. The mixture is single phase for higher salinity or calcium concentrations than that for either surfactant used alone. This makes it possible to inject the surfactant slug with polymer close to optimal conditions and yet be single phase. A formulation has been designed for a particular field application. It uses partially hydrolyzed polyacrylamide for mobility control. The addition of an alkali such as sodium carbonate makes possible in situ generation of naphthenic soap and significant reduction of synthetic surfactant adsorption. The design of the process to maximize the region of ultra-low IFT takes advantage of the observation that the ratio of soap to synthetic surfactant is a parameter in the conditions for optimal salinity. Even for a fixed ratio of soap to surfactant, the range of salinity for low IFT was wider than that reported for surfactant systems in the literature. Low temperature, forced displacement experiments in dolomite and silica sandpacks demonstrate that greater than 95% recovery of the waterflood remaining oil is possible with 0.2% surfactant concentration, 0.5 PV surfactant slug, with no alcohol. Compositional simulation of the displacement process demonstrates the role of soap/surfactant ratio on passage of the profile through the ultralow IFT region, the importance of a wide salinity range of low IFT, and the importance of the viscosity of the surfactant slug. Mobility control is essential for surfactant EOR. Foam is evaluated to improve the sweep efficiency of surfactant injected into fractured reservoirs as well as a

  20. Viscoelasticity Enhancement of Surfactant Solutions Depends on Molecular Conformation: Influence of Surfactant Headgroup Structure and Its Counterion.

    Science.gov (United States)

    Lutz-Bueno, Viviane; Pasquino, Rossana; Liebi, Marianne; Kohlbrecher, Joachim; Fischer, Peter

    2016-05-03

    During the anisotropic growth from globular to wormlike micelles, the basic interactions among distinct parts of the surfactant monomer, its counterion, and additives are fundamental to tune molecular self-assembly. We investigate the addition of sodium salicylate (NaSal) to hexadecyltrimethylammonium chloride and bromide (CTAC and CTAB), 1-hexadecylpyridinium chloride and bromide (CPyCl and CPyBr), and benzyldimethylhexadecylammonium chloride (BDMC), which have the same hydrophobic tail. Their potential to enhance viscoelasticity by anisotropic micellar growth upon salt addition was compared in terms of (i) the influence of the headgroup structure, and (ii) the influence of surfactant counterion type. Employing proton nuclear magnetic resonance ((1)H NMR), we focused on the molecular conformation of surfactant monomers in the core and polar shell regions of the micelles and their interactions with increasing concentration of NaSal. The viscoelastic response was investigated by rotational and oscillatory rheology. We show that micellar growth rates can be tuned by varying the flexibility and size of the surfactant headgroup as well as the dissociation degree of the surfactant counterion, which directly influences the strength of headgroup-counterion pairing. As a consequence, the morphological transitions depend directly on charge neutralization by electrostatic screening. For example, the amount of salt necessary to start the rodlike-to-wormlike micelle growth depends directly on the number of dissociated counterions in the polar shell.

  1. Reversibly enhanced aqueous solubilization of volatile organic compounds using a redox-reversible surfactant

    Institute of Scientific and Technical Information of China (English)

    Yingjie Li; Senlin Tian; Hong Mo; Ping Ning

    2011-01-01

    Surfactant-enhanced remediation (SER) is an effective method for the removal of volatile organic compounds (VOCs) from contaminated soils and groundwater.To reuse the surfactant the VOCs must be separated from the surfactant solutions.The water solubility of VOCs can be enhanced using reversible surfactants with a redox-acive group,(ferrocenylmethyl)dodecyldimethylammonium bromide (Fc12) and (ferrocenylmethyl)tetradecanedimethylammonium bromide (Fc14),above and below their critical micelle concentrations (CMC) under reducing (I+) and oxidative (I2+) conditions.The CMC values of Fc12 and Fc14 in I+ are 0.94 and 0.56 mmol/L and the solubilization of toluene by Fc12 and Fc14 in I+ for toluene is higher than the solubilization achieved with sodium dodecyl sulfate,cetyltrimethylammonium bromide and Trition X-114.The solubilization capacity of the ferrocenyl surfactants for each tested VOCs ranked as follows:ethylbenzene > toluene > benzene.The solubilities of VOCs by reversible surfactant in I+ were 30% higher than those in 12+ at comparable surfactant concentrations.The effects of Fc14 concentrations on VOCs removal efficiency were as follows:benzene > toluene > ethylbenzene.However,an improved removal efficiency was achieved at low ferrocenyl surfactant concentrations.Furthermore,the reversible surfactant could be recycled through chemical approaches to remove organic pollutants,which could significantly reduce the operating costs of SER technology.

  2. Research on surfactant flooding in high temperature and high-salinity reservoir for enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ming [Southwest Petroleum Univ., Chengdu, Sichuan (China). State Key Lab. of Oil and Gas Reservoir Geology and Exploitation; Southwest Petroleum Univ., Chengdu, Sichuan (China). School of Material Science and Engineering; Zhao, Jinzhou; Yang, Yan [Southwest Petroleum Univ., Chengdu, Sichuan (China). State Key Lab. of Oil and Gas Reservoir Geology and Exploitation; Wang, Xu [Southwest Petroleum Univ., Chengdu, Sichuan (China). School of Material Science and Engineering

    2013-05-15

    The aim of this work was to research the solution properties of a new surfactant flooding system for high temperature and high salinity reservoir, which include trimeric sulfonate surfactants 1,2,3-tri(2-oxypropyl sulfonation-3-alkylether-propoxyl) propanes (TTSS-n) and anion-nonionic surfactant NPSO [sodium nonyl phenol polyethyleneoxy ether sulfonate, (EO = 10)]. The critical micelle concentrations (CMCs) of five trimeric sulfonate surfactants were smaller than 400 mg L{sup -1}. Furthermore, their interfacial tensions (IFTs) could reach an ultralow value with Tazhong 4 oil at lower concentrations. Through optimized formulation, we found that TTSS-12 had better properties and was selected as the major component of the surfactant flooding system. We designed an optimal formulation of the surfactant flooding system with 1000 mg . L{sup -1} TTSS-12 and 1000 mg . L{sup -1} NPSO surfactant. The system with a very small surfactant concentration could reach ultralow IFT with Tazhong 4 crude oils at high temperature (110 C) and high concentration formation brine (112,228.8 mg/L TDS), which proved that the simpler component surfactant had better reservoir compatibility. NPSO could weaken the disadvantage of the surfactant TTSS-12 in oil/water interface. The stability of this surfactant flooding system was evaluated by aging time, static adsorption and chromatographic separation. All experiments showed that it still keeps ultralow IFT in high temperature and high salinity conditions. Coreflooding experimentation showed that average oil recovery reached 9.8 wt% by surfactant flooding, therefore, it is feasible to use as a surfactant flooding system for enhanced oil recovery (EOR). (orig.)

  3. Screening of mixed surfactant systems: Phase behavior studies and CT imaging of surfactant-enhanced oil recovery experiments

    Energy Technology Data Exchange (ETDEWEB)

    Llave, F.M.; Gall, B.L.; Lorenz, P.B.; Cook, I.M.; Scott, L.J.

    1993-11-01

    A systematic chemical screening study was conducted on selected anionic-nonionic and nonionic-nonionic systems. The objective of the study was to evaluate and determine combinations of these surfactants that would exhibit favorable phase behavior and solubilization capacity. The effects of different parameters including (a) salinity, (b) temperature, (c) alkane carbon number, (c) hydrophilic/lipophilic balance (HLB) of nonionic component, and (d) type of surfactant on the behavior of the overall chemical system were evaluated. The current work was conducted using a series of ethoxylated nonionic surfactants in combinations of several anionic systems with various hydrocarbons. Efforts to correlate the behavior of these mixed systems led to the development of several models for the chemical systems tested. The models were used to compare the different systems and provided some guidelines for formulating them to account for variations in salinity, oil hydrocarbon number, and temperature. The models were also evaluated to determine conformance with the results from experimental measurements. The models provided good agreement with experimental results. X-ray computed tomography (CT) was used to study fluid distributions during chemical enhanced oil recovery experiments. CT-monitored corefloods were conducted to examine the effect of changing surfactant slug size injection on oil bank formation and propagation. Reducing surfactant slug size resulted in lower total oil production. Oil recovery results, however, did not correlate with slug size for the low-concentration, alkaline, mixed surfactant system used in these tests. The CT measurements showed that polymer mobility control and core features also affected the overall oil recovery results.

  4. Adsorption of surfactants on sand surface in enhanced oil recovery: Isotherms, kinetics and thermodynamic studies

    Energy Technology Data Exchange (ETDEWEB)

    Bera, Achinta; Kumar, T.; Ojha, Keka; Mandal, Ajay, E-mail: mandal_ajay@hotmail.com

    2013-11-01

    Adsorption of surfactants onto reservoir rock surface may result in the loss and reduction of their concentrations in surfactant flooding, which may render them less efficient or ineffective in practical applications of enhanced oil recovery (EOR) techniques. Surfactant flooding for EOR received attraction due to its ability to increase the displacement efficiency by lowering the interfacial tension between oil and water and mobilizing the residual oil. This article highlights the adsorption of surfactants onto sand surface with variation of different influencing factors. It has been experimentally found that adsorption of cationic surfactant on sand surface is more and less for anionic surfactant, while non-ionic surfactant shows intermediate behaviour. X-ray diffraction (XRD) study of clean sand particles has been made to determine the main component present in the sand particles. The interaction between sand particles and surfactant has been studied by Fourier Transform Infrared (FTIR) Spectroscopy of the sand particles before and after aging with surfactant. Salinity plays an important role in adsorption of anionic surfactant. Batch experiments were also performed to understand the effects of pH and adsorbent dose on the sorption efficiency. The sand particles exhibited high adsorption efficiency at low pH for anionic and nonionic surfactants. But opposite trend was found for cationic surfactant. Adsorption data were analyzed by fitting with Langmuir, Freundlich, Redlich-Peterson, and Sips isotherm models. Results show that the Langmuir isotherm and pseudo-second order kinetics models suit the equilibrium and kinetics of adsorption on sand surface. Thermodynamics feasibility of the adsorption process was also studied to verify the spontaneity of the process.

  5. SURFACTANT-ENHANCED EXTRACTION TECHNOLOGY EVALUATION VERSUCHSEININCHTUNG ZUR GRUNDWASSER-UND ALTLASTENSANIERUNG (VEGAS) FACILITY, STUTTGART, GERMANY

    Science.gov (United States)

    This innovative technology evaluation report (ITER) summarized the results of an evaluation of a surfactant-enhanced extraction technology. This evaluation was conducted under a bilateral agreement between the United States (U.S.) Environmental Protection Agency (EPA) Superfund ...

  6. Surfactant-enhanced desorption and biodegradation of polycyclic aromatic hydrocarbons in contaminated soil.

    Science.gov (United States)

    Zhu, Hongbo; Aitken, Michael D

    2010-10-01

    We evaluated two nonionic surfactants, one hydrophobic (Brij 30) and one hydrophilic (C(12)E(8)), for their ability to enhance the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil after it had been treated in an aerobic bioreactor. The effects of each surfactant were evaluated at doses corresponding to equilibrium aqueous-phase concentrations well above the surfactant's critical micelle concentration (CMC), slightly above the CMC, and below the CMC. The concentrations of all 3- and 4-ring PAHs were significantly lower in the soil amended with Brij 30 at the two lower doses compared to controls, whereas removal of only the 3-ring PAHs was significantly enhanced at the highest Brij 30 dose. In contrast, C(12)E(8) did not enhance PAH removal at any dose. In the absence of surfactant, PAH desorbed from the soil over an 18 day period. Brij 30 addition at the lowest dose significantly increased the desorption of most PAHs, whereas the addition of C(12)E(8) at the lowest dose actually decreased the desorption of all PAHs. These findings suggest that the effects of the two surfactants on PAH biodegradation could be explained by their effects on PAH bioavailability. Overall, this study demonstrates that the properties of the surfactant and its dose relative to the corresponding aqueous-phase concentration are important factors in designing systems for surfactant-enhanced bioremediation of PAH-contaminated soils in which PAH bioavailability is limited.

  7. Surfactant enhanced disinfection of the human norovirus surrogate, tulane virus with organic acids and surfactant

    Science.gov (United States)

    Human infection with foodborne viruses can occur following consumption of contaminated food, person-to-person body contact, or release of aerosols. Combinatorial treatments of surfactants and organic acids may have synergistic or additive mechanisms to inactivate foodborne viruses and prevent outbr...

  8. Alkyl polyglycoside/1-naphthol formulations. A case study of surfactant enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Iglauer, Stefan; Wu, Yongfu; Shuler, Patrick; Tang, Yongchun [California Institute of Technology, Covina, CA (United States). Div. of Chemistry and Chemical Engineering; Goddard, William A. III [California Institute of Technology, Pasadena, CA (United States). Div. of Chemistry and Chemical Engineering

    2011-03-15

    We present a case study of surfactant enhanced oil recovery using Alkyl polyglucoside/1-naphthol formulations. Alkyl polyglucosides are a green, non-toxic and renewable surfactant class synthesized out of agricultural raw materials. We measured interfacial tensions versus n-octane and viscosities of these formulations and conducted one coreflood enhanced oil recovery (EOR) experiment where we recovered 82.6 % of initial oil in place demonstrating that these formulations are efficient EOR agents. (orig.)

  9. Pilot-scale demonstration of surfactant-enhanced PCE solubilization at the Bachman Road site. 1. Site characterization and test design.

    Science.gov (United States)

    Abriola, Linda M; Drummond, Chad D; Hahn, Ernest J; Hayes, Kim F; Kibbey, Tohren C G; Lemke, Lawrence D; Pennell, Kurt D; Petrovskis, Erik A; Ramsburg, C Andrew; Rathfelder, Klaus M

    2005-03-15

    A pilot-scale demonstration of surfactant-enhanced aquifer remediation (SEAR) was conducted to recover dense nonaqueous phase liquid (DNAPL) tetrachloroethene (PCE) from a sandy glacial outwash aquifer underlying a former dry cleaning facility at the Bachman Road site in Oscoda, MI. Part one of this two-part paper describes site characterization efforts and a comprehensive approach to SEAR test design, effectively integrating laboratory and modeling studies. Aquifer coring and drive point sampling suggested the presence of PCE-DNAPL in a zone beneath an occupied building. A narrow PCE plume emanating from the vicinity of this building discharges into Lake Huron. The shallow unconfined aquifer, characterized by relatively homogeneous fine-medium sand deposits, an underlying clay layer, and the absence of significant PCE transformation products, was judged suitable for the demonstration of SEAR. Tween 80 was selected for application based upon its favorable solubilization performance in batch and two-dimensional sand tank treatability studies, biodegradation potential, and regulatory acceptance. Three-dimensional flow and transport models were employed to develop a robust design for surfactant delivery and recovery. Physical and fiscal constraints led to an unusual hydraulic design, in which surfactant was flushed across the regional groundwater gradient, facilitating the delivery of concentrations of Tween 80 exceeding 1% (wt) throughout the treatment zone. The potential influence of small-scale heterogeneity on PCE-DNAPL distribution and SEAR performance was assessed through numerical simulations incorporating geostatistical permeability fields based upon available core data. For the examined conditions simulated PCE recoveries ranged from 94to 99%. The effluent treatment system design consisted of low-profile air strippers coupled with carbon adsorption to trap off-gas PCE and discharge of treated aqueous effluent to a local wastewater treatment plant. The

  10. Studies on interfacial tension and contact angle of synthesized surfactant and polymeric from castor oil for enhanced oil recovery

    Science.gov (United States)

    Babu, Keshak; Pal, Nilanjan; Bera, Achinta; Saxena, V. K.; Mandal, Ajay

    2015-10-01

    New synthesized polymeric surfactants have immensely attracted the researchers for further development of chemical enhanced oil recovery method particularly in surfactant flooding. Contact angle and interfacial tension measurement tests are the effective ways to identify proper chemicals/surfactants for enhanced oil recovery by chemical/surfactant flooding. In the present study a new polymeric surfactant was synthesized from pre-synthesized sodium methyl ester sulfonate (surfactant) and acrylamide for application in chemical enhanced oil recovery. The synthesized surfactant and polymeric surfactant were used to measure interfacial tension between their aqueous phase and crude oil phase to investigate the efficiency of the surfactants in reduction of interfacial tension. The synthesized polymeric surfactant has also ability to control the mobility because of its viscous nature in aqueous solution. Contact angles of solid-crude oil-surfactant interface were also measured to study the effect of the synthesized surfactant and polymeric surfactant on wettability alteration mechanism. Synergistic effect was studied by using NaCl and synthesized surfactants on interfacial tension. Dynamic interfacial tensions of the surfactant and polymeric surfactant solutions with crude oil were measured at different NaCl concentrations. Interfacial tension was found to be lowered up to 10-2 to 10-3 mN/m which is effective for oil recovery. Measurement of contact angle indicates the wettability change of the quartz surface. Comparative studies on efficiencies of synthesized sodium methyl ester sulfonate surfactant and polymeric surfactant were also carried out with respect to interfacial tension reduction and contact angle change.

  11. Surfactant-Enhanced Phytoremediation of Soils Contaminated with Hydrophobic Organic Contaminants: Potential and Assessment

    Institute of Scientific and Technical Information of China (English)

    GAO Yan-Zheng; LING Wan-Ting; ZHU Li-Zhong; ZHAO Bao-Wei; ZHENG Qing-Song

    2007-01-01

    Phytoremediation is becoming a cost-effective technology for the in-situ clean up of sites polluted with hydrophobic organic contaminants (HOCs). The major factors limiting phytoremediation are the mass transfer, rate of plant uptake, and microbial biodegradation of HOCs. This article discusses the potential of surfactants to enhance desorption, plant uptake, and biodegradation of HOCs in the contaminated sites. Positive effects of surfactants on phytoremediation have been recently observed in greenhouse studies. The presence of some nonionic surfactants including polyoxyethylene sorbitan monooleate (Tween 80) and polyoxyethylene(23)dodecanol (Brij35) at relatively low concentrations resulted in significant positive effects on phytoremediation for pyrene-contaminated soil. However, the anionic surfactant (sodium dodecyl sulfate, SDS) and the cationic surfactant (cetyltrimethylammonium bromide, CTMAB) were not useful because of their phytotoxicity or low efficiency for surfactant-enhanced phytoremediation (SEPR). The mechanisms of SEPR for HOC-contaminated sites were evaluated by considering experimental observations. In view of concerns about the cost effectiveness and toxicity of surfactants to plants, more research is needed to enhance the use of SEPR technology.

  12. Use of amine oxide surfactants for chemical flooding EOR (enhanced oil recovery)

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, D.K.

    1989-11-01

    The use of amine oxides with and without alcohols as cosolvents, and in combination with other surfactants as mixed micellar formulations for enhanced oil recovery by surfactant flooding was investigated. Amine oxides are a salt-tolerant class of surfactants that produce low interfacial tension and can develop viscosity without the addition of polymers. These salt-tolerant formulations generate three-phase regions with hydrocarbons over a broad salinity range, develop moderate solubilization, and produce low interfacial tensions, however oil recovery from amine oxide-alcohol phase behavior optimized formulations was directly dependent upon the quantity of surfactant injected. The large pore volume and high concentration of surfactant required prohibits their economic use as the primary surfactant in chemical flooding EOR. Dimethylalkylamine oxides are useful as cosurfactants and viscosifiers in formulations with other surfactants for chemical flooding EOR but the use of ethoxylated and propoxylated amine oxides should be avoided due to the decomposition of these amine oxides under reservoir conditions. Phase behavior, phase inversion temperatures, and viscosity scans have been correlated with surfactant structures to provide a guide for amine oxide applications in chemical flooding. 36 refs., 5 figs., 6 tabs.

  13. Practical Considerations and Challenges Involved in Surfactant Enhanced Bioremediation of Oil

    Directory of Open Access Journals (Sweden)

    Sagarika Mohanty

    2013-01-01

    Full Text Available Surfactant enhanced bioremediation (SEB of oil is an approach adopted to overcome the bioavailability constraints encountered in biotransformation of nonaqueous phase liquid (NAPL pollutants. Fuel oils contain n-alkanes and other aliphatic hydrocarbons, monoaromatics, and polynuclear aromatic hydrocarbons (PAHs. Although hydrocarbon degrading cultures are abundant in nature, complete biodegradation of oil is rarely achieved even under favorable environmental conditions due to the structural complexity of oil and culture specificities. Moreover, the interaction among cultures in a consortium, substrate interaction effects during the degradation and ability of specific cultures to alter the bioavailability of oil invariably affect the process. Although SEB has the potential to increase the degradation rate of oil and its constituents, there are numerous challenges in the successful application of this technology. Success is dependent on the choice of appropriate surfactant type and dose since the surfactant-hydrocarbon-microorganism interaction may be unique to each scenario. Surfactants not only enhance the uptake of constituents through micellar solubilization and emulsification but can also alter microbial cell surface characteristics. Moreover, hydrocarbons partitioned in micelles may not be readily bioavailable depending on the microorganism-surfactant interactions. Surfactant toxicity and inherent biodegradability of surfactants may pose additional challenges as discussed in this review.

  14. Surfactants enhance recovery of poorly soluble drugs during microdialysis sampling

    DEFF Research Database (Denmark)

    Koplin, Sebastian; Kumpugdee-Vollrath, Mont; Bauer-Brandl, Annette

    2017-01-01

    Aim of this project was to investigate the applicability of a recently developed in vitro microdialysis-sampling approach in connection with a dissolution-/permeation (D/P) system, especially the impact of surfactants within the perfusion fluid. The D/P-system is based on side-by-side chambers...... drug-dissolution (-release) and drug permeation. Furthermore, it should allow quantification of the unbound (free) drug concentration. In the first step, it was assessed, if the addition of the anionic surfactant sodium dodecyl sulphate (SDS) to the perfusate of the microdialysis system affects...... celecoxib, i.e. the fraction of drug, which is not associated with taurocholate surfactant micelles. In buffer, the measured concentrations matched the overall CXB concentrations. By the use of SDS-containing perfusates microdialysis sampling enabled reliable quantification of minute amounts of free CXB...

  15. Surfactant mediated enhanced biodegradation of hexachlorocyclohexane (HCH) isomers by Sphingomonas sp. NM05.

    Science.gov (United States)

    Manickam, Natesan; Bajaj, Abhay; Saini, Harvinder S; Shanker, Rishi

    2012-09-01

    Environmental biodegradation of several chlorinated pesticides is limited by their low solubility and sorption to soil surfaces. To mitigate this problem we quantified the effect of three biosurfactant viz., rhamnolipid, sophorolipid and trehalose-containing lipid on the dissolution, bioavailability, and biodegradation of HCH-isomers in liquid culture and in contaminated soil. The effect of biosurfactants was evaluated through the critical micelle concentration (CMC) value as determined for each isomer. The surfactant increased the solubilization of HCH isomers by 3-9 folds with rhamnolipid and sophorolipid being more effective and showing maximum solubilization of HCH isomers at 40 μg/mL, compared to trehalose-containing lipid showing peak solubilization at 60 μg/mL. The degradation of HCH isomers by Sphingomonas sp. NM05 in surfactant-amended liquid mineral salts medium showed 30% enhancement in 2 days as compared to degradation in 10 days in the absence of surfactant. HCH-spiked soil slurry incubated with surfactant also showed around 30-50% enhanced degradation of HCH which was comparable to the corresponding batch culture experiments. Among the three surfactants, sophorolipid offered highest solubilization and enhanced degradation of HCH isomers both in liquid medium and soil culture. The results of this study suggest the effectiveness of surfactants in improving HCH degradation by increased bioaccessibility.

  16. SURFACTANT ENHANCED REMEDIATION OF SOIL COLUMNS CONTAMINATED BY RESIDUAL TETRACHLOROETHYLENE

    Science.gov (United States)

    The ability of aqueous surfactant solutions to recover tetrachloroethylene (PCE) entrapped in Ottawa sand was evaluated in four column experiments. Residual PCE was emplaced by injecting 14C-labeled PCE into water-saturated soil columns and displacing the free product ...

  17. Enhanced desorption of phenanthrene from contaminated soil using anionic/nonionic mixed surfactant.

    Science.gov (United States)

    Zhou, Wenjun; Zhu, Lizhong

    2007-05-01

    A new approach using an anionic/nonionic mixed surfactant, sodium dodecyl sulphate (SDS) with Triton X-100 (TX100), was utilized for the desorption of phenanthrene from an artificial contaminated natural soil in an aim to improve the efficiency of surfactant remediation technology. The experimental results showed that the presence of SDS not only reduced the sorption of TX100 onto the natural soil, but also enhanced the solubilization of TX100 for phenanthrene, both of which resulted in the distribution of phenanthrene in soil-water systems decreasing with increasing mole fraction of SDS in surfactant solutions. These results can be attributed to the formation of mixed micelles in surfactant solution and the corresponding decrease in the critical micelle concentration of TX100 in mixed solution. The batch desorption experiments showed that the desorption percentage of phenanthrene from the contaminated soil with mixed solution was greater than that with single TX100 solution and appeared to be positively related to the mole fraction of SDS in surfactant solution. Thus, the anionic/nonionic mixed surfactants are more effective for the desorption of phenanthrene from the contaminated soil than a single nonionic surfactant.

  18. The application of a mulch biofilm barrier for surfactant enhanced polycyclic aromatic hydrocarbon bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Youngwoo; Lee, Woo-Hyung; Sorial, George [Department of Civil and Environmental Engineering, University of Cincinnati, 765 Baldwin Hall, PO Box 210071, Cincinnati, OH 45221-0071 (United States); Bishop, Paul L. [Department of Civil and Environmental Engineering, University of Cincinnati, 765 Baldwin Hall, PO Box 210071, Cincinnati, OH 45221-0071 (United States)], E-mail: Paul.Bishop@UC.edu

    2009-01-15

    Lab scale mulch biofilm barriers were constructed and tested to evaluate their performance for preventing the migration of aqueous and surfactant solubilized PAHs. The spatial distribution of viable PAH degrader populations and resultant biofilm formation were also monitored to evaluate the performance of the biobarrier and the prolonged surfactant effect on the PAH degrading microorganism consortia in the biobarrier. Sorption and biodegradation of PAHs resulted in stable operation of the system for dissolved phenanthrene and pyrene during 150 days of experimentation. The nonionic surfactant could increase the solubility of phenanthrene and pyrene significantly. However, the biobarrier itself couldn't totally prevent the migration of micellar solubilized phenanthrene and pyrene. The presence of surfactant and the resultant highly increased phenanthrene or pyrene concentration didn't appear to cause toxic effects on the attached biofilm in the biobarrier. However, the presence of surfactant did change the structural composition of the biofilm. - Mulch biofilm barrier showed potential for surfactant enhanced bioremediation, and the presence of surfactant changed the structural composition of the biofilm.

  19. Surfactant-activated lipase hybrid nanoflowers with enhanced enzymatic performance

    Science.gov (United States)

    Cui, Jiandong; Zhao, Yamin; Liu, Ronglin; Zhong, Cheng; Jia, Shiru

    2016-01-01

    Increasing numbers of materials have been extensively used as platforms for enzyme immobilization to improve catalytic performance. However, activity of the most of the enzymes was declined after immobilization. Here, we develop a surfactant-activated lipase-inorganic flowerlike hybrid nanomaterials with rational design based on interfacial activation and self-assembly. The resulting surfactant-activated lipase-inorganic hybird nanoflower (activated hNF-lipase) exhibited 460% and 200% higher activity than native lipase and conventional lipase-inorganic hybird nanoflower (hNF-lipase). Furthermore, the activated hNF-lipase displayed good reusability due to its monodispersity and mechanical properties, and had excellent long-time stability. The superior catalytic performances were attributed to both the conformational modulation of surfactants and hierarchical structure of nanoflowers, which not only anchored lipases in an active form, but also decreased the enzyme-support negative interaction and mass-transfer limitations. This new biocatalytic system is promising to find widespread use in applications related to biomedicine, biosensor, and biodiesel. PMID:27297609

  20. Sono-electroanalysis of copper: enhanced detection and determination in the presence of surfactants.

    Science.gov (United States)

    Hardcastle, Joanna Lorraine; Hignett, Geraldine; Melville, James L; Compton, Richard G

    2002-04-01

    Surfactant adsorption has been shown to have a passivating effect on the electrode surface during anodic stripping voltammetric measurements. In the present work the feasibility of sono-anodic stripping analysis for the determination of copper in aqueous media contaminated with surfactant has been studied at an unmodified bare glassy carbon electrode. We illustrate the deleterious effect of three common surfactants, sodium dodecyl sulfate (SDS), dodecyl pyridinium chloride (DPC) and Triton-X 100 (TX-100) on conventional electroanalysis. The analogous sono-electroanalytical response was investigated for each surfactant at ultrasound intensities above and below the cavitation threshold. The enhancement in the stripping signal observed is attributed to the increased mass transport due to acoustic streaming and above the cavitation threshold the intensity of cavitational events is significantly increased leading to shearing of adsorbed surfactant molecules from the surface. As a result accurate analyses for SDS concentrations up to 100 ppm are possible, with analytical signals visible in solutions of SDS and TX-100 of 1000 ppm. Analysis is reported in high concentration of surfactant with use of sono-solvent double extraction. The power of this technique is clearly illustrated by the ability to obtain accurate measurements of copper concentration from starting solutions containing 1000 ppm SDS or TX-100. This was also exemplified by analysis of the low concentration 0.3 microM Cu(II) solution giving a percentage recovery of 94% in the presence of 1000 ppm SDS or TX-100.

  1. Enhanced degradation of carbon tetrachloride by surfactant-modified zero-valent iron

    Institute of Scientific and Technical Information of China (English)

    MENG Ya-feng; GUAN Bao-hong; WU Zhong-biao; WANG Da-hui

    2006-01-01

    Sorption of carbon tetrachloride (CT) by zero-valent iron (ZVI) is the rate-limiting step in the degradation of CT, so the sorption capacity of ZVI is of great importance. This experiment was aimed at enhancing the sorption of CT by ZVI and the degradation rate of CT by modification of surfactants. This study showed that ZVI modified by cationic surfactants has favorable synergistic effect on the degradation of CT. The CT degradation rate of ZVI modified by cetyl pyridinium bromide (CPB) was higher than that of the unmodified ZVI by 130%, and the CT degradation rate of ZVI modified by cetyl trimethyl ammonium bromide (CTAB) was higher than that of the unmodified ZVI by 81%. This study also showed that the best degradation effect is obtained at the near critical micelle concentrations (CMC) and that high loaded cationic surfactant does not have good synergistic effect on the degradation due to its hydrophilicity and the block in surface reduction sites. Furthermore degradation of CT by ZVI modified by nonionic surfactant has not positive effect on the degradation as the ionic surfactant and the ZVI modified by anionic surfactant has hardly any obvious effects on the degradation.

  2. Model study of enhanced oil recovery by flooding with aqueous surfactant solution and comparison with theory.

    Science.gov (United States)

    Fletcher, Paul D I; Savory, Luke D; Woods, Freya; Clarke, Andrew; Howe, Andrew M

    2015-03-17

    With the aim of elucidating the details of enhanced oil recovery by surfactant solution flooding, we have determined the detailed behavior of model systems consisting of a packed column of calcium carbonate particles as the porous rock, n-decane as the trapped oil, and aqueous solutions of the anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT). The AOT concentration was varied from zero to above the critical aggregation concentration (cac). The salt content of the aqueous solutions was varied to give systems of widely different, post-cac oil-water interfacial tensions. The systems were characterized in detail by measuring the permeability behavior of the packed columns, the adsorption isotherms of AOT from the water to the oil-water interface and to the water-calcium carbonate interface, and oil-water-calcium carbonate contact angles. Measurements of the percent oil recovery by pumping surfactant solutions into calcium carbonate-packed columns initially filled with oil were analyzed in terms of the characterization results. We show that the measured contact angles as a function of AOT concentration are in reasonable agreement with those calculated from values of the surface energy of the calcium carbonate-air surface plus the measured adsorption isotherms. Surfactant adsorption onto the calcium carbonate-water interface causes depletion of its aqueous-phase concentration, and we derive equations which enable the concentration of nonadsorbed surfactant within the packed column to be estimated from measured parameters. The percent oil recovery as a function of the surfactant concentration is determined solely by the oil-water-calcium carbonate contact angle for nonadsorbed surfactant concentrations less than the cac. For surfactant concentrations greater than the cac, additional oil removal occurs by a combination of solubilization and emulsification plus oil mobilization due to the low oil-water interfacial tension and a pumping pressure increase.

  3. Numerical Modeling of Natural and Enhanced Denitrification Processes in Aquifers

    Science.gov (United States)

    Kinzelbach, Wolfgang; SchäFer, Wolfgang; Herzer, JöRg

    1991-06-01

    Nitrate modeling in the groundwater environment must incorporate microbial denitrification as the major process of nitrate elimination. A multispecies transport model is presented which describes the interaction of oxygen, nitrate, organic carbon, and bacteria. Three phases (mobile pore water, biophase, and aquifer material) are taken into account. The model is applied to a natural aquifer situation as well as to an in situ remediation case where nitrate is employed as an oxidant. In the natural aquifer it is shown that the release of organic carbon from the matrix is the controlling factor for denitrification. In the remediation case, on the other hand, the data suggest that diffusion limitation of the nutrient supply to the biophase controls bacterial growth.

  4. Enhancing plant-microbe associated bioremediation of phenanthrene and pyrene contaminated soil by SDBS-Tween 80 mixed surfactants.

    Science.gov (United States)

    Ni, Hewei; Zhou, Wenjun; Zhu, Lizhong

    2014-05-01

    The use of surfactants to enhance plant-microbe associated dissipation in soils contaminated with polycyclic aromatic hydrocarbons (PAHs) is a promising bioremediation technology. This comparative study was conducted on the effects of plant-microbe treatment on the removal of phenanthrene and pyrene from contaminated soil, in the presence of low concentration single anionic, nonionic and anionic-nonionic mixed surfactants. Sodium dodecyl benzene sulfonate (SDBS) and Tween 80 were chosen as representative anionic and nonionic surfactants, respectively. We found that mixed surfactants with concentrations less than 150 mg/kg were more effective in promoting plant-microbe associated bioremediation than the same amount of single surfactants. Only about (m/m) of mixed surfactants was needed to remove the same amount of phenanthrene and pyrene from either the planted or unplanted soils, when compared to Tween 80. Mixed surfactants (Tween 80. These results may be explained by the lower sorption loss and reduced interfacial tension of mixed surfactants relative to Tween 80, which enhanced the bioavailability of PAHs in soil and the microbial degradation efficiency. The higher remediation efficiency of low dosage SDBS-Tween 80 mixed surfactants thus advanced the technology of surfactant-enhanced plant-microbe associated bioremediation.

  5. Surfactant enhanced pyrene degradation in the rhizosphere of tall fescue (Festuca arundinacea).

    Science.gov (United States)

    Cheema, Sardar Alam; Khan, Muhammad Imran; Tang, Xianjin; Shen, Chaofeng; Farooq, Muhammad; Chen, Yingxu

    2016-09-01

    The present study was conducted to evaluate the effect of two non ionic surfactants (Tween 80 and Triton X-100), a biosurfactant (Lecithin), and randomly methylated-β-cyclodextrins (RAMEB) on the remediation of pyrene from soil planted with tall fescue (Festuca arundinacea). Soils with pyrene concentration of about 243 mg kg(-1) was grown with tall fescue and were individually amended with 0, 200, 600, 1000, and 1500 mg kg(-1) of Tween 80, Triton X-100, biosurfactant, and RAMEB. The results show that all surfactants significantly increased plant biomass compared to unamended soil. Dehydrogenase activity was also stimulated as a result of surfactant addition. Only 3.9 and 3.2 % of pyrene was decreased in the uncovered and covered abiotic sterile control, suggesting that microbial degradation was the main removal mechanism of pyrene from soil. In the planted treatment receiving no surfactant, the remediation of pyrene was 45 % which is significantly higher than that of corresponding unplanted control soil, suggesting that the cultivation of tall fescue alone could enhance the overall remediation of pyrene in soil. All surfactants had significantly higher rates of pyrene remediation compared to the unamended planted soil. Generally, RAMEB displayed the highest remediation rates, i.e., 64.4-79.1 % followed by the Triton X-100, i.e., 60.1-74.8 %. The positive impact of surfactants on pyrene remediation could possibly be because of their capacities to increase its bioavailability in soil. The evidence from this study suggests that the addition of surfactants could enhance phytoremediation of PAHs polluted soil.

  6. Enhancement of wadi recharge using dams coupled with aquifer storage and recovery wells

    KAUST Repository

    Missimer, Thomas M. M.

    2014-06-25

    Wadi channel recharge to the underlying alluvial aquifer is naturally limited by the flashy nature of flood events, evapotranspiration losses of water from the vadose zone, and aquifer heterogeneity, particularly low vertical hydraulic conductivity. Anthropogenic lowering of the water table in many wadi aquifers has also reduced the potential recharge by increasing the thickness of the vadose zone, causing interflow water loss from surface emergence and evaporation. A method to enhance recharge is to slow the flow within wadi channels by placement of dam structures, thereby ponding water and increasing the vertical head gradient to create a more rapid rate of infiltration and percolation. Effectiveness of wadi dams to enhance aquifer recharge reduces over time due to mud deposition within the reservoir caused by storm events. Up to 80 % of the water in old wadi reservoirs is lost to free-surface evaporation before infiltration and recharge can occur. One method to maintain or increase the rate of recharge is to convey clean water by gravity flow from the reservoir down-gradient to artificially recharge the aquifer using existing wells. This type of system is a low-cost and low-energy recharge method which could greatly enhance groundwater storage in wadi aquifers. Modeling results show that existing wells could store up to 1,000 m3/day under gravity-feed conditions and up to 3,900 m3/day with the shut-in of the well to produce a pressurized system. © 2014 Springer-Verlag Berlin Heidelberg.

  7. Combination of aquifer thermal energy storage and enhanced bioremediation

    NARCIS (Netherlands)

    Ni, Zhuobiao; Gaans, van Pauline; Smit, Martijn; Rijnaarts, Huub; Grotenhuis, Tim

    2016-01-01

    To meet the demand for sustainable energy, aquifer thermal energy storage (ATES) is widely used in the subsurface in urban areas. However, contamination of groundwater, especially with chlorinated volatile organic compounds (CVOCs), is often being encountered. This is commonly seen as an impedime

  8. ANAEROBIC DDT BIOTRANSFORMATION: ENHANCEMENT BY APPLICATION OF SURFACTANTS AND LOW OXIDATION REDUCTION POTENTIAL

    Science.gov (United States)

    Enhancement of anaerobic DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane) biotransformation by mixed cultures was studied with application of surfactants and oxidation reduction potential reducing agents. Without amendments, DDT transformation resulted mainly in the pr...

  9. BENCH-SCALE VISUALIZATION OF DNAPL REMEDIATION PROCESSES IN ANALOG HETEROGENEOUS AQUIFERS: SURFACTANT FLOODS, AND IN SITU OXIDATION USING PERMANGANATE

    Science.gov (United States)

    We have conducted well-controlled DNAPL remediation experiments using surfactants (Aerosol MA and Tween 80) to increase solubility and an oxidant (permanganate) to chemically degrade the DNAPL. Photographs and digital image analysis illustrate previously unobserved interactions b...

  10. Surfactant enhanced removal of PCE in a nominally two-dimensional, saturated, stratified porous medium

    Science.gov (United States)

    Walker, R. C.; Hofstee, C.; Dane, J. H.; Hill, W. E.

    1998-10-01

    Although surfactant enhanced remediation of nonaqueous phase liquids (NAPLs) by pump-and-treat technology has been studied extensively in the laboratory with one-dimensional columns, very few multi-dimensional investigations have been reported. In this study we focus on the removal of perchloroethylene (PCE) from a two-dimensional, saturated porous medium containing a low permeability sand layer situated in an otherwise high permeability sand. A PCE spill was applied at the surface of the porous medium and allowed to redistribute until static equilibrium was achieved. The porous medium was then flushed with various surfactant and co-solvent formulations injected at the PCE source location and extracted at the bottom of the porous medium using a configuration similar to that of Abdul and Ang [Abdul, S.A., Ang, C.C., 1994. In situ surfactant washing of polychlorinated biphenyls and oils from a contaminated field site: Phase II. Pilot study. Ground Water 32, 727-734]. Effluent samples were analyzed for dissolved PCE concentrations. Volumetric water and PCE content values were determined at a number of locations by means of dual-energy gamma radiation measurements. Once surfactant flushing had started, PCE moved as a distinct separate phase ahead of the surfactant front. Most of this downward moving PCE accumulated on top of the low permeability sand layer. Some PCE, however, passed quickly through this layer and subsequently through the high permeability sand below it. Movement of some of the PCE into and through the low permeability sand layer was attributed to local heterogeneities combined with reduced interfacial tensions associated with the surfactant formulation. Clean-up of PCE in most of the high permeability sand was considered to be effective. PCE accumulated on top of the fine layer, however, posed a significant challenge to remediation and required several pumping configurations and surfactant/co-solvent formulations before most of it was removed.

  11. Evaluation of the potential of alkali-surfactant-polymer (ASP) foams in enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Wang, L. A.; Romer-Zeron, L.; Kantzas, A. [University of Calgary, Dept. of Chemical and Petroleum Engineering, Calgary, AB (Canada)

    2004-07-01

    Results of a study of a new enhanced oil recovery technology, known as alkali-surfactant-polymer foams (ASPF), are discussed. The study was carried out through a series of laboratory core floods using sand packs and dead crude oil. The foaming solution was formulated using synthetic brine; a polycrylamide (AC 935) combined with the foaming surfactant (CD 1045) was chosen to provide the greatest gas mobility control capability and foam stability. Results demonstrated very high oil recovery efficiency resulting from ASPF flooding. Various combination of water flooding, foam flooding and gas flooding were investigated in an effort to determine the optimum injection scenarios for maximum oil recovery.

  12. Anionic surfactants enhance click reaction-mediated protein conjugation with ubiquitin.

    Science.gov (United States)

    Schneider, Daniel; Schneider, Tatjana; Aschenbrenner, Joos; Mortensen, Franziska; Scheffner, Martin; Marx, Andreas

    2016-03-01

    The Cu(I)-catalyzed alkyne-azide cycloaddition (CuAAC) has become increasingly important in the conjugation chemistry of biomolecules. For example, it is an efficient and convenient method to generate defined ubiquitin-protein conjugates. Here, we investigate the effect of surfactants on the efficiency of CuAAC for chemical protein ubiquitylation. We found that anionic surfactants enhance conjugate formation by up to 10-fold resulting in high yields even at low (i.e., micromolar) concentrations of the reactants. Notably, the herein investigated conjugates are functional and thus properly folded. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Aquifer/aquitard interfaces: mixing zones that enhance biogeochemical reactions

    Science.gov (United States)

    McMahon, P. B.

    2001-01-01

    Several important biogeochemical reactions are known to occur near the interface between aquifer and aquitard sediments. These reactions include O2 reduction; denitrification; and Fe3+, SO42-, and CO2 (methanogenesis) reduction. In some settings, these reactions occur on the aquitard side of the interface as electron acceptors move from the aquifer into the electron-donor-enriched aquitard. In other settings, these reactions occur on the aquifer side of the interface as electron donors move from the aquitard into the electron-acceptor-enriched, or microorganism-enriched, aquifer. Thus, the aquifer/aquitard interface represents a mixing zone capable of supporting greater microbial activity than either hydrogeologic unit alone. The extent to which biogeochemical reactions proceed in the mixing zone and the width of the mixing zone depend on several factors, including the abundance and solubility of electron acceptors and donors on either side of the interface and the rate at which electron acceptors and donors react and move across the interface. Biogeochemical reactions near the aquifer/aquitard interface can have a substantial influence on the chemistry of water in aquifers and on the chemistry of sediments near the interface. Résumé. Il se produit au voisinage de l'interface entre les aquifères et les imperméables plusieurs réactions biogéochimiques importantes. Il s'agit des réactions de réduction de l'oxygène, de la dénitrification et de la réduction de Fe3+, SO42- et CO2 (méthanogenèse). Dans certaines situations, ces réactions se produisent du côté imperméable de l'interface, avec des accepteurs d'électrons qui vont de l'aquifère vers l'imperméable riche en donneurs d'électrons. Dans d'autres situations, ces réactions se produisent du côté aquifère de l'interface, avec des donneurs d'électrons qui se déplacent de l'imperméable vers l'aquifère riche en accepteurs d'électrons ou en microorganismes. Ainsi, l'interface aquif

  14. Dynamic interfacial behavior of decyl methylnaphthalene sulfonate surfactants for enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Zhongkui; Ba Yan; Li Zongshi; Qiao Weihong; Cheng Luebai [State Key Lab. of Fine Chemicals, Dalian Univ. of Technology, Dalian (China)

    2004-10-01

    The high purity decyl methylnaphthalene sulfonate (DMNS) was synthesized, the purity was determined by HPLC and the structure was confirmed by IR, UV and ESI-MS. Dynamic interfacial tensions (DIT) between DMNS flooding systems and crude oil were measured and the effects of sodium carbonate concentration, surfactant concentration and sodium chloride concentration on the DIT behaviors were investigated. It's found that the surfactant concentration, alkali concentration and the salinity have obvious influences on DIT behaviors. DMNS possessed outstanding capacity and efficiency of lowering the DIT between oil and water. The minimum dynamic interfacial tension could reach 6.35 x 10{sup -6} mNm{sup -1} at a low concentration for added surfactant. DMNS might be used in Enhanced Oil Recovery with low costs and high efficiency. (orig.)

  15. Surfactant-directed polypyrrole/CNT nanocables: synthesis, characterization, and enhanced electrical properties.

    Science.gov (United States)

    Zhang, Xuetong; Zhang, Jin; Wang, Rongming; Zhu, Tao; Liu, Zhongfan

    2004-07-19

    We describe here a new approach to the synthesis of size-controllable polypyrrole/carbon nanotube (CNT) nanocables by in situ chemical oxidative polymerization directed by the cationic surfactant cetyltrimethylammonium bromide (CTAB) or the nonionic surfactant polyethylene glycol mono-p-nonylphenyl ether (Opi-10). When carbon nanotubes are dispersed in a solution containing a certain concentration of CTAB or Opi-10, the surfactant molecules are adsorbed and arranged regularly on the CNT surfaces. On addition of pyrrole, some of the monomer is adsorbed at the surface of CNTs and/or wedged between the arranged CTAB or Opi-10 molecules. When ammonium persulfate (APS) is added, pyrrole is polymerized in situ at the surfaces of the CNTs (core layer) and ultimately forms the outer shell of the nanocables. Such polypyrrole/CNT nanocables show enhanced electrical properties; a negative temperature coefficient of resistance at 77-300 K and a negative magnetoresistance at 10-200 K were observed.

  16. Desorption of hydrocarbon chains by association with ionic and nonionic surfactants under flow as a mechanism for enhanced oil recovery.

    Science.gov (United States)

    Terrón-Mejía, Ketzasmin A; López-Rendón, Roberto; Goicochea, Armando Gama

    2017-08-29

    The need to extract oil from wells where it is embedded on the surfaces of rocks has led to the development of new and improved enhanced oil recovery techniques. One of those is the injection of surfactants with water vapor, which promotes desorption of oil that can then be extracted using pumps, as the surfactants encapsulate the oil in foams. However, the mechanisms that lead to the optimal desorption of oil and the best type of surfactants to carry out desorption are not well known yet, which warrants the need to carry out basic research on this topic. In this work, we report non equilibrium dissipative particle dynamics simulations of model surfactants and oil molecules adsorbed on surfaces, with the purpose of studying the efficiency of the surfactants to desorb hydrocarbon chains, that are found adsorbed over flat surfaces. The model surfactants studied correspond to nonionic and cationic surfactants, and the hydrocarbon desorption is studied as a function of surfactant concentration under increasing Poiseuille flow. We obtain various hydrocarbon desorption isotherms for every model of surfactant proposed, under flow. Nonionic surfactants are found to be the most effective to desorb oil and the mechanisms that lead to this phenomenon are presented and discussed.

  17. Reducing plant uptake of PAHs by cationic surfactant-enhanced soil retention

    Energy Technology Data Exchange (ETDEWEB)

    Lu Li, E-mail: ll19840106@zju.edu.c [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhu Lizhong, E-mail: zlz@zju.edu.c [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, Zhejiang University, Hangzhou, Zhejiang 310029 (China)

    2009-06-15

    Reducing the transfer of contaminants from soils to plants is a promising approach to produce safe agricultural products grown on contaminated soils. In this study, 0-400 mg/kg cetyltrimethylammonium bromide (CTMAB) and dodecylpyridinium bromide (DDPB) were separately utilized to enhance the sorption of PAHs onto soils, thereby reducing the transfer of PAHs from soil to soil solution and subsequently to plants. Concentrations of phenanthrene and pyrene in vegetables grown in contaminated soils treated with the cationic surfactants were lower than those grown in the surfactant-free control. The maximum reductions of phenanthrene and pyrene were 66% and 51% for chrysanthemum (Chrysanthemum coronarium L.), 62% and 71% for cabbage (Brassica campestris L.), and 34% and 53% for lettuce (Lactuca sativa L.), respectively. Considering the impacts of cationic surfactants on plant growth and soil microbial activity, CTMAB was more appropriate to employ, and the most effective dose was 100-200 mg/kg. - Cationic surfactants could enhance the retention of PAHs in soil, and reduce PAH transfer to and accumulation in vegetables.

  18. Surfactant-enhanced alkaline flooding for light oil recovery. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wasan, D.T.

    1996-05-01

    In this report, we present the results of our experimental and theoretical studies in surfactant-enhanced alkaline flooding for light oil recovery. The overall objective of this work is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12. 0) for ultimate spontaneous emulsification and ultralow interfacial tension. In addition, we have (1) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, (2) investigated the mechanisms for spontaneous emulsification, (3) developed a technique to monitor low water content in oil and (4) developed a technique to study water-in-oil emulsion film properties, (5) investigated the effect of surfactant on the equilibrium and transient interfacial tension, (6) investigated the kinetics of oil removal from a silica surface, and (7) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, accounting for added surfactant. The results of the studies conducted during the course of this project are discussed.

  19. Surfactant-enhanced alkaline flooding for light oil recovery. Final report 1994--1995

    Energy Technology Data Exchange (ETDEWEB)

    Wasan, D.T.

    1995-12-01

    In this report, the authors present the results of their experimental and theoretical studies in surfactant-enhanced alkaline flooding for light oil recovery. The overall objective of this work is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12.0) for ultimate spontaneous emulsification and ultralow interfacial tension. In addition, the authors have (1) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, (2) investigated the mechanisms for spontaneous emulsification, (3) developed a technique to monitor low water content in oil, and (4) developed a technique to study water-in-oil emulsion film properties, (5) investigated the effect of surfactant on the equilibrium and transient interfacial tension, (6) investigated the kinetics of oil removal from a silica surface, and (7) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, accounting for added surfactant. The results of the studies conducted during the course of this project are summarized.

  20. Enhanced oil recovery by surfactant-enhanced volumetric sweep efficiency: First annual report for the period September 30, 1985-September 30, 1986. [Sandpacks

    Energy Technology Data Exchange (ETDEWEB)

    Harwell, J H; Scamehorn, J F

    1987-05-01

    Surfactant-enhanced volumetric sweep efficiency is a novel EOR method which utilizes precipitation/coacervation of surfactants to plug the most permeable regions of the reservoir, improving the efficiency of a waterflooding operation. This technique does not rely on reduction of interfacial tension between aqueous and oleic phases to enhance oil recovery. Therefore, even though surfactants are involved, this new technique is not a substitute or improvement on classical surfactant flooding; however, it has the potantial to compete with polymer flooding as an alternative sweep efficiency improvement method. In surfactant-enhanced volumetric sweep efficiency, a slug containing one kind of surfactant is injected into the reservoir, followed by a brine spacer. This is followed by injection of a second kind of surfactant which has lower adsorption than the first surfactant used. Anionic and cationic surfactants are one possible combination for this application. These may form either a precipitate or a coacervate upon mixing. Phase boundaries for some specific systems of this type have been determined over a wide range of conditions and a model developed to describe this behavior. Another possibility is the use of nonionic surfactants, which may form coacervate under proper conditions. The adsorption behavior of mixtures of anionic and nonionic surfactants was measured to aid in modeling the chromatographic effects with these surfactants in the reservoir. Studies with sandpacks of different permeabilities in parallel configuration using mixtures of anionic and cationic surfactants have demonstrated the capability of this method to reduce flow rates through a more permeable sandpack more than that through a less permeable sandpack. 4 refs., 23 figs., 8 tabs.

  1. Enhanced mineral alteration by petroleum biodegradation in a freshwater aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Hiebert, F.K. [RMT/Jones and Neuse, Inc., Austin, TX (United States); Bennett, P.C.; Folk, R.L.; Pope, S.R. [Univ. of Texas, Austin, TX (United States). Dept. of Geological Sciences

    1995-12-31

    Aerobic and anaerobic microbial degradation of petroleum hydrocarbons in shallow aquifers disturbs the geochemical equilibrium between water and mineral phases and accelerates the dissolution and precipitation of minerals. These effect were investigated in an oil-contaminated aquifer near Bemidji, Minnesota, using in situ microcosms with a 14-month reaction period and field column experiments. Minerals recovered from microcosms were studied by scanning electron microscopy (SEM). Groundwater chemistry was characterized before and after the experiment. The in situ microcosms yielded feldspar and quartz grains colonized with a variety of bacteria. On a microscale feldspars, quartz, and, in some cases, calcite dissolved in the immediate vicinity of attached bacteria, even though the saturation indices for these minerals in the bulk groundwater indicated that little to no dissolution should occur. On a local scale the metabolic production of CO{sub 2} and HCO{sub 3} resulting from acetate methanogenesis and the oxidation of aromatic hydrocarbons coupled with iron reduction provided a supply of reactants to the groundwater. Calcite precipitated in a wide variety of spiky morphologies and clay minerals formed on feldspar minerals.

  2. Innovative reactive layer to enhance soil aquifer treatment: successful installation in the Llobregat aquifer (Catalonia, ne Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, M.; Gilbert, O.; Bernat, X.; Valhondo, C.; Kock-Schulmeyer, M.; Huerta-Fontela, M.; Colomer, M. V.

    2014-10-01

    The Life+ ENSAT project has demonstrated the effectiveness of a reactive organic layer on the improvement of recharge water quality in an aquifer recharge system. The vegetal compost layer was installed at the bottom of an existing infiltration pond in the Llobregat Lower Valley (Barcelona region) with the purpose of promoting biodegradation and improving the removal emerging micro-pollutants from Llobregat River water. A comprehensive monitoring of water quality including bulk chemistry, emerging micro-pollutants and priority substances indicated that hydro biochemical changes within the organic layer enhance denitrification processes and reduce the levels of gemfibrozil and carbamazepine TP. This effect is due to the release of dissolved organic carbon which promotes biodegradation processes at local scale in the unsaturated zones, without affecting the furthest piezometers. The reactive layer is still active more than 3 years after its installation. The economic assessment of this innovative reactive layer shows that it is a promising solution for the improvement of aquifer recharge with low quality waters, not only technically but also from the economic sustainability standpoint. (Author)

  3. Surfactant-enhanced alkaline flooding for light oil recovery. Annual report, 1992--1993

    Energy Technology Data Exchange (ETDEWEB)

    Wasan, D.T.

    1994-08-01

    In this report, the authors present the results of experimental and theoretical studies in surfactant-enhanced alkaline flooding for light oil recovery. The overall objective of this work is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12.0) for ultimate spontaneous emulsification and ultralow interfacial tension. In addition, the authors have (1) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, (2) investigated the mechanisms for spontaneous emulsification, (3) developed a technique to monitor low water content in oil, and (4) developed a technique to study water-in-oil emulsion film properties.

  4. Enhanced dispersion of multiwall carbon nanotubes in natural rubber latex nanocomposites by surfactants bearing phenyl groups.

    Science.gov (United States)

    Mohamed, Azmi; Anas, Argo Khoirul; Bakar, Suriani Abu; Ardyani, Tretya; Zin, Wan Manshol W; Ibrahim, Sofian; Sagisaka, Masanobu; Brown, Paul; Eastoe, Julian

    2015-10-01

    Here is presented a systematic study of the dispersibility of multiwall carbon nanotubes (MWCNTs) in natural rubber latex (NR-latex) assisted by a series of single-, double-, and triple-sulfosuccinate anionic surfactants containing phenyl ring moieties. Optical polarising microscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Raman spectroscopy have been performed to obtain the dispersion-level profiles of the MWCNTs in the nanocomposites. Interestingly, a triple-chain, phenyl-containing surfactant, namely sodium 1,5-dioxo-1,5-bis(3-phenylpropoxy)-3-((3-phenylpropoxy)carbonyl) pentane-2-sulfonate (TCPh), has a greater capacity the stabilisation of MWCNTs than a commercially available single-chain sodium dodecylbenzenesulfonate (SDBS) surfactant. TCPh provides significant enhancements in the electrical conductivity of nanocomposites, up to ∼10(-2) S cm(-1), as measured by a four-point probe instrument. These results have allowed compilation of a road map for the design of surfactant architectures capable of providing the homogeneous dispersion of MWCNTs required for the next generation of polymer-carbon-nanotube materials, specifically those used in aerospace technology. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Solubilization and separation of p-tert-butylphenol using polyelectrolyte/surfactant complexes in colloid-enhanced ultrafiltration

    Energy Technology Data Exchange (ETDEWEB)

    Uchiyama, Hirotaka; Christian, S.D.; Tucker, E.E.; Scamehorn, J.F. (Univ. of Oklahoma, Norman, OK (United States))

    1994-03-15

    Water-soluble polyelectrolyte/surfactant complexes, involving oppositely charged species, can form at quite low thermodynamic activities of the surfactant. This fact can be exploited in colloid-enhanced ultrafiltration separations, where both molecular organic pollutants and toxic ions are to be removed from contaminated aqueous streams. Investigations have been made of (a) the solubilization and ultrafiltration of solutions of organic solutes in polymer/surfactant solutions, for comparison with studies of micellar surfactant solutions in the absence of added polymers; (b) the penetration of surfactant through the membrane (leakage of monomer) in dialysis and ultrafiltration experiments; and (c) the utility of polyelectrolytes as scavengers'' for surfactant species that-enter the permeate or filtrate in colloid-enhanced ultrafiltration separations. The polyelectrolyte chosen for the studies is sodium poly(styrenesulfonate) and the surfactant is cetylpyridinium chloride (hexadecylpyridinium chloride). A detailed study has been made of the solubilization and separation of p-tert-butylphenol in aqueous mixtures of sodium poly(styrenesulfonate) and cetylpyridinium chloride, at polyelectrolyte to surfactant mole ratios of two to one and three to one.

  6. Electrokinetically Enhanced Delivery for ERD Remediation of Chlorinated Ethenes in a Fractured Limestone Aquifer

    DEFF Research Database (Denmark)

    Broholm, Mette Martina; Hansen, Bente H.; With Nedergaard, Lærke;

    Leakage of the chlorinated solvents PCE and TCE into limestone aquifers from contaminated overburden and the long-lasting back diffusion from the secondary source in the limestone matrix pose a severe risk for contamination of drinking water resources. Dechlorination of PCE and TCE in limestone...... often accumulates cis-DCE due to incomplete dechlorination in the limestone aquifers, as observed downgradient of a PCE and TCE DNAPL source area at Naverland in Denmark. A microcosm study with limestone core material and groundwater from the Naverland site source area spiked with PCE showed...... that enhanced reductive dechlorination (ERD) by the addition of donor and specific degraders (KB1® culture) can lead to complete dechlorination of PCE and TCE in the limestone aquifer, provided sufficient contact between specific degraders, donor and specific degraders, is obtained. Advection-based delivery...

  7. One-dimensional porphyrin nanoassemblies assisted via graphene oxide: sheetlike functional surfactant and enhanced photocatalytic behaviors.

    Science.gov (United States)

    Guo, Peipei; Chen, Penglei; Liu, Minghua

    2013-06-12

    Surfactant-assisted self-assembly (SAS) has received much attention for supramolecular nanoassemblies, due to its simplicity and easiness in realizing a controllable assembly. However, in most of the existing SAS protocols, the employed surfactants work only as a regulator for a controllable assembly but not as active species for function improvement. In this paper, we report that a porphyrin, zinc 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine (ZnTPyP), could be assembled to form one-dimensional (1D) supramolecular nanostructures via a SAS method, wherein graphene oxide (GO) plays a fascinating role of sheetlike surfactant. We show that, when a chloroform or tetrahydrofuran solution of ZnTPyP is injected into an aqueous dispersion of GO, 1D supramolecular nanoassemblies of ZnTPyP with well-defined internal structures could be easily formulated in a controllable manner. Our experimental facts disclose that the complexation of ZnTPyP with the two-dimensional GO nanosheets plays an important role in this new type of SAS. More interestingly, compared with the 1D ZnTPyP nanoassemblies formulated via a conventional SAS, wherein cetyltrimethylammonium bromide is used as surfactant, those constructed via our GO-assisted SAS display distinctly enhanced photocatalytic activity for the photodegradation of rhodamine B under visible-light irradiation. Our new findings suggest that GO could work not only as an emergent sheetlike surfactant for SAS in terms of supramolecular nanoassembly but also as functional components during the performance of the assembled nanostructures.

  8. Microbial surfactant-enhanced mineral oil recovery under laboratory conditions.

    Science.gov (United States)

    Bordoloi, N K; Konwar, B K

    2008-05-01

    Microbial enhanced oil recovery (MEOR) is potentially useful to recover incremental oil from a reservoir being beyond primary and secondary recovery operations. Effort has been made to isolate and characterize natural biosurfactant produced by bacterial isolates collected from various oil fields of ONGC in Assam. Production of biosurfactant has been considered to be an effective major index for the purpose of enhanced oil recovery. On the basis of the index, four promising bacterial isolates: Pseudomonas aeruginosa (MTCC7815), P. aeruginosa (MTCC7814), P. aeruginosa (MTCC7812) and P. aeruginosa (MTCC8165) were selected for subsequent testing. Biosurfactant produced by the promising bacterial isolates have been found to be effective in the recovery of crude oil from saturated column under laboratory conditions. Two bacterial strains: P. aeruginosa (MTCC7815) and P. aeruginosa (MTCC7812) have been found to be the highest producer of biosurfactant. Tensiometer studies revealed that biosurfactants produced by these bacterial strains could reduce the surface tension (sigma) of the growth medium from 68 to 30 mN m(-1) after 96 h of growth. The bacterial biosurfactants were found to be functionally stable at varying pH (2.5-11) conditions and temperature of 100 degrees C. The treatment of biosurfactant containing, cell free culture broth in crude oil saturated sand pack column could release about 15% more crude oil at 90 degrees C than at room temperature and 10% more than at 70 degrees C under laboratory condition.

  9. Screening Nonionic Surfactants for Enhanced Biodegradation of Polycyclic Aromatic Hydrocarbons Remaining in Soil After Conventional Biological Treatment.

    Science.gov (United States)

    Adrion, Alden C; Nakamura, Jun; Shea, Damian; Aitken, Michael D

    2016-04-05

    A total of five nonionic surfactants (Brij 30, Span 20, Ecosurf EH-3, polyoxyethylene sorbitol hexaoleate, and R-95 rhamnolipid) were evaluated for their ability to enhance PAH desorption and biodegradation in contaminated soil after treatment in an aerobic bioreactor. Surfactant doses corresponded to aqueous-phase concentrations below the critical micelle concentration in the soil-slurry system. The effect of surfactant amendment on soil (geno)toxicity was also evaluated for Brij 30, Span 20, and POESH using the DT40 B-lymphocyte cell line and two of its DNA-repair-deficient mutants. Compared to the results from no-surfactant controls, incubation of the bioreactor-treated soil with all surfactants increased PAH desorption, and all except R-95 substantially increased PAH biodegradation. POESH had the greatest effect, removing 50% of total measured PAHs. Brij 30, Span 20, and POESH were particularly effective at enhancing biodegradation of four- and five-ring PAHs, including five of the seven carcinogenic PAHs, with removals up to 80%. Surfactant amendment also significantly enhanced the removal of alkyl-PAHs. Most treatments significantly increased soil toxicity. Only the no-surfactant control and Brij 30 at the optimum dose significantly decreased soil genotoxicity, as evaluated with either mutant cell line. Overall, these findings have implications for the feasibility of bioremediation to achieve cleanup levels for PAHs in soil.

  10. Enhanced production of erythritol and mannitol by Yarrowia lipolytica in media containing surfactants.

    Science.gov (United States)

    Rakicka, Magdalena; Rywińska, Anita; Cybulski, Krzysztof; Rymowicz, Waldemar

    2016-01-01

    Various chemical compounds, including surfactants, when introduced to culture media may increase the permeability of cellular membranes and thereby affect the quantity of metabolites excreted by cells. The aim of the present study was to evaluate the impact of detergents including Triton X-100, Span 20 and Tween 80 on erythritol production from glycerol by Yarrowia lipolytica Wratislavia K1 in a shake-flask experiment, batch and fed-batch cultures. When Span 20 was added to a fed-batch culture with glycerol as a carbon source (300gL(-1)), erythritol production increased by 15% compared to the culture without the surfactant where it reached 142gL(-1) after 5 days, which corresponded to 0.47gg(-1) yield and productivity of 1.1gL(-1)h(-1). Therefore, it was concluded that Span 20 considerably enhanced the production of this polyol from glycerol.

  11. Enhanced production of erythritol and mannitol by Yarrowia lipolytica in media containing surfactants

    Directory of Open Access Journals (Sweden)

    Magdalena Rakicka

    2016-06-01

    Full Text Available Abstract Various chemical compounds, including surfactants, when introduced to culture media may increase the permeability of cellular membranes and thereby affect the quantity of metabolites excreted by cells. The aim of the present study was to evaluate the impact of detergents including Triton X-100, Span 20 and Tween 80 on erythritol production from glycerol by Yarrowia lipolytica Wratislavia K1 in a shake-flask experiment, batch and fed-batch cultures. When Span 20 was added to a fed-batch culture with glycerol as a carbon source (300 g L-1, erythritol production increased by 15% compared to the culture without the surfactant where it reached 142 g L-1 after 5 days, which corresponded to 0.47 g g-1 yield and productivity of 1.1 g L-1 h-1. Therefore, it was concluded that Span 20 considerably enhanced the production of this polyol from glycerol.

  12. Evaluation of Clay and Fumed Silica Nanoparticles on Adsorption of Surfactant Polymer during Enhanced Oil Recovery

    National Research Council Canada - National Science Library

    Cheraghian, Goshtasp

    2017-01-01

    .... The effects of nano concentration on static adsorption of surfactant were investigated at variable condition polymer and surfactant concentration and nanoparticles are critical parameters influence...

  13. Enhanced Oil Recovery from Oil-wet Carbonate Rock by Spontaneous Imbibition of Aqueous Surfactant Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Standnes, Dag Chun

    2001-09-01

    The main theme of this thesis is an experimental investigation of spontaneous imbibition (SI) of aqueous cationic surfactant solution into oil-wet carbonate (chalk- and dolomite cores). The static imbibition process is believed to represent the matrix flow of oil and water in a fractured reservoir. It was known that aqueous solution of C{sub 12}-N(CH{sub 3}){sub 3}Br (C12TAB) was able to imbibe spontaneously into nearly oil-wet chalk material, but the underlying mechanism was not understood. The present work was therefore initiated, with the following objectives: (1) Put forward a hypothesis for the chemical mechanism underlying the SI of C12TAB solutions into oil-wet chalk material based on experimental data and (2) Perform screening tests of low-cost commercially available surfactants for their ability to displace oil by SI of water into oil-wet carbonate rock material. It is essential for optimal use of the surfactant in field application to have detailed knowledge about the mechanism underlying the SI process. The thesis also discusses some preliminary experimental results and suggests mechanisms for enhanced oil recovery from oil-wet carbonate rock induced by supply of thermal energy.

  14. Mobilization and micellar solubilization of NAPL contaminants in aquifer rocks

    Science.gov (United States)

    Javanbakht, Gina; Goual, Lamia

    2016-02-01

    Surfactant-enhanced aquifer remediation is often performed to overcome the capillary forces that keep residual NAPL phases trapped within contaminated aquifers. The surfactant selection and displacement mechanism usually depend on the nature of NAPL constituents. For example, micellar solubilization is often used to cleanup DNAPLs from aquifers whereas mobilization is desirable in aquifers contaminated by LNAPLs. Although the majority of crude oils are LNAPLs, they often contain heavy organic macromolecules such as asphaltenes that are classified as DNAPLs. Asphaltenes contain surface-active components that tend to adsorb on rocks, altering their wettability. Previous studies revealed that surfactants that formed Winsor type III microemulsions could promote both mobilization and solubilization. However the extent by which these two mechanisms occur is still unclear, particularly in oil-contaminated aquifers. In this study we investigated the remediation of oil-contaminated aquifers using an environmentally friendly surfactant such as n-Dodecyl β-D-maltoside. Focus was given on asphaltenes to better understand the mechanisms of surfactant cleanup. Through phase behavior, spontaneous imbibition, dynamic interfacial tension and contact angle measurements, we showed that microemulsions formed by this surfactant are able to mobilize bulk NAPL (containing 9 wt.% asphaltenes) in the porous rock and solubilize DNAPL (i.e., 4-6 wt.% adsorbed asphaltenes) from the rock surface. Spontaneous imbibition tests, in particular, indicated that the ratio of mobilized to solubilized NAPL is about 6:1. Furthermore, aging the cores in NAPL beyond 3 days allowed for more NAPL to be trapped in the large pores of the rock but did not alter the amount of asphaltenes adsorbed on the mineral surface.

  15. Micellar-enhanced ultrafiltration membrane (MEUF) of Batik wastewater using Cetylpyridinium chloride surfactant

    Science.gov (United States)

    Aryanti, Nita; Pramudono, Bambang; Prawira, Christ Nadya P.; Renardi, Rheza; Fatikhatul K. Ika, S.

    2015-12-01

    In batik production, reactive dyes such as remazol, indigosol, naphtol and rapid are used in the dying process. Batik wastewater contains high level of reactive dyes, wax and sodium salts and is characterized with high Chemical Oxygen Demand (COD), Total Suspended Solids (TSS) as well as high concentration of phenol and Ammonia. Micellar-Enhanced Ultrafiltration Membrane (MEUF) is one of promising technology to separate low molecular weight substances such as dyes. The MEUF process involves combination of ultrafiltration membrane and surfactant at concentration higher than surfactant's Critical Micelle Concentration (CMC). This technique combines high selectivity of reverse osmosis membrane and high flux of ultrafiltration membrane but with lower pressure. Ultrafiltration of batik waste water without surfactant (UF) and with addition of surfactant (MEUF) were studied in order to compare the performance of both systems. The Batik wastewater were obtained from batik industry in Semarang and Surakarta, Central Java, Indonesia. Cetyl Pyridinium Chloride at concentration of 2 and 4 times of its CMC were used. Flatsheet ultrafiltration membrane was made from Polyethersulphone (12% w/w), N-methyl Pyrrolidone (83% w/w) and Polyethylene Glycol (5% w/w). The performance of the UF and MEUF were evaluated based on flux profiles and rejections (COD, TSS, concentration of Ammonia). The results showed that the MEUF had superior performance than the UF. Concentration of COD, TSS, phenol and ammonia were reduced significantly. The rejection of COD were 92.74% and 94.15%. Moreover, the MEUF was capable to reduce the TSS with the rejection of 86.26% and 65%. The concentration of ammonia in permeate were 0.43 ppm and below 0.01 ppm.

  16. Enhanced degradation of mono aromatic hydrocarbons in sandy aquifer materials

    Energy Technology Data Exchange (ETDEWEB)

    Corseuil, Henry X. [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Sanitaria; Weber Junior, W.J. [Michigan Univ., Ann Arbor, MI (United States). Dept. of Civil and Environmental Engineering

    1993-12-31

    The use of an inoculation technique to enhance rates of in-situ biodegradation of toxic organic contaminants by increasing subsurface populations of specific microorganisms is described. An external biologically active carbon (BAC) adsorber is demonstrated to be an efficient reactor system for collection, acclimation and enrichment of microorganisms for the inoculation process (author). 15 refs., 3 figs.

  17. Enhancement of in situ microbial remediation of aquifers

    Science.gov (United States)

    Fredrickson, J.K.; Brockman, F.J.; Streile, G.P.; Cary, J.W.; McBride, J.F.

    1993-11-30

    Methods are provided for remediating subsurface areas contaminated by toxic organic compounds. An innocuous oil, such as vegetable oil, mineral oil, or other immiscible organic liquid, is introduced into the contaminated area and permitted to move therethrough. The oil concentrates or strips the organic contaminants, such that the concentration of the contaminants is reduced and such contaminants are available to be either pumped out of the subsurface area or metabolized by microorganisms. Microorganisms may be introduced into the contaminated area to effect bioremediation of the contamination. The methods may be adapted to deliver microorganisms, enzymes, nutrients and electron donors to subsurface zones contaminated by nitrate in order to stimulate or enhance denitrification. 4 figures.

  18. Remediation of nitrobenzene contaminated soil by combining surfactant enhanced soil washing and effluent oxidation with persulfate.

    Directory of Open Access Journals (Sweden)

    Jingchun Yan

    Full Text Available The combination of surfactant enhanced soil washing and degradation of nitrobenzene (NB in effluent with persulfate was investigated to remediate NB contaminated soil. Aqueous solution of sodium dodecylbenzenesulfonate (SDBS, 24.0 mmol L-1 was used at a given mass ratio of solution to soil (20:1 to extract NB contaminated soil (47.3 mg kg-1, resulting in NB desorption removal efficient of 76.8%. The washing effluent was treated in Fe2+/persulfate and Fe2+/H2O2 systems successively. The degradation removal of NB was 97.9%, being much higher than that of SDBS (51.6% with addition of 40.0 mmol L-1 Fe2+ and 40.0 mmol L-1 persulfate after 15 min reaction. The preferential degradation was related to the lone pair electron of generated SO4•-, which preferably removes electrons from aromatic parts of NB over long alkyl chains of SDBS through hydrogen abstraction reactions. No preferential degradation was observed in •OH based oxidation because of its hydrogen abstraction or addition mechanism. The sustained SDBS could be reused for washing the contaminated soil. The combination of the effective surfactant-enhanced washing and the preferential degradation of NB with Fe2+/persulfate provide a useful option to remediate NB contaminated soil.

  19. Enhanced hydrolysis of bamboo biomass by chitosan based solid acid catalyst with surfactant addition in ionic liquid.

    Science.gov (United States)

    Si, Wenqing; Li, Yichen; Zheng, Jie; Wei, Shun'an; Wang, Dan

    2017-10-15

    Surfactants were used for the hydrolysis of bamboo biomass to enhance lignocellulose hydrolysis. Tween 80, polyethylene glycol 4000 (PEG 4000), and sodium dodecyl sulfate (SDS) were tested as surfactants for improving the bamboo hydrolysis with a novel sulfonated cross-linked chitosan solid acid catalyst (SCCAC) in ionic liquid (IL). Compared to the use of only SCCAC in 1-Butyl-3-methylimidazolium chloride ([BMIM]Cl), the surfactants facilitated hydrolysis and improved the yield of total reducing sugar (TRS) under the same conditions. Tween 80 was the most effective surfactant, with a TRS yield of 68.01% achieved at 120°C after 24h. Surfactants broke the lignocellulose structure, promoted lignin removal, and increased positive interactions between cellulose and the catalyst, which were favorable for hydrolysis. This novel surfactant-assisted hydrolysis strategy with SCCAC and IL as the solvent demonstrated a promise for the large-scale transformation of biomass into biofuels and bioproducts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Study on the reutilization of clear fracturing flowback fluids in surfactant flooding with additives for Enhanced Oil Recovery (EOR.

    Directory of Open Access Journals (Sweden)

    Caili Dai

    Full Text Available An investigation was conducted to study the reutilization of clear fracturing flowback fluids composed of viscoelastic surfactants (VES with additives in surfactant flooding, making the process more efficient and cost-effective. The clear fracturing flowback fluids were used as surfactant flooding system with the addition of α-olefin sulfonate (AOS for enhanced oil recovery (EOR. The interfacial activity, emulsification activity and oil recovery capability of the recycling system were studied. The interfacial tension (IFT between recycling system and oil can be reduced by 2 orders of magnitude to 10(-3 mN/m, which satisfies the basic demand of surfactant flooding. The oil can be emulsified and dispersed more easily due to the synergetic effect of VES and AOS. The oil-wet surface of quartz can be easily converted to water-wet through adsorption of surfactants (VES/AOS on the surface. Thirteen core plug flooding tests were conducted to investigate the effects of AOS concentrations, slug sizes and slug types of the recycling system on the incremental oil recovery. The investigations prove that reclaiming clear fracturing flowback fluids after fracturing operation and reuse it in surfactant flooding might have less impact on environment and be more economical.

  1. Study on the reutilization of clear fracturing flowback fluids in surfactant flooding with additives for Enhanced Oil Recovery (EOR).

    Science.gov (United States)

    Dai, Caili; Wang, Kai; Liu, Yifei; Fang, Jichao; Zhao, Mingwei

    2014-01-01

    An investigation was conducted to study the reutilization of clear fracturing flowback fluids composed of viscoelastic surfactants (VES) with additives in surfactant flooding, making the process more efficient and cost-effective. The clear fracturing flowback fluids were used as surfactant flooding system with the addition of α-olefin sulfonate (AOS) for enhanced oil recovery (EOR). The interfacial activity, emulsification activity and oil recovery capability of the recycling system were studied. The interfacial tension (IFT) between recycling system and oil can be reduced by 2 orders of magnitude to 10(-3) mN/m, which satisfies the basic demand of surfactant flooding. The oil can be emulsified and dispersed more easily due to the synergetic effect of VES and AOS. The oil-wet surface of quartz can be easily converted to water-wet through adsorption of surfactants (VES/AOS) on the surface. Thirteen core plug flooding tests were conducted to investigate the effects of AOS concentrations, slug sizes and slug types of the recycling system on the incremental oil recovery. The investigations prove that reclaiming clear fracturing flowback fluids after fracturing operation and reuse it in surfactant flooding might have less impact on environment and be more economical.

  2. Enhanced aqueous solubility of polycyclic aromatic hydrocarbons by green diester-linked cationic gemini surfactants and their binary solutions

    Science.gov (United States)

    Panda, Manorama; Fatma, Nazish; Kabir-ud-Din

    2016-07-01

    Three homologues of a novel biodegradable diester-linked cationic gemini surfactant series, CmH2m+1 (CH3)2N+(CH2COOCH2)2N+(CH3)2CmH2m+1.2Cl- (m-E2-m; m = 12, 14, 16), were used for investigation of the solubilization of polycyclic aromatic hydrocarbons (PAHs) such as naphthalene, anthracene and pyrene in single as well as binary surfactant solutions. Physicochemical parameters of the pure/mixed systems were derived by conductivity and surface tension measurements. Dissolution capacity of the equimolar binary surfactant solutions towards the PAHs was studied from the molar solubilization ratio (MSR), micelle-water partition coefficient (Km) and free energy of solubilization (ΔGs0) of the solubilizates. Influence of hydrophobic chain length of the dimeric surfactants on solubilization was characterized. Aqueous solubility of the PAHs was enhanced linearly with concentration of the surfactant in all the pure and mixed gemini-gemini surfactant systems.

  3. In-situ sonication for enhanced recovery of aquifer microbial communities.

    Science.gov (United States)

    Ugolini, Fabio; Henneberger, Ruth; Bürgmann, Helmut; Zeyer, Josef; Schroth, Martin H

    2014-01-01

    Sampling methods for characterization of microbial communities in aquifers should target both suspended and attached microorganisms (biofilms). We investigated the effectiveness and reproducibility of low-frequency (200 Hz) sonication pulses on improving extraction efficiency and quality of microorganisms from a petroleum-contaminated aquifer in Studen (Switzerland). Sonication pulses at different power levels (0.65, 0.9, and 1.1 kW) were applied to three different groundwater monitoring wells. Groundwater samples extracted after each pulse were compared with background groundwater samples for cell and adenosine tri-phosphate concentration. Turbidity values were obtained to assess the release of sediment fines and associated microorganisms. The bacterial community in extracted groundwater samples was analyzed by terminal-restriction-fragment-length polymorphism and compared with communities obtained from background groundwater samples and from sediment cores. Sonication enhanced the extraction efficiency up to 13-fold, with most of the biomass being associated with the sediment fines extracted with groundwater. Consecutive pulses at constant power were decreasingly effective, while pulses with higher power yielded the best results both in terms of extraction efficiency and quality. Our results indicate that low-frequency sonication may be a viable and cost-effective tool to improve the extraction of microorganisms from aquifers, taking advantage of existing groundwater monitoring wells.

  4. Optimization of Variable Ventilation for Physiology, Immune Response and Surfactant Enhancement in Preterm Lambs

    Directory of Open Access Journals (Sweden)

    Erzsébet Bartolák-Suki

    2017-06-01

    Full Text Available Preterm infants often require mechanical ventilation due to lung immaturity including reduced or abnormal surfactant. Since cyclic stretch with cycle-by-cycle variability is known to augment surfactant release by epithelial cells, we hypothesized that such in vivo mechanotransduction improves surfactant maturation and hence lung physiology in preterm subjects. We thus tested whether breath-by-breath variability in tidal volume (VT in variable ventilation (VV can be tuned for optimal performance in a preterm lamb model. Preterm lambs were ventilated for 3 h with conventional ventilation (CV or two variants of VV that used a maximum VT of 1.5 (VV1 or 2.25 (VV2 times the mean VT. VT was adjusted during ventilation to a permissive pCO2 target range. Respiratory mechanics were monitored continuously using the forced oscillation technique, followed by postmortem bronchoalveolar lavage and tissue collection. Both VVs outperformed CV in blood gas parameters (pH, SaO2, cerebral O2 saturation. However, only VV2 lowered PaCO2 and had a higher specific respiratory compliance than CV. VV2 also increased surfactant protein (SP-B release compared to VV1 and stimulated its production compared to CV. The production and release of proSP-C however, was increased with CV compared to both VVs. There was more SP-A in both VVs than CV in the lung, but VV2 downregulated SP-A in the lavage, whereas SP-D significantly increased in CV in both the lavage and lung. Compared to CV, the cytokines IL-1β, and TNFα decreased with both VVs with less inflammation during VV2. Additionally, VV2 lungs showed the most homogeneous alveolar structure and least inflammatory cell infiltration assessed by histology. CV lungs exhibited over-distension mixed with collapsed and interstitial edematous regions with occasional hemorrhage. Following VV1, some lambs had normal alveolar structure while others were similar to CV. The IgG serum proteins in the lavage, a marker of leakage, were the

  5. Significantly Enhanced Actuation Performance of IPMC by Surfactant-Assisted Processable MWCNT/Nafion Composite

    Institute of Scientific and Technical Information of China (English)

    Qingsong He; Min Yu; Dingshan Yu; Yan Ding; Zhendong Dai

    2013-01-01

    The performance of Ionic Polymer Metal Composite (IPMC) actuator was significantly enhanced by incorporating surfactant-assisted processable Multi-Walled Carbon Nanotubes (MWCNTs) into a Nation solution.Cationic surfactant Cetyl Trimethyl Ammonium Bromide (CTAB) was employed to disperse MWCNTs in the Nation matrix,forming a homogeneous and stable dispersion of nanotubes.The processing did not involve any strong acid treatment and thus effectively preserved the excellent electronic properties associated with MWCNT.The as-obtained MWCNT/Nafion-IPMC actuator was tested in terms of conductivity,bulk and surface morphology,blocking force and electric current.It was shown that the blocking force and the current of the new IPMC are 2.4 times and 1.67 times higher compared with a pure Nation-based IPMC.Moreover,the MWCNT/IPMC performance is much better than previously reported Nafion-IPMC doped by acid-treated MWCNT.Such significantly improved performance should be attributed to the improvement of electrical property associated with the addition of MWCNTs without acid treatment.

  6. Synthesis and properties evaluation of nonionic-anionic surfactants suitable for enhanced oil recovery using sea water

    Energy Technology Data Exchange (ETDEWEB)

    Sha Ou [Lanzhou Inst. of Chemical Physics, Chinese Academy of Sciences (China); Shanghai Petrochemical Research Inst., SINOPEC (China); Zhang Weidong [Shanghai Petrochemical Research Inst., SINOPEC (China); Lu Runhua [Chengdu Inst. of Biology, Chinese Academy of Sciences (China)

    2008-03-15

    In view of imperfections of conventional anionic and nonionic surfactants used for enhanced oil recovery, especially the characteristics of high salinity and high Calcium/Magnesium for sea water flooding, a new novel displacement agent suitable for sea water flooding was synthesized through alkoxylation, epoxidation, sulfonation reaction with fatty alcohol as core. The structure of the product was characterized by IR. The properties of the product, including salt tolerance, temperature resistance etc. were evaluated. At 70 C, when the concentration of this surfactant is 0.3%, the interfacial tension between simulated water solution and Bohai1A-4 well crude reaches 10{sup -3} mN/m order, the salt tolerance reaches 50 000 mg/L, the resistance to calcium and magnesium reaches 2000 mg/L. The laboratory physical simulation test shows that the binary complex system (polymer + surfactant) can enhance the recovery ratio by 17.9%, while better synergistic effect of the system is obtained. (orig.)

  7. Enhancing drought resilience with conjunctive use and managed aquifer recharge in California and Arizona

    Science.gov (United States)

    Scanlon, Bridget R.; Reedy, Robert C.; Faunt, Claudia; Pool, Donald R.; Uhlman, Kristine;

    2016-01-01

    Projected longer‐term droughts and intense floods underscore the need to store more water to manage climate extremes. Here we show how depleted aquifers have been used to store water by substituting surface water use for groundwater pumpage (conjunctive use, CU) or recharging groundwater with surface water (Managed Aquifer Recharge, MAR). Unique multi‐decadal monitoring from thousands of wells and regional modeling datasets for the California Central Valley and central Arizona were used to assess CU and MAR. In addition to natural reservoir capacity related to deep water tables, historical groundwater depletion further expanded aquifer storage by ~44 km3 in the Central Valley and by ~100 km3 in Arizona, similar to or exceeding current surface reservoir capacity by up to three times. Local river water and imported surface water, transported through 100s of km of canals, is substituted for groundwater (≤15 km3/yr, CU) or is used to recharge groundwater (MAR, ≤1.5 km3/yr) during wet years shifting to mostly groundwater pumpage during droughts. In the Central Valley, CU and MAR locally reversed historically declining water‐level trends, which contrasts with simulated net regional groundwater depletion. In Arizona, CU and MAR also reversed historically declining groundwater level trends in Active Management Areas. These rising trends contrast with current declining trends in irrigated areas that lack access to surface water to support CU or MAR. Use of depleted aquifers as reservoirs could expand with winter flood irrigation or capturing flood discharges to the Pacific (0 – 1.6 km3/yr, 2000–2014) with additional infrastructure in California. Because flexibility and expanded portfolio options translate to resilience, CU and MAR enhance drought resilience through multi‐year storage, complementing shorter term surface reservoir storage, and facilitating water markets.

  8. Enhancing drought resilience with conjunctive use and managed aquifer recharge in California and Arizona

    Science.gov (United States)

    Scanlon, Bridget R.; Reedy, Robert C.; Faunt, Claudia C.; Pool, Donald; Uhlman, Kristine

    2016-03-01

    Projected longer-term droughts and intense floods underscore the need to store more water to manage climate extremes. Here we show how depleted aquifers have been used to store water by substituting surface water use for groundwater pumpage (conjunctive use, CU) or recharging groundwater with surface water (managed aquifer recharge, MAR). Unique multi-decadal monitoring from thousands of wells and regional modeling datasets for the California Central Valley and central Arizona were used to assess CU and MAR. In addition to natural reservoir capacity related to deep water tables, historical groundwater depletion further expanded aquifer storage by ˜44 km3 in the Central Valley and by ˜100 km3 in Arizona, similar to or exceeding current surface reservoir capacity by up to three times. Local river water and imported surface water, transported through 100s of km of canals, is substituted for groundwater (≤15 km3 yr-1, CU) or is used to recharge groundwater (MAR, ≤1.5 km3 yr-1) during wet years shifting to mostly groundwater pumpage during droughts. In the Central Valley, CU and MAR locally reversed historically declining water-level trends, which contrasts with simulated net regional groundwater depletion. In Arizona, CU and MAR also reversed historically declining groundwater level trends in active management areas. These rising trends contrast with current declining trends in irrigated areas that lack access to surface water to support CU or MAR. Use of depleted aquifers as reservoirs could expand with winter flood irrigation or capturing flood discharges to the Pacific (0-1.6 km3 yr-1, 2000-2014) with additional infrastructure in California. Because flexibility and expanded portfolio options translate to resilience, CU and MAR enhance drought resilience through multi-year storage, complementing shorter term surface reservoir storage, and facilitating water markets.

  9. Impact of surfactant type for ionic liquid pretreatment on enhancing delignification of rice straw.

    Science.gov (United States)

    Chang, Ken-Lin; Chen, Xi-Mei; Wang, Xiao-Qin; Han, Ye-Ju; Potprommanee, Laddawan; Liu, Jing-Yong; Liao, Yu-Ling; Ning, Xun-An; Sun, Shui-Yu; Huang, Qing

    2017-03-01

    This work describes an environmentally friendly method for pretreating rice straw by using 1-Allyl-3-methylimidazolium chloride ([AMIM]Cl) as an ionic liquid (IL) assisted by surfactants. The impacts of surfactant type (including nonionic-, anionic-, cationic- and bio-surfactant) on the ionic liquid pretreatment were investigated. The bio-surfactant+IL-pretreated rice straw showed significant lignin removal (26.14%) and exhibited higher cellulose conversion (36.21%) than the untreated (16.16%) rice straw. The cellulose conversion of the rice straw pretreated with bio-surfactant+IL was the highest and the lowest was observed for pretreated with cationic-surfactant+IL. Untreated and pretreated rice straw was thoroughly characterized through SEM and AFM. In conclusion, the results provided an effective and environmental method for pretreating lignocellulosic substrates by using green solvent (ionic liquid) and biodegradable bio-surfactant.

  10. Systematic Phase Behaviour Study and Foam Stability Analysis for Optimal Alkaline/Surfactant/Foam Enhanced Oil Recovery

    NARCIS (Netherlands)

    Hosseini Nasab, S.M.; Zitha, P.L.J.

    2015-01-01

    Alkaline-Surfactant-Foam (ASF) flooding is a recently introduced enhanced oil recovery (EOR) method. This paper presents laboratory study of this ASF to better understand its mechanisms. The focus is on the interaction of ASF chemical agents with oil and in the presence and absence of naphthenic com

  11. Systematic Phase Behaviour Study and Foam Stability Analysis for Optimal Alkaline/Surfactant/Foam Enhanced Oil Recovery

    NARCIS (Netherlands)

    Hosseini Nasab, S.M.; Zitha, P.L.J.

    2015-01-01

    Alkaline-Surfactant-Foam (ASF) flooding is a recently introduced enhanced oil recovery (EOR) method. This paper presents laboratory study of this ASF to better understand its mechanisms. The focus is on the interaction of ASF chemical agents with oil and in the presence and absence of naphthenic com

  12. Enhanced transdermal bioavailability of testosterone propionate via surfactant-modified ethosomes

    Directory of Open Access Journals (Sweden)

    Meng S

    2013-08-01

    Full Text Available Shu Meng,1 Zaixing Chen,2 Liqun Yang,1 Wei Zhang,1 Danhua Liu,1 Jing Guo,1 Yanmin Guan,1 Jianxin Li11Liaoning Research Institute of Family Planning, Shenyang, Liaoning Province, People's Republic of China; 2School of Pharmacy, China Medical University, Shenyang, Liaoning Province, People's Republic of ChinaAbstract: The current investigation aimed to evaluate the transdermal potential of novel testosterone propionate (TP ethosomes and liposomes prepared by surfactant modification. The effect of hexadecyl trimethyl ammonium bromide and cremophor EL-35 on the particle size and zeta potential of the prepared vesicles was investigated. The entrapment efficiency and stability, as well as in vitro and in vivo skin permeation, were studied with the various techniques, such as differential scanning calorimetry, confocal laser scanning microscopy, transmission electron microscopy, dynamic light scattering, and so on. The results indicated that the ethosomes were defined as spherical, unilamellar structures with low polydispersity (0.100 ± 0.015 and nanometric size (156.5 ± 3.5 nm. The entrapment efficiency of TP in ethosomal and liposomal carriers was 92.7% ± 3.7% and 64.7% ± 2.1%, respectively. The stability profile of the prepared TP ethosomal system assessed for 120 days revealed very low aggregation and very low growth in vesicular size. TP ethosomes also provided an enhanced transdermal flux of 37.85 ± 2.8 µg/cm2/hour and a decreased lag time of 0.18 hours across mouse skin. The skin permeation efficiency of the TP ethosomes as further assessed by confocal laser scanning microscopy revealed enhanced permeation of rhodamine red-loaded formulations to the deeper layers of the skin (260 µm than that of the liposomal formation (120 µm.Keywords: testosterone propionate, surfactant-modified ethosomes, liposomes, confocal laser scanning microscopy

  13. Removal of As, Cd, Cu, Ni, Pb, and Zn from a highly contaminated industrial soil using surfactant enhanced soil washing

    Science.gov (United States)

    Torres, Luis G.; Lopez, Rosario B.; Beltran, Margarita

    Surfactant enhanced soil washing (SESW) was applied to an industrial contaminated soil. A preliminary characterization of the soil regarding the alkaline-earth metals, Na, K, Ca and Mg took values of 2866, 2036, 2783 and 4149 mg/kg. The heavy metals As, Cd, Cu, Pb, Ni and Zn, had values of 4019, 14, 35582, 70, 2603, and 261 mg/kg, respectively. When using different surfactants, high removal of Cu, Ni and Zn were found, and medium removals for Pb, As and Cd. In the case of these three metals, tap water removed more than the surfactant solutions, except for the case of As. There were surfactants with average removals (this is, the removal for all the metals studied) of 67.1% (Tween 80), 64.9% (Surfacpol 14104) and 61.2% (Emulgin W600). There were exceptional removals using Texapon N-40 (83.2%, 82.8% and 86.6% for Cu, Ni and Zn), Tween 80 (85.9, 85.4 and 81.5 for Cd, Zn and Cu), Polafix CAPB (79%, 83.2% and 49.7% for Ni, Zn and As). The worst results were obtained with POLAFIX LO with a global removal of 45%, well below of the average removal with tap water (50.2%).All removal efficiencies are reported for a one step washing using 0.5% surfactant solutions, except for the case of mezquite gum, where a 0.1% solution was employed.

  14. Sequential application of chelating agents and innovative surfactants for the enhanced electroremediation of real sediments from toxic metals and PAHs.

    Science.gov (United States)

    Hahladakis, John N; Lekkas, Nikolaos; Smponias, Andreas; Gidarakos, Evangelos

    2014-06-01

    This study focused on the sequential application of a chelating agent (citric acid) followed by a surfactant in the simultaneous electroremediation of real contaminated sediments from toxic metals and Polycyclic Aromatic Hydrocarbons (PAHs). Furthermore, the efficiency evaluation of two innovative non-ionic surfactants, commercially known as Poloxamer 407 and Nonidet P40, was investigated. The results indicated a removal efficacy of approximately 43% and 48% for the summation of PAHs (SUM PAHs), respectively for the aforementioned surfactants, much better than the one obtained by the use of Tween 80 (nearly 21%). Individual PAHs (e.g. fluorene) were removed in percentages that reached almost 84% and 92% in the respective electrokinetic experiments when these new surfactants were introduced. In addition, the combined-enhanced sequential electrokinetic treatment with citric acid improved dramatically the removal of Zn and As, compared to the unenhanced run, but did not favor the other toxic metals examined. Since no improvement in metal removal percentages occurred when Tween 80 was used, significant contribution to this matter should also be attributed to the solubilization capacity of these innovative, in electrokinetic remediation, non-ionic surfactants.

  15. Evaluation of surfactant flushing for remediating EDC-tar contamination

    Science.gov (United States)

    Liang, Chenju; Hsieh, Cheng-Lin

    2015-06-01

    Ethylene dichloride tar (EDC-tar) is a dense non-aqueous phase liquid (DNAPL) waste originated from the process of vinyl chloride production, with major constituents including chlorinated aliphatic and aromatic hydrocarbons. This study investigated the feasibility of Surfactant Enhanced Aquifer Remediation (SEAR) for treating EDC-tar contaminated aquifers. Initial experiments explored the potential to enhance the apparent solubility of EDC-tar using single or mixed surfactants. The results showed that an aqueous solution mixed anionic and non-ionic surfactants (i.e., SDS/Tween 80) exhibited higher EDC-tar apparent solubility and lower surface tension than other surfactant systems tested. Additionally, alkaline pH aids in increasing the EDC-tar apparent solubility. In column flushing experiments, it was seen that the alkaline mixed SDS/Tween 80 solution showed better removal of pure EDC-tar from silica sand porous media. Furthermore, separation of EDC-tar in the surfactant solution was conducted employing a salting-out effect. Significant separation of DNAPL was observed when 13 wt.% or more NaCl was added to the solution. Overall, this study evaluates the feasibility of using SEAR for remediating EDC-tar contaminated subsurface soil and groundwater.

  16. Enhanced bioaccumulation of dietary contaminants in catfish with exposure to the waterborne surfactant linear alkylbenzene sulfonate.

    Science.gov (United States)

    Tan, Xiaobing; Yim, Sun-Young; Uppu, Prasanna; Kleinow, Kevin M

    2010-08-15

    Fish bioaccumulate a variety of contaminants and act as an exposure portal to the human consumer. Surfactants, known pharmaceutically to alter membrane permeability, change drug bioavailability and attenuate transporter function are also found in contaminant mixtures in the aquatic environment. The overall objective of this study was to determine if the surfactant C-12 linear alkylbenzene sulfonate (LAS) at environmentally relevant concentrations, alters the disposition and enhances bioaccumulation of co-exposed dietary xenobiotics in the catfish. Included for study were the carcinogen benzo(a)pyrene (BaP), pharmaceutical, ivermectin (IVM), and P-glycoprotein (P-gp) substrate rhodamine 123 (Rho-123), each exhibiting different dispositional footprints. Rho-123 transport into bile and membrane fluidity was examined in isolated perfused livers from control and LAS exposed catfish. Mass balance residue assessments were performed on catfish following in vivo exposure for 12 days to LAS in water at 0, 100 or 300 microg/L with 6 days of (3)H-IVM or (3)H-BaP gavage treatments. LAS at 1, 5 and 20 microM in the perfused liver, significantly decreased the transport of Rho-123 (1 microM) into bile by 18.6, 38.1 and 66.7%, respectively. Fluorescence anisotropy measurements demonstrated a 29.7% increase in fluidity at the (1 microM, 348 microg/L) LAS concentration. In vivo mass balance studies indicated that waterborne LAS (100 and 300 microg/L) increased the dietary dose remaining in fish by 39% and 78% for (3)H-IVM and 50 and 157% for (3)H-BaP. LAS at environmentally relevant concentrations altered the bioavailability and disposition of dietary xenobiotics in the catfish. Co-exposure with LAS increases xenobiotic bioaccumulation, potential toxicity of mixture components to the fish and the potential for residue transfer from fish to the consumer.

  17. Shifts in microbial community structure during in situ surfactant-enhanced bioremediation of polycyclic aromatic hydrocarbon-contaminated soil.

    Science.gov (United States)

    Wang, Lingwen; Li, Feng; Zhan, Yu; Zhu, Lizhong

    2016-07-01

    This study aims to reveal the microbial mechanism of in situ surfactant-enhanced bioremediation (SEBR). Various concentrations of rhamnolipids, Tween 80, and sodium dodecyl benzenesulfonate (SDBS) were separately sprayed onto soils contaminated with polycyclic aromatic hydrocarbons (PAHs) for years. Within 90 days, the highest level of degradation (95 %) was observed in the soil treated with rhamnolipids (10 mg/kg), followed by 92 % degradation with Tween 80 (50 mg/kg) and 90 % degradation with SDBS (50 mg/kg). The results of the microbial phospholipid fatty acids (PLFAs) suggest that bacteria dominated the enhanced PAH biodegradation (94 % of the maximum contribution). The shift of bacterial community structure during the surfactant treatment was analyzed by using the 16S rRNA gene high-throughput sequencing. In the presence of surfactants, the number of the operational taxonomic units (OTUs) associated with Bacillus, Pseudomonas, and Sphingomonas increased from 2-3 to 15-30 % at the end of the experiment (two to three times of control). Gene prediction with phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) shows that the PAH-degrading genes, such as 1-hydroxy-2-naphthoate dioxygenase and PAH dioxygenase large subunit, significantly increased after the surfactant applications (p bioremediation.

  18. Enhanced transdermal bioavailability of testosterone propionate via surfactant-modified ethosomes

    Science.gov (United States)

    Meng, Shu; Chen, Zaixing; Yang, Liqun; Zhang, Wei; Liu, Danhua; Guo, Jing; Guan, Yanmin; Li, Jianxin

    2013-01-01

    The current investigation aimed to evaluate the transdermal potential of novel testosterone propionate (TP) ethosomes and liposomes prepared by surfactant modification. The effect of hexadecyl trimethyl ammonium bromide and cremophor EL-35 on the particle size and zeta potential of the prepared vesicles was investigated. The entrapment efficiency and stability, as well as in vitro and in vivo skin permeation, were studied with the various techniques, such as differential scanning calorimetry, confocal laser scanning microscopy, transmission electron microscopy, dynamic light scattering, and so on. The results indicated that the ethosomes were defined as spherical, unilamellar structures with low polydispersity (0.100 ± 0.015) and nanometric size (156.5 ± 3.5 nm). The entrapment efficiency of TP in ethosomal and liposomal carriers was 92.7% ± 3.7% and 64.7% ± 2.1%, respectively. The stability profile of the prepared TP ethosomal system assessed for 120 days revealed very low aggregation and very low growth in vesicular size. TP ethosomes also provided an enhanced transdermal flux of 37.85 ± 2.8 μg/cm2/hour and a decreased lag time of 0.18 hours across mouse skin. The skin permeation efficiency of the TP ethosomes as further assessed by confocal laser scanning microscopy revealed enhanced permeation of rhodamine red-loaded formulations to the deeper layers of the skin (260 μm) than that of the liposomal formation (120 μm). PMID:23990718

  19. Enhanced transdermal bioavailability of testosterone propionate via surfactant-modified ethosomes.

    Science.gov (United States)

    Meng, Shu; Chen, Zaixing; Yang, Liqun; Zhang, Wei; Liu, Danhua; Guo, Jing; Guan, Yanmin; Li, Jianxin

    2013-01-01

    The current investigation aimed to evaluate the transdermal potential of novel testosterone propionate (TP) ethosomes and liposomes prepared by surfactant modification. The effect of hexadecyl trimethyl ammonium bromide and cremophor EL-35 on the particle size and zeta potential of the prepared vesicles was investigated. The entrapment efficiency and stability, as well as in vitro and in vivo skin permeation, were studied with the various techniques, such as differential scanning calorimetry, confocal laser scanning microscopy, transmission electron microscopy, dynamic light scattering, and so on. The results indicated that the ethosomes were defined as spherical, unilamellar structures with low polydispersity (0.100 ± 0.015) and nanometric size (156.5 ± 3.5 nm). The entrapment efficiency of TP in ethosomal and liposomal carriers was 92.7% ± 3.7% and 64.7% ± 2.1%, respectively. The stability profile of the prepared TP ethosomal system assessed for 120 days revealed very low aggregation and very low growth in vesicular size. TP ethosomes also provided an enhanced transdermal flux of 37.85 ± 2.8 μg/cm(2)/hour and a decreased lag time of 0.18 hours across mouse skin. The skin permeation efficiency of the TP ethosomes as further assessed by confocal laser scanning microscopy revealed enhanced permeation of rhodamine red-loaded formulations to the deeper layers of the skin (260 μm) than that of the liposomal formation (120 μm).

  20. Combination of aquifer thermal energy storage and enhanced bioremediation: resilience of reductive dechlorination to redox changes.

    Science.gov (United States)

    Ni, Zhuobiao; van Gaans, Pauline; Smit, Martijn; Rijnaarts, Huub; Grotenhuis, Tim

    2016-04-01

    To meet the demand for sustainable energy, aquifer thermal energy storage (ATES) is widely used in the subsurface in urban areas. However, contamination of groundwater, especially with chlorinated volatile organic compounds (CVOCs), is often being encountered. This is commonly seen as an impediment to ATES implementation, although more recently, combining ATES and enhanced bioremediation of CVOCs has been proposed. Issues to be addressed are the high water flow velocities and potential periodic redox fluctuation that accompany ATES. A column study was performed, at a high water flow velocity of 2 m/h, simulating possible changes in subsurface redox conditions due to ATES operation by serial additions of lactate and nitrate. The impacts of redox changes on reductive dechlorination as well as the microbial response of Dehalococcoides (DHC) were evaluated. The results showed that, upon lactate addition, reductive dechlorination proceeded well and complete dechlorination from cis-DCE to ethene was achieved. Upon subsequent nitrate addition, reductive dechlorination immediately ceased. Disruption of microorganisms' retention was also immediate and possibly detached DHC which preferred attaching to the soil matrix under biostimulation conditions. Initially, recovery of dechlorination was possible but required bioaugmentation and nutrient amendment in addition to lactate dosing. Repeated interruption of dechlorination and DHC activity by nitrate dosing appeared to be less easily reversible requiring more efforts for regenerating dechlorination. Overall, our results indicate that the microbial resilience of DHC in biosimulated ATES conditions is sensitive to redox fluctuations. Hence, combining ATES with bioremediation requires dedicated operation and monitoring on the aquifer geochemical conditions.

  1. Solubilization isotherms of aromatic solutes in surfactant aggregates

    Energy Technology Data Exchange (ETDEWEB)

    Gadelle, F.; Koros, W.J.; Schechter, R.S. (Univ. of Texas, Austin, TX (United States). Dept. of Chemical Engineering)

    1995-03-01

    Several factors affecting solubilization of aromatic solutes in surfactant micelles have been investigated. Solubilization isotherms of benzene, toluene, and chlorobenzene in various aqueous micellar solutions were determined using head space gas chromatography. Cationic surfactants such as cetylpyridinium chloride or cetyltrimethylammonium bromide present high solubilization capacities. Comparable anionic surfactants exhibit lower solubilization and a greater tendency to precipitate. It was observed that nonionic surfactants show high solubilization on a molar basis. Solubilization in mixed cationic-anionic micelles was also investigated. It also appears that the molecular size of the solute determines the extent of the solubilization. Finally, the shape of the different isotherms indicates that knowing the amount solubilized at saturation of the micellar solution is not sufficient to estimate solubilization at solute concentrations lower than the solute aqueous solubility. Solubilization of organics in surfactant micelles is of major importance in many applications. One new application is micellar-enhanced ultrafiltration. Another application of interest is the surfactant-enhanced aquifer remediation, a process in which a micellar aqueous solution is flushed into contaminated groundwaters to enhance recovery of pollutants by micellar solubilization.

  2. Enhanced removal of a human norovirus surrogate from fresh vegetables and fruits by a combination of surfactants and sanitizers.

    Science.gov (United States)

    Predmore, Ashley; Li, Jianrong

    2011-07-01

    Fruits and vegetables are major vehicles for transmission of food-borne enteric viruses since they are easily contaminated at pre- and postharvest stages and they undergo little or no processing. However, commonly used sanitizers are relatively ineffective for removing human norovirus surrogates from fresh produce. In this study, we systematically evaluated the effectiveness of surfactants on removal of a human norovirus surrogate, murine norovirus 1 (MNV-1), from fresh produce. We showed that a panel of surfactants, including sodium dodecyl sulfate (SDS), Nonidet P-40 (NP-40), Triton X-100, and polysorbates, significantly enhanced the removal of viruses from fresh fruits and vegetables. While tap water alone and chlorine solution (200 ppm) gave only <1.2-log reductions in virus titer in all fresh produce, a solution containing 50 ppm of surfactant was able to achieve a 3-log reduction in virus titer in strawberries and an approximately 2-log reduction in virus titer in lettuce, cabbage, and raspberries. Moreover, a reduction of approximately 3 logs was observed in all the tested fresh produce after sanitization with a solution containing a combination of 50 ppm of each surfactant and 200 ppm of chlorine. Taken together, our results demonstrate that the combination of a surfactant with a commonly used sanitizer enhanced the efficiency in removing viruses from fresh produce by approximately 100 times. Since SDS is an FDA-approved food additive and polysorbates are recognized by the FDA as GRAS (generally recognized as safe) products, implementation of this novel sanitization strategy would be a feasible approach for efficient reduction of the virus load in fresh produce.

  3. Voltammetric behaviour of drotaverine hydrochloride in surfactant media and its enhancement determination in Tween-20.

    Science.gov (United States)

    Jain, Rajeev; Vikas; Rather, Jahangir Ahmad

    2011-02-01

    Simple, sensitive and rapid adsorptive voltammetric behaviour of drotaverine hydrochloride onto the HMDE has been explored and validated in surfactant media by using cyclic, differential pulse and square-wave voltammetry. Addition of Tween-20 to the drotaverine hydrochloride containing electrolyte enhances the reduction current signal. The voltammograms of the drug with Tween-20 in phosphate buffers of pH 2.5-11.0 exhibit a single well defined reduction peak which may be due to the reduction of -CC- group. The cyclic voltammetric studies indicated the reduction of drotaverine hydrochloride at the electrode surface through two electron irreversible step and diffusion-controlled. The peak current showed a linear dependence with the drug concentration over the range 0.8-7.2μgmL(-1). The calculated LOD and LOQ are 1.8 and 6.0ngmL(-1) by SWCAdSV and 8.1 and 27.2ngmL(-1) by DPCAdSV, respectively. The procedure was applied to the assay of the drug in tablet form with mean percentage recoveries of 100.2% with SWCAdSV and 99.7% with DPCAdSV. The validity of the proposed methods was further assessed by applying a standard addition technique.

  4. Drivers and applications of integrated clean-up technologies for surfactant-enhanced remediation of environments contaminated with polycyclic aromatic hydrocarbons (PAHs).

    Science.gov (United States)

    Liang, Xujun; Guo, Chuling; Liao, Changjun; Liu, Shasha; Wick, Lukas Y; Peng, Dan; Yi, Xiaoyun; Lu, Guining; Yin, Hua; Lin, Zhang; Dang, Zhi

    2017-06-01

    Surfactant-enhanced remediation (SER) is considered as a promising and efficient remediation approach. This review summarizes and discusses main drivers on the application of SER in removing polycyclic aromatic hydrocarbons (PAHs) from contaminated soil and water. The effect of PAH-PAH interactions on SER efficiency is, for the first time, illustrated in an SER review. Interactions between mixed PAHs could enhance, decrease, or have no impact on surfactants' solubilization power towards PAHs, thus affecting the optimal usage of surfactants for SER. Although SER can transfer PAHs from soil/non-aqueous phase liquids to the aqueous phase, the harmful impact of PAHs still exists. To decrease the level of PAHs in SER solutions, a series of SER-based integrated cleanup technologies have been developed including surfactant-enhanced bioremediation (SEBR), surfactant-enhanced phytoremediation (SEPR) and SER-advanced oxidation processes (SER-AOPs). In this review, the general considerations and corresponding applications of the integrated cleanup technologies are summarized and discussed. Compared with SER-AOPs, SEBR and SEPR need less operation cost, yet require more treatment time. To successfully achieve the field application of surfactant-based technologies, massive production of the cost-effective green surfactants (i.e. biosurfactants) and comprehensive evaluation of the drivers and the global cost of SER-based cleanup technologies need to be performed in the future. Copyright © 2017. Published by Elsevier Ltd.

  5. Surfactant-Enhanced Spreading of Sessile Water Drops on Polypropylene Surfaces.

    Science.gov (United States)

    Wang, Xiang; Venzmer, Joachim; Bonaccurso, Elmar

    2016-08-23

    Spreading of water drops resting in equilibrium on polypropylene surfaces was initiated by dispensing surfactant-laden droplets on their apex. Upon contact of the two drops two processes were kicked-off: surfactant from the droplets spread along the water/air interface of the sessile drops and a train of capillary waves propagated along the sessile drops. The contact line of the sessile drops remained initially pinned and started spreading only when surfactant reached it while the capillary waves did not have an apparent effect on initiating drop spreading. However, surfactant influenced the propagation velocity of the capillary waves. Though the spreading dynamics of such nonhomogeneously mixed surfactant/water drops on polypropylene surfaces was initially different from that of homogeneously mixed drops, the later spreading dynamics was similar and was dominated by viscosity and surface tension in both cases. These results can help in discriminating the path of action of surfactants in bulk and at the water/air interface, which is also relevant for understanding phenomena such as superspreading.

  6. Surfactant adsorption study in sandstone for enhanced oil recovery; Estudo da adsorcao de tensoativos em arenitos para recuperacao avancada de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Curbelo, Fabiola D.S.; Santanna, Vanessa C.; Barros Neto, Eduardo L. de; Dutra Junior, Tarcilio V.; Dantas Neto, Afonso A. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Engenharia Quimica; Garnica, Alfredo I.C. [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Dept. de Tecnologia Quimica e de Alimentos; Lucena Neto, Marciano [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Dantas, Tereza N.C. [Faculdade Natalense para o Desenvolvimento do RN (FARN), Natal, RN (Brazil)

    2004-07-01

    Adsorption of surfactants from aqueous solutions in porous media is very important in Enhanced Oil Recovery (EOR) of oil reservoirs because surfactant loss due to adsorption on the reservoir rocks weakens the effectiveness of the injected chemical slug in reducing oil-water tension (IFT) and makes the process uneconomical. In this paper, two nonionic surfactants, such as alkyl phenol polyoxyethylene, with different ethoxylation degrees were studied, ENP95 and ENP150. The results of flow experiments of surfactant solutions in porous media showed that adsorption was higher for ENP95 because it has smaller ethoxylation degree than ENP150. This occurs what with increasing length of the head group, the molecules become more hydrophilic and, in associated structures, the steric hindrance between the head groups increases. Generally speaking, adsorption appears to be a cooperative process involving lateral interaction between surfactant and weak interaction with the solid surface. (author)

  7. Studies on interfacial behavior and wettability change phenomena by ionic and nonionic surfactants in presence of alkalis and salt for enhanced oil recovery

    Science.gov (United States)

    Kumar, Sunil; Mandal, Ajay

    2016-05-01

    Surfactant flooding is one of the most promising method of enhanced oil recovery (EOR) used after the conventional water flooding. The addition of alkali improves the performance of surfactant flooding due to synergistic effect between alkali and surfactant on reduction of interfacial tension (IFT), wettability alteration and emulsification. In the present study the interfacial tension, contact angle, emulsification and emulsion properties of cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and polysorbate 80 (Tween 80) surfactants against crude oil have been investigated in presence of sodium chloride (NaCl) and alkalis viz. sodium hydroxide (NaOH), sodium carbonate (Na2CO3), ammonium hydroxide (NH4OH), sodium metaborate (SMB) and diethanolamine (DEA). All three surfactants significantly reduce the IFT values, which are further reduced to ultra-low value (∼10-4 mN/m) by addition of alkalis and salt. It has been found experimentally that alkali-surfactant systems change the wettability of an intermediate-wet quartz rock to water-wet. Emulsification of crude oil by surfactant and alkali has also been investigated in terms of the phase volume and stability of emulsion. A comparative FTIR analysis of crude oil and different emulsions were performed to investigate the interactions between crude oil and displacing water in presence of surfactant and alkali.

  8. Design and screening of synergistic blends of SiO2 nanoparticles and surfactants for enhanced oil recovery in high-temperature reservoirs

    Science.gov (United States)

    Thi Le, Nhu Y.; Khanh Pham, Duy; Le, Kim Hung; Nguyen, Phuong Tung

    2011-09-01

    SiO2 nanoparticles (NPs) were synthesized by the sol-gel method in an ultrasound reactor and monodispersed NPs with an average particle size of 10-12 nm were obtained. The synergy occurring in blending NPs and anionic surfactant solutions was identified by ultra-low interfacial tension (IFT) reduction measured by a spinning drop tensiometer (Temco500). The oil displacement efficiency of the synergistic blends and surfactant solutions at Dragon South-East (DSE) reservoir temperature was evaluated using contact angle measurement (Dataphysics OCA 20). It was found that SiO2/surfactant synergistic blends displace oil as well as their original surfactant solutions at the same 1000 ppm total concentration. Abundant slag appearing in the SiO2/surfactant medium during oil displacement could be attributed to an adsorption of surfactants onto the NPs. The results indicate that at a concentration of 1000 ppm in total, the original surfactant SS16-47A and its blend with SiO2 NPs in the ratio of 8:2 exhibited an IFT reduction as high as fourfold of the IFT recorded for the DSE oil-brine interface and very high speed of oil displacement. Therefore, it could potentially be applicable to enhanced oil recovery (EOR) in high-temperature reservoirs with high hardness-injection-brine, like the one at DSE. This opens up a new direction for developing effective EOR compositions, which require less surfactant and are environmentally safer.

  9. Enhanced Molecular Recognition between Nucleobases and Guanine-5'-monophosphate-disodium (GMP) by Surfactant Aggregates in Aqueous Solution.

    Science.gov (United States)

    Liu, Zhang; Wang, Dong; Cao, Meiwen; Han, Yuchun; Xu, Hai; Wang, Yilin

    2015-07-15

    Only specific base pairs on DNA can bind with each other through hydrogen bonds, which is called the Watson-Crick (W/C) pairing rule. However, without the constraint of DNA chains, the nucleobases in bulk aqueous solution usually do not follow the W/C pairing rule anymore because of the strong competitive effect of water and the multi-interaction edges of nucleobases. The present work applied surfactant aggregates noncovalently functionalized by nucleotide to enhance the recognition between nucleobases without DNA chains in aqueous solution, and it revealed the effects of their self-assembling ability and morphologies on the recognition. The cationic ammonium monomeric, dimeric, and trimeric surfactants DTAB, 12-3-12, and 12-3-12-3-12 were chosen. The surfactants with guanine-5'-monophosphate-disodium (GMP) form micelles, vesicles, and fingerprint-like and plate-like aggregates bearing the hydrogen-bonding sites of GMP, respectively. The binding parameters of these aggregates with adenine (A), uracil (U), guanine (G), and cytosine(C) indicate that the surfactants can promote W/C recognitions in aqueous solution when they form vesicles (GMP/DTAB) or plate-like aggregates (GMP/12-3-12) with proper molecular packing compactness, which not only provide hydrophobic environments but also shield non-W/C recognition edges. However, the GMP/12-3-12 micelles with loose molecular packing, the GMP/12-3-12 fingerprint-like aggregates where the hydrogen bond sites of GMP are occupied by itself, and the GMP/12-3-12-3-12 vesicles with too strong self-assembling ability cannot promote W/C recognition. This work provides insight into how to design self-assemblies with the performance of enhanced molecule recognition.

  10. Enhanced recovery and dissolution of griseofulvin nanoparticles from surfactant-free nanocomposite microparticles incorporating wet-milled swellable dispersants.

    Science.gov (United States)

    Bhakay, Anagha; Azad, Mohammad; Vizzotti, Emanuel; Dave, Rajesh N; Bilgili, Ecevit

    2014-11-01

    Nanocomposite microparticles (NCMPs) incorporating drug nanoparticles and wet-milled swellable dispersant particles were investigated as a surfactant-free drug delivery vehicle with the goal of enhancing the nanoparticle recovery and dissolution rate of poorly water-soluble drugs. Superdisintegrants were used as inexpensive, model, swellable dispersant particles by incorporating them into NCMP structure with or without wet-stirred media milling along with the drug. Suspensions of griseofulvin (GF, model drug) along with various dispersants produced by wet-milling were coated onto Pharmatose® to prepare NCMPs in a fluidized bed process. Hydroxypropyl cellulose (HPC, polymer) alone and with sodium dodecyl sulfate (SDS, surfactant) was used as base-line stabilizer/dispersant during milling. Croscarmellose sodium (CCS, superdisintegrant) and Mannitol were used as additional dispersants to prepare surfactant-free NCMPs. Nanoparticle recovery during redispersion and dissolution of the various GF-laden NCMPs were examined. Suspensions prepared by co-milling GF/HPC/CCS or milling GF/HPC/SDS were stable after 30 h of storage. After drying, due to its extensive swelling capacity, incorporation of wet-milled CCS in the NCMPs caused effective breakage of the NCMP structure and bursting of nanoparticle clusters, ultimately leading to fast recovery of the GF nanoparticles. Optimized wet co-milling and incorporation of CCS in NCMP structure led to superior dispersant performance over incorporation of unmilled CCS or physically mixed unmilled CCS with NCMPs. The enhanced redispersion correlated well with the fast GF dissolution from the NCMPs containing either CCS particles or SDS. Overall, swellable dispersant (CCS) particles, preferably in multimodal size distribution, enable a surfactant-free formulation for fast recovery/dissolution of the GF nanoparticles.

  11. Micro-scale displacement of NAPL by surfactant and microemulsion in heterogeneous porous media

    Science.gov (United States)

    Javanbakht, Gina; Arshadi, Maziar; Qin, Tianzhu; Goual, Lamia

    2017-07-01

    Industrial processes such as remediation of oil-contaminated aquifers and enhanced oil recovery (EOR) often utilize chemical additives to increase the removal of non-aqueous phase liquids (NAPLs) from subsurface formations. Although the majority of crude oils are classified as LNAPLs, they often contain heavy molecules (DNAPLs) such as asphaltenes that tend to adsorb on minerals and alter their wettability. Effective additives are therefore those that can reduce the threshold capillary pressure, thus mobilizing LNAPL inside pore spaces and solubilizing DNAPL from rock surfaces. Nonionic surfactants in brine have often been injected to oil or contaminated aquifer formations in order to enhance NAPL displacement through IFT reduction. Recent studies revealed that surfactant-based microemulsions have a higher tendency to alter the wettability of surfaces, compared to surfactants alone, leading to more effective NAPL removal. However, the impact of these additives on pore-scale displacement mechanisms and multi-phase fluid occupancy in porous media is, to date, still unclear. In this study, x-ray microtomography experiments were performed to investigate the impact of surfactants and microemulsions on the mobilization and solubilization of NAPL in heterogeneous rocks. Saturation profiles indicated that an incremental NAPL removal was attained by addition of microemulsion to brine, compared with surfactant. Residual cluster size distributions revealed that microemulsions could break up large clusters into smaller disconnected ones, improving their mobilization in the rock. In-situ contact angle measurements showed that microemulsions could reverse the wettability of rough contaminated surfaces to a higher extent than surfactants. Unlike surfactant alone, the surfactant-solvent blend in the carrier fluid of microemulsions was able to penetrate rough grain surfaces, particularly those of dolomite cement, and desorb asphaltenes in the form of small-emulsified NAPL droplets

  12. Novel strategy involving surfactant-polymer combinations for enhanced stability of aqueous teflon dispersions.

    Science.gov (United States)

    Sharma, Mukesh; Bharatiya, Bhavesh; Mehta, Krupali; Shukla, Atindra; Shah, Dinesh O

    2014-06-24

    Among various polymers, the Teflon surface possesses extreme hydrophobicity (low surface energy), which is of great interest to both industry and academia. In this report, we discuss the stability of aqueous Teflon dispersions (particle size range of 100-3000 nm) formulated by a novel strategy that involves distinct combinations of surfactant and polymer mixtures for dispersion stabilization. As a first step, the hydrophobic Teflon particles were wetted using a range of surfactants (ionic, Triton, Brij, Tween, and Pluronic series) bearing different hydrophobic-lipophilic balance (HLB) and further characterized by contact angle and liquid penetration in packed powder measurements. The interaction between hydrophobic chains of surfactants and the Teflon particle surface is the driving force resulting in wetting of the Teflon particle surface. Further, these wetted particles in aqueous solutions were mixed with various polymers, for example, poly(vinyl alcohol) (PVA), polyvinylpyrrolidone (PVP), hydroxyethyl cellulose (HEC), and hydroxypropyl methyl cellulose (HPMC). The rate of sedimentation for the final dispersions was measured using a pan suspended into the dispersion from a transducer recording the increase in weight with time. A significant stability was noticed for Teflon particles suspended in surfactant + polymer mixtures, which was linearly proportional to the concentration of added polymer. The observed phenomenon can be possibly explained by molecular interactions between the hydrophobic chains of surfactant molecules and polar groups in the polymer architecture. Brij-O10 + HEC mixture was found to be the best surfactant-polymer combination for decreasing the sedimentation of the Teflon particles in the final dispersion. As measured by dynamic light scattering (DLS), the hydrodynamic volume of the Teflon particles increases up to ∼55% in the final formulation. These dispersions could be further explored for various technological applications such as

  13. Comparison between micro-emulsion and surfactant solution flooding efficiency for enhanced oil recovery in TinFouye Oil Field

    Energy Technology Data Exchange (ETDEWEB)

    Bouabboune, M.; Benhadid, S. [Applied and Theoretical Fluid Mechanical Laboratory, Algiers (Algeria). Faculty of Physics; Hammouch, N. [Sonatrach, Hydra, Algiers (Algeria). Forage Division

    2006-07-01

    The TinFouye (TFY) reservoir is among the largest oil reservoirs discovered in Algeria. The reservoir has been extensively gas lifted for many years, but gas lift is now reaching its economic limits. Therefore, a tertiary enhancement method is needed. This report investigated the technical feasibility of applying a microemulsion flood to TFY reservoir. The purpose of the study was to optimize the concentration of surfactant, in order to obtain a lower interfacial tension between oil and microemulsion phases, and a high viscosity of the microemulsion compared to that of the oil phase. Another objective was to test the effectiveness of the obtained optimum chemical system for the displacement of residual oil saturation after waterflooding (secondary recovery). TinFouye reservoir conditions and samples were used in this study. Geomechanical equipment was used for the displacement experiments in porous media. Two optimum microemulsion compositions were determined through phase behavior studies: 4 wt per cent anionic surfactant, 2.5 wt per cent pentanol, total salinity of 0.5 g/l. Two surfactant solutions were prepared with the same anionic and alcohol concentration as those of the optimized microemulsions. This made it possible to compare the efficiency of displacing residual oil saturation. 12 refs., 5 tabs., 4 figs.

  14. 2D sandbox experiments of surfactant foams for mobility control and enhanced LNAPL recovery in layered soils

    Science.gov (United States)

    Longpré-Girard, Mélanie; Martel, Richard; Robert, Thomas; Lefebvre, René; Lauzon, Jean-Marc

    2016-10-01

    The ability of surfactant foam to enhance mobility control and LNAPL recovery in a heterogeneous porous media was investigated through sandbox experiments with p-xylene used as LNAPL. A layered heterogeneous porous media was represented in a 2D sandbox filled with two layers of coarse and medium silica sand. Based on previous tests, the surfactant solution used was Ammonyx Lo at a concentration of 0.1% (w/w). The sandbox experimental program included tracer tests done under both uncontaminated and contaminated conditions, foam injection under uncontaminated conditions and surfactant solution and foam injection under contaminated conditions. Tracer tests indicated that the permeability contrast between sand layers was increased by LNAPL contamination. Foam injection under uncontaminated conditions presented a S-shaped front that indicated a better mobility control than the piston-shaped front obtained during tracer tests. During foam injection, complete sweep of the sandbox was achieved with 1.8 pore volume (PV) compared to 2.8 PV during tracer injection, thus indicating better mobility control with foam. Pre-flush of the contaminated sandbox with surfactant solution initiated p-xylene mobilization but no free phase was recovered at the effluent. A negligible p-xylene residual saturation was reached following foam injection in the contaminated sandbox. However, mass balance indicated a total recovery of only 48% of the initial p-xylene, thus indicating an underestimation of the recovery by volatilization. Recovery by volatilization was corrected, which gave the following proportions of LNAPL recovery mechanisms: 19% by mobilization, 16% by dissolution and 65% by volatilization. Results show the potential efficiency of foam remediation of LNAPL source zones in heterogeneous porous media. Still, further developments are needed prior to field scale application, which could benefit from in situ foam production that would simplify on-site operations.

  15. Nonionic surfactant enhanced semipermanent coatings for capillary electrophoresis of inorganic anions without use of organic additives.

    Science.gov (United States)

    Yao, Lihua; Liu, Qian; Li, Yi; Yao, Shouzhuo

    2011-09-01

    Separation of inorganic anions by capillary electrophoresis (CE) is usually conducted in co-electroosmotic mode due to the large electrophoretic mobilities of inorganic anions. Semipermanent surfactant coatings have been shown to be effective for CE of inorganic anions due to their strong capability of electroosmotic flow (EOF) manipulation. However, semipermanent coatings often suffer from their unsatisfactory stability. In addition, organic solvent additives are usually required to adjust the selectivity, which also aggravate the degradation of coating. In this work, a novel semipermanent coating consisting of cationic Gemini surfactant 18-10-18 and nonionic surfactant Tween 20 was developed to separate inorganic anions in CE. This coating is easy to prepare and more stable than pure Gemini coating. The introduction of nonionic surfactant in the coating not only suppresses the reversed EOF but can also adjust the selectivity of separation. Good separations of six model anions were achieved, the separation efficiency was as high as 65040-169700 plates/m and the RSDs of the migration times were less than 0.5 and 2.5% for run-to-run and day-to-day assays, respectively. Calibration curves were linear in the range of 0.05-5.0 mM; the detection limits ranged from 20 to 50 μM. More importantly, no organic solvents are required in the background buffer to achieve the satisfactory separations. This guarantees the coating stability and makes the method greener than most of other methods for CE of inorganic anions.

  16. Remediation of a hexachlorobenzene-contaminated soil by surfactant-enhanced electrokinetics coupled with microscale Pd/Fe PRB.

    Science.gov (United States)

    Wan, Jinzhong; Li, Zhirong; Lu, Xiaohua; Yuan, Songhu

    2010-12-15

    Treatment of soils contaminated with chlorinated hydrophobic organic compounds (CHOCs) remains a challenge for environmental scientists worldwide. In this study surfactant-enhanced electrokinetics (SEEK) was coupled with permeable reactive barrier (PRB) composed of microscale Pd/Fe to treat a hexachlorobenzene (HCB)-contaminated soil. A nonionic surfactant, Triton X-100 (TX-100), was selected as the solubility-enhancing agent. Five bench-scale tests were conducted to investigate the performance of EK-PRB on HCB removal from soils. Results showed that the HCB removal was generally increased by a factor of 4 by EK coupled with PRB compared with EK alone (60% versus 13%). In the EK-PRB system, HCB was removed from soil through several sequential processes: the movement driven by electroosmotic flow (EOF) in the anode column, the complete adsorption/degradation by the reactive Pd/Fe particles in PRB, and the consequent movement by EOF and probable electrochemical reactions in the cathode column. TX-100 was supposed to be a superior enhancement agent for HCB removal, not only in the EOF movement process but also in the Pd/Fe degradation process. This study indicates that the combination of SEEK and Pd/Fe PRB is efficient and promising to remove CHOCs from contaminated soils.

  17. Enhanced transdermal bioavailability of testosterone propionate via surfactant-modified ethosomes

    OpenAIRE

    Meng S; Chen Z; Yang L; Zhang W; Liu D; Guo J; Guan Y; Li J

    2013-01-01

    Shu Meng,1 Zaixing Chen,2 Liqun Yang,1 Wei Zhang,1 Danhua Liu,1 Jing Guo,1 Yanmin Guan,1 Jianxin Li11Liaoning Research Institute of Family Planning, Shenyang, Liaoning Province, People's Republic of China; 2School of Pharmacy, China Medical University, Shenyang, Liaoning Province, People's Republic of ChinaAbstract: The current investigation aimed to evaluate the transdermal potential of novel testosterone propionate (TP) ethosomes and liposomes prepared by surfactant modifica...

  18. Part 1: Vadose-zone column studies of toluene (enhanced bioremediation) in a shallow unconfined aquifer

    Science.gov (United States)

    Tindall, J.A.; Friedel, M.J.; Szmajter, R.J.; Cuffin, S.M.

    2005-01-01

    The objectives of the laboratory study described in this paper were (1) to determine the effectiveness of four nutrient solutions and a control in stimulating the microbial degradation of toluene in the unsaturated zone as an alternative to bioremediation methodologies such as air sparging, in situ vitrification, or others (Part I), and (2) to compare the effectiveness of the addition of the most effective nutrient solution from Part I (modified Hoagland type, nitrate-rich) and hydrogen peroxide (H2O2) on microbial degradation of toluene for repeated, simulated spills in the unsaturated zone (Part II). For Part 1, fifteen columns (30-cm diameter by 150-cm height), packed with air-dried, 0.25-mm, medium-fine sand, were prepared to simulate shallow unconfined aquifer conditions. Toluene (10 mL) was added to the surface of each column, and soil solution and soil gas samples were collected from the columns every third day for 21 days. On day 21, a second application of toluene (10 mL) was made, and the experiment was run for another 21 days. Solution 4 was the most effective for microbial degradation in Part I. For Part II, three columns were designated nutrient-rich 3-day toluene columns and received toluene injections every 3 days; three columns were designated as nutrient-rich 7-day columns and received toluene injections every 7 days; and two columns were used as controls to which no nutrient was added. As measured by CO2 respiration, the initial benefits for aerobic organisms from the O2 enhancement were sustained by the bacteria for only a short period of time (about 8 days). Degradation benefits from the nutrient solution were sustained throughout the experiment. The O2 and nutrient-enhanced columns degraded significantly more toluene than the control columns when simulating repeated spills onto the unsaturated zone, and demonstrated a potentially effective in situ bioremediation technology when used immediately or within days after a spill. The combined usage

  19. The role of clay in enhancing attenuation of trace organic contaminants during managed aquifer recharge

    Science.gov (United States)

    Regnery, J.; Strasser, A.; Hake, E.; Wing, A.; Drewes, J. E.

    2013-12-01

    For more hydrophobic trace organic contaminants present in surface water or reclaimed water applied for managed aquifer recharge (MAR), sorption onto organic matter can play a major role in attenuation in subsurface systems as the retardation allows more time for biotransformation. In case of low organic matter, other sorptive processes such as interactions with mineral surfaces gain importance. Especially for positively charged molecules, sorption onto clay materials by cation exchange will play a significant role. However, if the cation exchange capacity is limited or sorption of trace organic contaminants to clay materials is reversible due to changes in geochemical conditions (i.e., pH, ion strength), this might not provide a sustainable removal pathway. The objective of this study is to investigate how sorption to clay can enhance the removal of trace organic contaminants during MAR with the goal of evaluating the feasibility (i.e., infiltration capacity) and benefit (i.e., retardation of recalcitrant compounds) of introducing clay materials as reactive barriers in MAR systems. Laboratory-scale soil column experiments and batch sorption experiments using well characterized soil mixtures with different clay percentages under abiotic conditions and spiked at environmentally relevant concentration levels were conducted to derive soil water distribution coefficients for a suite of 15 trace organic chemicals (i.e., pharmaceutical residues, personal care products, household chemicals) and to quantify their sorption/desorption potential. All clay materials used in this study were characterized by X-ray diffraction to obtain information regarding their sorption processes. Furthermore, results were compared with geochemical field data from a full-scale MAR site in Colorado where significant amounts of clay in the subsurface were present. Preliminary results indicated that certain clay materials bear a great potential to retain moderately hydrophobic compounds such as

  20. Investigation on stabilization of CO2 foam by ionic and nonionic surfactants in presence of different additives for application in enhanced oil recovery

    Science.gov (United States)

    Kumar, Sunil; Mandal, Ajay

    2017-10-01

    Application of foam in upstream petroleum industry specifically in enhanced oil recovery (EOR) has gained significant interest in recent years. In view of this, an attempt has been paid to design the suitable foaming agents (foamer) by evaluating the influence of three surfactants, five nanoparticles and several additives. Experimental investigations have been carried out in order to examine the mechanism of foam generation in presence of sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB) and polysorbate 80 (Tween 80) as anionic, cationic and nonionic surfactants by using the CO2 as gaseous component. It has been found that ionic surfactants show the higher foam life compared to nonionic surfactant. Out of different nano particles used, namely alumina (Al2O3) zirconium oxide (ZrO2), calcium carbonate (CaCO3), boron nitride (BN) and silica (SiO2), boron nitride shows the maximum improvement of foam stability. The foam stability of surfactant-nanoparticles foam is further increased by addition of different additives viz. polymer, alcohol and alkali. The results show that, the designed foaming solution have nearly 2.5 times higher half-decay time (t1/2) compared to the simple surfactant system. Finally, it has been found that gas injection rate plays an important role in obtaining a uniform and stabilized foam.

  1. Surfactant-free Synthesis of CuO with Controllable Morphologies and Enhanced Photocatalytic Property

    OpenAIRE

    Wang, Xing; Yang, Jiao; Shi, Liuxue; Gao, Meizhen

    2016-01-01

    A green synthesis for nanoleave, nanosheet, spindle-like, rugby-like, dandelion-like and flower-like CuO nanostructures (from 2D to 3D) is successfully achieved through simply hydrothermal synthetic method without the assistance of surfactant. The morphology of CuO nanostructures can be easily tailored by adjusting the amount of ammonia and the source of copper. By designing a time varying experiment, it is verified that the flower- and dandelion-like CuO structures are synthesized by the sel...

  2. Enhanced CO2 adsorptive performance of PEI/SBA-15 adsorbent using phosphate ester based surfactants as additives.

    Science.gov (United States)

    Cheng, Dandan; Liu, Yue; Wang, Haiqiang; Weng, Xiaole; Wu, Zhongbiao

    2015-12-01

    In this study, a series of polyetherimide/SBA-15: 2-D hexagonal P6mm, Santa Barbara USA (PEI/SBA-15) adsorbents modified by phosphoric ester based surfactants (including tri(2-ethylhexyl) phosphate (TEP), bis(2-ethylhexyl) phosphate (BEP) and trimethyl phosphonoacetate (TMPA)) were prepared for CO2 adsorption. Experimental results indicated that the addition of TEP and BEP had positive effects on CO2 adsorption capacity over PEI/SBA-15. In particular, the CO2 adsorption amount could be improved by around 20% for 45PEI-5TEP/SBA-15 compared to the additive-free adsorbent. This could be attributed to the decrease of CO2 diffusion resistance in the PEI bulk network due to the interactions between TEP and loaded PEI molecules, which was further confirmed by adsorption kinetics results. In addition, it was also found that the cyclic performance of the TEP-modified adsorbent was better than the surfactant-free one. This could be due to two main reasons, based on the results of in situ DRIFT and TG-DSC tests. First and more importantly, adsorbed CO2 species could be desorbed more rapidly over TEP-modified adsorbent during the thermal desorption process. Furthermore, the enhanced thermal stability after TEP addition ensured lower degradation of amine groups during adsorption/desorption cycles.

  3. Viscosity measurements of CO2-in-water foam with dodecyl polypropoxy sulfate surfactants for enhanced oil recovery application

    Science.gov (United States)

    Pramudita, Ria Ayu; Ryoo, Won Sun

    2016-08-01

    Apparent viscosities of CO2-in-water foams were measured in a wide range of shear rate from 50 to 105 inverse second for enhanced oil recovery (EOR) application. The CO2-in-water dispersions, made of 50:50 weight proportions of CO2 and water with 1 wt.% surfactant concentration, were prepared in high-pressure recirculation apparatus under pressure where CO2 density becomes 0.7, 0.8, and 0.9 g/mL at each temperature of 35, 45, and 55°C. The surfactants used for the foam generation were sodium dodecyl polypropoxy sulfates with average propoxylation degrees of 4.7 and 6.2. The foam viscosity showed shear thinning behaviors with power-law indices ranging from 0.80 to 0.85, and approached a Newtonian regime in the lower shear rate range at several tens of inverse second. Zero-shear viscosity values projected from experimental data based on Ellis model were as high as 57.4 mPa·s and enough to control the mobility of water and CO2 in oil reservoirs.

  4. Optimization of Design of Aquifer Storage and Recovery System (ASTR) for Enhanced Infiltration Rate with Reduced Cost at the Coastal Aquifers of South-Western Bangladesh

    Science.gov (United States)

    Nawrin, N.; Ahmed, K. M.; Rahman, M. M.

    2016-12-01

    Increasing salinity of natural drinking water sources has been reported as one of the many problems that affect low-income countries. Safe potable water sources in coastal Bangladesh have become contaminated by varying degrees of salinity due to saltwater intrusion, cyclone and storm surges and increased shrimp and crab farming along the coastal areas. This crisis is also exacerbated owing to climate change. The problem of salinity can have serious implications to public health. Here Managed Aquifer Recharge (MAR) has been ascertained as a better solution to overcome the fresh water shortage in the coastal belt of Bangladesh in terms of groundwater quality improvement and supply fresh water even during the dry period. 19 MAR systems have been built and tested in the area for providing community water supply by way of creating freshwater buffer zone in the brackish aquifers through artificial recharge of pond or rooftop rainwater. These existing ASTR schemes consist of sand filtration tank with 4 to 6 large diameter infiltration wells filled with sorted gravel. These larger diameter recharge wells make the construction and maintenance expensive and little difficult for the rural communities. Therefore, modification of design is required for enhancing infiltration rates with reduced costs. As the design of the existing MAR system have confronted some problems, the details of design, construction and performance have been studied from previous investigations and a new modified ASTR scheme has been demonstrated to amplify the infiltration rate along with monitoring scheme. Smaller 4 inch diameter empty recharge wells and PVC screen have been used in the newly developed design. Daily infiltration rate has been increased to 8 to 10 m3/d compared to 4 to 6 m3/d in the old design. Three layered sand filtration tank has been prepared by modification of an abandoned PSF. Time needed for lowering EC to acceptable limits has been found to be significantly lower than the pre

  5. Novel serine-based gemini surfactants as chemical permeation enhancers of local anesthetics: A comprehensive study on structure-activity relationships, molecular dynamics and dermal delivery.

    Science.gov (United States)

    Teixeira, Raquel S; Cova, Tânia F G G; Silva, Sérgio M C; Oliveira, Rita; do Vale, M Luísa C; Marques, Eduardo F; Pais, Alberto A C C; Veiga, Francisco J B

    2015-06-01

    This work aims at studying the efficacy of a series of novel biocompatible, serine-based surfactants as chemical permeation enhancers for two different local anesthetics, tetracaine and ropivacaine, combining an experimental and computational approach. The surfactants consist of gemini molecules structurally related, but with variations in headgroup charge (nonionic vs. cationic) and in the hydrocarbon chain lengths (main and spacer chains). In vitro permeation and molecular dynamics studies combined with cytotoxicity profiles were performed to investigate the permeation of both drugs, probe skin integrity, and rationalize the interactions at molecular level. Results show that these enhancers do not have significant deleterious effects on the skin structure and do not cause relevant changes on cell viability. Permeation across the skin is clearly improved using some of the selected serine-based gemini surfactants, namely the cationic ones with long alkyl chains and shorter spacer. This is noteworthy in the case of ropivacaine hydrochloride, which is not easily administered through the stratum corneum. Molecular dynamics results provide a mechanistic view of the surfactant action on lipid membranes that essentially corroborate the experimental observations. Overall, this study suggests the viability of these serine-based surfactants as suitable and promising delivery agents in pharmaceutical formulations.

  6. Sucrose esters as biocompatible surfactants for penetration enhancement: An insight into the mechanism of penetration enhancement studied using stratumcorneum model lipids and Langmuir monolayers.

    Science.gov (United States)

    Todosijević, Marija N; Brezesinski, Gerald; Savić, Snežana D; Neubert, Reinhard H H

    2017-03-01

    Up to now, the molecular mechanism of the penetration enhancing effect of sucrose esters (SEs) on stratumcorneum (SC) has not been explained in details. In this study, variety of surface sensitive techniques, including surface pressure-area (π-A) isotherms, infrared reflection-absorption spectroscopy (IRRAS), and Brewster angle microscopy (BAM), have been used to investigate interactions between SEs and SC intercellular lipids. A monolayer of the mixture of ceramide AS C18:18, stearic acid and cholesterol in the molar ratio of 1:1:0.7 on an aqueous subphase is a good model to mimic a single layer of intercellular SC lipids. The π-A isotherms of mixed monolayers and parameters derived from the curves demonstrated the interaction between nonionic surfactants such as SEs and SC lipids. With increasing SE concentration, the resultant monolayer films became more fluid and better compressible. IRRAS measurements showed that SEs disordered the acyl chains of SC lipids, and the BAM images demonstrated the modification of the domain structures in SC monolayers. Longer chain-SE has a stronger disordering effect and is better miscible with ceramides in comparison to SE with a shorter hydrophobic part. In conclusion, this study demonstrates the disordering effect of SEs on the biomimetic SC model, pointing out that small changes in the structure of surfactant may have a strong influence on a penetration enhancement of lipophilic drugs through intercellular lipids of skin. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Enhanced removal of soluble Cr(VI) by using zero-valent iron composite supported by surfactant-modified zeolites.

    Science.gov (United States)

    Dang, Hongyu; Zhang, Yongxiang; Du, Peiwen

    2014-01-01

    Zero-valent iron (ZVI) was immobilized onto surfactant-modified zeolites (SMZ) using calcium alginate. Scanning electron microscopy showed that ZVI powder was uniformly immobilized on the surface of the SMZ. The added ZVI powder resulted in enhanced dichromate removal efficiency and the heterogeneous surface of the composite. The adsorption of dichromate onto the ZVI-SMZ composites fitted well to a pseudo-second-order model and the Langmuir adsorption isotherm. The maximum dichromate adsorption capacity of the composite was 2.49 mg/g at the temperature of 293 K. Higher removal efficiency was obtained at pH lower than 7. X-ray photoelectron spectrometry revealed that the composites combined the strong reductive quality of ZVI and superior adsorption of SMZ.

  8. Fabrication of Biphase BiVO4 Particles with Enhanced Photocatalytic Performance via a Surfactant-Free Hydrothermal Route

    Science.gov (United States)

    Qian, Hongzhi; Lai, Min; Huang, Xiaogu; Wang, Wei; Xu, Chaoqi; Yong, Haibo; Wen, Yan; Zhou, Yingjie

    2016-04-01

    Biphase bismuth vanadate (BiVO4) particles have been synthesized using a surfactant-free hydrothermal strategy. Biphase BiVO4 were formed at pH=3, 5 and 7 with a bandgap between 2.28eV and 2.86eV, which are those of monoclinic and tetragonal phases, respectively. Photocatalytic tests on the degradation of rhodamine B (RhB) under visible-light irradiation showed that biphase BiVO4 with both monoclinic and tetragonal structures synthesized at pH=3 achieved enhanced photocatalytic performance in comparison with pure monoclinic and tetragonal phases, which was attributed to the heterostructures leading to low recombination rate of electron-hole pairs.

  9. Foam Delivery of Hydrogen for Enhanced Aquifer Contacting and Anaerobic Bioremediation of Chlorinated Solvents

    Science.gov (United States)

    2005-11-01

    and an ethoxylated nonionic hydrophile, along with the anionic surfactant, SDS, void of ethoxy groups but con- taining a C12 hydrophobe and a sulfate...PCE reduction step, and a lag in PCE reduction to DCE was overcome by a short acclimation period. Increasing the degree of ethoxylation to an average...laundromat wastewater pond. Water Res 26:123–127. 36. Huber M, Meyer U, Rys P. 2000. Biodegradation mechanisms of linear alcohol ethoxylates under

  10. Enhanced solubilization and desorption of organochlorine pesticides (OCPs) from soil by oil-swollen micelles formed with a nonionic surfactant.

    Science.gov (United States)

    Zheng, Guanyu; Selvam, Ammaiyappan; Wong, Jonathan W C

    2012-11-06

    The effect of oil-swollen micelles formed with nonionic surfactant polyoxyethylene sorbitan monooleate (Tween 80), cosurfactant 1-pentanol, and linseed oil on the solubilization and desorption of organochlorine pesticides (OCPs) including DDT and γ-HCH from both loam soil and clay soil were investigated. Results showed that the solubilizing capacities of oil-swollen micelles were dependent on the critical micelle concentration (CMC) of Tween 80. Once the concentrations of oil-swollen micelles exceeded the CMC of Tween 80, the oil-swollen micelles exhibited much higher solubilizing capacity than empty Tween 80 micelles for the two OCPs. Desorption tests revealed that oil-swollen micelles could successfully enhance desorption of OCPs from both loam soil and clay soil. However, compared with the efficiencies achieved by empty Tween 80 micelles, oil-swollen micelles exhibited their superiority to desorb OCPs only in loam soil-water system while was less effective in clay soil-water system. Distribution of Tween 80, 1-pentanol and linseed oil in soil-water system revealed that the difference in the sorption behavior of linseed oil onto the two soils is responsible for the different effects of oil-swollen micelles on the desorption of OCPs in loam soil and clay soil systems. Therefore, oil-swollen micelles formed with nonionic surfactant Tween 80 are better candidates over empty micelle counterparts to desorb OCPs from soil with relatively lower sorption capacity for oil fraction, which may consequently enhance the availability of OCPs in soil environment during remediation processes of contaminated soil.

  11. Surfactant-free Synthesis of CuO with Controllable Morphologies and Enhanced Photocatalytic Property

    Science.gov (United States)

    Wang, Xing; Yang, Jiao; Shi, Liuxue; Gao, Meizhen

    2016-03-01

    A green synthesis for nanoleave, nanosheet, spindle-like, rugby-like, dandelion-like and flower-like CuO nanostructures (from 2D to 3D) is successfully achieved through simply hydrothermal synthetic method without the assistance of surfactant. The morphology of CuO nanostructures can be easily tailored by adjusting the amount of ammonia and the source of copper. By designing a time varying experiment, it is verified that the flower- and dandelion-like CuO structures are synthesized by the self-assembly and Ostwald ripening mechanism. Structural and morphological evolutions are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectra. Additionally, the CuO nanostructures with different morphologies could serve as a potential photocatalyst on the photodecomposition of rhodamine B (RhB) aqueous solutions in the presence of H2O2 under visible light irradiation.

  12. Ozone/UV treatment to enhance biodegradation of surfactants in industrial wastewater. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Cline, J.E. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States); Sullivan, P.F. [Specialty Industrial Products, Inc., Spartanburg, SC (United States); Lovejoy, M.A.; Collier, J. [Sun River Innovations, Ltd., Lexington, KY (United States); Adams, C.D. [Univ. of Missouri, Rolla, MO (United States)

    1996-10-01

    The new owners of a surfactant manufacturing plant wanted to triple production but were limited by the plant`s wastewater treatment capacity. Mass balance calculations indicated that little aerobic biodegradation was occurring in the plant`s wastewater treatment system. Literature reviews and laboratory tests confirmed that as much as 60% of the plant`s products might resist aerobic biodegradation. Overall chemical losses, both solid and aqueous, were estimated at 3.8% of theoretical. Organic loadings to the wastewater treatment system were 170 kg/d of which 50 kg/d reached the biological treatment system. Pollution prevention measures have allowed a > 20% increase in production levels with a > 30% decrease in effluent volume and no increase in discharge of chemical oxygen demand (COD). A new dissolved air flotation (DAF) system removes 70% of the organic loading. Sludge volumes are lower by an order of magnitude than with the clarifier/drum-filter process it replaced.

  13. Enhancement of intestinal absorption of poorly absorbed hydrophilic compounds by simultaneous use of mucolytic agent and non-ionic surfactant.

    Science.gov (United States)

    Takatsuka, Shinya; Kitazawa, Takeo; Morita, Takahiro; Horikiri, Yuji; Yoshino, Hiroyuki

    2006-01-01

    The effect of co-administration of a mucolytic agent with a penetration enhancer was assessed on the intestinal absorption of poorly absorbed hydrophilic compounds. Fluorescein isothiocyanate-labeled dextran with average molecular weight of ca. 4.4 kDa (FD-4) was used as a model compound, and N-acetylcysteine (NAC) was used as a mucolytic agent. Sodium caprate (C10), tartaric acid (TA), sodium taurodeoxycholate (TDC), sodium dodecyl sulfate (SDS), p-t-octyl phenol polyoxyethylene-9.5 (Triton X-100, TX-100) were selected as penetration enhancers with different mechanisms of action. Various dosing solutions containing a penetration enhancer in the absence or in the presence of NAC were directly administered into the exposed rat jejunum, and the bioavailability of FD-4 up to 2 h was determined. The extent of improvement by co-administration was highly dependent on the penetration enhancer species applied. The observed enhancement was thought to result from the mucolytic activity of NAC, which can reduce the mucus viscosity and facilitate the penetration of FD-4 to mucosal membrane. Among the combinations tested, the simultaneous administration of NAC and TX-100 provided the highest enhancement (22.5-fold) of intestinal FD-4 absorption compared to the control. Although the detailed mechanism for the observed drastic improvement is unclear, one possible reason was thought to be due to the improved diffusivity of TX-100 micellar system in the mucus layer. All these results suggest that the combination of a mucolytic agent and a non-ionic surfactant may have potential as an enhancing system for peroral delivery of poorly absorbed hydrophilic compounds like protein and peptide drugs.

  14. Metathesis depolymerizable surfactants

    Science.gov (United States)

    Jamison, Gregory M.; Wheeler, David R.; Loy, Douglas A.; Simmons, Blake A.; Long, Timothy M.; McElhanon, James R.; Rahimian, Kamyar; Staiger, Chad L.

    2008-04-15

    A class of surfactant molecules whose structure includes regularly spaced unsaturation in the tail group and thus, can be readily decomposed by ring-closing metathesis, and particularly by the action of a transition metal catalyst, to form small molecule products. These small molecules are designed to have increased volatility and/or enhanced solubility as compared to the original surfactant molecule and are thus easily removed by solvent extraction or vacuum extraction at low temperature. By producing easily removable decomposition products, the surfactant molecules become particularly desirable as template structures for preparing meso- and microstructural materials with tailored properties.

  15. Study of the enhanced oil recovery with surfactant based systems; Estudo de recuperacao avancada de petroleo por sistemas a base de tensoativos

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro Neto, Valdir Cotrim; Paulino, Luisa Cimatti; Acyoly, Alessandra; Santos, Enio Rafael M.; Dantas Neto, Afonso Avelino [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    The recent changes in the world scenario, the large reserves of heavy oils and also the lack of new discoveries of large petroleum fields are indications that, in the near future, the oil recovery by conventional methods will be limited. In order to increase the efficiency of the extraction process, it must be used enhanced recovery methods. One of these technologies is the injection of surfactant solutions, where exists a chemical interaction between the injected fluid and the reservoir's fluid. With this in mind, this work was developed with two main objectives: to study of parameters that influence the surfactant behavior in solution, namely the critical micelle concentration (CMC), the surface and interface tensions between fluids and the evaluation of oil recovery with these solutions. After the Botucatu sandstone (Brazil) porosity study, the plug samples were submitted to assay steps comprising saturation with seawater and petroleum, conventional recovery with seawater and enhanced recovery with surfactant solutions. The solutions were studied in enhanced recovery step, when the plug samples could already be compared to a mature field. The PJN surfactant, at a concentration 1000% above CMC in water, had a higher recovery factor, causing the original oil in place to be recovered by an extra 20.97%, after conventional recovery with seawater. (author)

  16. Enhanced oil recovery by surfactant-enhanced volumetric sweep efficiency: Second annual report, September 30, 1986-September 30, 1987

    Energy Technology Data Exchange (ETDEWEB)

    Harwell, J H; Scamehorn, J F

    1988-04-01

    It is widely known that heterogeneities in oil reservoirs occurring as a result of permeability variations in the rock can have a detrimental effect on an oil recovery process; preferential diversion of injected displacement fluid occurs through the high-permeability zones, leaving the lower-permeability zones at a high residual oil content at a time when it is no longer economically viable to continue the oil recovery process. A novel oil recovery process is described which aims to improve the volumetric sweep efficiency of oil recovery. High-permeability zones are partially or completely plugged off by using the chromatographic and phase behavior of surfactants and their mixtures and the preferential invasion of high-permeability areas by low-viscosity injected fluids. The plugging will divert flow into regions of higher oil saturation. 85 refs., 46 figs., 6 tabs.

  17. Surfactant-soil interactions during surfactant-amended remediation of contaminated soils by hydrophobic organic compounds: a review.

    Science.gov (United States)

    Laha, Shonali; Tansel, Berrin; Ussawarujikulchai, Achara

    2009-01-01

    Surfactants are amphiphilic molecules that reduce aqueous surface tension and increase the solubility of hydrophobic organic compounds (HOCs). Surfactant-amended remediation of HOC-contaminated soils and aquifers has received significant attention as an effective treatment strategy - similar in concept to using soaps and detergents as washing agents to remove grease from soiled fabrics. The proposed mechanisms involved in surfactant-amended remediation include: lowering of interfacial tension, surfactant solubilization of HOCs, and the phase transfer of HOC from soil-sorbed to pseudo-aqueous phase. However, as with any proposed chemical countermeasures, there is a concern regarding the fate of the added surfactant. This review summarizes the current state of knowledge regarding nonionic micelle-forming surfactant sorption onto soil, and serves as an introduction to research on that topic. Surfactant sorption onto soil appears to increase with increasing surfactant concentration until the onset of micellization. Sorbed-phase surfactant may account for the majority of added surfactant in surfactant-amended remediation applications, and this may result in increased HOC partitioning onto soil until HOC solubilization by micellar phase surfactant successfully competes with increased HOC sorption on surfactant-modified soil. This review provides discussion of equilibrium partitioning theory to account for the distribution of HOCs between soil, aqueous phase, sorbed surfactant, and micellar surfactant phases, as well as recently developed models for surfactant sorption onto soil. HOC partitioning is characterized by apparent soil-water distribution coefficients in the presence of surfactant.

  18. Enhanced molecular order in polythiophene films electropolymerized in a mixed electrolyte of anionic surfactants and boron trifluoride diethyl etherate.

    Science.gov (United States)

    Santoso, Handoko T; Singh, Virendra; Kalaitzidou, Kyriaki; Cola, Baratunde A

    2012-03-01

    We synthesized polythiophene (PTh) films on stainless steel electrodes using chronoamperometry in boron trifluoride diethyl etherate (BFEE) electrolyte with anionic surfactants. The presence of the anionic surfactants in BFEE reduced the oxidation potential of thiophene and increased the oxidation current during electropolymerization. The measured in-plane electrical conductivity of PTh films synthesized in the presence of anionic surfactants was up to 300% higher than that of films synthesized under similar conditions without surfactants. The observed increase in conductivity reflects the improved order and packing of polymer chains revealed by X-ray diffraction.

  19. Enhanced spectrophotometric determination of Losartan potassium based on its physicochemical interaction with cationic surfactant

    Science.gov (United States)

    Abdel-Fattah, Laila; Abdel-Aziz, Lobna; Gaied, Mariam

    2015-02-01

    In this study, a simple and sensitive spectrophotometric method was developed for determination of Losartan potassium (LST K), an angiotensin-II receptor (type AT1) antagonist, in presence of cationic surfactant cetyltrimethylammonium bromide (CTAB). The physicochemical interaction of LST K with CTAB was investigated. The effect of cationic micelles on the spectroscopic and acid-base properties of LST K was studied at pH 7.4. The binding constant (Kb) and the partition coefficient (Kx) of LST K-CTAB were 1.62 × 105 M-1 and 1.38 × 105; respectively. The binding of LST K to CTAB micelles implied a shift in drug acidity constant (ΔpKa = 0.422). The developed method is linear over the range 0.5-28 μg mL-1. The accuracy was evaluated and was found to be 99.79 ± 0.509% and the relative standard deviation for intraday and interday precision was 0.821 and 0.963; respectively. The method was successfully applied to determine LST K in pharmaceutical formulations.

  20. Both Phosphorus Fertilizers and Indigenous Bacteria Enhance Arsenic Release into Groundwater in Arsenic-Contaminated Aquifers.

    Science.gov (United States)

    Lin, Tzu-Yu; Wei, Chia-Cheng; Huang, Chi-Wei; Chang, Chun-Han; Hsu, Fu-Lan; Liao, Vivian Hsiu-Chuan

    2016-03-23

    Arsenic (As) is a human carcinogen, and arsenic contamination in groundwater is a worldwide public health concern. Arsenic-affected areas are found in many places but are reported mostly in agricultural farmlands, yet the interaction of fertilizers, microorganisms, and arsenic mobilization in arsenic-contaminated aquifers remains uncharacterized. This study investigates the effects of fertilizers and bacteria on the mobilization of arsenic in two arsenic-contaminated aquifers. We performed microcosm experiments using arsenic-contaminated sediments and amended with inorganic nitrogenous or phosphorus fertilizers for 1 and 4 months under aerobic and anaerobic conditions. The results show that microcosms amended with 100 mg/L phosphorus fertilizers (dipotassium phosphate), but not nitrogenous fertilizers (ammonium sulfate), significantly increase aqueous As(III) release in arsenic-contaminated sediments under anaerobic condition. We also show that concentrations of iron, manganese, potassium, sodium, calcium, and magnesium are increased in the aqueous phase and that the addition of dipotassium phosphate causes a further increase in aqueous iron, potassium, and sodium, suggesting that multiple metal elements may take part in the arsenic release process. Furthermore, microbial analysis indicates that the dominant microbial phylum is shifted from α-proteobacteria to β- and γ-proteobacteria when the As(III) is increased and phosphate is added in the aquifer. Our results provide evidence that both phosphorus fertilizers and microorganisms can mediate the release of arsenic to groundwater in arsenic-contaminated sediments under anaerobic condition. Our study suggests that agricultural activity such as the use of fertilizers and monitoring phosphate concentration in groundwater should be taken into consideration for the management of arsenic in groundwater.

  1. Experimental investigations on the fluid flow mechanism in porous media of enhanced oil recovery by alkli/surfactant/polymer flooding

    Institute of Scientific and Technical Information of China (English)

    WANG Jialu; SHEN Pingping; CHEN Yongzhong; ZHANG Zubo; JIA Xu; TIAN Yuling

    2005-01-01

    The fluid flow mechanism in porous media of enhanced oil recovery by Alkli/ Surfactant/ Polymer (ASP) flooding is investigated by measuring production performance, pressure distribution and saturation distribution through installing differential pressure transducers and saturation measuring probes in a physical model of vertical heterogeneous reservoir. The fluid flow variation in porous media is the main reason of enhanced oil recovery of ASP flooding. The pressure field and saturation field are nonlinearly coupled together and the interaction between them results in the fluid flow variation in the reservoir. In a vertical heterogeneous reservoir, the ASP agents initially flow in the high permeability layer, and fluid changes the flow direction toward the low and the middle permeability layers because the resistance in the high permeability layer is increased under the physical and chemical action of adsorption, retention and emulsion. ASP flooding displaces out not only the residual oil in the high permeability layer, but also the remaining oil in the low and the middle permeability layers by increasing swept volume and displacing efficiency.

  2. Enhanced recovery of unconventional gas. Volume II. The program. [Tight gas basins; Devonian shale; coal seams; geopressured aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Kuuskraa, V.A.; Brashear, J.P.; Doscher, T.M.; Elkins, L.E.

    1978-10-01

    This study was conducted to assist public decision-makers in selecting among many choices to obtain new gas supplies by addressing 2 questions: 1) how severe is the need for additional future supplies of natural gas, and what is the economic potential of providing part of future supply through enhanced recovery from unconventional natural gas resources. The study also serves to assist the DOE in designing a cost-effective R and D program to stimulate industry to recover this unconventional gas and to produce it sooner. Tight gas basins, Devonian shale, methane from coal seams, and methane from geopressured aquifers are considered. It is concluded that unconventional sources, already providing about 1 Tcf per year, could provide from 3 to 4 Tcf in 1985 and from 6 to 8 Tcf in 1990 (at $1.75 and $3.00 per Mcf, respectively). However, even with these additions to supply, gas supply is projected to remain below 1977 usage levels. (DLC)

  3. DNAPL在透镜体及表面活性剂作用下的运移研究%Investigation of the migration characteristic of DNAPL in aquifer with lenses and under the action of surfactant flushing

    Institute of Scientific and Technical Information of China (English)

    程洲; 吴吉春; 徐红霞; 王嘉诚; 高燕维; 李京; 董姝楠

    2014-01-01

    选择四氯乙烯(PCE)作为典型重非水相液体(DNAPLs)污染物,进行 PCE 在二维砂箱中的运移及修复实验,采用一种改进光透法探讨DNAPL在含不同透镜体非均质含水层中的运移和饱和度分布特性.在此基础上,考察非离子表面活性剂(吐温80)对DNAPL的原位冲洗修复效果.结果表明,在模拟天然地下水流条件下,当 PCE 运移到达各透镜体时,PCE 均未进入透镜体而是在其上方聚集形成污染池,然后逐渐侧向扩散,即使在较粗透镜体(20/30目和40/60目石英砂按1:1质量比例混合)上也无法进入.吐温80对 PCE 的修复效果显著,冲洗58h后,94.2%的PCE被去除.表面活性剂的引入能够减小PCE和水的界面张力,界面张力的减小量可达38.8dyn/cm,相应各透镜体上覆界面处的毛细压力水头值会有不同程度的减小,在较粗透镜体上的PCE可以穿透透镜体并继续向下运移.透镜体的毛细截留作用会限制修复后期的修复效率,修复75,3520min的修复效率分别为0.63,0.05g/g,其中较粗透镜体上截留的PCE相对其他较细透镜体容易移出.%Tetrachloroethylene (PCE) was selected as the representative DNAPL to carry out the migration experiments in a two-dimensional (2-D) sandbox, and a modified light transmission visualization method was used to study the migration and saturation distribution characteristics in heterogeneous aquifer containing different lenses, based on which, the recovery effect of DNAPL by situ flushing with a non-ionic surfactant (Tween 80) was investigated. The results showed that, when reaching the low permeability lenses, PCE did not migrate downward but pooled on the surfaces then migrated sideways on the surface of the coarser lens which was packed with a 1:1mixture of 20/30 mesh accusand and 40/60 mesh accusand in homogeneous saturated porous media under natural water flow velocity condition. The recovery effect of PCE made by Tween 80 was prominent, 94.2%of PCE was

  4. Optimized mixed oils remarkably reduce the amount of surfactants in microemulsions without affecting oral bioavailability of ibuprofen by simultaneously enlarging microemulsion areas and enhancing drug solubility.

    Science.gov (United States)

    Chen, Yizhen; Tuo, Jue; Huang, Huizhi; Liu, Dan; You, Xiuhua; Mai, Jialuo; Song, Jiaqi; Xie, Yanqi; Wu, Chuanbin; Hu, Haiyan

    2015-06-20

    The toxicity and irritation associated with high amounts of surfactants restrict the extensive utilization of microemulsions. To address these shortcomings, employing mixed oils to enlarge microemulsion areas therefore reducing surfactant contents is a promising strategy. However, what kinds of mixed oils are more efficient in enlarging microemulsion areas still remains unclear. In this research, we found that the chain length and degree of unsaturation of oils play a key role in enlarging microemulsion areas. The combination of moderate chain saturated oil caprylic/capric triglyceride (GTCC) with long chain unsaturated oil glycerol trioleate significantly increased the microemulsion areas. Solubility of ibuprofen in the mixed oils was unexpectedly and remarkably increased (almost 300mg/mL) compared with that (around 100mg/mL) of the single oil (GTCC), which also resulted in greatly increased solubility of ibuprofen in mixed oils-containing microemulsions. By optimizing the mixed oil formulation, the absolute amount of surfactant in drug-loaded microemulsions was reduced but increased drug oral bioavailability in rats was maintained. It could be concluded that the combined use of moderate chain oils and long chain unsaturated oils could not only acquire enlarged microemulsion areas but also enhanced drug solubility, therefore doubly reducing surfactant amount, which is extremely beneficial for developing safe microemulsions.

  5. Influence of surfactants in self-microemulsifying formulations on enhancing oral bioavailability of oxyresveratrol: Studies in Caco-2 cells and in vivo.

    Science.gov (United States)

    Sangsen, Yaowaporn; Wiwattanawongsa, Kamonthip; Likhitwitayawuid, Kittisak; Sritularak, Boonchoo; Graidist, Potchanapond; Wiwattanapatapee, Ruedeekorn

    2016-02-10

    Self-microemulsifying drug delivery systems (SMEDDS) containing two types (Tween80 and Labrasol) and two levels (low; 5% and high; 15%) of co-surfactants were formulated to evaluate the impact of surfactant phase on physical properties and oral absorption of oxyresveratrol (OXY). All formulations showed a very rapid release in the simulated gastric fluid (SGF) pH 1.2. After dilution with different media, the microemulsion droplet sizes of the Tween80-based (∼26 to 36 nm) were smaller than that of the Labrasol-based systems (∼34 to 45 nm). Both systems with high levels of surfactant increased the Caco-2 cells permeability of OXY compared to those with low levels of surfactant (1.4-1.7 folds) and the unformulated OXY (1.9-2.0 folds). It was of interest, that there was a reduction (4.4-5.3 folds) in the efflux transport of OXY from both systems compared to the unformulated OXY. The results were in good agreement with the in vivo absorption studies of such OXY-formulations in rats. Significantly greater values of Cmax and AUC(0-10h) (psurfactant in the SMEDDS to enhance oral drug bioavailability.

  6. Numerical Simulation and Optimization of Enhanced Oil Recovery by the In Situ Generated CO2 Huff-n-Puff Process with Compound Surfactant

    Directory of Open Access Journals (Sweden)

    Yong Tang

    2016-01-01

    Full Text Available This paper presents the numerical investigation and optimization of the operating parameters of the in situ generated CO2 Huff-n-Puff method with compound surfactant on the performance of enhanced oil recovery. First, we conducted experiments of in situ generated CO2 and surfactant flooding. Next, we constructed a single-well radial 3D numerical model using a thermal recovery chemical flooding simulator to simulate the process of CO2 Huff-n-Puff. The activation energy and reaction enthalpy were calculated based on the reaction kinetics and thermodynamic models. The interpolation parameters were determined through history matching a series of surfactant core flooding results with the simulation model. The effect of compound surfactant on the Huff-n-Puff CO2 process was demonstrated via a series of sensitivity studies to quantify the effects of a number of operation parameters including the injection volume and mole concentration of the reagent, the injection rate, the well shut-in time, and the oil withdrawal rate. Based on the daily production rate during the period of Huff-n-Puff, a desirable agreement was shown between the field applications and simulated results.

  7. Enhanced photocatalytic degradation of norfloxacin in aqueous Bi2WO6 dispersions containing nonionic surfactant under visible light irradiation.

    Science.gov (United States)

    Tang, Lin; Wang, Jiajia; Zeng, Guangming; Liu, Yani; Deng, Yaocheng; Zhou, Yaoyu; Tang, Jing; Wang, Jingjing; Guo, Zhi

    2016-04-05

    Photocatalytic degradation is an alternative method to remove pharmaceutical compounds in water, however it is hard to achieve efficient rate because of the poor solubility of pharmaceutical compounds in water. This study investigated the photodegradation of norfloxacin in a nonionic surfactant Triton-X100 (TX100)/Bi2WO6 dispersion under visible light irradiation (400-750nm). It was found that the degradation of poorly soluble NOF can be strongly enhanced with the addition of TX100. TX100 was adsorbed strongly on Bi2WO6 surface and accelerated NOF photodegradation at the critical micelle concentration (CMC=0.25mM). Higher TX100 concentration (>0.25mM) lowered the degradation rate. In the presence of TX100, the degradation rate reached the maximum value when the pH value was 8.06. FTIR analyses demonstrated that the adsorbed NOF on the catalyst was completely degraded after 2h irradiation. According to the intermediates identified by HPLC/MS/MS, three possible degradation pathways were proposed to include addition of hydroxyl radical to quinolone ring, elimination of piperazynilic ring in fluoroquinolone molecules, and replacement of F atoms on the aromatic ring by hydroxyl radicals. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. A novel dendritic surfactant for enhanced microcystin-LR detection by double amplification in a quartz crystal microbalance biosensor.

    Science.gov (United States)

    Xia, Yuetong; Zhang, Jianping; Jiang, Long

    2011-08-01

    Enhanced sensitivity for the hepatotoxin microcystin-LR (MC-LR) was achieved in a quartz crystal microbalance (QCM) system via double amplification. For primary amplification, an innovative interface on the QCM was obtained as a matrix by the vesicle layer formed by our synthetic dendritic surfactant, bis (amidoethyl-carbamoylethyl) octadecylamine (C18N3). The vesicle matrix was then functionalised by an optimised concentration of monoclonal antibodies against MC-LR (anti-MC-LR) to detect the analyte. The results showed that a detection limit of 100 ng/mL was achieved by primary amplification. To achieve higher sensitivity, secondary amplification was implemented with anti-MC-LR gold nanoparticle (AuNPs) conjugates as probes, which lowered the detection limit for MC-LR to 1 ng/mL (the maximum concentration recommended by the World Health Organization [WHO] in drinking water for humans). The QCM immunosensor reported here has advantages such as high sensitivity, portability, simplicity, and cost-effectiveness for MC-LR detection. It would be uniquely superior compared with current MC-LR detection techniques for on-the-spot water detection. Furthermore, the methodology described here is also potentially significant in many fields for the routine monitoring of environmental and food safety.

  9. Enhanced CO oxidation activity of CuO/CeO2 catalyst prepared by surfactant-assisted impregnation method

    Institute of Scientific and Technical Information of China (English)

    孙帅帅; 毛东森; 俞俊

    2015-01-01

    A modified CuO/CeO2 catalyst was prepared by surfactant-assisted impregnation method and showed better catalytic activity for low temperature CO oxidation than that from conventional impregnation method. The physicochemical properties of different CuO/CeO2 catalysts were characterized by thermogravimetric and differential scanning calorimetric measurements (TG-DSC), X-ray diffraction (XRD), N2 adsorption-desorption, Raman spectroscopy, H2 temperature-programmed reduction (H2-TPR), tem-perature-programmed desorption of O2 (O2-TPD), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The re-sults suggested that the addition of hexadecyl trimethyl ammonium bromide (CTAB) into the impregnation solution could improve the dispersion of CuO species, which could facilitate Cu2+ incorporating into CeO2 lattice and strengthened the synergistic effects between CuO and CeO2,making the lattice oxygen more active, and eventually resulting in enhanced activity for CO oxidation.

  10. DNA association-enhanced physical stability of catanionic vesicles composed of ion pair amphiphile with double-chain cationic surfactant.

    Science.gov (United States)

    Lee, Jung; Chang, Chien-Hsiang

    2014-09-01

    Physical stability control of vesicle/DNA complexes is a key issue for the development of catanionic vesicles composed of ion pair amphiphile (IPA) as DNA carriers. In this work, physical stability characteristics of the complexes of DNA with positively charged catanionic vesicles composed of an IPA and a double-chain cationic surfactant, dihexadecyldimethylammonium bromide (DHDAB), were explored. It was found that in water, the mixed IPA/DHDAB catanionic vesicles became stable when the mole fraction of DHDAB (xDHDAB) was increased up to 0.5. The improved physical stability of the vesicles with a high xDHDAB could be related to the enhanced electrostatic interaction between the vesicles. When the catanionic vesicles interacted with DNA, excellent physical stability was detected for the vesicle/DNA complexes especially with a high xDHDAB. However, this could not be fully explained by the electrostatic interaction effect, and the role of molecular packing within the vesicular bilayers was apparently important. The corresponding Langmuir monolayer study demonstrated that the molecular packing of mixed IPA/DHDAB layers became ordered with DNA association due to inhibited desorption of the positively charged moiety of the IPA. Moreover, the DNA association-induced improvement in the molecular packing of the mixed IPA/DHDAB layers became pronounced with increased xDHDAB. The results imply that one can fabricate catanionic vesicle/DNA complexes with excellent physical stability through the improved molecular packing in the IPA vesicular bilayers with DHDAB addition and DNA association.

  11. Enhanced production of Monacolin K by addition of precursors and surfactants in submerged fermentation of Monascus purpureus 9901.

    Science.gov (United States)

    Zhang, Jun; Wang, Yuan-Long; Lu, Li-Ping; Zhang, Bo-Bo; Xu, Gan-Rong

    2014-01-01

    The main problem in Monacolin K (MK) production by submerged fermentation of Monascus purpureus is low productivity. In this study, on one hand, addition of precursors was used to activate the biosynthesis of MK. When 4.0 g/L of sodium citrate was supplemented at the 48th H of the fermentation, the final MK production reached to 1,658.9 ± 28.5 mg/L after 20 day of fermentation, which was improved by 52.6% compared with that of the control. On the other hand, addition of surfactants could increase the permeability of cell membrane, thus driving more intracellular metabolites secreted into the fermentation broth and alleviating the product inhibition. When 40.0 g/L of Triton X-100 was added at the beginning of the fermentation, the final MK production reached to 2,026.0 ± 30.4 mg/L after 20 day of fermentation, which was improved by 84.9% compared with that of the control. These results are helpful to provide some new insights into the biosynthetic regulation on MK production; the approach can be applied to other fungal fermentation processes for enhancing production of useful metabolites.

  12. Voltammetric Determination of Estrogens Based on the Enhancement Effect of Surfactant at Carbon Paste Electrode

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Highly sensitive voltammetric method for the determination of estrogens, based on the enhancement effect of cetyltrimethylammonium bromide (CTAB) has been described. In the presence of CTAB, the oxidation peak currents of estrogens (estradiol, estrone, estriol, estradiol valerate and diethylstilbestrol) at the carbon paste electrode (CPE) increased significantly after open-circuit accumulation. The peak current was proportional to the concentration of estradiol over the range from 5×10-9 to 2.5×10-6 mol\\5L-1. The detection limit was 8×10-10 mol\\5L-1 at 6 min of accumulation. The total amounts of estrogens in the blood serums were determined and the average recovery was 104.92%. Under the conditions used, the electrode process of estradiol was examined and the mechanism for peak current enhancement was also discussed.

  13. ADSORPTION OF SURFACTANT ON CLAYS

    Science.gov (United States)

    Surfactants used to enhance remediation of soils by soil washing are often lost in the process. Neither the amount nor the cause of this loss is known. It is assumed that clays present in the soil are responsible for the loss of the surfactant. In this papere, adsorption prope...

  14. Alluvial Aquifer

    Data.gov (United States)

    Kansas Data Access and Support Center — This coverage shows the extents of the alluvial aquifers in Kansas. The alluvial aquifers consist of unconsolidated Quaternary alluvium and contiguous terrace...

  15. Surfactant-promoted Prussian Blue-modified carbon electrodes: enhancement of electro-deposition step, stabilization, electrochemical properties and application to lactate microbiosensors for the neurosciences.

    Science.gov (United States)

    Salazar, P; Martín, M; O'Neill, R D; Roche, R; González-Mora, J L

    2012-04-01

    We report here for the first time a comparison of the beneficial effects of different cationic surfactants - cetyl trimethyl ammonium bromide (CTAB), benzethonium chloride (BZT) and cetylpyridinium chloride (CPC) - for the electrochemical synthesis of Prussian Blue (PB) films, using cyclic voltammetry (CV), on screen-printed carbon electrodes (SPCEs). Their electrochemical properties were investigated, paying special attention to parameters such as the amount of PB deposited, film thickness, charge transfer rate, permeability, reversibility, stability and sensitivity to hydrogen peroxide detection. All surfactant-enhanced PB-modified SPCEs displayed a significant improvement in their electrochemical properties compared with PB-modified SPCEs formed in the absence of surfactants. Surfactant-modified electrodes displayed a consistently higher PB surface concentration value of 2.1±0.4×10(-8) mol cm(-2) (mean±SD, n=3) indicating that PB deposition efficiency was improved 2-3 fold. K(+) and Na(+) permeability properties of the films were also studied, as were kinetic parameters, such as the surface electron transfer rate constant (k(s)) and the transfer coefficient (α). The hydrogen peroxide sensitivity of surfactant-modified PB films generated by 10 electro-deposition CV cycles gave values of 0.63 A M(-1) cm(-2), which is higher than those reported previously for SPCEs by other authors. Finally, the first lactate microbiosensor described in the literature based on BZT-modified PB-coated carbon fiber electrodes is presented. Its very small cross-section (~10 μm diameter) makes it particularly suitable for neuroscience studies in vivo.

  16. Using hydrochemical data and modelling to enhance the knowledge of groundwater flow and quality in an alluvial aquifer of Zagreb, Croatia

    Energy Technology Data Exchange (ETDEWEB)

    Marković, Tamara, E-mail: tmarkovic@hgi-cgs.hr; Brkić, Željka; Larva, Ozren

    2013-08-01

    The Zagreb alluvial aquifer system is located in the southwest of the Pannonian Basin in the Sava Valley in Croatia. It is composed of Quaternary unconsolidated deposits and is highly utilised, primarily as a water supply for the more than one million inhabitants of the capital city of Croatia. To determine the origin and dynamics of the groundwater and to enhance the knowledge of groundwater flow and the interactions between the groundwater and surface water, extensive hydrogeological and hydrochemical investigations have been completed. The groundwater levels monitored in nested observation wells and the lithological profile indicate that the aquifer is a single hydrogeologic unit, but the geochemical characteristics of the aquifer indicate stratification. The weathering of carbonate and silicate minerals has an important role in groundwater chemistry, especially in the area where old meanders of the Sava River existed. Groundwater quality was observed to be better in the deeper parts of the aquifer than in the shallower parts. Furthermore, deterioration of the groundwater quality was observed in the area under the influence of the landfill. The stable isotopic composition of all sampled waters indicates meteoric origin. NETPATH-WIN was used to calculate the mixing proportions between initial waters (water from the Sava River and groundwater from “regional” flow) in the final water (groundwater sampled from observation wells). According to the results, the mixing proportions of “regional” flow and the river water depend on hydrological conditions, the duration of certain hydrological conditions and the vicinity of the Sava River. Moreover, although the aquifer system behaves as a single hydrogeologic unit from a hydraulic point of view, it still clearly demonstrates geochemical stratification, which could be a decisive factor in future utilisation strategies for the aquifer system. - Highlights: • The Zagreb aquifer is the largest utilised source of

  17. Surfactant analysis in oil-containing fluids

    Energy Technology Data Exchange (ETDEWEB)

    Gronsveld, J.; Faber, M.J. (Koninklijke Shell Exploratie en Produktie Laboratorium, Rijswijk (Netherlands))

    The total surfactant concentration in aqueous phase samples can be analysed with a potentiometric titration. In enhanced oil recovery research, however, the surfactant is produced not only in aqueous phase samples but also in oleic phase samples. The oleic constituents in the oliec phase samples interfere in the surfactant analysis and, therefore, the titration method has been adapted. (orig.).

  18. An exogenous surfactant-producing Bacillus subtilis facilitates indigenous microbial enhanced oil recovery

    Directory of Open Access Journals (Sweden)

    Peike eGao

    2016-02-01

    Full Text Available This study used an exogenous lipopeptide-producing Bacillus subtilis to strengthen the indigenous microbial enhanced oil recovery (IMEOR process in a water-flooded reservoir in the laboratory. The microbial processes and driving mechanisms were investigated in terms of the changes in oil properties and the interplay between the exogenous Bacillus subtilis and indigenous microbial populations. The exogenous Bacillus subtilis is a lipopeptide producer, with a short growth cycle and no oil-degrading ability. The Bacillus subtilis facilitates the IMEOR process through improving oil emulsification and accelerating microbial growth with oil as the carbon source. Microbial community studies using quantitative PCR and high-throughput sequencing revealed that the exogenous Bacillus subtilis could live together with reservoir microbial populations, and did not exert an observable inhibitory effect on the indigenous microbial populations during nutrient stimulation. Core-flooding tests showed that the combined exogenous and indigenous microbial flooding increased oil displacement efficiency by 16.71%, compared with 7.59% in the control where only nutrients were added, demonstrating the application potential in enhanced oil recovery in water-flooded reservoirs, in particular, for reservoirs where IMEOR treatment cannot effectively improve oil recovery.

  19. An Exogenous Surfactant-Producing Bacillus subtilis Facilitates Indigenous Microbial Enhanced Oil Recovery.

    Science.gov (United States)

    Gao, Peike; Li, Guoqiang; Li, Yanshu; Li, Yan; Tian, Huimei; Wang, Yansen; Zhou, Jiefang; Ma, Ting

    2016-01-01

    This study used an exogenous lipopeptide-producing Bacillus subtilis to strengthen the indigenous microbial enhanced oil recovery (IMEOR) process in a water-flooded reservoir in the laboratory. The microbial processes and driving mechanisms were investigated in terms of the changes in oil properties and the interplay between the exogenous B. subtilis and indigenous microbial populations. The exogenous B. subtilis is a lipopeptide producer, with a short growth cycle and no oil-degrading ability. The B. subtilis facilitates the IMEOR process through improving oil emulsification and accelerating microbial growth with oil as the carbon source. Microbial community studies using quantitative PCR and high-throughput sequencing revealed that the exogenous B. subtilis could live together with reservoir microbial populations, and did not exert an observable inhibitory effect on the indigenous microbial populations during nutrient stimulation. Core-flooding tests showed that the combined exogenous and indigenous microbial flooding increased oil displacement efficiency by 16.71%, compared with 7.59% in the control where only nutrients were added, demonstrating the application potential in enhanced oil recovery in water-flooded reservoirs, in particular, for reservoirs where IMEOR treatment cannot effectively improve oil recovery.

  20. Vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction for the determination of triazine herbicides in water samples by microemulsion electrokinetic chromatography.

    Science.gov (United States)

    Li, Ran-Hong; Liu, Dong-Hui; Yang, Zhong-Hua; Zhou, Zhi-Qiang; Wang, Peng

    2012-07-01

    A novel method based on the combination of microemulsion electrokinetic chromatography (MEEKC) and vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction (VSLLME) was developed for the determination of five triazine herbicides (simazine, atrazine, ametryn, prometryn, and terbutryn) in water samples. The five triazine herbicides were baseline separated by using the microemulsion buffer containing a 10 mmol/L borate buffer at pH 9.5, 2.5% (w/v) SDS as surfactant, 0.8% (w/v) ethyl acetate as oil phase, and 6.0% (w/v) 1-butanol as cosurfactant. The optimum extraction conditions of VSLLME were as follows: 100 μL chloroform was used as extraction solvent, 5.0 × 10⁻⁵ mol/L Tween-20 was chosen as the surfactant to enhance the emulsification, and the extraction process was carried out by vortex mixing for 3 min. Under these optimum experimental conditions, the calibration curve was linear in the range of 2.0-200.0 ng/mL, with the correlation coefficients (r²) varying from 0.9927 to 0.9958. The detection limits of the method varied from 0.41 to 0.62 ng/mL. The purposed method was applied to the determination of five triazine herbicides in real water samples, and the recoveries were between 80.6 and 107.3%.

  1. Determination of Lead in Water Samples Using a New Vortex-Assisted, Surfactant-Enhanced Emulsification Liquid-Liquid Microextraction Combined with Graphite Furnace Atomic Absorption Spectrometry.

    Science.gov (United States)

    Peng, Guilong; He, Qiang; Lu, Ying; Mmereki, Daniel; Pan, Weiliang; Tang, Xiaohui; Zhou, Guangming; Mao, Yufeng; Su, Xaioxuan

    2016-04-01

    A low toxic solvent-based vortex-assisted surfactant-enhanced emulsification liquid-liquid microextraction (LT-VSLLME) combined with graphite furnace atomic absorption spectrometry was developed for the extraction and determination of lead (Pb) in water samples. In the LT-VSLLME method, the extraction solvent was dispersed into the aqueous samples by the assistance of vortex agitator. Meanwhile, the addition of a surfactant, which acted as an emulsifier, could enhance the speed of the mass-transfer from aqueous samples to the extraction solvent. The influences of analytical parameters, including extraction solvent type and its volume, surfactant type and its volume, pH, concentration of chelating agent, salt effect and extraction time were investigated. Under the optimized conditions, a good relative standard deviation of 3.69% at 10 ng L(-1) was obtained. The calibration graph showed a linear pattern in the ranges of 5-30 ngL(-1), with a limit of detection of 0.76 ng L(-1). The linearity was obtained by five points in the concentration range of 5-30 ngL(-1). The enrichment factor was 320. The procedure was applied to wastewater and river water, and the accuracy was assessed through the analysis of the recovery experiments.

  2. Applying Reactive Barrier Technology to Enhance Microbially-mediated Denitrification during Managed Aquifer Recharge

    Science.gov (United States)

    Beganskas, S.; Weir, W. B.; Harmon, R. E.; Gorski, G.; Fisher, A. T.; Saltikov, C.; Young, K. S.; Runneals, D.; Teo, E. K.; Stoneburner, B.; Hernandez, J.

    2015-12-01

    We are running field experiments to observe and quantify microbially-mediated water quality improvement via denitrification during infiltration in the shallow subsurface. Nitrate is a pervasive groundwater contaminant, and nitrate removal through denitrification can occur during infiltration in natural and anthropogenic systems, including during managed aquifer recharge (MAR). The rate of denitrification can vary depending on factors such as infiltration rate; previous work suggests that denitrification rates can increase monotonically with infiltration rates until reaching a critical threshold. We are performing controlled field tests of variables that affect denitrification rate, including sampling to link water chemistry changes to microbial ecology and activity. This study explores how microbial activity and denitrification rates respond to different infiltration rates and the presence or absence of a reactive material (wood chips, a carbon source). We are conducting four two-week-long tests, each under different conditions. For each test, we measure bulk infiltration rate (the sum of lateral and vertical infiltration), vertical infiltration rate using heat as a tracer, and water level. We collect surface and subsurface water samples daily, and we collect soil samples at the start and end of each test. For each water sample, we are measuring NO3-, NO2-, NH3, DOC, and N and O isotopes in nitrate. Soil samples will be tested for grain size, total C/N, and the presence of microbiological genes associated with denitrification. These results will expand our knowledge of the conditions under which denitrification occurs by implicating specific microorganisms and physical infiltration parameters. Our design has the potential for additional experimentation with variables that impact water chemistry during infiltration. This study has broad applications for designing MAR systems that effectively improve water supply and water quality.

  3. Mesoporous Silica Nanoparticles Loaded with Surfactant: Low Temperature Magic Angle Spinning 13C and 29Si NMR Enhanced by Dynamic Nuclear Polarization

    Energy Technology Data Exchange (ETDEWEB)

    Lafon, Olivier [Universite de Lille Nord de France; Thankamony, Aany S. Lilly [Universite de Lille Nord de France; Kokayashi, Takeshi [Ames Laboratory; Carnevale, Diego [Ecole Polytechnique Federale de Lausanne; Vitzthum, Veronika [Ecole Polytechnique Federale de Lausanne; Slowing, Igor I. [Ames Laboratory; Kandel, Kapil [Ames Laboratory; Vezin, Herve [Universite de Lille Nord de France; Amoureux, Jean-Paul [Universite de Lille Nord de France; Bodenhausen, Geoffrey [Ecole Polytechnique Federale de Lausanne; Pruski, Marek [Ames Laboratory

    2012-12-21

    We show that dynamic nuclear polarization (DNP) can be used to enhance NMR signals of 13C and 29Si nuclei located in mesoporous organic/inorganic hybrid materials, at several hundreds of nanometers from stable radicals (TOTAPOL) trapped in the surrounding frozen disordered water. The approach is demonstrated using mesoporous silica nanoparticles (MSN), functionalized with 3-(N-phenylureido)propyl (PUP) groups, filled with the surfactant cetyltrimethylammonium bromide (CTAB). The DNP-enhanced proton magnetization is transported into the mesopores via 1H–1H spin diffusion and transferred to rare spins by cross-polarization, yielding signal enhancements εon/off of around 8. When the CTAB molecules are extracted, so that the radicals can enter the mesopores, the enhancements increase to εon/off ≈ 30 for both nuclei. A quantitative analysis of the signal enhancements in MSN with and without surfactant is based on a one-dimensional proton spin diffusion model. The effect of solvent deuteration is also investigated.

  4. Absorption-enhancing effects of gemini surfactant on the intestinal absorption of poorly absorbed hydrophilic drugs including peptide and protein drugs in rats.

    Science.gov (United States)

    Alama, Tammam; Kusamori, Kosuke; Katsumi, Hidemasa; Sakane, Toshiyasu; Yamamoto, Akira

    2016-02-29

    In general, the intestinal absorption of small hydrophilic molecules and macromolecules like peptides, after oral administration is very poor. Absorption enhancers are considered to be one of the most promising agents to enhance the intestinal absorption of drugs. In this research, we focused on a gemini surfactant, a new type of absorption enhancer. The intestinal absorption of drugs, with or without sodium dilauramidoglutamide lysine (SLG-30), a gemini surfactant, was examined by an in situ closed-loop method in rats. The intestinal absorption of 5(6)-carboxyfluorescein (CF) and fluorescein isothiocyanate-dextrans (FDs) was significantly enhanced in the presence of SLG-30, such effect being reversible. Furthermore, the calcium levels in the plasma significantly decreased when calcitonin was co-administered with SLG-30, suggestive of the increased intestinal absorption of calcitonin. In addition, no significant increase in the of lactate dehydrogenase (LDH) activity or in protein release from the intestinal epithelium was observed in the presence of SLG-30, suggestive of the safety of this compound. These findings indicate that SLG-30 is an effective absorption-enhancer for improving the intestinal absorption of poorly absorbed drugs, without causing serious damage to the intestinal epithelium.

  5. Switchable Surfactants

    National Research Council Canada - National Science Library

    Yingxin Liu; Philip G. Jessop; Michael Cunningham; Charles A. Eckert; Charles L. Liotta

    2006-01-01

    .... We report that long-chain alkyl amidine compounds can be reversibly transformed into charged surfactants by exposure to an atmosphere of carbon dioxide, thereby stabilizing water/alkane emulsions...

  6. Heterogeneity-enhanced gas phase formation in shallow aquifers during leakage of CO2-saturated water from geologic sequestration sites

    Science.gov (United States)

    Plampin, Michael R.; Lassen, Rune N.; Sakaki, Toshihiro; Porter, Mark L.; Pawar, Rajesh J.; Jensen, Karsten H.; Illangasekare, Tissa H.

    2014-12-01

    A primary concern for geologic carbon storage is the potential for leakage of stored carbon dioxide (CO2) into the shallow subsurface where it could degrade the quality of groundwater and surface water. In order to predict and mitigate the potentially negative impacts of CO2 leakage, it is important to understand the physical processes that CO2 will undergo as it moves through naturally heterogeneous porous media formations. Previous studies have shown that heterogeneity can enhance the evolution of gas phase CO2 in some cases, but the conditions under which this occurs have not yet been quantitatively defined, nor tested through laboratory experiments. This study quantitatively investigates the effects of geologic heterogeneity on the process of gas phase CO2 evolution in shallow aquifers through an extensive set of experiments conducted in a column that was packed with layers of various test sands. Soil moisture sensors were utilized to observe the formation of gas phase near the porous media interfaces. Results indicate that the conditions under which heterogeneity controls gas phase evolution can be successfully predicted through analysis of simple parameters, including the dissolved CO2 concentration in the flowing water, the distance between the heterogeneity and the leakage location, and some fundamental properties of the porous media. Results also show that interfaces where a less permeable material overlies a more permeable material affect gas phase evolution more significantly than interfaces with the opposite layering.

  7. A novel approach to enhancement of surface properties of CdO films by using surfactant: dextrin

    Science.gov (United States)

    Sahin, Bünyamin; Bayansal, Fatih; Yüksel, Mustafa

    2015-12-01

    We studied the effect of an organic surfactant, dextrin, concentration on structural, morphological and optical properties of nanostructured CdO films deposited on glass substrates by using an easy and low-cost SILAR method. Microstructures of the nanostructured CdO films were optimized by adjusting dextrin concentration. XRD, SEM and UV-Vis Spectroscopy were used to study phase structure, surface morphology and optical properties of CdO films. Furthermore, effects of dextrin concentration on the surface roughness characteristics of CdO samples were reported. The results showed that the presence of organic surfactant highly affected the physical properties of CdO nanomaterials.

  8. Intrinsic and enhanced bioremediation in aquifers contaminated with chlorinated and aromatic hydrocarbons in The Netherlands

    NARCIS (Netherlands)

    Rijnaarts, H.H.M.; Aalst-van Leeuwen, M.A. van; Heiningen, E. van; Buyzen, H. van; Sinke, A.; Liere, H.C. van; Harkes, M.; Baartmans, R.; Bosma, T.N.P.; Doddema, H.J.

    1998-01-01

    The feasibility of intrinsic and enhanced bioremediation approaches for 16 contaminated sites in the Netherlands are discussed. At at least five out of 10 chlorinated solvent sites, natural attenuation can be used as one of the tools to prevent further dispersion of the plume. At two sites stimulati

  9. Enhanced sugar production from pretreated barley straw by additive xylanase and surfactants in enzymatic hydrolysis for acetone-butanol-ethanol fermentation.

    Science.gov (United States)

    Yang, Ming; Zhang, Junhua; Kuittinen, Suvi; Vepsäläinen, Jouko; Soininen, Pasi; Keinänen, Markku; Pappinen, Ari

    2015-01-01

    This study aims to improve enzymatic sugar production from dilute sulfuric acid-pretreated barley straw for acetone-butanol-ethanol (ABE) fermentation. The effects of additive xylanase and surfactants (polyethylene glycol [PEG] and Tween) in an enzymatic reaction system on straw hydrolysis yields were investigated. By combined application of 2g/100g dry-matter (DM) xylanase and PEG 4000, the glucose yield was increased from 53.2% to 86.9% and the xylose yield was increased from 36.2% to 70.2%, which were considerably higher than results obtained with xylanase or surfactant alone. The ABE fermentation of enzymatic hydrolysate produced 10.8 g/L ABE, in which 7.9 g/L was butanol. The enhanced sugar production increased the ABE yield from 93.8 to 135.0 g/kg pretreated straw. The combined application of xylanase and surfactants has a large potential to improve sugar production from barley straw pretreated with a mild acid and that the hydrolysate showed good fermentability in ABE production. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Application of Optimized Vortex-Assisted Surfactant-Enhanced DLLME for Preconcentration of Thymol and Carvacrol, and Their Determination by HPLC-UV: Response Surface Methodology.

    Science.gov (United States)

    Ghaedi, Mehrorang; Roosta, Mostafa; Khodadoust, Saeid; Daneshfar, Ali

    2015-08-01

    A novel vortex-assisted surfactant-enhanced dispersive liquid-liquid microextraction combined with high-performance liquid chromatography (VASEDLLME-HPLC) was developed for the determination of thymol and carvacrol (phenolic compound). In this method, the extraction solvent (CHCl3) was dispersed into the aqueous samples via a vortex agitator and addition of the surfactant (Triton X-100). The preliminary experiments were undertaken to select the best extraction solvent and surfactant. The influences of effective variables were investigated using a Plackett-Burman 2(7-4) screening design and then, the significant variables were optimized by using a central composite design combined with desirability function. Working under optimum conditions specified as: 140 µL CHCl3, 0.08% (w/v, Triton X-100), 3 min extraction time, 6 min centrifugation at 4,500 rpm, pH 7, 0.0% (w/v) NaCl permit achievement of high and reasonable linear range over 0.005-4.0 mg L(-1) with R(2) = 0.9998 (n = 10). The separation of thymol and carvacrol was achieved in <14 min using a C18 column and an isocratic binary mobile phase acetonitrile-water (55:45, v/v) with a flow rate of 1.0 mL min(-1). The VASEDLLME is applied for successful determination of carvacrol and thymol in different thyme and pharmaceutical samples with relative standard deviation <4.7% (n = 5).

  11. Carbonate aquifers

    Science.gov (United States)

    Cunningham, Kevin J.; Sukop, Michael; Curran, H. Allen

    2012-01-01

    Only limited hydrogeological research has been conducted using ichnology in carbonate aquifer characterization. Regardless, important applications of ichnology to carbonate aquifer characterization include its use to distinguish and delineate depositional cycles, correlate mappable biogenically altered surfaces, identify zones of preferential groundwater flow and paleogroundwater flow, and better understand the origin of ichnofabric-related karst features. Three case studies, which include Pleistocene carbonate rocks of the Biscayne aquifer in southern Florida and Cretaceous carbonate strata of the Edwards–Trinity aquifer system in central Texas, demonstrate that (1) there can be a strong relation between ichnofabrics and groundwater flow in carbonate aquifers and (2) ichnology can offer a useful methodology for carbonate aquifer characterization. In these examples, zones of extremely permeable, ichnofabric-related macroporosity are mappable stratiform geobodies and as such can be represented in groundwater flow and transport simulations.

  12. Enhanced flushing of polychlorinated biphenyls contaminated sands using surfactant foam: effect of partition coefficient and sweep efficiency.

    Science.gov (United States)

    Wang, Hao; Chen, Jiajun

    2012-01-01

    Foam flushing is an in situ soil remediation technology based on the traditional surfactant flushing method. The contribution of mobility control to contaminant removal by foam is helpful for improving this technology. Foam flushing of polychlorinated biphenyl (PCB)-contaminated unconsolidated media was performed to evaluate the effect of the partition coefficient (PC) and sweep efficiency (SE) on PCB removal. Column flushing with surfactant solution and foam with different types and concentrations of surfactant was carried out for PCB removal. Two types of quartz sand were investigated to evaluate the Jamin effect on the SE value of the washing agent. The results demonstrate that a small PC value and large SE value are necessary to achieve high PCB removal for foam flushing. Compared with solution flushing, the introduction of foam can effectively control the mobility of the washing agent. Similar to solution flushing, solubilization is a key factor which dominates the removal of PCBs in foam flushing. In addition, the SE value and PCB removal by foam flushing is less affected by particle size. Therefore, foam flushing was proved to be more effective in porous media with low hydraulic conductivity and high porosity. An integrated flushing with water, surfactant solution and foam was performed and the results prove that this technology successfully combines the advantages of solution solubilization and mobility control by foam, and thus further increases the remediation efficiency of PCBs to 94.7% for coarse sand.

  13. Enhanced flushing of polychlorinated biphenyls contaminated sands using surfactant foam: Effect of partition coefficient and sweep efficiency

    Institute of Scientific and Technical Information of China (English)

    Hao Wang; Jiajun Chen

    2012-01-01

    Foam flushing is an in situ soil remediation technology based on the traditional surfactant flushing method.The contribution of mobility control to contaminant removal by foam is helpful for improving this technology.Foam flushing of polychlorinated biphenyl (PCB)-contaminated unconsolidated media was performed to evaluate the effect of the partition coefficient (PC) and sweep efficiency (SE) on PCB removal.Column flushing with surfactant solution and foam with different types and concentrations of surfactant was carried out for PCB removal.Two types of quartz sand were investigated to evaluate the Jamin effect on the SE value of the washing agent.The results demonstrate that a small PC value and large SE value are necessary to achieve high PCB removal for foam flushing.Compared with solution flushing,the introduction of foam can effectively control the mobility of the washing agent.Similar to solution flushing,solubilization is a key factor which dominates the removal of PCBs in foam flushing.In addition,the SE value and PCB removal by foam flushing is less affected by particle size.Therefore,foam flushing was proved to be more effective in porous media with low hydraulic conductivity and high porosity.An integrated flushing with water,surfactant solution and foam was performed and the results prove that this technology successfully combines the advantages of solution solubilization and mobility control by foam,and thus further increases the remediation efficiency of PCBs to 94.7% for coarse sand.

  14. Roles of surfactants and particle shape in the enhanced thermal conductivity of TiO2 nanofluids

    Science.gov (United States)

    Yang, Liu; Chen, Xielei; Xu, Mengkai; Du, Kai

    2016-09-01

    Although several forms of thermal conductivity models for nanofluid have been established, few models for nanofluids containing surfactants or columnar nanoparticles are found. This paper intends to consider the surfactants and particle shape effect in the thermal conductivity of TiO2 nanofluids. The thermal conductivity models for respectively spherical and columnar TiO2 nanofluids are proposed by considering the influences of solvation nanolayer and the end effect of columnar nanoparticles. The thicknesses of the solvation nanolayers are defined by the surfactant molecular length and a few atomic distances for nanofluid with and without surfactant respectively. The end effect of the columnar nanoparticles is considered by analyzing the different thermal resistances and probability of the heat conduction for the selected small element in axial direction and radial direction. Finally, the present models and some other existing models were compared with some available experimental data and the comparison results show the present models achieve higher accuracy and precision for all the four kinds of applications.

  15. Surfactant-enhanced spectrofluorimetric determination of total aflatoxins from wheat samples after magnetic solid-phase extraction using modified Fe3O4 nanoparticles

    Science.gov (United States)

    Manafi, Mohammad Hanif; Allahyari, Mehdi; Pourghazi, Kamyar; Amoli-Diva, Mitra; Taherimaslak, Zohreh

    2015-07-01

    The extraction and preconcentration of total aflatoxins (including aflatoxin B1, B2, G1, and G2) using magnetic nanoparticles based solid phase extraction (MSPE) followed by surfactant-enhanced spectrofluorimetric detection was proposed. Ethylene glycol bis-mercaptoacetate modified silica coated Fe3O4 nanoparticles as an efficient antibody-free adsorbent was successfully applied to extract aflatoxins from wheat samples. High surface area and strong magnetization properties of magnetic nanoparticles were utilized to achieve high enrichment factor (97), and satisfactory recoveries (92-105%) using only 100 mg of the adsorbent. Furthermore, the fast separation time (less than 10 min) avoids many time-consuming cartridge loading or column-passing procedures accompany with the conventional SPE. In determination step, signal enhancement was performed by formation of Triton X-100 micelles around the analytes in 15% (v/v) acetonitrile-water which dramatically increase the sensitivity of the method. Main factors affecting the extraction efficiency and signal enhancement of the analytes including pH of sample solution, desorption conditions, extraction time, sample volume, adsorbent amount, surfactant concentration and volume and time of micelle formation were evaluated and optimized. Under the optimum conditions, wide linear range of 0.1-50 ng mL-1 with low detection limit of 0.03 ng mL-1 were obtained. The developed method was successfully applied to the extraction and preconcentration of aflatoxins in three commercially available wheat samples and the results were compared with the official AOAC method.

  16. Surfactant-enhanced spectrofluorimetric determination of total aflatoxins from wheat samples after magnetic solid-phase extraction using modified Fe₃O₄ nanoparticles.

    Science.gov (United States)

    Manafi, Mohammad Hanif; Allahyari, Mehdi; Pourghazi, Kamyar; Amoli-Diva, Mitra; Taherimaslak, Zohreh

    2015-07-01

    The extraction and preconcentration of total aflatoxins (including aflatoxin B1, B2, G1, and G2) using magnetic nanoparticles based solid phase extraction (MSPE) followed by surfactant-enhanced spectrofluorimetric detection was proposed. Ethylene glycol bis-mercaptoacetate modified silica coated Fe3O4 nanoparticles as an efficient antibody-free adsorbent was successfully applied to extract aflatoxins from wheat samples. High surface area and strong magnetization properties of magnetic nanoparticles were utilized to achieve high enrichment factor (97), and satisfactory recoveries (92-105%) using only 100mg of the adsorbent. Furthermore, the fast separation time (less than 10 min) avoids many time-consuming cartridge loading or column-passing procedures accompany with the conventional SPE. In determination step, signal enhancement was performed by formation of Triton X-100 micelles around the analytes in 15% (v/v) acetonitrile-water which dramatically increase the sensitivity of the method. Main factors affecting the extraction efficiency and signal enhancement of the analytes including pH of sample solution, desorption conditions, extraction time, sample volume, adsorbent amount, surfactant concentration and volume and time of micelle formation were evaluated and optimized. Under the optimum conditions, wide linear range of 0.1-50 ng mL(-1) with low detection limit of 0.03 ng mL(-1) were obtained. The developed method was successfully applied to the extraction and preconcentration of aflatoxins in three commercially available wheat samples and the results were compared with the official AOAC method.

  17. Development of a home-made extraction device for vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction with lighter than water organic solvents.

    Science.gov (United States)

    Yang, Zhong-Hua; Wang, Peng; Zhao, Wen-ting; Zhou, Zhi-Qiang; Liu, Dong-Hui

    2013-07-26

    We have developed a novel vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction using the low density solvent for the determination of eight organophosphorus pesticides (OPPs) in water samples. The key point of this method is the application of a special home-made extraction device. The influence parameters relevant to this method were systemically investigated and the optimum conditions were as follow: 35μL of toluene was used as extraction solvent and 0.2mmol L-1 Triton X-100 was chosen as the surfactant to enhance the emulsification. Under the optimum experimental conditions, the limit of detections (LODs) of the method was ranged between 0.01 and 0.05μgL(-1) and the relative standard deviations (RSDs) were 2.9-8.1%. The calibration curve was linear in the range of 0.1-50.0μgL(-1), with the correlation coefficients (r) varying from 0.9949 to 0.9991. Finally, the developed method has been successfully applied to the determination of eight organophosphorus pesticides in river, reservoir and well water samples with recoveries between 82.1% and 98.7%.

  18. An anionic surfactant for EOR applications

    Science.gov (United States)

    Sagir, Muhammad; Tan, Isa M.; Mushtaq, Muhammad

    2014-10-01

    This work is to investigate the new anionic surfactants for the Enhanced Oil Recovery (EOR) application. Sulfonated anionic surfactant was produced by attaching SO3 to an ethoxylated alcohol to increase the performance of the surfactant. Methallyl chloride and ethoxylated alcohol was reacted followed by the reaction with sodium bisulfite to produce anionic sulfonated surfactant in 80.3 % yield. The sulfonation reaction parameters such as reactants mole ratio, reaction temperature and catalyst amount were optimized. The generation and stability of foam from the synthesized surfactant is also tested and results are reported. The synthesized novel surfactant was further investigated for the effect on the CO2 mobility in porous media and the findings are presented here. This in house developed surfactant has a great potential for CO2- EOR applications.

  19. Innovation in surfactant therapy II: surfactant administration by aerosolization.

    Science.gov (United States)

    Pillow, J Jane; Minocchieri, S

    2012-01-01

    Instilled bolus surfactant is the only approved surfactant treatment for neonatal respiratory distress syndrome. However, recent trends towards increased utilization of noninvasive respiratory support for preterm infants with surfactant deficiency have created a demand for a similarly noninvasive means of administering exogenous surfactant. Past approaches to surfactant nebulization met with varying success due to inefficient aerosol devices resulting in low intrapulmonary delivery doses of surfactant with variable clinical effectiveness. The recent development of vibrating membrane nebulizers, coupled with appropriate positioning of the interface device, indicates that efficient delivery of aerosolized surfactant is now a realistic goal in infants. Evidence of clinical effect despite low total administered dose in pilot studies, together with suggestions of enhanced homogeneity of pulmonary distribution indicate that this therapy may be applied in a cost-effective manner, with minimal patient handling and disruption. These studies need to be subjected to appropriately designed randomized controlled trials. Further work is also required to determine the optimum delivery route (mask, intranasal prong, nasopharyngeal or laryngeal), dosing amount and redosing interval.

  20. Certain surfactants significantly enhance the activity of antibiotics in the mouse model of MTB and drug resistant MTB infection and effectively remove the bacteria from a pulmonary cavity in human ex-vivo study.

    Science.gov (United States)

    Risin, Semyon A; Hunter, Robert L; Kobak, Mikhail; Ariel, Boris; Vishnevsky, Boris; Erokhin, Vladislav; Demikhova, Olga; Bocharova, Irina; Stoops, James K

    2014-01-01

    Surfactants have the potential to overcome natural resistance of MTB to antibiotics which is mediated by barriers that impede the penetration of drugs to their targets. A major component of this barrier is trehalose dimycolate (TDM) which surrounds the bacteria with a thick lipid shield. In this study dodecyl maltoside (DDM) was evaluated for this purpose. This surfactant is an excellent cellular permeabilizing agent with associated low toxicity. The administration of the surfactant as an aerosol into the lungs of the infected mice achieved a 5-10 times enhancement of the isoniazid (INH) treatment gauged by the reduction of the colony forming units. This study also established proof of principle that surfactants alone applied as an aerosol can reduce the bacteria count in lungs infected with MTB. The potential of the surfactant in the therapy of human cavitary TB was also investigated using a surgically removed lung from a patient with extreme drug resistant MTB (XDR-TB). A cavity in this lung was flushed with DDM solution ex-vivo. The procedure readily removed the bacteria, excessive amounts of TDM and necrotic tissue from the cavity. These studies demonstrate that DDM can disrupt the layers of TDM and free embedded MTB and, consequently, surfactants have promise as a proficient modality for the treatment of pulmonary MTB.

  1. Fullerene surfactants and their use in polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Jen, Kwan-Yue; Yip, Hin-Lap; Li, Chang-Zhi

    2015-12-15

    Fullerene surfactant compounds useful as interfacial layer in polymer solar cells to enhance solar cell efficiency. Polymer solar cell including a fullerene surfactant-containing interfacial layer intermediate cathode and active layer.

  2. Use of time series and harmonic constituents of tidal propagation to enhance estimation of coastal aquifer heterogeneity

    Science.gov (United States)

    Hughes, Joseph D.; White, Jeremy T.; Langevin, Christian D.

    2010-01-01

    A synthetic two‐dimensional model of a horizontally and vertically heterogeneous confined coastal aquifer system, based on the Upper Floridan aquifer in south Florida, USA, subjected to constant recharge and a complex tidal signal was used to generate 15‐minute water‐level data at select locations over a 7‐day simulation period.   “Observed” water‐level data were generated by adding noise, representative of typical barometric pressure variations and measurement errors, to 15‐minute data from the synthetic model. Permeability was calibrated using a non‐linear gradient‐based parameter inversion approach with preferred‐value Tikhonov regularization and 1) “observed” water‐level data, 2) harmonic constituent data, or 3) a combination of “observed” water‐level and harmonic constituent data.    In all cases, high‐frequency data used in the parameter inversion process were able to characterize broad‐scale heterogeneities; the ability to discern fine‐scale heterogeneity was greater when harmonic constituent data were used.  These results suggest that the combined use of highly parameterized‐inversion techniques and high frequency time and/or processed‐harmonic constituent water‐level data could be a useful approach to better characterize aquifer heterogeneities in coastal aquifers influenced by ocean tides.

  3. Ozark Aquifer

    Data.gov (United States)

    Kansas Data Access and Support Center — These digital maps contain information on the altitude of the base and top, the extent, and the potentiometric surface of the Ozark aquifer in Kansas. The Ozark...

  4. Enhanced biodegradation of asphalt in the presence of Tween surfactants, Mn(2+) and H2O2 by Pestalotiopsis sp. in liquid medium and soil.

    Science.gov (United States)

    Yanto, Dede Heri Yuli; Tachibana, Sanro

    2014-05-01

    Asphalt and fractions thereof can contaminate water and soil environments. Forming as residues in distillation products in crude oil refineries, asphalts consist mostly of asphaltene instead of aliphatics, aromatics, and resins. The high asphaltene content might be responsible for the decrease in bioavailability to microorganisms and therefore reduce the biodegradability of asphalt in the environment. In this study, the effect on asphalt biodegradation by Pestalotiopsis sp. in liquid medium and soil of nonionic Tween surfactants in the presence of Mn2+ and H2O2 was examined. The degradation was enhanced by Tween 40 or Tween 80 (0.1%) in the presence of Mn2+ (1 mM) and H2O2 (0.05 mM). A Tween surfactant, Mn2+, and H2O2 can overcome bioavailability-mediated constraints and increase ligninolytic activities, particularly manganese peroxidase and laccase activities. The study is significant for the bioremediation of asphalt and/or viscous-crude oil-contaminated environments.

  5. Scaling-up parameters for site restoration process using surfactant-enhanced soil washing coupled with wastewater treatment by Fenton and Fenton-like processes.

    Science.gov (United States)

    Bandala, Erick R; Cossio, Horacio; Sánchez-Lopez, Adriana D; Córdova, Felipe; Peralta-Herández, Juan M; Torres, Luis G

    2013-01-01

    Estimation of scaling-up parameters for a site restoration process using a surfactant-enhanced soil washing (SESW) process followed by the application of advanced oxidation processes (Fenton and photo-Fenton) was performed. For the SESW, different parameters were varied and the soil washing efficiency for pesticide (2,4-D) removal assessed. The resulting wastewater was treated using the Fenton reaction in the absence and presence of ultraviolet (UV) radiation for pesticide removal. Results showed that agitation speed of 1550 rpm was preferable for the best pesticide removal from contaminated soil. It was possible to wash contaminated soils with different soil concentrations; however the power drawn was higher as the soil concentration increased. Complete removal of the pesticide and the remaining surfactant was achieved using different reaction conditions. The best degradation conditions were for the photo-Fenton process using [Fe(II)] = 0.3 mM; [H2O2] = 4.0 mM where complete 2,4-D and sodium dodecylsulfate (SDS) removal was observed after 8 and 10 minutes of reaction, respectively. Further increase in the hydrogen peroxide or iron salt concentration did not show any improvement in the reaction rate. Kinetic parameters, i.e. reaction rate constant and scaling-up parameters, were determined. It was shown that, by coupling both processes (SESW and AOPs), it is possible the restoration of contaminated sites.

  6. A Synergistic Effect of Surfactant and ZrO2 Underlayer on Photocurrent Enhancement and Cathodic Shift of Nanoporous Fe2O3 Photoanode.

    Science.gov (United States)

    Shinde, Pravin S; Lee, Su Yong; Choi, Sun Hee; Lee, Hyun Hwi; Ryu, Jungho; Jang, Jum Suk

    2016-08-31

    Augmenting the donor density and nanostructure engineering are the crucial points to improve solar water oxidation performance of hematite (α-Fe2O3). This work addresses the sluggish water oxidation reaction associated with hematite photoanode by tweaking its internal porosity. The porous hematite photoanodes are fabricated by a novel synthetic strategy via pulse reverse electrodeposition (PRED) method that involves incorporation of a cationic CTAB surfactant in a sulfate electrolyte and spin-coated ZrO2 underlayer (UL) on FTO. CTAB is found to be beneficial in promoting the film growth rate during PRED. Incorporation of Zr(4+) ions from ZrO2 UL and Sn(4+) ions from FTO into the Fe2O3 lattice via solid-state diffusion reaction during pertinent annihilation of surfactant molecules at 800 °C produced internally porous hematite films with improved carrier concentration. The porous hematite demonstrated a sustained photocurrent enhancement and a significant cathodic shift of 130 mV relative to the planar hematite under standard illumination conditions (AM 1.5G) in 1 M NaOH electrolyte. The absorption, electrochemical impedance spectroscopy and Mott-Schottky analyses revealed that the ZrO2 UL and CTAB not only increased the carrier density and light harvesting but also accelerated the surface oxidation reaction kinetics, synergistically boosting the performance of internally porous hematite photoanodes.

  7. Vortex-assisted surfactant-enhanced emulsification microextraction based on solidification of floating organic drop combined with high performance liquid chromatography for determination of naproxen and nabumetone.

    Science.gov (United States)

    Asadi, Mohammad; Haji Shabani, Ali Mohammad; Dadfarnia, Shayessteh; Abbasi, Bijan

    2015-12-18

    A novel, rapid, simple and green vortex-assisted surfactant-enhanced emulsification microextraction method based on solidification of floating organic drop was developed for simultaneous separation/preconcentration and determination of ultra trace amounts of naproxen and nabumetone with high performance liquid chromatography-fluorescence detection. Some parameters influencing the extraction efficiency of analytes such as type and volume of extractant, type and concentration of surfactant, sample pH, KCl concentration, sample volume, and vortex time were investigated and optimized. Under optimal conditions, the calibration graph exhibited linearity in the range of 3.0-300.0ngL(-1) for naproxen and 7.0-300.0ngL(-1) for nabumetone with a good coefficient of determination (R(2)>0.999). The limits of detection were 0.9 and 2.1ngL(-1). The relative standard deviations for inter- and intra-day assays were in the range of 5.8-10.1% and 3.8-6.1%, respectively. The method was applied to the determination of naproxen and nabumetone in urine, water, wastewater and milk samples and the accuracy was evaluated through recovery experiments.

  8. A Synergistic Effect of Surfactant and ZrO2 Underlayer on Photocurrent Enhancement and Cathodic Shift of Nanoporous Fe2O3 Photoanode

    Science.gov (United States)

    Shinde, Pravin S.; Lee, Su Yong; Choi, Sun Hee; Lee, Hyun Hwi; Ryu, Jungho; Jang, Jum Suk

    2016-08-01

    Augmenting the donor density and nanostructure engineering are the crucial points to improve solar water oxidation performance of hematite (α-Fe2O3). This work addresses the sluggish water oxidation reaction associated with hematite photoanode by tweaking its internal porosity. The porous hematite photoanodes are fabricated by a novel synthetic strategy via pulse reverse electrodeposition (PRED) method that involves incorporation of a cationic CTAB surfactant in a sulfate electrolyte and spin-coated ZrO2 underlayer (UL) on FTO. CTAB is found to be beneficial in promoting the film growth rate during PRED. Incorporation of Zr4+ ions from ZrO2 UL and Sn4+ ions from FTO into the Fe2O3 lattice via solid-state diffusion reaction during pertinent annihilation of surfactant molecules at 800 °C produced internally porous hematite films with improved carrier concentration. The porous hematite demonstrated a sustained photocurrent enhancement and a significant cathodic shift of 130 mV relative to the planar hematite under standard illumination conditions (AM 1.5G) in 1 M NaOH electrolyte. The absorption, electrochemical impedance spectroscopy and Mott-Schottky analyses revealed that the ZrO2 UL and CTAB not only increased the carrier density and light harvesting but also accelerated the surface oxidation reaction kinetics, synergistically boosting the performance of internally porous hematite photoanodes.

  9. Sorption of a nonionic surfactant Tween 80 by minerals and soils.

    Science.gov (United States)

    Kang, Soyoung; Jeong, Hoon Young

    2015-03-02

    Batch experiments were conducted to evaluate Tween 80 sorption by oxides, aluminosilicates, and soils. For oxides, the sorption by silica and alumina follow linear isotherms, and that by hematite follows a Langmuir isotherm. Considering isotherm type and surface coverage, Tween 80 may partition into the silica/alumina-water interface, whereas it may bind to hematite surface sites. Among aluminosilicates, montmorillonite shows the greatest sorption due to the absorption of Tween 80 into interlayers. For other aluminosilicates, it sorbs to surfaces, with the sorption increasing as plagioclaseTween 80 sorption. The greater sorption by untreated soils than H2O2-treated soils indicates that soil organic matter is a vital sorbent. The sorption hysteresis, contributed to by clay minerals and soil organic matter, is characterized by the greater sorption during the desorption than the sorption stages. This suggests the potential difficulty in removing surfactants from soils. Also, sorption of surfactants can adversely affect surfactant-enhanced remediation by decreasing the aquifer permeability and the availability of surfactants for micellar solubilization.

  10. Injection of Zero Valent Iron into an Unconfined Aquifer Using Shear-Thinning Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J.; Vermeul, Vincent R.; Mendoza, Donaldo P.; Fritz, Brad G.; Mackley, Rob D.; Oostrom, Martinus; Wietsma, Thomas W.; Macbeth, Tamzen

    2011-02-18

    Approximately 190 kg of two micron-diameter zero-valent iron (ZVI) particles were injected into a test zone in the top two meters of an unconfined aquifer within a trichloroethene (TCE) source area. A shear-thinning fluid was used to enhance ZVI delivery in the subsurface to a radial distance of up to four meters from a single injection well. The ZVI particles were mixed in-line with the injection water, shear-thinning fluid, and a low concentration of surfactant. ZVI was observed at each of the seven monitoring wells within the targeted radius of influence during injection. Additionally, all wells within the targeted zone showed low TCE concentrations and primarily dechlorination products present 44 days after injection. These results suggest that ZVI can be directly injected into an aquifer with shear-thinning fluids and extends the applicability of ZVI to situations where other emplacement methods may not be viable.

  11. Vortex-assisted surfactant-enhanced emulsification liquid-liquid microextraction for the determination of carbamates in juices by micellar electrokinetic chromatography tandem mass spectrometry.

    Science.gov (United States)

    Moreno-González, David; Huertas-Pérez, José F; García-Campaña, Ana M; Gámiz-Gracia, Laura

    2015-07-01

    A new method based on vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction has been developed for the extraction of carbamate pesticides in juice samples prior to their determination by micellar electrokinetic chromatography coupled to tandem mass spectrometry. This sample treatment allowed the satisfactory extraction and the extract clean-up of 25 carbamates from different fruit and vegetal juices (banana, tomato, and peach). In this study, the addition of ammonium perfluorooctanoate in the aqueous sample in combination with vortex agitation, provided very clean extracts with short extraction times. Under optimized conditions, recoveries of the proposed method for these pesticides from fortified juice samples ranged from 81% to 104%, with relative standard deviations lower than 15%. Limits of quantification were between 2.3µgkg(-)(1) and 4.7µgkg(-)(1), showing the high sensitivity of this fast and simple method.

  12. Use of Mathematical Models in the Design and Performance Evaluation of a Surfactant Flushing Demonstration at the Bachman Road Site

    Science.gov (United States)

    Abriola, L. M.; Drummond, C. D.; Lemke, L. D.; Rathfelder, K. M.; Pennell, K. D.

    2001-05-01

    This presentation provides an overview of the design and performance evaluation of a surfactant enhanced remediation pilot demonstration conducted in the summer of 2000 at a former dry cleaning facility in Oscoda, Michigan, USA. The unconfined contaminated formation is composed of relatively homogeneous glacial outwash sands, underlain by a thick clay layer. Core samples have revealed the presence of a reasonably persistent coarse sand and gravel layer at a depth of 11-16 feet and a sand/silt/clay transition zone at the base of the aquifer. A narrow tetrachloroethylene (PCE) plume emanates from the suspected source area, beneath the former dry cleaning building, and discharges into Lake Huron, approximately 700 feet down gradient. There is little evidence of microbial plume attenuation at the site. Aqueous samples from multilevel piezometers installed beneath the building have confirmed the presence of residual PCE within the coarse sand and gravel layer and have detected consistently high PCE concentrations at the base of the aquifer. The actual distribution and volume of entrapped PCE, however, is unknown. A surfactant injection and recovery scheme was designed and implemented to effectively flush the identified source area beneath the building. In this scheme, a line of water injection wells was installed behind the surfactant injection points to control surfactant delivery and maximize solubilized plume capture. Prior to surfactant injection, conservative and partitioning tracer tests were also conducted to confirm sweep and estimate source zone mass. Mass recovery calculations indicate that more than 94% of the injected surfactant and approximately 19 liters of PCE were recovered during the test. This volume of DNAPL is consistent with estimated low saturations within the swept zone. Single and multiphase transport models were employed to aid in remedial design and predict system performance. For the model simulations, input parameters were determined from

  13. Interactions of organic contaminants with mineral-adsorbed surfactants

    Science.gov (United States)

    Zhu, L.; Chen, B.; Tao, S.; Chiou, C.T.

    2003-01-01

    Sorption of organic contaminants (phenol, p-nitrophenol, and naphthalene) to natural solids (soils and bentonite) with and without myristylpyridinium bromide (MPB) cationic surfactant was studied to provide novel insight to interactions of contaminants with the mineral-adsorbed surfactant. Contaminant sorption coefficients with mineral-adsorbed surfactants, Kss, show a strong dependence on surfactant loading in the solid. At low surfactant levels, the Kss values increased with increasing sorbed surfactant mass, reached a maximum, and then decreased with increasing surfactant loading. The Kss values for contaminants were always higher than respective partition coefficients with surfactant micelles (Kmc) and natural organic matter (Koc). At examined MPB concentrations in water the three organic contaminants showed little solubility enhancement by MPB. At low sorbed-surfactant levels, the resulting mineral-adsorbed surfactant via the cation-exchange process appears to form a thin organic film, which effectively "adsorbs" the contaminants, resulting in very high Kss values. At high surfactant levels, the sorbed surfactant on minerals appears to form a bulklike medium that behaves essentially as a partition phase (rather than an adsorptive surface), with the resulting Kss being significantly decreased and less dependent on the MPB loading. The results provide a reference to the use of surfactants for remediation of contaminated soils/sediments or groundwater in engineered surfactant-enhanced washing.

  14. Reactive Transport Modeling of the Enhancement of Density-Driven CO2 Convective Mixing in Carbonate Aquifers and its Potential Implication on Geological Carbon Sequestration.

    Science.gov (United States)

    Islam, Akand; Sun, Alexander Y; Yang, Changbing

    2016-01-01

    We study the convection and mixing of CO2 in a brine aquifer, where the spread of dissolved CO2 is enhanced because of geochemical reactions with the host formations (calcite and dolomite), in addition to the extensively studied, buoyancy-driven mixing. The nonlinear convection is investigated under the assumptions of instantaneous chemical equilibrium, and that the dissipation of carbonate rocks solely depends on flow and transport and chemical speciation depends only on the equilibrium thermodynamics of the chemical system. The extent of convection is quantified in term of the CO2 saturation volume of the storage formation. Our results suggest that the density increase of resident species causes significant enhancement in CO2 dissolution, although no significant porosity and permeability alterations are observed. Early saturation of the reservoir can have negative impact on CO2 sequestration.

  15. Determination of melamine in soil samples using surfactant-enhanced hollow fiber liquid phase microextraction followed by HPLC–UV using experimental design

    Directory of Open Access Journals (Sweden)

    Ali Sarafraz Yazdi

    2015-11-01

    Full Text Available Surfactant-enhanced hollow fiber liquid phase (SE-HF-LPME microextraction was applied for the extraction of melamine in conjunction with high performance liquid chromatography with UV detection (HPLC–UV. Sodium dodecyl sulfate (SDS was added firstly to the sample solution at pH 1.9 to form hydrophobic ion-pair with protonated melamine. Then the protonated melamine–dodecyl sulfate ion-pair (Mel–DS was extracted from aqueous phase into organic phase immobilized in the pores and lumen of the hollow fiber. After extraction, the analyte-enriched 1-octanol was withdrawn into the syringe and injected into the HPLC. Preliminary, one variable at a time method was applied to select the type of extraction solvent. Then, in screening step, the other variables that may affect the extraction efficiency of the analyte were studied using a fractional factorial design. In the next step, a central composite design was applied for optimization of the significant factors having positive effects on extraction efficiency. The optimum operational conditions included: sample volume, 5 mL; surfactant concentration, 1.5 mM; pH 1.9; stirring rate, 1500 rpm and extraction time, 60 min. Using the optimum conditions, the method was analytically evaluated. The detection limit, relative standard deviation and linear range were 0.005 μg mL−1, 4.0% (3 μg mL−1, n = 5 and 0.01–8 μg mL−1, respectively. The performance of the procedure in extraction of melamine from the soil samples was good according to its relative recoveries in different spiking levels (95–109%.

  16. Liquid-liquid extraction for surfactant-contaminant separation and surfactant reuse

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, M.A. [Surbec Environmental, Norman, OK (United States); Sabatini, D.A.; Harwell, J.H. [Univ. of Oklahoma, Norman, OK (United States)

    1997-07-01

    Liquid-liquid extraction was investigated for use with surfactant enhanced subsurface remediation. A surfactant liquid-liquid extraction model (SLLEM) was developed for batch equilibrium conditions based on contaminant partitioning between micellar, water, and solvent phases. The accuracy of this fundamental model was corroborated with experimental results (using naphthalene and phenanthrene as contaminants and squalane as the extracting solvent). The SLLEM model was then expanded to nonequilibrium conditions. The effectiveness of this nonequilibrium model was corroborated with experimental results from continuous flow hollow fiber membrane systems. The validated models were used to conduct a sensitivity analysis evaluating the effects of surfactants on the removal of the contaminants in liquid-liquid extraction systems. In addition, liquid-liquid extraction is compared to air stripping for surfactant-contaminant separation. Finally, conclusions are drawn as to the impact of surfactants on liquid-liquid extraction processes, and the significance of these impacts on the optimization of surfactant-enhanced subsurface remediation.

  17. Enhanced production and characterization of a solvent stable amylase from solvent tolerant Bacillus tequilensis RG-01: thermostable and surfactant resistant.

    Science.gov (United States)

    Tiwari, Soni; Shukla, Neha; Mishra, Pooja; Gaur, Rajeeva

    2014-01-01

    Ten bacterial strains isolated from the soil samples in the presence of cyclohexane were screened for amylase production. Among them, culture RG-01 was adjudged as the best amylase producer and was identified as Bacillus tequilensis from MTCC, Chandigarh. The isolate showed maximum amylase production (8100 U/mL) in the presence of starch, peptone, and Ca(2+) ions at 55°C pH 7.0 within 24 h of incubation. The enzyme was stable in the presence of n-dodecane, isooctane, n-decane, xylene, toluene, n-hexane, n-butanol, and cyclohexane, respectively. The presence of benzene, methanol, and ethanol marginally reduced the amylase stability, respectively. The enzyme was showed it 100% activity at 55°C and pH 7.0 with 119% and 127% stability at 55°C and pH 7.0, respectively. The enzyme was also stable in the presence of SDS, Tween-40, Tween-60, and Tween-80 (1%) and was found stimulatory effect, respectively. Only Triton-X-100 showed a moderate inhibitory effect (5%) on amylase activity. This isolate (Bacillus tequilensis RG-01) may be useful in several industrial applications owing to its thermotolerant and organic solvents and surfactants resistance characteristics.

  18. In situ generation of steam and alkaline surfactant for enhanced oil recovery using an exothermic water reactant (EWR)

    Science.gov (United States)

    Robertson, Eric P

    2011-05-24

    A method for oil recovery whereby an exothermic water reactant (EWR) encapsulated in a water soluble coating is placed in water and pumped into one or more oil wells in contact with an oil bearing formation. After the water carries the EWR to the bottom of the injection well, the water soluble coating dissolves and the EWR reacts with the water to produce heat, an alkali solution, and hydrogen. The heat from the EWR reaction generates steam, which is forced into the oil bearing formation where it condenses and transfers heat to the oil, elevating its temperature and decreasing the viscosity of the oil. The aqueous alkali solution mixes with the oil in the oil bearing formation and forms a surfactant that reduces the interfacial tension between the oil and water. The hydrogen may be used to react with the oil at these elevated temperatures to form lighter molecules, thus upgrading to a certain extent the oil in situ. As a result, the oil can flow more efficiently and easily through the oil bearing formation towards and into one or more production wells.

  19. Enhanced Production and Characterization of a Solvent Stable Amylase from Solvent Tolerant Bacillus tequilensis RG-01: Thermostable and Surfactant Resistant

    Directory of Open Access Journals (Sweden)

    Soni Tiwari

    2014-01-01

    Full Text Available Ten bacterial strains isolated from the soil samples in the presence of cyclohexane were screened for amylase production. Among them, culture RG-01 was adjudged as the best amylase producer and was identified as Bacillus tequilensis from MTCC, Chandigarh. The isolate showed maximum amylase production (8100 U/mL in the presence of starch, peptone, and Ca2+ ions at 55°C pH 7.0 within 24 h of incubation. The enzyme was stable in the presence of n-dodecane, isooctane, n-decane, xylene, toluene, n-hexane, n-butanol, and cyclohexane, respectively. The presence of benzene, methanol, and ethanol marginally reduced the amylase stability, respectively. The enzyme was showed it 100% activity at 55°C and pH 7.0 with 119% and 127% stability at 55°C and pH 7.0, respectively. The enzyme was also stable in the presence of SDS, Tween-40, Tween-60, and Tween-80 (1% and was found stimulatory effect, respectively. Only Triton-X-100 showed a moderate inhibitory effect (5% on amylase activity. This isolate (Bacillus tequilensis RG-01 may be useful in several industrial applications owing to its thermotolerant and organic solvents and surfactants resistance characteristics.

  20. Avaliação do desempenho de surfactantes para a solubilização de fases líquidas não aquosas em meio aquoso Evaluating surfactant performance as solubilizer of non-aqueous phase liquids within aqueous media

    Directory of Open Access Journals (Sweden)

    Elizabeth Fátima de Souza

    2010-01-01

    Full Text Available The presence of non-aqueous phase liquids (NAPLs in the subsurface is a threat to public health as well as a serious environmental issue. NAPLs may remain adsorbed or form lenses floating on aquifers causing long-term contaminations. Surfactants may increase NAPLs solubility, enhancing the pump-and-treatment performance. Size, shape, hydration and ionization degree of the micelles define the affinity and the space available for the solubilization of a particular contaminating agent. The tests carried out at laboratory scale, taking into account the NAPL to be removed and the medium characteristics were useful to select surfactants and evaluate their efficiency as NAPLs solubilizers.

  1. Dimeric Surfactants: Promising Ingredients of Cosmetics and Toiletries

    Directory of Open Access Journals (Sweden)

    Naveen Kumar

    2013-11-01

    Full Text Available Surfactants are an essential ingredient for cosmetic, toiletries and personal care products for enhancing their performance. Dimeric surfactants demonstrate superiority compared to conventional surfactants in all areas of application. Dimeric surfactants are extremely promising for utilization in various cosmetic formulations viz. shampoo, lotions, creams, conditioners etc. These surfactants possess extremely unique surface properties viz. lower surface tension, unique micellization, low critical micelle concentration (CMC and antimicrobial activity, higher solubilization etc. Dimerics enhance the performances of cosmetics in an extraordinary manner and provide eco-friendly preparations for human epidermis.

  2. Surfactant enhanced washing of heavily oil-contaminated soil%表面活性剂清洗处理重度石油污染土壤

    Institute of Scientific and Technical Information of China (English)

    卢媛; 马小东; 孙红文; 张闻

    2009-01-01

    Four kinds of anionic-nonionic mixed surfaetant were used in surfactant enhanced washing of oilcontaminated soil samples from Shengli Oilfield,in Dongying City of Shandong Province.The effects of different systems with variOUS mass ratios of anionic and nonionic surfactants.total surfaetant concentrations,temperatures and assistant washing agents on oil removal efficiency were studied.The optimum conditions are:mixed surfactants of LAS and T×100 with a mass ratio of 8:2.total surfactant concentrations of 3 g/L,assistant washing agents concentration of 5 s/L.and a temperature of 75℃.After washing,the oil content of sample reduces from 20%to 4.6%.achieves an oil removal of 76.9%.The resuhs from wash water reusing experiments show that reusing from 30% to 100% of the wash water can remove more than 55% of oil contaminants in the first reusing process.In wash water's second time reusing.it can still achieve an oil removal of 18.8%.%为了优化表面活性剂清洗处理重度石油污染土壤的方法和具体洗脱条件参数,采集山东省东营市胜利油田污染土壤,研究了阴离子-非离子混合表面活性剂对该土壤中石油类污染物的去除效果.应用化学热洗原理,主要考查了表面活性剂配比、投加量、清洗温度及清洗助剂对去除效果的影响.实验得到的清洗处理最佳条件为:使用LAS与TX-100质量比为8:2的组合表面活性剂,总表面活性剂浓度为3 g/L,助剂硅酸钠浓度为5 g/L,75℃条件下搅拌1 h.清洗后土壤含油量从20%下降到4.6%,去除率达到76.9%.废水回用实验表明,清洗处理的废水对土壤中石油烃类物质仍有一定的去除效果.废水回用比从30%到100%时,对土壤中石油烃的去除率都可达到55%以上.对废水进行二次回用时仍能去除18.8%的污染物.

  3. DEMONSTRATION OF PILOT-SCALE PERVAPORATION SYSTEMS FOR VOLATILE ORGANIC COMPOUND REMOVAL FROM A SURFACTANT ENHANCED AQUIFER REMEDIATION FLUID II. HOLLOW FIBER MEMBRANE MODULE. (R825511C027)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  4. Sorption of a nonionic surfactant Tween 80 by minerals and soils

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Soyoung, E-mail: soyoung@pusan.ac.kr; Jeong, Hoon Young, E-mail: hjeong@pusan.ac.kr

    2015-03-02

    Highlights: • Tween 80 sorption varies significantly among soil minerals. • Sorption mechanisms and atomic compositions explain to mineral-specific sorption. • Clay minerals and SOM in soils are the key contributors to Tween 80 sorption. • Hysteresis suggests the potential difficulty in removing residual surfactants. - Abstract: Batch experiments were conducted to evaluate Tween 80 sorption by oxides, aluminosilicates, and soils. For oxides, the sorption by silica and alumina follow linear isotherms, and that by hematite follows a Langmuir isotherm. Considering isotherm type and surface coverage, Tween 80 may partition into the silica/alumina–water interface, whereas it may bind to hematite surface sites. Among aluminosilicates, montmorillonite shows the greatest sorption due to the absorption of Tween 80 into interlayers. For other aluminosilicates, it sorbs to surfaces, with the sorption increasing as plagioclase < vermiculite < kaolinite. This results from the relative reactivity among surface sites: ≡NaOH, ≡CaOH << ≡SiOH < ≡AlOH. Experiments using dry- and wet-sieved soils reveal that fine-grained clay minerals, difficult to separate by dry-sieving, contribute significantly to Tween 80 sorption. The greater sorption by untreated soils than H{sub 2}O{sub 2}-treated soils indicates that soil organic matter is a vital sorbent. The sorption hysteresis, contributed to by clay minerals and soil organic matter, is characterized by the greater sorption during the desorption than the sorption stages. This suggests the potential difficulty in removing surfactants from soils. Also, sorption of surfactants can adversely affect surfactant-enhanced remediation by decreasing the aquifer permeability and the availability of surfactants for micellar solubilization.

  5. Influence of surfactant structures in luminescence enhancement dynamics during nucleation and growth of aqueous ZnS nanoparticles and their photoactivation due to illumination with UV/visible light

    Energy Technology Data Exchange (ETDEWEB)

    Mehta, S.K., E-mail: skmehta@pu.ac.i [Department of Chemistry and Centre for Advanced Studies in Chemistry, Panjab University, Chandigarh 160 014 (India); Kumar, Sanjay [Department of Chemistry and Centre for Advanced Studies in Chemistry, Panjab University, Chandigarh 160 014 (India)

    2010-12-15

    Nanostructured semiconductor architectures have attractive optical properties mainly including bright photoluminescence (PL) resulting from the radiative recombination of charge carriers on surface states. Various approaches have been employed for the modification of surface states of these nanostructures to design new nanomaterials with enhanced PL primarily in aqueous medium to enable their applications in biological samples. Here, we report the varying efficiencies of three commercial surfactants viz. cetyltrimethylammonium bromide (CTAB), cetyltrimethylammonium chloride (CTAC) and cetylpyridinium chloride (CPyC) on the dynamics of PL emission enhancement during initial growth and Ostwald ripening of ZnS nanoparticles (NPs). The counterion has been estimated to behave differently to govern the PL enhancement. The exceptionally high tendency of CPyC in PL enhancement has been assigned to participation of {pi}-electrons of pyridinium ring. The impact of UV-light in photoactivation of surfactant stabilized ZnS NPs has been utilized in exploring significance of surfactants in improving the surface emitting states in water soluble semiconductor NPs.

  6. Perstraction of Intracellular Pigments through Submerged Fermentation of Talaromyces spp. in a Surfactant Rich Media: A Novel Approach for Enhanced Pigment Recovery

    Directory of Open Access Journals (Sweden)

    Lourdes Morales-Oyervides

    2017-06-01

    Full Text Available A high percentage of the pigments produced by Talaromyces spp. remains inside the cell, which could lead to a high product concentration inhibition. To overcome this issue an extractive fermentation process, perstraction, was suggested, which involves the extraction of the intracellular products out of the cell by using a two-phase system during the fermentation. The present work studied the effect of various surfactants on secretion of intracellular pigments produced by Talaromyces spp. in submerged fermentation. Surfactants used were: non-ionic surfactants (Tween 80, Span 20 and Triton X-100 and a polyethylene glycerol polymer 8000, at different concentrations (5, 20, 35 g/L. The highest extracellular pigment yield (16 OD500nm was reached using Triton X-100 (35 g/L, which was 44% higher than the control (no surfactant added. The effect of addition time of the selected surfactant was further studied. The highest extracellular pigment concentration (22 OD500nm was achieved when the surfactant was added at 120 h of fermentation. Kinetics of extracellular and intracellular pigments were examined. Total pigment at the end of the fermentation using Triton X-100 was 27.7% higher than the control, confirming that the use of surfactants partially alleviated the product inhibition during the pigment production culture.

  7. 应用于提高石油采收率和家庭洗衣的表面活性剂%Surfactants for household laundry and enhanced oil recoverys

    Institute of Scientific and Technical Information of China (English)

    Kirk H. Raney; 岳霄(译)

    2016-01-01

    There are very dissimilar between household laundry and enhanced oil recoverys, however, some striking similarities noted between them. Household laundering wil be a huge market for surfactants, chemical enhanced oil recovery has tremendous growth potential and hence could complete for surfactant supply. This article wil describe these similarities, as wel as some subtle differences.%家庭洗衣和化学驱油(EOR)中使用的表面活性剂有非常大的差异,但也有某些惊人的相似性。尽管家庭洗衣仍将是最大的表面活性剂消费市场,但EOR用表面活性剂具有更大的增长潜能。本文将对这两种用途的表面活性剂作具体的分析。

  8. Thermally cleavable surfactants

    Science.gov (United States)

    McElhanon, James R.; Simmons, Blake A.; Zifer, Thomas; Jamison, Gregory M.; Loy, Douglas A.; Rahimian, Kamyar; Long, Timothy M.; Wheeler, David R.; Staiger, Chad L.

    2006-04-04

    Two new surfactant molecules are reported which contain thermally labile Diels-Alder adducts connecting the polar and non-polar sections of each molecule. The two surfactants possess identical non-polar dodecyl tail segments but exhibit different polar headgroups. The surfactants become soluble in water when anionic salts are formed through the deprotonation of the surfactant headgroups by the addition of potassium hydroxide. When either surfactant is exposed to temperature above about 60.degree. C., the retro Diels-Alder reaction occurs, yielding hydrophilic and hydrophobic fragments and the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.

  9. Thermally cleavable surfactants

    Energy Technology Data Exchange (ETDEWEB)

    McElhanon, James R. (Manteca, CA); Simmons, Blake A. (San Francisco, CA); Zifer, Thomas (Manteca, CA); Jamison, Gregory M. (Albuquerque, NM); Loy, Douglas A. (Albuquerque, NM); Rahimian, Kamyar (Albuquerque, NM); Long, Timothy M. (Urbana, IL); Wheeler, David R. (Albuquerque, NM); Staiger, Chad L. (Albuquerque, NM)

    2009-09-29

    Two new surfactant molecules are reported which contain thermally labile Diels-Alder adducts connecting the polar and non-polar sections of each molecule. The two surfactants possess identical non-polar dodecyl tail segments but exhibit different polar headgroups. The surfactants become soluble in water when anionic salts are formed through the deprotonation of the surfactant headgroups by the addition of potassium hydroxide. When either surfactant is exposed to temperature above about 60.degree. C., the retro Diels-Alder reaction occurs, yielding hydrophilic and hydrophobic fragments or the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.

  10. Thermally cleavable surfactants

    Energy Technology Data Exchange (ETDEWEB)

    McElhanon, James R. (Manteca, CA); Simmons, Blake A. (San Francisco, CA); Zifer, Thomas (Manteca, CA); Jamison, Gregory M. (Albuquerque, NM); Loy, Douglas A. (Albuquerque, NM); Rahimian, Kamyar (Albuquerque, NM); Long, Timothy M. (Urbana, IL); Wheeler, David R. (Albuquerque, NM); Staiger, Chad L. (Albuquerque, NM)

    2009-11-24

    Two new surfactant molecules are reported which contain thermally labile Diels-Alder adducts connecting the polar and non-polar sections of each molecule. The two surfactants possess identical non-polar dodecyl tail segments but exhibit different polar headgroups. The surfactants become soluble in water when anionic salts are formed through the deprotonation of the surfactant headgroups by the addition of potassium hydroxide. When either surfactant is exposed to temperature above about 60.degree. C., the retro Diels-Alder reaction occurs, yielding hydrophilic and hydrophobic fragments or the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.

  11. Ultrasound-Assisted Surfactant-Enhanced Emulsification Micro-Extraction Followed by HPLC for Determination of Preservatives in Water, Beverages and Personal Care Products.

    Science.gov (United States)

    Jan-E, Sudarat; Santaladchaiyakit, Yanawath; Burakham, Rodjana

    2017-01-01

    An ultrasound-assisted surfactant-enhanced emulsification micro-extraction (UASEME) procedure has been developed for pre-concentration of benzoic acid (BA) and paraben preservatives, including methylparaben, ethylparaben, propylparaben and butylparaben, prior to high-performance liquid chromatography-ultraviolet (HPLC-UV) analysis. Separations were performed on a Lichrospher RP-18 endcapped 5 µm, using an isocratic mobile phase of 40% acetonitile, at a flow rate of 1 mL min(-1) The selected UASEME conditions comprised the use of 10 mL sample extract, 125 µL 1-octanol as extraction solvent and 0.05 mmol L(-1) Tween 20 as emulsifier, 0.5% sodium chloride, ultrasonication time of 6 min and centrifugation time of 10 min. Method performance demonstrated wide linear range between 0.5 and 7,000 µg L(-1) (R(2) > 0.9903) and limits of detection between 0.03 and 10 µg L(-1), which providing the enrichment factors of 15-184. The method precision (relative standard deviation) was HPLC-UV has been successfully applied to determine four paraben preservatives in various sample matrices such as water, beverages and personal care products. The recoveries in the range of 70-138.1% were obtained. However, BA could not be determined in real sample extracts. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Microfluidic Synthesis Enables Dense and Uniform Loading of Surfactant-Free PtSn Nanocrystals on Carbon Supports for Enhanced Ethanol Oxidation.

    Science.gov (United States)

    Wu, Fuxiang; Zhang, Dongtang; Peng, Manhua; Yu, Zhihui; Wang, Xiayan; Guo, Guangsheng; Sun, Yugang

    2016-04-11

    Developing new synthetic methods for carbon supported catalysts with improved performance is of fundamental importance in advancing proton exchange membrane fuel cell (PEMFC) technology. Continuous-flow, microfluidic reactions in capillary tube reactors are described, which are capable of synthesizing surfactant-free, ultrafine PtSn alloyed nanoparticles (NPs) on various carbon supports (for example, commercial carbon black particles, carbon nanotubes, and graphene sheets). The PtSn NPs are highly crystalline with sizes smaller than 2 nm, and they are highly dispersed on the carbon supports with high loadings up to 33 wt%. These characteristics make the as-synthesized carbon-supported PtSn NPs more efficient than state of the art commercial Pt/C catalysts applied to the ethanol oxidation reaction (EOR). Significantly enhanced mass catalytic activity (two-times that of Pt/C) and improved stability are obtained. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Appraising options to reduce shallow groundwater tables and enhance flow conditions over regional scales in an irrigated alluvial aquifer system

    Science.gov (United States)

    Morway, Eric D.; Gates, Timothy K.; Niswonger, Richard G.

    2013-01-01

    Some of the world’s key agricultural production systems face big challenges to both water quantity and quality due to shallow groundwater that results from long-term intensive irrigation, namely waterlogging and salinity, water losses, and environmental problems. This paper focuses on water quantity issues, presenting finite-difference groundwater models developed to describe shallow water table levels, non-beneficial groundwater consumptive use, and return flows to streams across two regions within an irrigated alluvial river valley in southeastern Colorado, USA. The models are calibrated and applied to simulate current baseline conditions in the alluvial aquifer system and to examine actions for potentially improving these conditions. The models provide a detailed description of regional-scale subsurface unsaturated and saturated flow processes, thereby enabling detailed spatiotemporal description of groundwater levels, recharge to infiltration ratios, partitioning of ET originating from the unsaturated and saturated zones, and groundwater flows, among other variables. Hybrid automated and manual calibration of the models is achieved using extensive observations of groundwater hydraulic head, groundwater return flow to streams, aquifer stratigraphy, canal seepage, total evapotranspiration, the portion of evapotranspiration supplied by upflux from the shallow water table, and irrigation flows. Baseline results from the two regional-scale models are compared to model predictions under variations of four alternative management schemes: (1) reduced seepage from earthen canals, (2) reduced irrigation applications, (3) rotational lease fallowing (irrigation water leased to municipalities, resulting in temporary dry-up of fields), and (4) combinations of these. The potential for increasing the average water table depth by up to 1.1 and 0.7 m in the two respective modeled regions, thereby reducing the threat of waterlogging and lowering non-beneficial consumptive use

  14. Enhanced photocatalytic degradation of norfloxacin in aqueous Bi{sub 2}WO{sub 6} dispersions containing nonionic surfactant under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Lin, E-mail: tanglin@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Wang, Jiajia [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Zeng, Guangming, E-mail: zgming@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Liu, Yani; Deng, Yaocheng; Zhou, Yaoyu; Tang, Jing; Wang, Jingjing; Guo, Zhi [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China)

    2016-04-05

    Highlights: • TX100 strongly enhanced the adsorption and photodegradation of NOF in Bi{sub 2}WO{sub 6} dispersions under visible light irradiation (400–750 nm). • Cu{sup 2+} (10 mM) significantly suppressed the photocatalytic degradation of NOF. • FT-IR demonstrated that the NOF adsorbed on Bi{sub 2}WO{sub 6} was completely degraded. • Three possible photocatalytic degradation pathways of NOF were proposed, according to the HPLC/MS/MS analysis. - Abstract: Photocatalytic degradation is an alternative method to remove pharmaceutical compounds in water, however it is hard to achieve efficient rate because of the poor solubility of pharmaceutical compounds in water. This study investigated the photodegradation of norfloxacin in a nonionic surfactant Triton-X100 (TX100)/Bi{sub 2}WO{sub 6} dispersion under visible light irradiation (400–750 nm). It was found that the degradation of poorly soluble NOF can be strongly enhanced with the addition of TX100. TX100 was adsorbed strongly on Bi{sub 2}WO{sub 6} surface and accelerated NOF photodegradation at the critical micelle concentration (CMC = 0.25 mM). Higher TX100 concentration (>0.25 mM) lowered the degradation rate. In the presence of TX100, the degradation rate reached the maximum value when the pH value was 8.06. FTIR analyses demonstrated that the adsorbed NOF on the catalyst was completely degraded after 2 h irradiation. According to the intermediates identified by HPLC/MS/MS, three possible degradation pathways were proposed to include addition of hydroxyl radical to quinolone ring, elimination of piperazynilic ring in fluoroquinolone molecules, and replacement of F atoms on the aromatic ring by hydroxyl radicals.

  15. Interfacial behavior of pure surfactants for enhanced oil recovery. Part 1. A study on the adsorption and distribution of cetylbenzene sulfonate

    Energy Technology Data Exchange (ETDEWEB)

    Weihong Qiao; Liangjun Dong; Zhongkui Zhao; Jie Yang; Huamin Li; Zongshi Li [Dalian Univ. of Technology (China)

    2003-04-01

    The contents of pure alkyl benzene sulfonate surfactants in both the aqueous and oil phases were determined. The diffusion, adsorption and distribution of the surfactants in the oil and aqueous phases were studied at dynamic equilibrium and the effects of different structures on diffusion were investigated. N-nonane was used as the oil phase. The results indicate that the contents of the surfactants on both sides of the interface tend to increase with increasing sodium hydroxide and sodium chloride concentrations. The corresponding interfacial tensions, however, decrease gradually, and the quantities adsorbed at the oil-water interface reach a maximum value. The content of surfactant at the interface tends to be higher when the benzene ring is located near the middle of the carbon chain, so resulting in ultralow interfacial tension. (orig.)

  16. The importance of surfactant proteins-New aspects on macrophage phagocytosis.

    Science.gov (United States)

    Tschernig, Thomas; Veith, Nils T; Diler, Ebru; Bischoff, Markus; Meier, Carola; Schicht, Martin

    2016-11-01

    Surfactant and its components have multiple functions. The so called collectins are surfactant proteins which opsonize bacteria and improve pulmonary host defense via the phagocytosis and clearance of microorganisms and particles. In this special issue of the Annals of Anatomy a new surfactant protein, Surfactant Associated 3, is highlighted. As outlined in this mini review Surfactant Associated 3 is regarded as an enhancer of phagocytosis. In addition, the role played by SP-A is updated and open research questions raised.

  17. The Synergistic Effect of Anionic Surfactant on Adsorption Enhancement of the Carotenoids Extract using Mesoporous Hydroxyapatite Nanoparticles

    Directory of Open Access Journals (Sweden)

    Supalak Kongsri

    2015-09-01

    Full Text Available Fish hydroxyapatite (FHAp was prepared from fish scale waste by alkaline heat treatment. The obtained nanoparticles (21 nm of FHAp with high crystallinity (89.5% were used as biocompatible adsorbent for an adsorption of plant carotenoids extract. For optimum conditions of batch adsorption study, experimental parameters including pH of solution, adsorbent dosage, an initial concentration of carotenoids, amount of sodium dodecyl sulfate (SDS, contact time and temperature were investigated in details. From the results, the carotenoids adsorption of the FHAp was drastically enhanced in the presence of SDS through their hydrophobic interactions between the carotenoids and the cationic element FHAp via the anionic head of SDS by electrostatic and ion-exchange interactions and surface complexation. The adsorption behaviors fitted well by pseudo-second order kinetic model and Freundlich adsorption isotherm. Thermodynamic data demonstrated that the adsorption behaviors of the carotenoids on the hydroxyapatite nanoparticles were spontaneously endothermic and physisorption process.

  18. Property Changes in Aqueous Solutions due to Surfactant Treatment of PCE: Implications to Geophysical Measurements

    Science.gov (United States)

    Werkema, D. D.

    2007-12-01

    Select physicochemical properties of aqueous solutions composed of surfactants, dye, and perchloroethylene (PCE) were evaluated through a response surface quadratic design model of experiment. Nine surfactants, which are conventionally used in the remediation of PCE, were evaluated with varying concentrations of PCE and indicator dyes in aqueous solutions. Two hundred forty experiments were performed using PCE as a numerical factor (coded A) from 0 to 200 parts per million (ppm), dye type (coded B) as a 3-level categorical factor, and surfactant type (coded C) as a 10-level categorical factor. Five responses were measured: temperature (°C), pH, conductivity (μS/cm), dissolved oxygen (DO, mg/L), and density (g/mL). Diagnostics proved a normally distributed predictable response for all measured responses except pH. The Box-Cox plot for transforms recommended a power transform for the conductivity response with lambda (λ) = 0.50, and for the DO response, λ =2.2. The overall mean of the temperature response proved to be a better predictor than the linear model. The conductivity response is best fitted with a linear model using significant coded terms B and C. Both DO and density also showed a linear model with coded terms A, B, and C for DO; and terms A and C for density. Some of the surfactant treatments of PCE significantly alter the conductivity, DO, and density of the aqueous solution. However, the magnitude of the density response is so small that it does not exceed the instrument tolerance. Results for the conductivity and DO responses provide predictive models for the surfactant treatment of PCE and may be useful in determining the potential for geophysically monitoring surfactant enhanced aquifer remediation (SEAR) of PCE. As the aqueous physicochemical properties change due to surfactant remediation efforts, so will the properties of the subsurface pore water which are influential factors in geophysical measurements. Geoelectrical methods are potentially

  19. Vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction with solidification of floating organic droplet combined with flame atomic absorption spectrometry for the fast determination of cadmium in water samples.

    Science.gov (United States)

    Peng, Guilong; Lu, Ying; He, Qiang; Mmereki, Daniel; Tang, Xiaohui; Zhong, Zhihui; Zhao, Xiaolong

    2016-01-01

    A novel vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction with solidification of floating organic droplet (VSLLME-SFO) was developed for the fast, simple and efficient determination of cadmium (Cd) in water samples followed by flame atomic absorption spectrometry (FAAS). In the VSLLME-SFO process, the addition of surfactant (as an emulsifier), could enhance the mass transfer from the aqueous solution into the extraction solvent. The extraction solvent could be dispersed into the aqueous phase under vigorous shaking with the vortex. In this paper, we investigated the influences of analytical parameters, including pH, extraction solvent type and its volume, surfactant type and its volume, concentration of chelating agent, salt effect and vortex time, on the extraction efficiency of Cd. Under the optimized conditions, the limit of detection was 0.16 μg/L. The analyte enrichment factor was 37.68. The relative standard deviation was 3.2% (10 μg/L, n = 10) and the calibration graph was linear, ranging from 0.5 to 30 μg/L. The proposed method was successfully applied for the analysis of ultra-trace Cd in river water and wastewater samples.

  20. Low-density solvent-based vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction combined with gas chromatography-mass spectrometry for the fast determination of phthalate esters in bottled water.

    Science.gov (United States)

    Zhang, Yufeng; Lee, Hian Kee

    2013-01-25

    For the first time, a novel low-density solvent-based vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction (LDS-VSLLME) was developed for the fast, simple and efficient determination of six phthalate esters (PEs) in bottled water samples followed by gas chromatography-mass spectrometry (GC-MS). In the extraction procedure, the aqueous sample solution was injected into a mixture of extraction solvent (toluene) and surfactant (cetyltrimethyl ammonium bromide), which were placed in a glass tube with conical bottom, to form an emulsion by the assistance of vortex agitation. After extraction and phase separation by centrifugation, and removal of the spent sample, the toluene extract was collected and analyzed by GC-MS. The addition of surfactant enhanced the dispersion of extraction solvent in aqueous sample and was also favorable for the mass transfer of the analytes from the aqueous sample to the extraction solvent. Moreover, using a relatively less toxic surfactant as the emulsifier agent overcame the disadvantages of traditional organic dispersive solvents that are usually highly toxic and expensive and might conceivably decrease extraction efficiency to some extent since they are not as effective as surfactants themselves in generating an emulsion. With the aid of surfactant and vortex agitation to achieve good organic extraction solvent dispersion, extraction equilibrium was achieved within 1 min, indicating it was a fast sample preparation technique. Another prominent feature of the method was the simple procedure to collect a less dense than water solvent by a microsyringe. After extraction and phase separation, the aqueous sample was removed using a 5-mL syringe, thus leaving behind the extract, which was retrieved easily. This novel method simplifies the use of low-density solvents in DLLME. Under the optimized conditions, the proposed method provided good linearity in the range of 0.05-25 μg/L, low limits of detection (8-25 ng

  1. Novel mixed metal Ag(I)-Sb(III)-metallotherapeutics of the NSAIDs, aspirin and salicylic acid: Enhancement of their solubility and bioactivity by using the surfactant CTAB.

    Science.gov (United States)

    Gkaniatsou, E I; Banti, C N; Kourkoumelis, N; Skoulika, S; Manoli, M; Tasiopoulos, A J; Hadjikakou, S K

    2015-09-01

    The already known Ag(I)-Sb(III) compound of the formula {Ag(Ph3Sb)3(NO3)} (1) and two novel mixed metal Ag(I)-Sb(III) metallotherapeutics of the formulae {Ag(Ph3Sb)3(SalH)}(2) and {Ag(Ph3Sb)3(Asp)}(3) (SalH2=salicylic acid, AspH=aspirin or 2-acetylsalicylic acid and Ph3Sb=triphenyl antimony(III)) have been synthesised and characterised by m.p., vibrational spectroscopy (mid-FT-IR), (13)C-,(1)H-NMR, UV-visible (UV-vis) spectroscopic techniques, high resolution mass spectroscopy (HRMS) and X-ray crystallography. Compounds 1,-3 were treated with the surfactant cetyltrimethylammonium bromide (CTAB) in order to enhance their solubility and as a consequence their bioactivity. The resulting micelles a-c were characterised with X-ray powder diffraction (XRPD) analysis, X-ray fluorescence (XRF) spectroscopy, Energy-dispersive X-ray spectroscopy (EDX), conductivity, Thermal gravimetry-differential thermal analysis (TG-DTA), and atomic absorption. Compounds 1-3 and the relevant micelles a-c were evaluated for their in vitro cytotoxic activity against human cancer cell lines: MCF-7 (breast, estrogen receptor (ER) positive), MDA-MB-231 (breast, ER negative) and MRC-5 (normal human fetal lung fibroblast cells) with sulforhodamine B (SRB) colorimetric assay. The results show significant increase in the activity of micelles compared to that of the initial compounds. Moreover, micelles exhibited lower activity against normal cells than tumor cells. The binding affinity of a-c towards the calf thymus (CT)-DNA, lipoxygenase (LOX) and glutathione (GSH) was studied by the fluorescent emission light and UV-vis spectroscopy.

  2. The Synergetic Enhancement Foaming Properties in Mixed Zwitterionic and Anionic Surfactant Systems%两性/阴离子型表面活性剂协同增强起泡性能研究

    Institute of Scientific and Technical Information of China (English)

    路传波; 张炳花; 李丙成; 郑祖业; 王汉威; 范海明; 康万利

    2015-01-01

    利用 Waring Blender 法研究了不同矿化度下两性离子表面活性剂十六烷基磺基甜菜碱(HDPS)与阴离子型表面活性剂十二烷基硫酸钠(SDS)单一体系和复配体系的起泡性能,分析了两性/阴离子型表面活性剂间相互作用对起泡性能的影响。结果表明,由于两性和阴离子型表面活性剂亲水基间的静电吸引作用既增强了复配体系的表面活性,又促进了复配体系在气液表面形成更加紧密的吸附膜,因而在清水和高矿化度水质中,HDPS/SDS复配体系的泡沫综合指数均高于单一表面活性剂体系,表现出协同增强泡沫性能的作用。%The foam properties of single and mixed surfactant systems prepared by zwitterionic surfactant N-hexadecyl-N,N-dimethyl-3-ammonio-1-propane sulfonate (HDPS)and anionic surfactant sodium dodecyl sulfate(SDS)were investigated by Waring Blender method.And the effect of intermolecular interaction between HDPS and SDS on the foam properties was analyzed.It has been found that the electrostatic attraction between the headgroups of HDPS and SDS not only reinforces the surface activity but also promotes the formation of compacted adsorption film in the gas-liquid surface for the mixed surfactant system.Therefore the foam comprehensive exponents of mixed HDPS and SDS surfactant systems are higher than that of each single surfactant in clean water and highly mineralized water,which exhibits the synergetic enhancement foaming properties.

  3. Tunable, antibacterial activity of silicone polyether surfactants.

    Science.gov (United States)

    Khan, Madiha F; Zepeda-Velazquez, Laura; Brook, Michael A

    2015-08-01

    Silicone surfactants are used in a variety of applications, however, limited data is available on the relationship between surfactant structure and biological activity. A series of seven nonionic, silicone polyether surfactants with known structures was tested for in vitro antibacterial activity against Escherichia coli BL21. The compounds varied in their hydrophobic head, comprised of branched silicone structures with 3-10 siloxane linkages and, in two cases, phenyl substitution, and hydrophilic tail of 8-44 poly(ethylene glycol) units. The surfactants were tested at three concentrations: below, at, and above their Critical Micelle Concentrations (CMC) against 5 concentrations of E. coli BL21 in a three-step assay comprised of a 14-24h turbidometric screen, a live-dead stain and viable colony counts. The bacterial concentration had little effect on antibacterial activity. For most of the surfactants, antibacterial activity was higher at concentrations above the CMC. Surfactants with smaller silicone head groups had as much as 4 times the bioactivity of surfactants with larger groups, with the smallest hydrophobe exhibiting potency equivalent to sodium dodecyl sulfate (SDS). Smaller PEG chains were similarly associated with higher potency. These data link lower micelle stability and enhanced permeability of smaller silicone head groups to antibacterial activity. The results demonstrate that simple manipulation of nonionic silicone polyether structure leads to significant changes in antibacterial activity.

  4. Selection of surfactant in remediation of DDT-contaminated soil by comparison of surfactant effectiveness.

    Science.gov (United States)

    Guo, Ping; Chen, Weiwei; Li, Yueming; Chen, Tao; Li, Linhui; Wang, Guanzhu

    2014-01-01

    With an aim to select the most appropriate surfactant for remediation of DDT-contaminated soil, the performance of nonionic surfactants Tween80, TX-100, and Brij35 and one anionic surfactant sodium dodecyl benzene sulfonate (SDBS) in enhancement of DDT water solubility and desorption of DDT from contaminated soil and their adsorption onto soil and ecotoxicities were investigated in this study. Tween80 had the highest solubilizing and soil-washing ability for DDT among the four experimental surfactants. The adsorption loss of surfactants onto soil followed the order of TX-100 > Tween80 > Brij35 > SDBS. The ecotoxicity of Tween80 to ryegrass (Lolium perenne L.) was lowest. The overall performance considering about the above four aspects suggested that Tween80 should be selected for the remediation of DDT-contaminated soil, because Tween80 had the greatest solubilizing and soil-washing ability for DDT, less adsorption loss onto soil, and the lowest ecotoxicity in this experiment.

  5. Synthesis and properties evaluation of sulfobetaine surfactant with double hydroxyl

    Science.gov (United States)

    Zhou, Ming; Luo, Gang; Zhang, Ze; Li, Sisi; Wang, Chengwen

    2017-09-01

    A series of sulfobetaine surfactants {N-[(3-alkoxy-2-hydroxyl)propoxy] ethyl-N,N-dimethyl-N-(2-hydroxyl)propyl sulfonate} ammonium chloride were synthesized with raw materials containing linear saturated alcohol, N,N-dimethylethanolamine, sodium 3-chloro-2-hydroxyl propane sulfonic acid and epichlorohydrin. The molecule structures of sulfobetaine surfactants were characterized by FTIR, 1HNMR and elemental analysis. Surface tension measurements can provide us information about the surface tension at the CMC (γCMC), pC20, Γmax and Amin. The pC20 values of sulfobetaine surfactants increase with the hydrophobic chain length increasing. Amin values of the surfactants decrease with increasing hydrophobic chain length from 10 to 14. The critical micelle concentration (CMC) and surface tension (γCMC) values of the sulfobetaine surfactants decrease with increasing hydrophobic chain length from 10 to 16. The lipophilicity of surfactant was enhanced with the increase of the carbon chain, however, the ability of anti-hard water was weakened. The minimum oil/water interfacial tension of four kinds of sulfobetaine surfactants is 10-2-10-3 mN/m magnitude, which indicates that the synthesized bis-hydroxy sulfobetaine surfactants have a great ability to reduce interfacial tension in the surfactant flooding system. The surface tension (γCMC) values of synthesized surfactants were lower compared with conventional anionic surfactant sodium dodecyl sulfonate.

  6. Pulmonary surfactant adsorption is increased by hyaluronan or polyethylene glycol.

    Science.gov (United States)

    Taeusch, H William; Dybbro, Eric; Lu, Karen W

    2008-04-01

    In acute lung injuries, inactivating agents may interfere with transfer (adsorption) of pulmonary surfactants to the interface between air and the aqueous layer that coats the interior of alveoli. Some ionic and nonionic polymers reduce surfactant inactivation in vitro and in vivo. In this study, we tested directly whether an ionic polymer, hyaluronan, or a nonionic polymer, polyethylene glycol, enhanced adsorption of a surfactant used clinically. We used three different methods of measuring adsorption in vitro: a modified pulsating bubble surfactometer; a King/Clements device; and a spreading trough. In addition we measured the effects of both polymers on surfactant turbidity, using this assay as a nonspecific index of aggregation. We found that both hyaluronan and polyethylene glycol significantly increased the rate and degree of surfactant material adsorbed to the surface in all three assays. Hyaluronan was effective in lower concentrations (20-fold) than polyethylene glycol and, unlike polyethylene glycol, hyaluronan did not increase apparent aggregation of surfactant. Surfactant adsorption in the presence of serum was also enhanced by both polymers regardless of whether hyaluronan or polyethylene glycol was included with serum in the subphase or added to the surfactant applied to the surface. Therefore, endogenous polymers in the alveolar subphase, or exogenous polymers added to surfactant used as therapy, may both be important for reducing inactivation of surfactant that occurs with various lung injuries.

  7. Enhancements to the Mississippi Embayment Regional Aquifer Study (MERAS) groundwater-flow model and simulations of sustainable water-level scenarios

    Science.gov (United States)

    Clark, Brian R.; Westerman, Drew A.; Fugitt, D. Todd

    2013-01-01

    Arkansas continues to be one of the largest users of groundwater in the Nation. As such, long-term planning and management are essential to ensure continued availability of groundwater and surface water for years to come. The Mississippi Embayment Regional Aquifer Study (MERAS) model was developed previously as a tool to evaluate groundwater availability within the Mississippi embayment, which encompasses much of eastern Arkansas where the majority of groundwater is used. The Arkansas Water Plan is being updated for the first time since 1990 and serves as the State’s primary, comprehensive water-resources planning and guidance document. The MERAS model was selected as the best available tool for evaluation of specific water-use pumping scenarios that are currently being considered by the State of Arkansas. The model, developed as part of the U.S. Geological Survey Groundwater Resources Program’s assessment of the Nation’s groundwater availability, is proving to be invaluable to the State as it works toward development of a sustained yield pumping strategy. One aspect of this investigation was to evaluate multiple methods to improve the match of observed to simulated groundwater levels within the Mississippi River Valley alluvial and middle Claiborne (Sparta) aquifers in the MERAS model. Five primary methods were evaluated: (1) explicit simulation of evapotranspiration (ET), (2) upgrade of the Multi-Node Well (MNW2) Package, (3) geometry improvement within the Streamflow Routing (SFR) Package, (4) parameter estimation of select aquifer properties with pilot points, and (5) modification of water-use estimates. For the planning purposes of the Arkansas Water Plan, three scenarios were developed to evaluate potential future conditions: (1) simulation of previously optimized pumping values within the Mississippi River Valley alluvial and the middle Claiborne aquifers, (2) simulated prolonged effects of pumping at average recent (2000–5) rates, and (3) simulation

  8. Hydrogeologic Heterogeneity Enhances the Transfer of Salt Toward the High-Quality Deep Aquifers of the Western San Joaquin Valley (CA, USA)

    Science.gov (United States)

    Henri, C. V.; Harter, T.; Zhang, H.

    2016-12-01

    Increasing anthropogenic and drought stresses lead salinity to be of serious concern within regard to with the sustainability of regional groundwater quality. Agricultural basins of the Central Valley, CA (USA) are, and will continue to be, impacted by salinity issues in the coming future decades and or centuries. The aquifer system below the Western San Joaquin Valley is characterized by a shallow unconfined aquifer with high salinity overlying high quality semi-confined and deeper confined aquifers. A key challenge in the area is to predict if, when and how water traveling from the the low-quality shallow groundwater will reach and degrade the deeper semi-confined and confined aquifers. Previous studies, accounting for a simplified description of the aquifer hydraulic properties in their flow model, concluded that saline shallow groundwater would need 200-400 years to reach the semi-confined aquifer and 250-600 years to impact the deeper confined aquifer. However, well known heterogeneities in aquifer hydraulic properties significantly impact contaminant transport due to preferential flow paths and increased dispersion. Our study aims to (1) better understand the impact of heterogeneous hydraulic properties on the distribution of travel times from non-point source contamination, and (2) reassess the temporal scale of salt transfer into the deeper aquifers of the Western San Joaquin Valley. A detailed non-stationary geostatistical model was developed to describe the spatial variability of hydrofacies in great detail at the basin scale. The hydraulic properties corresponding to each hydrofacies are then calibrated in order to reproduce water fluxes previously modeled and calibrated. Subsequently, we use the random-walk particle tracking method to simulate the advective-dispersive transport of salt throughout the study area from a non-point source zone represented by the entire top layer of the model. The flux concentrations of solute crossing a series of monitoring

  9. Influence of surfactants in forced dynamic dewetting.

    Science.gov (United States)

    Henrich, Franziska; Fell, Daniela; Truszkowska, Dorota; Weirich, Marcel; Anyfantakis, Manos; Nguyen, Thi-Huong; Wagner, Manfred; Auernhammer, Günter K; Butt, Hans-Jürgen

    2016-09-20

    In this work we show that the forced dynamic dewetting of surfactant solutions depends sensitively on the surfactant concentration. To measure this effect, a hydrophobic rotating cylinder was horizontally half immersed in aqueous surfactant solutions. Dynamic contact angles were measured optically by extrapolating the contour of the meniscus to the contact line. Anionic (sodium 1-decanesulfonate, S-1DeS), cationic (cetyl trimethylammonium bromide, CTAB) and nonionic surfactants (C4E1, C8E3 and C12E5) with critical micelle concentrations (CMCs) spanning four orders of magnitude were used. The receding contact angle in water decreased with increasing velocity. This decrease was strongly enhanced when adding surfactant, even at surfactant concentrations of 10% of the critical micelle concentration. Plots of the receding contact angle-versus-velocity almost superimpose when being plotted at the same relative concentration (concentration/CMC). Thus the rescaled concentration is the dominating property for dynamic dewetting. The charge of the surfactants did not play a role, thus excluding electrostatic effects. The change in contact angle can be interpreted by local surface tension gradients, i.e. Marangoni stresses, close to the three-phase contact line. The decrease of dynamic contact angles with velocity follows two regimes. Despite the existence of Marangoni stresses close to the contact line, for a dewetting velocity above 1-10 mm s(-1) the hydrodynamic theory is able to describe the experimental results for all surfactant concentrations. At slower velocities an additional steep decrease of the contact angle with velocity was observed. Particle tracking velocimetry showed that the flow profiles do not differ with and without surfactant on a scales >100 μm.

  10. Surfactants in tribology

    CERN Document Server

    Biresaw, Girma

    2014-01-01

    Surface science and tribology play very critical roles in many industries. Manufacture and use of almost all consumer and industrial products rely on the application of advanced surface and tribological knowledge. The fourth in a series, Surfactants in Tribology, Volume 4 provides an update on research and development activities connecting surfactants and tribological phenomena. Written by renowned subject matter experts, the book demonstrates how improved design of surfactants can be harnessed to control tribological phenomena. Profusely illustrated and copiously referenced, the chapters also

  11. Surfactant Supplementation to Enhance the Production of Vitamin K2 Metabolites in Shake Flask Cultures Using Escherichia sp. Mutant FM3-1709

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2014-01-01

    Full Text Available The effects of the addition of various surfactants on the cell growth and production of vitamin K2 metabolites, such as intracellular menaquinone-4 (MK-4, extracellular MK-4, intracellular MK-6 and extracellular MK-6, were studied in the submerged culture of Escherichia sp. All of the added surfactants caused the extension of the exponential phase. Betaine, polyoxyethylene oleyl ether and Tween-80 were favourable to the cell growth of Escherichia sp. mutant strain FM3-1709. The highest cell growth (Xmax, biomass production rate (Qx and biomass yield (Yx/s were (12.6±0.2 g/L, (0.21±0.01 g/(L·h and (2.42± 0.02 g/g, respectively. The results show that the addition of all surfactants led to a lower production of intracellular MK-4, whereas the production of extracellular MK-4 increased remarkably. Among the five investigated surfactants, the addition of the nonionic surfactant polyoxyethylene oleyl ether (1.0 g/L led to the highest production of extracellular MK-4 ((33.6±0.4 mg/L, MK-6 ((2.56±0.07 mg/L and the highest yield of total MK-4 ((47.6±0.4 mg/L and MK-6 ((6.0±0.1 mg/L. The addition of polyoxyethylene oleyl ether proved to be more beneficial for the secretion of MK-4 than MK-6.

  12. POLYMERIC SURFACTANT STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    P.M. Saville; J.W. White

    2001-01-01

    Polymeric surfactants are amongst the most widespread of all polymers. In nature, proteins and polysaccharides cause self organization as a result of this surfactancy; in industry, polymeric surfactants play key roles in the food, explosives and surface coatings sectors. The generation of useful nano- and micro-structures in films and emulsions as a result of polymer amphiphilicity and the application of mechanical stress is discussed. The use of X-ray and neutron small angle scattering and reflectivity to measure these structures and their dynamic properties will be described. New results on linear and dendritic polymer surfactants are presented.

  13. Dendrimer-surfactant interactions.

    Science.gov (United States)

    Cheng, Yiyun; Zhao, Libo; Li, Tianfu

    2014-04-28

    In this article, we reviewed the interactions between dendrimers and surfactants with particular focus on the interaction mechanisms and physicochemical properties of the yielding dendrimer-surfactant aggregates. In order to provide insight into the behavior of dendrimers in biological systems, the interactions of dendrimers with bio-surfactants such as phospholipids in bulk solutions, in solid-supported bilayers and at the interface of phases or solid-states were discussed. Applications of the dendrimer-surfactant aggregates as templates to guide the synthesis of nanoparticles and in drug or gene delivery were also mentioned.

  14. Surfactant Sector Needs Urgent Readjustment

    Institute of Scientific and Technical Information of China (English)

    Huang Hongzhou

    2007-01-01

    @@ Surfactant industrial system has been basically established After 50 years' development, China has already established a surfactant industrial system with a relatively complete product portfolio and can produce 4714 varieties of surfactants in cationic,anionic, nonionic and amphoteric categories.

  15. Use of surfactants for the remediation of contaminated soils: a review.

    Science.gov (United States)

    Mao, Xuhui; Jiang, Rui; Xiao, Wei; Yu, Jiaguo

    2015-03-21

    Due to the great harm caused by soil contamination, there is an increasing interest to apply surfactants to the remediation of a variety of contaminated soils worldwide. This review article summarizes the findings of recent literatures regarding remediation of contaminated soils/sites using surfactants as an enhancing agent. For the surfactant-based remedial technologies, the adsorption behaviors of surfactants onto soil, the solubilizing capability of surfactants, and the toxicity and biocompatibility of surfactants are important considerations. Surfactants can enhance desorption of pollutants from soil, and promote bioremediation of organics by increasing bioavailability of pollutants. The removal of heavy metals and radionuclides from soils involves the mechanisms of dissolution, surfactant-associated complexation, and ionic exchange. In addition to the conventional ionic and nonionic surfactants, gemini surfactants and biosurfactants are also applied to soil remediation due to their benign features like lower critical micelle concentration (CMC) values and better biocompatibility. Mixed surfactant systems and combined use of surfactants with other additives are often adopted to improve the overall performance of soil washing solution for decontamination. Worldwide the field studies and full-scale remediation using surfactant-based technologies are yet limited, however, the already known cases reveal the good prospect of applying surfactant-based technologies to soil remediation.

  16. Influence of operating parameters on surfactant-enhanced washing to remedy PAHs contaminated soil%工艺参数对表面活性剂洗涤修复PAHs污染土壤的影响

    Institute of Scientific and Technical Information of China (English)

    吴威; 陈家军; 彭胜

    2012-01-01

    Surfactant-enhanced(TritonX-100 and Tween-80) soil washing technology was applied to investigate the influence of stirring speed,washing time,surfactant concentration,liquid/solid ratio,temperature,and on-and-off mode on the final removal of PAHs from contaminated soil.The optimum operating parameters were gained through a series of beaker experiments.The optimum washing time is 30 and 60 min respectively with TritonX-100 and Tween-80 as surfactant.As far other process parameters,the optimum value is the same with TritonX-100 or Tween-80.The optimum values of stirring speed,surfactant concentration,liquid/solid ratio,temperature,and on-and-off mode are 250 r/min,5 g/L,room temperature and continuous stirring,respectively.The overall residual ratio is less than 10 % under the conditions of above obtained optimum parameter values,which is basically in compliance with the remediation goals for five target PAHs.Therefore,it is very reasonable and feasible to apply surfactant-enhanced soil washing to remedy PAHs contaminated soil.%采用土壤洗涤(soil-washing)技术,分别用TritonX-100和Tween-80为强化洗涤剂研究了搅拌强度、洗涤时间、表面活性剂浓度、液固比、温度和间歇搅拌6个工艺参数对PAHs污染土壤洗涤效果的影响。通过一系列烧杯搅拌实验得到最佳洗涤工艺参数。TritonX-100和Tween-80的最佳洗涤时间分别是30 min和60 min,其他工艺参数最佳条件均相同。分别是搅拌强度为250 r/min,表面活性剂浓度为5 g/L,液固比为10∶1,温度为室温和连续搅拌。在此最佳工艺参数条件下,污染土中PAHs的残留率〈10%,基本上满足目标污染物的修复目标。应用表面活性剂强化洗涤技术修复PAHs污染土壤是合理和可行的。

  17. Effects of Surfactant Adsorption on Surficial Wettability of Nonwoven Fabrics

    Institute of Scientific and Technical Information of China (English)

    CAI Bing; TANG Bing; LI Rui-xia; WU Da-cheng

    2002-01-01

    All types of surfactants (cationic, anionic and nonionic)reported in this paper could enhance the surficiai wettability of polypropylene (PP) and polyethylene terephthalate (PET) nonwoven fabrics. However, the effects of cationic and nonionic surfactants were better.The longer the treatment time of surfactants on the nonwoven fabrics, the better the surficial wettability.The surficial rewetting time would no longer change above a certain treatment time. The rewettability of nonwoven fabrics could be evidently improved just when the concentration of surfactants was just above the CMC,except for sodium dodecylbenzene sulfonate (LAS). The finer the fibers and the looser the structures, the better the surficial rewettability of nonwoven fabrics.

  18. Ultrasound-assisted surfactant-enhanced emulsification microextraction based on the solidification of a floating organic droplet used for the simultaneous determination of six fungicide residues in juices and red wine.

    Science.gov (United States)

    You, Xiangwei; Wang, Suli; Liu, Fengmao; Shi, Kaiwei

    2013-07-26

    A novel ultrasound-assisted surfactant-enhanced emulsification microextraction technique based on the solidification of a floating organic droplet followed by high performance liquid chromatography with diode array detection was developed for simultaneous determination of six fungicide residues in juices and red wine samples. The low-toxicity solvent, 1-dodecanol, was used as an extraction solvent. For its low density and proper melting point near room temperature, the extractant droplet was collected easily by solidifying it at a low temperature. The surfactant, Tween 80, was used as an emulsifier to enhance the dispersion of the water-immiscible extraction solvent into an aqueous phase, which hastened the mass-transfer of the analytes. Organic dispersive solvent typically required in common dispersive liquid-liquid microextraction methods was not used in the proposed method. Some parameters (e.g., the type and volume of extraction solvent, the type and concentration of surfactant, ultrasound extraction time, salt addition, and volume of samples) that affect the extraction efficiency were optimized. The proposed method showed a good linearity within the range of 5μgL(-1)-1000μgL(-1), with the correlation coefficients (γ) higher than 0.9969. The limits of detection for the method ranged from 0.4μgL(-1) to 1.4μgL(-1). Further, this simple, practical, sensitive, and environmentally friendly method was successfully applied to determine the target fungicides in juice and red wine samples. The recoveries of the target fungicides in red wine and fruit juice samples were 79.5%-113.4%, with relative standard deviations that ranged from 0.4% to 12.3%.

  19. Branched alkyl alcohol propoxylated sulfate surfactants for improved oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Y.; Iglauer, S.; Shuler, P.; Tang, Y. [California Institute of Technology, Covina, CA (US). Power, Environmental and Energy Research (PEER) Center; Goddard, W.A. III [California Institute of Technology, Pasadena, CA (United States). Materials and Process Simulation Center

    2010-05-15

    This investigation considers branched alkyl alcohol propoxylated sulfate surfactants as candidates for chemical enhanced oil recovery (EOR) applications. Results show that these anionic surfactants may be preferred candidates for EOR as they can be effective at creating low interfacial tension (IFT) at dilute concentrations, without requiring an alkaline agent or cosurfactant. In addition, some of the formulations exhibit a low IFT at high salinity, and hence may be suitable for use in more saline reservoirs. Adsorption tests onto kaolinite clay indicate that the loss of these surfactants can be comparable to or greater than other types of anionic surfactants. Surfactant performance was evaluated in oil recovery core flood tests. Selected formulations recovered 35-50% waterflood residual oil even with dilute 0.2 wt% surfactant concentrations from Berea sandstone cores. (orig.)

  20. SURFACTANTS IN LUBRICATION

    Science.gov (United States)

    Surfactants are one of the most widely applied materials by consumers and industry. The application areas for surfactants span from everyday mundane tasks such as cleaning, to highly complex processes involving the formulation of pharmaceuticals, foods, pesticides, lubricants, etc. Even though sur...

  1. Dynamic covalent surfactants

    NARCIS (Netherlands)

    Minkenberg, C.B.

    2012-01-01

    In this thesis the development of surfactant aggregates with fast exchange dynamics between the aggregated and non-aggregated state is described. Dynamic surfactant exchange plays an important role in natural systems, for instance in cell signaling, cell division, and uptake and release of cargo. Re

  2. Use of surfactants for the remediation of contaminated soils: A review

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Xuhui, E-mail: clab@whu.edu.cn [School of Resource and Environmental Science, Wuhan University, Wuhan 430072 (China); Jiang, Rui; Xiao, Wei [School of Resource and Environmental Science, Wuhan University, Wuhan 430072 (China); Yu, Jiaguo, E-mail: jiaguoyu@yahoo.com [State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

    2015-03-21

    Highlights: • The recent advances in use of surfactant for soil remediation are reviewed. • The mechanisms of surfactant-based soil remediation are discussed. • A review on the application of different types of surfactants is made. • The future research direction of surfactant-based technologies is suggested. - Abstract: Due to the great harm caused by soil contamination, there is an increasing interest to apply surfactants to the remediation of a variety of contaminated soils worldwide. This review article summarizes the findings of recent literatures regarding remediation of contaminated soils/sites using surfactants as an enhancing agent. For the surfactant-based remedial technologies, the adsorption behaviors of surfactants onto soil, the solubilizing capability of surfactants, and the toxicity and biocompatibility of surfactants are important considerations. Surfactants can enhance desorption of pollutants from soil, and promote bioremediation of organics by increasing bioavailability of pollutants. The removal of heavy metals and radionuclides from soils involves the mechanisms of dissolution, surfactant-associated complexation, and ionic exchange. In addition to the conventional ionic and nonionic surfactants, gemini surfactants and biosurfactants are also applied to soil remediation due to their benign features like lower critical micelle concentration (CMC) values and better biocompatibility. Mixed surfactant systems and combined use of surfactants with other additives are often adopted to improve the overall performance of soil washing solution for decontamination. Worldwide the field studies and full-scale remediation using surfactant-based technologies are yet limited, however, the already known cases reveal the good prospect of applying surfactant-based technologies to soil remediation.

  3. Synergistic effect of low-frequency ultrasound and surfactants on skin permeability.

    Science.gov (United States)

    Tezel, Ahmet; Sens, Ashley; Tuchscherer, Joe; Mitragotri, Samir

    2002-01-01

    Low-frequency ultrasound (20 kHz) and surfactants have been individually shown to enhance transdermal drug transport. In this study, we investigated the synergistic effect of ultrasound and surfactants on transdermal drug delivery. Surfactants with different head group chemistries including anionic, cationic, and nonionic with varying tail lengths (8-16-carbon atoms) were studied. We found that surfactants possessing anionic and cationic head groups were more potent than those possessing nonionic head groups in increasing skin conductivity in the presence of ultrasound. Furthermore, for surfactants possessing the same head group, those with a 14-carbon tail length were found to be most effective in enhancing skin permeability. The data presented in this report show that ultrasound and surfactants synergistically enhance skin permeability. Two mechanisms are shown to play a role in this synergistic effect. First, ultrasound enhances surfactant delivery (enhanced delivery) into the skin and, second, ultrasound disperses surfactant (enhanced dispersion) within the skin. In general, surfactants that are potent enhancers by themselves are potent enhancers in the presence of ultrasound as well. We performed imaging experiments to assess the effect of ultrasound on delivery of a model permeant, sulforhodamine B, into the skin. These experiments show that ultrasound enhances surfactant delivery and dispersion in the skin.

  4. EFFECTS OF SURFACTANTS ON FLUORANTHENE MINERALIZATION BY SPHINGOMONAS PAUCIMOBILIS STRAIN EPA 505

    Science.gov (United States)

    Past results from surfactant-enhanced biodegradation studies have been equivocal because of inhibitory effects of the surfactants and a poor understanding of the characteristics of PAH-degrading microorganisms that make them responsive to surfactants. We have studied the minerali...

  5. Surfactant process for promoting gas hydrate formation and application of the same

    Science.gov (United States)

    Rogers, Rudy E.; Zhong, Yu

    2002-01-01

    This invention relates to a method of storing gas using gas hydrates comprising forming gas hydrates in the presence of a water-surfactant solution that comprises water and surfactant. The addition of minor amounts of surfactant increases the gas hydrate formation rate, increases packing density of the solid hydrate mass and simplifies the formation-storage-decomposition process of gas hydrates. The minor amounts of surfactant also enhance the potential of gas hydrates for industrial storage applications.

  6. Surfactants in the environment.

    Science.gov (United States)

    Ivanković, Tomislav; Hrenović, Jasna

    2010-03-01

    Surfactants are a diverse group of chemicals that are best known for their wide use in detergents and other cleaning products. After use, residual surfactants are discharged into sewage systems or directly into surface waters, and most of them end up dispersed in different environmental compartments such as soil, water or sediment. The toxic effects of surfactants on various aquatic organisms are well known. In general, surfactants are present in the environment at levels below toxicity and in Croatia below the national limit. Most surfactants are readily biodegradable and their amount is greatly reduced with secondary treatment in wastewater treatment plants. The highest concern is the release of untreated wastewater or wastewater that has undergone primary treatment alone. The discharge of wastewater polluted with massive quantities of surfactants could have serious effects on the ecosystem. Future studies of surfactant toxicities and biodegradation are necessary to withdraw highly toxic and non-biodegradable compounds from commercial use and replace them with more environmentally friendly ones.

  7. Pulmonary surfactant and lung transplantation

    NARCIS (Netherlands)

    Erasmus, Michiel Elardus

    1997-01-01

    Pulmonary surfactant lowers the surface tension at the air-water interface inside the alveolus. This is achieved by adsorption of surfactant phospholipids at the air-water interface, a process controlled by surfactant-associated proteins, such as SP-A. In this way, surfactant prevents collapse of th

  8. Feeding strategies for groundwater enhanced biodenitrification in an alluvial aquifer: Chemical, microbial and isotope assessment of a 1D flow-through experiment

    Energy Technology Data Exchange (ETDEWEB)

    Vidal-Gavilan, G., E-mail: georginavidal@biorem.cat [D D' ENGINY BIOREM S.L., Madrazo 68, bxs., 08006 Barcelona (Spain); Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristallografia, Mineralogia i Dipòsits MInerals, Universitat de Barcelona, Martí i Franquès s/n, 08028 Barcelona (Spain); Carrey, R., E-mail: rcarrey@ub.edu [Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristallografia, Mineralogia i Dipòsits MInerals, Universitat de Barcelona, Martí i Franquès s/n, 08028 Barcelona (Spain); Solanas, A., E-mail: asolanas@ub.edu [Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Avgda. Diagonal 645, 08028 Barcelona (Spain); Soler, A., E-mail: albertsolergil@ub.edu [Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristallografia, Mineralogia i Dipòsits MInerals, Universitat de Barcelona, Martí i Franquès s/n, 08028 Barcelona (Spain)

    2014-10-01

    Nitrate-removal through enhanced in situ biodenitrification (EISB) is an existing alternative for the recovery of groundwater quality, and is often suggested for use in exploitation wells pumping at small flow-rates. Innovative approaches focus on wider-scale applications, coupling EISB with water-management practices and new monitoring tools. However, before this approach can be used, some water-quality issues such as the accumulation of denitrification intermediates and/or of reduced compounds from other anaerobic processes must be addressed. With such a goal, a flow-through experiment using 100 mg-nitrate/L groundwater was built to simulate an EISB for an alluvial aquifer. Heterotrophic denitrification was induced through the periodic addition of a C source (ethanol), with four different C addition strategies being evaluated to improve the quality of the denitrified water. Chemical, microbial and isotope analyses of the water were performed. Biodenitrification was successfully stimulated by the daily addition of ethanol, easily achieving drinking water standards for both nitrate and nitrite, and showing an expected linear trend for nitrogen and oxygen isotope fractionation, with a εN/εO value of 1.1. Nitrate reduction to ammonium was never detected. Water quality in terms of remaining C, microbial counts, and denitrification intermediates was found to vary with the experimental time, and some secondary microbial respiration processes, mainly manganese reduction, were suspected to occur. Carbon isotope composition from the remaining ethanol also changed, from an initial enrichment in {sup 13}C-ethanol compared to the value of the injected ethanol (− 30.6‰), to a later depletion, achieving δ{sup 13}C values well below the initial isotope composition (to a minimum of − 46.7‰). This depletion in the heavy C isotope follows the trend of an inverse fractionation. Overall, our results indicated that most undesired effects on water quality may be controlled

  9. Bending elasticity of charged surfactant layers: the effect of mixing.

    Science.gov (United States)

    Bergström, L Magnus

    2006-08-01

    surfactants, and k(c) is further reduced in anionic/cationic surfactant mixtures where the surfactant in excess has the smaller tail volume. Likewise, the reduction of k(c) is enhanced in mixtures of an ionic and a nonionic surfactant where the ionic surfactant has the smaller tail. The effective bilayer bending constant (k(bi)) is also found to be reduced by mixing, and as a result, k(bi) is seen to go through a minimum at some intermediate composition. The reduction of k(bi) is expected to be most pronounced in mixtures of two oppositely charged surfactants where the surfactant in excess has the smaller tail in agreement with experimental observations.

  10. Effects of Surfactant on Solubility and Microbial Conversion of Steroid

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Enhancing the dispersion and dissolution of substrate particles in substrate/water suspension is a feasible way to improve steroid bioconversion. The aim of the present study is to investigate the effects of applying surfactant to microbial conversion system on the dispersion, solubilization and in turn bioconversion of steroid substrate. The model system is hydroxylation of substrate 16α-,17α-epoxy-4-pregnene-3,20-dine by microbial enzymes from Rhizopus nigricanl. The results show that the presence of substrate leads to an increase in critical micelle concentration (CMC) of surfactant PSE compared with the normal CMC of PSE in aqueous solution. The grinding time during substrate suspension preparation affects the substrate aqueous solubility differently with the varied surfactant concentrations while barely making any difference in substrate solubility in the absence of surfactant. The properly prolonged grinding time can make up for the loss in substrate solubility arising from the reduction in surfactant concentration. The surfactant complexes composed of surfactants PSE and MGE at appropriate ratios are screened out with orthodoxy experiment method, the interaction between PSE and MGE exerts the most prominent effects on substrate bioconversion, and the surfactant complexes show more beneficial effects on steroid bioconversion than the surfactant PSE used alone.

  11. Phosphine oxide surfactants revisited.

    Science.gov (United States)

    Stubenrauch, Cosima; Preisig, Natalie; Laughlin, Robert G

    2016-04-01

    This review summarizes everything we currently know about the nonionic surfactants alkyl dimethyl (C(n)DMPO) and alkyl diethyl (C(n)DEPO) phosphine oxide (PO surfactants). The review starts with the synthesis and the general properties (Section 2) of these compounds and continues with their interfacial properties (Section 3) such as surface tension, surface rheology, interfacial tension and adsorption at solid surfaces. We discuss studies on thin liquid films and foams stabilized by PO surfactants (Section 4) as well as studies on their self-assembly into lyotropic liquid crystals and microemulsions, respectively (Section 5). We aim at encouraging colleagues from both academia and industry to take on board PO surfactants whenever possible and feasible because of their broad variety of excellent properties.

  12. 基于数值模拟探讨提高咸水层CO2封存注入率的途径%Numerical investigation for enhancing injectivity of CO2 storage in saline aquifers

    Institute of Scientific and Technical Information of China (English)

    许雅琴; 张可霓; 王洋

    2012-01-01

    咸水层CO2地质封存是减少大气中CO2排放量的有效途径.CO2注入率是衡量咸水层中CO2注入能力的有效因素,因此,研究注入速率的变化规律及提高的措施是很有工程价值的.在很多区域,地层的低渗透性限制了CO2的注入率.针对鄂尔多斯盆地的水文地质条件,通过数值模拟,探讨在低渗透性咸水层中提高CO2注入率的途径,包括改变储层中的盐度、采用水平井注入、增加注入井段的长度以及采取水力压裂等工程措施.其中改变储层中的盐度可通过在注入C02前向储层中注入一定量的水来实现.模拟结果表明,这些方式可以有效地提高CO2注入率,其中水平井改造方式和水力压裂工程措施效果显著,盐度改造措施在地层初始含盐度较高时,会有更好的效果.研究结果可为鄂尔多斯盆地和类似地区的咸水层CO2地质封存项目提供参考.%CO2 storage in deep saline aquifers is considered to be an imperative practical mean for reducing greenhouse gas emissions. Injectivity is one of key factors for determining the feasibility for storage of CO2 in a brine field. Research into the injection rate variation rules and the measures to improve is of great value. Many saline aquifers have relatively low permeability which limits the injection rate of CO2 to the aquifers. In this paper, numerical simulation studies of carbon dioxide storage in brine-saturated reservoirs have been conducted to investigate the approaches for enhancing injectivity through changing the fluid salinity in aquifer, using horizontal well or longer injection screen, and introducing hydraulic fracturing for storage aquifer improvement. Changing fluid salinity can be implemented through injecting a slug of fresh water prior to commencement of CO2 injection. Setup of the models is loosely based on the hydrogeological conditions in Ordos basin. Modeling results indicate that these approaches can effectively improve the

  13. Enrichment of surfactant from its aqueous solution using ultrasonic atomization.

    Science.gov (United States)

    Takaya, Haruko; Nii, Susumu; Kawaizumi, Fumio; Takahashi, Katsuroku

    2005-08-01

    Dilute aqueous solutions of dodecyl-benzenesulfonic acid sodium salt (DBS-Na) and polyoxyethylenenonylphenyl ethers (PONPEs) were ultrasonically atomized. The surfactants were concentrated in collected mist droplets. The enrichment ratio increased with decreasing surfactant concentration. Depending on the surfactant's molecular weight and affinity to water, different enrichment ratio was observed in the range of low feed concentrations. For anionic surfactant, DBS-Na, the enrichment ratio was significantly improved by KCl addition and a peak appeared on the plot of the ratio against KCl concentration. Addition of NaCl or CaCl2 . 2H2O to the surfactant solution also enhanced the enrichment ratio; however, the effect was relatively small. Such behaviors of the ratio were interpreted as enhanced interfacial adsorption of the surfactant and a lack of supply of surfactant monomers from liquid bulk because of slow breaking of surfactant micelles. Time required for collecting an amount of mist was also observed. Among the three salt systems, the time for KCl system was twice as long as others. This fact suggested that the formation of smaller droplets in KCl system.

  14. The use of surfactant in lung transplantation.

    Science.gov (United States)

    Amital, Anat; Shitrit, David; Raviv, Yael; Saute, Milton; Medalion, Benjamin; Bakal, Llana; Kramer, Mordechai R

    2008-12-15

    Lung transplantation impairs surfactant activity, which may contribute to primary graft dysfunction (PGD). Prompted by studies in animals and a few reports in humans, this study sought to determine if the administration of surfactant during transplantation serves as an effective preventive measure. An open, randomized, controlled prospective design was used. Forty-two patients scheduled for single (n=38) or double (n=4) lung transplantation at a major tertiary medical center were randomly assigned to receive, or not, intraoperative surfactant treatment. In the treated group, bovine surfactant was administered at a dose of 20 mg phospholipids/kg through bronchoscope after the establishment of bronchial anastomosis. The groups were compared for oxygenation (PaO2/FiO2), chest X-ray findings, PGD grade, and outcome. Compared with the untreated group, the patients who received surfactant were characterized by better postoperative oxygenation mean PaO2/FiO2 (418.8+/-123.8 vs. 277.9+/-165 mm Hg, P=0.004), better chest radiograph score, a lower PGD grade (0.66 vs. 1.86, P=0.005), fewer cases of severe PGD (1 patient vs. 12, P<0.05), earlier extubation (by 2.2 hr; 95% CI 1.1-4.3 hr, P=0.027), shorter intensive care unit stay (by 2.3 days; 95% CI 1.47-3.74 days, P=0.001), and better vital capacity at 1 month (61% vs. 50%, P=0.022). One treated and 2 untreated patients died during the first postoperative month. Surfactant instillation during lung transplantation improves oxygenation, prevents PGD, shortens intubation time, and enhances early posttransplantation recovery. Further, larger studies are needed to assess whether surfactant should be used routinely in lung transplantation.

  15. Surfactant studies for bench-scale operation

    Science.gov (United States)

    Hickey, Gregory S.; Sharma, Pramod K.

    1993-01-01

    A phase 2 study has been initiated to investigate surfactant-assisted coal liquefaction, with the objective of quantifying the enhancement in liquid yields and product quality. This report covers the second quarter of work. The major accomplishments were: completion of coal liquefaction autoclave reactor runs with Illinois number 6 coal at processing temperatures of 300, 325, and 350 C, and pressures of 1800 psig; analysis of the filter cake and the filtrate obtained from the treated slurry in each run; and correlation of the coal conversions and the liquid yield quality to the surfactant concentration. An increase in coal conversions and upgrading of the liquid product quality due to surfactant addition was observed for all runs.

  16. Impact of a surfactant on the electroactivity of proteins at an aqueous-organogel microinterface array.

    Science.gov (United States)

    O'Sullivan, Shane; Arrigan, Damien W M

    2013-02-05

    The impact of surfactant addition to the organic phase on the electroactivity of proteins at the aqueous-organogel interface was examined by voltammetry. The presence of bis(2-ethylhexyl)sulfosuccinate (AOT) in the organogel phase, as the sodium salt, caused marked changes in the peak currents for myoglobin detection. The protein desorption voltammetric peak exhibited a 6-fold increase in the current compared to the corresponding experiment without surfactant. Interfacial coverage showed a 17-fold increase in the adsorbed protein at the interface, from 50 pmol cm(-2), in the absence of surfactant, to 850 pmol cm(-2), in the presence of 10 mM surfactant. Additionally, the presence of the surfactant resulted in a second pair of adsorption/desorption peaks at lower potentials and in a change in the capacitance of the system. The formation of surfactant-protein and surfactant-protein-organic anion deposits is proposed on the basis of these features, leading to increased voltammetric signals for myoglobin, hemoglobin, and cytochrome c. The mechanism of protein-surfactant interaction was probed by using the surfactant as the anion in the organic phase electrolyte salt. Repetitive cyclic voltammetry of cytochrome c showed that in the presence of surfactant there was an enhancement of the signal, caused by a buildup of the protein-surfactant-electrolyte anion assembly at the interface. These findings provide the basis for surfactant-modified interfaces to enhance the electroanalytical performance for protein detection.

  17. Aquifer Storage Recovery (ASR) of chlorinated municipal drinking water in a confined aquifer

    Science.gov (United States)

    Izbicki, John A.; Petersen, Christen E.; Glotzbach, Kenneth J.; Metzger, Loren F.; Christensen, Allen H.; Smith, Gregory A.; O'Leary, David R.; Fram, Miranda S.; Joseph, Trevor; Shannon, Heather

    2010-01-01

    About 1.02 x 106 m3 of chlorinated municipal drinking water was injected into a confined aquifer, 94-137 m below Roseville, California, between December 2005 and April 2006. The water was stored in the aquifer for 438 days, and 2.64 x 106 m3 of water were extracted between July 2007 and February 2008. On the basis of Cl data, 35% of the injected water was recovered and 65% of the injected water and associated disinfection by-products (DBPs) remained in the aquifer at the end of extraction. About 46.3 kg of total trihalomethanes (TTHM) entered the aquifer with the injected water and 37.6 kg of TTHM were extracted. As much as 44 kg of TTHMs remained in the aquifer at the end of extraction because of incomplete recovery of injected water and formation of THMs within the aquifer by reactions with freechlorine in the injected water. Well-bore velocity log data collected from the Aquifer Storage Recovery (ASR) well show as much as 60% of the injected water entered the aquifer through a 9 m thick, high-permeability layer within the confined aquifer near the top of the screened interval. Model simulations of ground-water flow near the ASR well indicate that (1) aquifer heterogeneity allowed injected water to move rapidly through the aquifer to nearby monitoring wells, (2) aquifer heterogeneity caused injected water to move further than expected assuming uniform aquifer properties, and (3) physical clogging of high-permeability layers is the probable cause for the observed change in the distribution of borehole flow. Aquifer heterogeneity also enhanced mixing of native anoxic ground water with oxic injected water, promoting removal of THMs primarily through sorption. A 3 to 4-fold reduction in TTHM concentrations was observed in the furthest monitoring well 427 m downgradient from the ASR well, and similar magnitude reductions were observed in depth-dependent water samples collected from the upper part of the screened interval in the ASR well near the end of the extraction

  18. Decision Support System for Aquifer Recharge (AR) and Aquifer Storage and Recovery (ASR) Planning, Design, and Evaluation Decision Support System for Aquifer Recharge (AR) and Aquifer Storage and Recovery (ASR) Planning, Design, and Evaluation – Principles and Technical Basis

    Science.gov (United States)

    Aquifer recharge (AR) is a technical method being utilized to enhance groundwater resources through man-made replenishment means, such as infiltration basins and injections wells. Aquifer storage and recovery (ASR) furthers the AR techniques by withdrawal of stored groundwater at...

  19. Surfactant-Amino Acid and Surfactant-Surfactant Interactions in Aqueous Medium: a Review.

    Science.gov (United States)

    Malik, Nisar Ahmad

    2015-08-01

    An overview of surfactant-amino acid interactions mainly in aqueous medium has been discussed. Main emphasis has been on the solution thermodynamics and solute-solvent interactions. Almost all available data on the topic has been presented in a lucid and simple way. Conventional surfactants have been discussed as amphiphiles forming micelles and amino acids as additives and their effect on the various physicochemical properties of these conventional surfactants. Surfactant-surfactant interactions in aqueous medium, various mixed surfactant models, are also highlighted to assess their interactions in aqueous medium. Finally, their applied part has been taken into consideration to interpret their possible uses.

  20. Mechanisms for lowering of interfacial tension in alkali/acidic oil systems; Effect of added surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Rudin, J. Wasan, D.T. (Illinois Inst. of Tech., Chicago, IL (United States). Dept. of Chemical Engineering)

    1992-08-01

    This paper reports that experimental studies are conducted in order to determine the physicochemical mechanism responsible for lowering of interfacial tension in alkali, surfactant, and surfactant-enhanced alkali/acidic oil systems. A well-defined model oil is chosen to examine the influence of various surfactants and surfactant mixtures, such as oleic acid and its ionic counterpart, sodium dodecyl sulfate, petroleum sulfonate, and isobutanol, on equilibrium interfacial tension. With added surfactant alone, the interfacial tension goes through an ultralow minimum with increasing acid concentration. This proves for the first time that the un-ionized acid species plays a major role in affecting interfacial tension, and the ionized acid species.

  1. NUMERICAL SIMULATION AND FIELD IMPLEMENTATION OF SURFACTANT FLOODING

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Based on the features of surfactant flooding, a mathematical model for surfactant flooding is established. The adsorption-retention, convection diffusion of surfactant and influence of concentration change upon relative permeability curve are included in the model. The novel description of adsorption quantity of surfactant and relative permeability curve are presented, which enhance the coincidence between mathematical model and field practice, the relative errors of main development indexes are within 6%. The model is applied to the numerical research of the surfactant flooding in the untabulated beds of Xing1-3 surfactant flooding pilot site of No.4 Oil Production Company of Daqing Oilfield, the influences of surfactant concentration, injection quantity, slug combination mode upon the development effect and economic benefit are quantitatively analyzed, the injection scheme is optimized as follows: surfactant concentration is 0.5%, slug volume is 0.02 PV, slug combination mode is 2 slugs. After the implementation of scheme in oilfield, the cumulative increase of oil is 2186.0 t, up to nearly 30%.

  2. PIROLISIS LIGNIN DARI LIMBAH INDUSTRI KELAPA SAWIT UNTUK PENGEMBANGAN SURFAKTAN DALAM PROSES ENHANCE OIL RECOVERY (EOR (Pyrolysis of Lignin From Waste of Palm Oil Industries for The Development of Surfactants for Enhance Oil Recovery (EOR

    Directory of Open Access Journals (Sweden)

    Suryo Purwono

    2001-12-01

    Full Text Available ABSTRAK Pirolisis dari lignin yang berasal dari limbah industri kelapa sawit dapat menghasilkan alkohol dan derivatif lainnyd yang dapat digunakan sehagai surfaktan. Prosedur penelitian proses pirolisis ini odalah sebagai berikut: I serabut atau tandan sisa pengolahon kelapa sawit yang sudah dikeringkan dimasukkan kedalam reaktor dengan berat tertentu dan dipanaskan sampai suhu yang diinginkan, 2 produk pirolisis yang keluar dari reoktor kemudian didinginkan sampoi mencapai suhu kamor, 3 hasil cair ditampung didalam gelas ukur dan hasil gasnya ditampung di suatu botol tertentu. Suhu paling baik yang dicapai adalah 4A0 "C untuk lignin yong berasal dari serabut dan 350'C untuk lignin yang berasal dari tandan kelapa sawit. Surfaktan yang dihasilkan sekitar j4 sampai 38% dari produk pirolisis. Pada penelitian ini kecepatan reaksi dianggap order satu. Hasil penelitian menunjukkan bahwa surfakton yang dihasilkan dapat membentuk emulsi dengan minyak menta.h. Hal ini menunjukkon bahwa surfaktan yang dihasilkan dapat digunakan sebagai bahan untuk proses EOR.   ABSTRACT Pyrolysis of lignin from waste of palm oil industries produces alcohol and its derivatives which can be sulfonated to become surfactant. The experimental procedures for the pyrolysis process were as follows: 1 dried palm oil husks at a certain weight were put into the pyrolysis reactor and heated up to a certain temperafure; 2 the product leaving the reactor was cooled down to room temperature; and 3 the liquid product was collected in a flask while the gas product was put into a big bottle. The best temperature obtained for producing liquid product was 400 oC for lignin from palm oil fruit fibers and 350 oC for lignin from palm oil fruit stems. The surfactant developed was in the range between 34 and 38% from the pyrolysis product. In this experiment, the reaction rate was assumed to be in first order. The result showed that the surfactant obtained from the experiment could form emulsion

  3. Adsorption of mixed cationic-nonionic surfactant and its effect on bentonite structure.

    Science.gov (United States)

    Zhang, Yaxin; Zhao, Yan; Zhu, Yong; Wu, Huayong; Wang, Hongtao; Lu, Wenjing

    2012-01-01

    The adsorption of cationic-nonionic mixed surfactant onto bentonite and its effect on bentonite structure were investigated. The objective was to improve the understanding of surfactant behavior on clay mineral for its possible use in remediation technologies of soil and groundwater contaminated by toxic organic compounds. The cationic surfactant used was hexadecylpyridinium bromide (HDPB), and the nonionic surfactant was Triton X-100 (TX100). Adsorption of TX100 was enhanced significantly by the addition of HDPB, but this enhancement decreased with an increase in the fraction of the cationic surfactant. Part of HDPB was replaced by TX100 which decreased the adsorption of HDPB. However, the total adsorbed amount of the mixed surfactant was still increased substantially, indicating the synergistic effect between the cationic and nonionic surfactants. The surfactant-modified bentonite was characterized by Brunauer-Emmett-Teller specific surface area measurement, Fourier transform infrared spectroscopy, and thermogravimetric-derivative thermogravimetric/differential thermal analyses. Surfactant intercalation was found to decrease the bentonite specific surface area, pore volume, and surface roughness and irregularities, as calculated by nitrogen adsorption-desorption isotherms. The co-adsorption of the cationic and nonionic surfactants increased the ordering conformation of the adsorbed surfactants on bentonite, but decreased the thermal stability of the organobentonite system.

  4. Bioremediation of chlorinated ethenes in aquifer thermal energy storage

    NARCIS (Netherlands)

    Ni, Z.

    2015-01-01

      Subjects: bioremediation; biodegradation; environmental biotechnology, subsurface and groundwater contamination; biological processes; geochemistry; microbiology The combination of enhanced natural attenuation (ENA) of chlorinated volatile organic compounds (CVOCs) and aquife

  5. Bioremediation of chlorinated ethenes in aquifer thermal energy storage

    NARCIS (Netherlands)

    Ni, Z.

    2015-01-01

      Subjects: bioremediation; biodegradation; environmental biotechnology, subsurface and groundwater contamination; biological processes; geochemistry; microbiology The combination of enhanced natural attenuation (ENA) of chlorinated volatile organic compounds (CVOCs) and aquife

  6. Sizing up surfactant synthesis.

    Science.gov (United States)

    Han, SeungHye; Mallampalli, Rama K

    2014-08-01

    Phosphatidylcholine is generated through de novo synthesis and remodeling involving a lysophospholipid. In this issue of Cell Metabolism, research from the Shimizu lab (Harayama et al., 2014) demonstrates the highly selective enzymatic behavior of lysophospholipid acyltransferases. The authors present an enzymatic model for phosphatidylcholine molecular species diversification that impacts surfactant formation.

  7. Structural studies of lamellar surfactant systems under shear

    DEFF Research Database (Denmark)

    Mortensen, K.

    2001-01-01

    Recent experimental studies on concentrated surfactant systems are reviewed. Particular attention is focused on the transformation from planar lamellar sheets to multilamellar vesicles. It is discussed whether both of these states are thermodynamic stable, or if the MLV is an artifact of shear...... induced factors. Recent studies includes the dependence on shear, and dependence on salt and cosurfactants, and thereby related lamellar defects. The review include moreover the demonstration that polymeric amphiphiles dramatically enhance the quality of classical surfactants. (C) 2001 Elsevier Science...

  8. How to Attain an Ultralow Interfacial Tension and a Three-Phase Behavior with a Surfactant Formulation for Enhanced Oil Recovery: A Review. Part 2. Performance Improvement Trends from Winsor's Premise to Currently Proposed Inter- and Intra-Molecular Mixtures.

    Science.gov (United States)

    Salager, Jean-Louis; Forgiarini, Ana M; Márquez, Laura; Manchego, Lisbeth; Bullón, Johnny

    2013-01-01

    The minimum interfacial tension occurrence along a formulation scan at the so-called optimum formulation is discussed to be related to the interfacial curvature. The attained minimum tension is inversely proportional to the domain size of the bicontinuous microemulsion and to the interfacial layer rigidity, but no accurate prediction is available. The data from a very simple ternary system made of pure products accurately follows the correlation for optimum formulation, and exhibit a linear relationship between the performance index as the logarithm of the minimum tension at optimum, and the formulation variables. This relation is probably too simple when the number of variables is increased as in practical cases. The review of published data for more realistic systems proposed for enhanced oil recovery over the past 30 years indicates a general guidelines following Winsor's basic studies concerning the surfactant-oil-water interfacial interactions. It is well known that the major performance benefits are achieved by blending amphiphilic species at the interface as intermolecular or intramolecular mixtures, sometimes in extremely complex formulations. The complexity is such that a good knowledge of the possible trends and an experienced practical know-how to avoid trial and error are important for the practitioner in enhanced oil recovery.

  9. EPA Sole Source Aquifers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Information on sole source aquifers (SSAs) is widely used in assessments under the National Environmental Policy Act and at the state and local level. A national...

  10. Lower Cretaceous aquifers

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Lower Cretaceous aquifers in the states of Montana, Wyoming, South Dakota, Kansas, Nebraska, Iowa, and Minnesota..

  11. The effect of surfactant on pollutant biosorption of Trametes versicolor

    Science.gov (United States)

    Gül, Ülküye Dudu; Silah, Hülya; Akbaş, Halide; Has, Merve

    2016-04-01

    The major problem concerning industrial wastewater is treatment of dye and heavy metal containing effluents. Industrial effluents are also contained surfactants that are used as levelling, dispersing and wetting agents. The purpose of this study was to investigate the effect of surfactant on textile dye biosorption properties of a white rot fungus named Trametes versicolor. Reactive dyes are commonly used in textile industry because of their advantages such as brightness and excellent color fastness. A recative textile dye, called Everzol Black, was used in this study. The low-cost mollasses medium is used for fungal growth. The usage of mollases, the sugar refinery effluent as a source of energy and nutrients, gained importance because of reducing the cost and also reusing another waste. In biosorption process the effect of surfactant on dye removal properties of T. versicolor was examined as a function of pH, dye consentration and surfactant concentration. The results of this study showed that the surfactant enhanced the dye removal capacity of Trametes versicolor. The dye and surfactant molecules were interacted electrostatically and these electrostatic interactions improved dye removal properties of filamentous fungus T. versicolor. The results of this study recommended the use of surfactants as an inducer in textile wastewater treatment technologies.

  12. Surfactants in microbiology and biotechnology: Part 2. Application aspects.

    Science.gov (United States)

    Singh, Ajay; Van Hamme, Jonathan D; Ward, Owen P

    2007-01-01

    Surfactants are amphiphilic compounds which can reduce surface and interfacial tensions by accumulating at the interface of immiscible fluids and increase the solubility, mobility, bioavailability and subsequent biodegradation of hydrophobic or insoluble organic compounds. Chemically synthesized surfactants are commonly used in the petroleum, food and pharmaceutical industries as emulsifiers and wetting agents. Biosurfactants produced by some microorganisms are becoming important biotechnology products for industrial and medical applications due to their specific modes of action, low toxicity, relative ease of preparation and widespread applicability. They can be used as emulsifiers, de-emulsifiers, wetting and foaming agents, functional food ingredients and as detergents in petroleum, petrochemicals, environmental management, agrochemicals, foods and beverages, cosmetics and pharmaceuticals, and in the mining and metallurgical industries. Addition of a surfactant of chemical or biological origin accelerates or sometimes inhibits the bioremediation of pollutants. Surfactants also play an important role in enhanced oil recovery by increasing the apparent solubility of petroleum components and effectively reducing the interfacial tensions of oil and water in situ. However, the effects of surfactants on bioremediation cannot be predicted in the absence of empirical evidence because surfactants sometimes stimulate bioremediation and sometimes inhibit it. For medical applications, biosurfactants are useful as antimicrobial agents and immunomodulatory molecules. Beneficial applications of chemical surfactants and biosurfactants in various industries are discussed in this review.

  13. Exogenous surfactant suppresses inflammation in experimental endotoxin-induced lung injury.

    Science.gov (United States)

    Mittal, Neha; Sanyal, Sankar Nath

    2009-01-01

    Our objective was to evaluate the anti-inflammatory effects of exogenous surfactant and surfactant phospholipids on the lipopolysaccharide (LPS)-induced lung injury. Exogenous surfactant (porcine surfactant) and surfactant phospholipid (dipalmitoyl phospholipid DPPC, hexadecanol, tylaxopol) were instilled intratracheally with LPS in rats. Expression of surfactant apoproteins (SP-A) and the cyclooxygenase enzymes (COX-1 and -2) was studied by immunohistochemistry, and apoptosis was analyzed by in situ terminal dUTP nick end labeling TUNEL assay. The intracellular reactive oxygen species (ROS) was measured in the isolated macrophages by fluorescence measurement with dichlorofluorescein diacetate (DCFH-DA). LPS-induced oxidative burst and apoptosis at 72 hours were reduced by both porcine and synthetic surfactant. SP-A as well as COX-1 and -2 expressions were suppressed with synthetic surfactant treatment, whereas with porcine surfactant (P-SF) the SP-A expression was enhanced in response to LPS administration. These results indicate that exogenous surfactant inhibits LPS-induced inflammation. This anti-inflammatory activity may be an important outcome of surfactant therapy in endotoxin-induced respiratory distress.

  14. Effects of surfactants and salt on Henry's constant of n-hexane.

    Science.gov (United States)

    Yang, Chunping; Chen, Fayuan; Luo, Shenglian; Xie, Gengxin; Zeng, Guangming; Fan, Changzheng

    2010-03-15

    n-Hexane biological removal is intrinsically limited by its hydrophobic nature and low bioavailability. The addition of surfactants could enhance the transport of volatile organic compounds (VOCs) and change the gas-liquid equilibrium of VOCs. In this paper, the effects of four surfactants, sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB), tert-octylphenoxypoly-ethoxyethanol (Triton X-100), polyoxyethylene (20) sorbitan monooleate (Tween 80), and sodium nitrate on apparent Henry's constant of n-hexane in surfactant solutions were investigated. The apparent Henry's constants were significantly reduced when surfactants concentrations exceeded their critical micelle concentrations (cmc's). On a cmc basis, the anionic surfactant SDS was found to have the greatest effect on the apparent Henry's constant with CTAB succeeding, then followed by Triton X-100 and Tween 80. However, the apparent Henry's constant of n-hexane decreased even more rapidly when Triton X-100, a nonionic surfactant, was added than when the ionic surfactant of SDS or CTAB was applied under identical mass concentration and other conditions. These results suggest that Triton X-100 have the biggest solubilization of n-hexane among the four surfactants. Sodium nitrate slightly decreased the apparent Henry's constant of n-hexane in surfactant solutions, and could be considered as a cosolvent in the surfactant-(n-hexane) solution. In addition, the relationship between apparent Henry's constant and surfactant concentration was further developed.

  15. Brush border membrane vesicle and Caco-2 cell line: Two experimental models for evaluation of absorption enhancing effects of saponins, bile salts, and some synthetic surfactants

    Directory of Open Access Journals (Sweden)

    Eskandar Moghimipour

    2016-01-01

    Full Text Available The aim of this study was to investigate the influence of absorption enhancers in the uptake of hydrophilic compounds. The permeation of the two hydrophilic drug models gentamicin and 5 (6-carboxyfluorescein (CF across the brush border membrane vesicles and Caco-2 cell lines were evaluated using total saponins of Acanthophyllum squarrosum, Quillaja saponaria, sodium lauryl sulfate, sodium glycocholate, sodium taurodeoxycholate , and Tween 20 as absorption enhancers. Transepithelial electrical resistance (TEER measurement was utilized to assess the paracellular permeability of cell lines. Confocal laser scanning microscopy (CLSM was performed to obtain images of the distribution of CF in Caco-2 cells. These compounds were able to loosen tight junctions, thus increasing paracellular permeability. CLSM confirmed the effect of these absorption enhancers on CF transport across Caco-2 lines and increased the Caco-2 permeability via transcellular route. It was also confirmed that the decrease in TEER was transient and reversible after removal of permeation enhancers.

  16. Adsorption of mixed cationic-nonionic surfactant and its effect on bentonite structure

    Institute of Scientific and Technical Information of China (English)

    Yaxin Zhang; Yan Zhao; Yong Zhu; Huayong Wu; Hongtao Wang; Wenjing Lu

    2012-01-01

    The adsorption of cationic-nordonic mixed surfactant onto bentonite and its effect on bentonite structure were investigated.The objective was to improve the understanding of surfactant behavior on clay mineral for its possible use in remediation technologies of soil and groundwater contaminated by toxic organic compounds.The cationic surfactant used was hexadecylpyridinium bromide(HDPB),and the nonionic suffactant was Triton X-100(TX100).Adsorption of TX100 was enhanced significantly by the addition of HDPB,but this enhancement decreased with an increase in the fraction of the cationic surfactant.Part of HDPB was replaced by TX100 which decreased the adsorption of HDPB.However,the total adsorbed amount of the mixed surfactant was still increased substantially,indicating the synergistic effect between the cationic and nonionic surfactants.The surfactant-modified bentonite was characterized by Brunauer-Emmett-Teller specific surface area measurement,Fourier transform infrared spectroscopy,and thermogravimetric-derivative thermogravimetric/differential thermal analyses.Surfactant intercalation was found to decrease the bentonite specific surface area,pore volume,and surface roughness and irregularities,as calculated by nitrogen adsorption-desorption isotherms.The co-adsorption of the cationic and nonionic surfactants increased the ordering conformation of the adsorbed surfactants on bentonite,but decreased the thermal stability of the organobentonite system.

  17. 曝气强化非离子表面活性剂洗涤法修复柴油污染土壤%Remediation of diesel-contaminated soil by aeration enhanced washing with nonionic surfactant

    Institute of Scientific and Technical Information of China (English)

    汤志涛; 陈泉源

    2016-01-01

    The diesel-contaminated soil was remediated by ex-situ aeration enhanced washing method with nonionic surfactant. The factors affecting the washing effect were investigated,and the washing mechanism was studied by determination of surface tension and contact angle. The experimental results show that:The washing effect of diesel oil from diesel-contaminated soil can be enhanced by aeration and the removal rate of diesel oil is increased by 10%-20%;The order of washing effect by 3 kinds of nonionic surfactants is Brij-35>TX-100>Tw-80;Under the optimum conditions of Brij-35 concentration one time of CMC,aeration rate 7.5 L/min,washing time 60 mine and washing solution pH 11.0,the removal rate of diesel oil is 77.4%,the oil content of the diesel-contaminated soil is decreased from 7.0%to 1.6%,the contact angle is decreased from 24.12° to 6.65°,and the hydrophily of the soil can be recovered after washing;The surface tension of the washing solution is decreased with the increase of surfactant concentration,but not affected by washing solution pH.%采用异位修复法,利用非离子表面活性剂洗涤柴油污染土壤,并在洗涤过程中曝气强化。考察了洗涤效果的影响因素,并通过表面张力和接触角的测定探讨了洗涤机理。实验结果表明:曝气对污染土壤中柴油的洗脱有强化作用,可提高洗脱率10%~20%;3种非离子表面活性剂的洗脱效果优劣次序为聚氧乙烯月桂醚(Brij-35)>曲拉通X-100(TX-100)>吐温-80(Tw-80);在表面活性剂浓度为1倍临界胶束浓度、曝气量为7.5 L/min、洗涤时间为60 min、洗涤液pH为11.0的优化条件下,Brij-35对柴油的洗脱率达77.4%,污染土样的含油率从7.0%降至1.6%,接触角从24.12°降至6.65°,可基本恢复土壤的亲水性;洗涤液的表面张力随表面活性剂浓度的增加而降低,但不受洗涤液pH的影响。

  18. MICROBIAL SURFACTANTS. I. GLYCOLIPIDS

    Directory of Open Access Journals (Sweden)

    Pirog T. Р.

    2014-02-01

    Full Text Available The review is devoted to surface-active glycolipids. The general characteristics, the physiological role of the rhamnolipids, trehalose lipids, sophorolipids, mannosylerythritol lipids and their traditional producers — the representatives of the genera Pseudozyma, Pseudomonas, Rhodococcus and Candida are given. The detailed analysis of the chemical structure, the stages of the biosynthesis and the regulation of some low molecular glycolipids are done. The own experimental data concerning the synthesis intensification, the physiological role and the practical use of Rhodococcus erythropolis IMV Ac-5017, Acinetobacter calcoaceticus IMV B-7241 and Nocardia vaccinii IMV B-7405 surfactants, which are a complex of the glyco-, phospho-, amino- and neutral lipids (glycolipids of all strains are presented by trehalose mycolates are summarized. It was found that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants have protective, antimicrobial and antiadhesive properties. It was shown that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants preparation of cultural liquid intensified the degradation of oil in water due to the activation of the natural petroleum-oxidizing microflora.

  19. MICROBIAL SURFACTANTS. II. LIPOPEPTIDES

    Directory of Open Access Journals (Sweden)

    T. P. Pirog

    2014-04-01

    Full Text Available The classification and the chemical structure of the lipopeptides and their producers (bacteria of the genera Bacillus and Pseudomonas are given. The role of the lipopeptides in cells motility, biofilm formation, metal binding and xenobiotics degradation and their action on the cells of pro- and eukaryotes is summarized. The stages of the nonribosomal lipopeptides synthesis and the role of two-component (GacA/GacS, ComA/ComP and the quorum system regulation of this process are shown. The potential of lactic acid bacteria and marine microorganisms as alternative surfactants producers (glycolipids, lipopeptides, phospholipids and fatty acids, glycolipopeptides are discussed. Their productivity and advantages over traditional producers are given as well. The properties of surfactants synthesized by lactic acid bacteria (the reduction of the surface tension, the critical micelle concentration, the stability in a wide range of pH, the temperature, the biological activity are summarized. Surfactants of nonpathogenic probiotic bacteria could be used as effective antimicrobial agents and antiadhesive and marine producers which able to synthesize unique metabolites that are not produced by other microorganisms.

  20. Gemini ester quat surfactants and their biological activity.

    Science.gov (United States)

    Łuczyński, Jacek; Frąckowiak, Renata; Włoch, Aleksandra; Kleszczyńska, Halina; Witek, Stanisław

    2013-03-01

    Cationic gemini surfactants are an important class of surface-active compounds that exhibit much higher surface activity than their monomeric counterparts. This type of compound architecture lends itself to the compound being easily adsorbed at interfaces and interacting with the cellular membranes of microorganisms. Conventional cationic surfactants have high chemical stability but poor chemical and biological degradability. One of the main approaches to the design of readily biodegradable and environmentally friendly surfactants involves inserting a bond with limited stability into the surfactant molecule to give a cleavable surfactant. The best-known example of such a compound is the family of ester quats, which are cationic surfactants with a labile ester bond inserted into the molecule. As part of this study, a series of gemini ester quat surfactants were synthesized and assayed for their biological activity. Their hemolytic activity and changes in the fluidity and packing order of the lipid polar heads were used as the measures of their biological activity. A clear correlation between the hemolytic activity of the tested compounds and their alkyl chain length was established. It was found that the compounds with a long hydrocarbon chain showed higher activity. Moreover, the compounds with greater spacing between their alkyl chains were more active. This proves that they incorporate more easily into the lipid bilayer of the erythrocyte membrane and affect its properties to a greater extent. A better understanding of the process of cell lysis by surfactants and of their biological activity may assist in developing surfactants with enhanced selectivity and in widening their range of application.

  1. Surfactants at the Design Limit.

    Science.gov (United States)

    Czajka, Adam; Hazell, Gavin; Eastoe, Julian

    2015-08-04

    This article analyzes how the individual structural elements of surfactant molecules affect surface properties, in particular, the point of reference defined by the limiting surface tension at the aqueous cmc, γcmc. Particular emphasis is given to how the chemical nature and structure of the hydrophobic tails influence γcmc. By comparing the three different classes of surfactants, fluorocarbon, silicone, and hydrocarbon, a generalized surface packing index is introduced which is independent of the chemical nature of the surfactants. This parameter ϕcmc represents the volume fraction of surfactant chain fragments in a surface film at the aqueous cmc. It is shown that ϕcmc is a useful index for understanding the limiting surface tension of surfactants and can be useful for designing new superefficient surfactants.

  2. Experimental study on thermophoresis of colloids in aqueous surfactant solutions

    Science.gov (United States)

    Dong, Ruo-Yu; Zhou, Yi; Yang, Chun; Cao, Bing-Yang

    2015-12-01

    Thermophoresis refers to the motion of particles under a temperature gradient and it is one of the particle manipulation techniques. Regarding the thermophoresis of particles in liquid media, however, many open questions still remain, especially the role of the interfacial effect. This work reports on a systematic experimental investigation of surfactant effects, especially the induced interfacial effect, on the thermophoresis of colloids in aqueous solutions via a microfluidic approach. Two kinds of commonly used surfactants, sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB), are selected and the results show that from relatively large concentrations, the two surfactants can greatly enhance the thermophilic mobilities. Specifically, it is found that the colloid-water interfaces modified with more polar end groups can potentially lead to a stronger thermophilic tendency. Due to the complex effects of surfactants, further theoretical model development is needed to quantitatively describe the dependence of thermophoresis on the interface characteristics.

  3. Application of Ultrasound-Assisted Surfactant-Enhanced Emulsification Microextraction Based on Solidification of Floating Organic Droplets and High Performance Liquid Chromatography for Preconcentration and Determination of Alprazolam and Chlordiazepoxide in Human Serum Samples.

    Science.gov (United States)

    Goudarzi, Nasser; Amirnavaee, Monavar; Arab Chamjangali, Mansour; Farsimadan, Sahar

    2017-03-03

    An improved microextraction method is proposed on the basis of ultrasound-assisted surfactant-enhanced emulsification and solidification of a floating organic droplet procedure combined with high performance liquid chromatography for the preconcentration and quantification of alprazolam (ALP) and chlordiazepoxide (CHL) present in a number of human serum samples. Several parameters affecting the extraction efficiency were investigated by the Plackett -Burman factorial design as the screening design. Then the response surface methodology based on the Box-Behnken design was used to optimize the effective parameters in the proposed procedure. The limits of detection for the proposed method were found to be 3.0 and 3.1 ng mL-1 for CHL and ALP, respectively. The calibration curves obtained for the method were linear in the ranges of 10.0-3,500.0 and 10.0-3,000.0 ng mL-1 for CHL and ALP, respectively, with a good determination coefficient. The recoveries of the drugs in the spiked human serum samples were above 93.0%. The developed method was successfully applied to the analysis of these studied drugs in human serum samples. The pre-treatment of the serum samples was performed using acetonitrile to remove the proteins. The proposed procedure was an accurate and reliable one for the determination and preconcentration of these drugs in blood samples.

  4. Tuning of protein-surfactant interaction to modify the resultant structure.

    Science.gov (United States)

    Mehan, Sumit; Aswal, Vinod K; Kohlbrecher, Joachim

    2015-09-01

    Small-angle neutron scattering and dynamic light scattering studies have been carried out to examine the interaction of bovine serum albumin (BSA) protein with different surfactants under varying solution conditions. We show that the interaction of anionic BSA protein (pH7) with surfactant and the resultant structure are strongly modified by the charge head group of the surfactant, ionic strength of the solution, and mixed surfactants. The protein-surfactant interaction is maximum when two components are oppositely charged, followed by components being similarly charged through the site-specific binding, and no interaction in the case of a nonionic surfactant. This interaction of protein with ionic surfactants is characterized by the fractal structure representing a bead-necklace structure of micellelike clusters adsorbed along the unfolded protein chain. The interaction is enhanced with ionic strength only in the case of site-specific binding of an anionic surfactant with an anionic protein, whereas it is almost unchanged for other complexes of cationic and nonionic surfactants with anionic proteins. Interestingly, the interaction of BSA protein with ionic surfactants is significantly suppressed in the presence of nonionic surfactant. These results with mixed surfactants thus can be used to fold back the unfolded protein as well as to prevent surfactant-induced protein unfolding. For different solution conditions, the results are interpreted in terms of a change in fractal dimension, the overall size of the protein-surfactant complex, and the number of micelles attached to the protein. The interplay of electrostatic and hydrophobic interactions is found to govern the resultant structure of complexes.

  5. The Effects of Periodic Wall Stretch on Surfactant and Liquid Transport

    Science.gov (United States)

    Bull, Joseph; Halpern, David; Grotberg, James

    1999-11-01

    The cycle-mean transport of soluble surfactant and airway surface liquid is examined using a mathematical model of Marangoni flows which accounts for airway branching and for time-periodic radial and axial airway stretch. The transport of surfactant and liquid is fundamental to surfactant replacement therapy as well as liquid and surfactant clearance from healthy lungs. The majority of surfactant and liquid transport occurs in the cycle-mean spreading which follows the very brief initial transient spreading phase. We consider either delivery of surfactants into the lung, by setting the proximal boundary condition to a higher concentration compared to the distal boundary condition, or removal from the lung by switching these end conditions. Starting with a steady-state, non-cycled, non-uniform, surfactant distribution we find that transport of surfactant into the lung is enhanced for larger strain amplitudes and frequency, though frequency is less important. For surfactant clearance from the lung we find, as in the case of delivery, that larger strain amplitude enhances transport. But, cycling frequency has the opposite effect with larger frequencies leading to reduced transport. Liquid clearance is enhanced by larger strain amplitudes and slower frequencies. This work supported by NIH grant HL-41126 and NSF grant CTS-9412523.

  6. Kinetics of degradation of surfactant-solubilized fluoranthene by a Sphingomonas paucimobilis

    Energy Technology Data Exchange (ETDEWEB)

    Willumsen, P.A. (National Environmental Research Institute, Roskilde (Denmark). Dept. of Marine Ecology and Microbiology); Arvin, E. (Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Environmental Science and Engineering)

    1999-08-01

    To achieve a better quantitative understanding of the stimulating or inhibiting effect of surfactants on the metabolism of polycyclic aromatic hydrocarbons (PAHs), a biodegradation model describing solubilization, bioavailability, and biodegradation of crystalline fluoranthene is proposed and used to model experimental data. The degradation was investigated in batch systems containing the PAH-degrading bacterium Sphingomonas paucimobilis strain EPA505, the nonionic surfactant Triton X-100, and a fluoranthene-amended liquid mineral salts medium. Surfactant-enhanced biodegradation is complex; however, the biodegradation model predicted fluoranthene disappearance and the initial mineralization well. Surfactant-amendment did increase fluoranthene mineralization rates by strain EPA505; however, the increases were not proportional to the rates of fluoranthene solubilization. The surfactant clearly influenced the microbial PAH metabolism as indicated by a rapid accumulation of colored products and by a surfactant -related decreased in the overall extent of fluoranthene mineralization. Model estimations of the bioavailability of micelle-solubilized fluoranthene, the relatively fast fluoranthene disappearance, and the accumulation of extracellular compounds in the degradation system suggest that low availability of micellar fluoranthene is not the only factor controlling surfactant-enhanced biodegradation. Also factors such as the extent of accumulation and bioavailability of the PAH metabolites and the crystalline solubilization rate in the presence of surfactants may determine the overall effect of surfactant-enhanced biodegradation of high molecular weight PAHs.

  7. 含氟表面活性剂对固体表面润湿性的影响及应用%The Effect of Fluoro-Surfactants on Wettability of Solid Surface and Enhancing Oil Recovery

    Institute of Scientific and Technical Information of China (English)

    代彦臣

    2013-01-01

    利用座滴法研究了含氟表面活性剂在石英表面形成的吸附膜的润湿性质,考察了温度及不同类型电解质对其接触角的影响趋势,并开展了室内模拟驱油实验。研究发现,两性含氟表面活性剂可以有效地改变石英表面的润湿性,在蒸馏水及模拟地层水的条件下都可以使亲水的石英表面变为中性。同时,两性含氟表面活性剂具有较好的抗盐性及耐温性。室内模拟驱油实验显示,两性含氟表面活性剂将岩心的润湿性控制在中性弱亲水状态,促进孔道水膜剥离,减小水驱渗流阻力,从而降低水驱压力和提高原油采收率。%The wetting properties of quartz surface modified by adsorption films of fluoro-surfactants were investigated using the sessile drop analysis .The influences of temperature and different electrolytes were expounded and laboratory simulation of displacement testing was carried out . The results show that zwitterionic fluoro-surfactant FO1 will effectively alter the wettability of quartz surface .FO1 can both modify the quartz surface from hydrophilic surface to neutral one in distilled water and formation water .Meanwhile ,FO1 shows better heat resistance and salt tolerance .The result of laboratory simulation of displacement experiment show that the core surface is controlled in slightly water-wetting by zwitterionic fluoro-surfactan solutions ,which is beneficial to the removing of the water film from core surface and reducing the percolation resistance of water flooding ,and results in decrease of water injection pressure and enhancement of the oil recovery .

  8. BINDING ISOTHERMS SURFACTANT-PROTEINS

    Directory of Open Access Journals (Sweden)

    Elena Irina Moater

    2011-12-01

    Full Text Available The interactions between surfactants and proteins shows some similarities with interactions between surfactants and polymers, but the hydrophobic amphoteric nature of proteins and their secondary and tertiary structure components make them different from conventional polymer systems. Many studies from the past about surfactant - proteins bonding used the dialysis techniques. Other techniques used to determine the binding isotherm, included ultrafiltration, ultracentrifugation, potentiometry, ion-selective electrode method and surface tension. High affinity isotherms which are typical of an anionic surfactant - protein bonding, exhibit an initial increase steep followed by a slow growth region and then a vertical growth above a certain concentration. This isotherm is typical of ionic surfactant to protein binding. Often the high affinity initial bond appears at very low concentrations of surfactant and therefore in some protein-surfactant systems, the exact shape of the isotherm in this region may be missing. The surfactant - protein binding is influenced by a number of variables such as the nature and chain length of surfactant, pH, ionic strength, temperature, nature of this protein and additives.

  9. Coupling Surfactant Flushing and Bioaugmentation for PCE-DNAPL Source Zone Treatment

    Science.gov (United States)

    Cápiro, N. L.; Granbery, E. K.; Amos, B. K.; Löffler, F. E.; Pennell, K. D.

    2008-12-01

    Enhanced solubilization flushing using a biodegradable surfactant (Tween 80) was combined with bioaugmentation to initiate microbial reductive dechlorination and detoxify residual tetrachloroethene (PCE)- dense nonaqueous phase liquid (DNAPL). Dechlorination activity, spatial distribution of Dehalococcoides spp., and down-gradient plume development were monitored in a 2-D aquifer cell equipped with eighteen sampling ports. Saturation distributions of the PCE-DNAPL source zone were quantified using a light transmission system to determine the ganglia-to-pool (GTP) volume ratio, which was approximately 1.5 (i.e., 60% ganglia and 40% pools) prior to surfactant flushing. Flushing with three pore volumes (PVs) of 4% (w/w) Tween 80 solution recovered approximately 55% of the original PCE mass and reduced PCE effluent concentration from saturation (200 mg/L) to less than 50 mg/L. Following the introduction of reduced basal salts medium amended with 10 mM lactate, nine side ports located upstream and within the initial PCE- DNAPL source zone were augmented with Bio-Dechlor INOCULUM (BDI), a PCE-to-ethene dechlorinating consortium. Flux-averaged measurements of aqueous effluent samples revealed the conversion of PCE to cis-dichloroethene (DCE) with minimal lag time (7 days, approx. 1 PV), and vinyl chloride and ethene were detected within 10 PVs after bioaugmentation. Quantitative real-time PCR (qPCR) targeting Dehalococcoides spp. demonstrated growth once aqueous PCE concentrations decreased below inhibitory levels (~540 mM), with significant growth (2 to 4-orders of magnitude) near the remaining source zone. These results demonstrate the successful colonization of a pool-dominated (NAPL saturation >0.13) PCE- DNAPL source zone by a dechlorinating consortium following partial mass removal, and the potential for locally bioenhanced DNAPL dissolution.

  10. Voies de recherche en matière de récupération assistée du pétrole par tensio-actifs Research Lines in Enhanced Oil Recovery by Surfactants

    Directory of Open Access Journals (Sweden)

    Baviere M.

    2006-11-01

    Full Text Available Quelle que soit la conjoncture économique, le procédé de récupération assistée du pétrole par injection d'agents tensio-actifs nécessite une mise en oeuvre très élaborée pour tirer le meilleur parti des produits et donc pour franchir le seuil de rentabilité. Il apparaît par ailleurs que son champ d'application doit être étendu aux conditions de réservoir couramment rencontrées, notamment les fortes salinités, par l'utilisation de structures chimiques adaptées. Pour réduire les pertes de tensio-actifs par adsorption sur la roche, et par suite, préserver l'efficacité du fluide micellaire, deux techniques sont étudiées à l'Institut Français du Pétrole. L'une d'entre elles consiste à réduire l'adsorption en augmentant le pH de la formation à l'aide d'agents alcalins. Dans l'autre méthode, les molécules adsorbées sont remises en solution par un agent désorbant ajouté à l'eau de chasse. L'extension du procédé aux gisements salés est illustrée avec une famille de tensio-actifs qui ont un comportement prometteur dans ces conditions, les sulfonates d'oléfines alpha. Il apparaît que l'efficacité interfaciale de ces produits ne doit pas être seule prise en compte, mais également la solubilité, la stabilité chimique, le comportement rhéologique et l'adsorption sur les surfaces minérales. No matter what the economic situation may be, the process of enhanced oil recovery (EOR by surfactant flooding requires very sophisticated implementation to take maximum advantage of the chemicals and hence to cross the threshold of economic feasibility. It seems, moreover, that the scope of application of this process must be enlarged to meet the reservoir conditions commonly encountered, particularly high salinity, by the use of suitable chemical structures. To reduce surfactant losses by adsorption on the rock and then to preserve the efficiency of the micellar fluid, two techniques are being investigated at the Institut

  11. Interaction of nonionic surfactant AEO9 with ionic surfactants

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-guo; YIN Hong

    2005-01-01

    The interaction in two mixtures of a nonionic surfactant AEO9 (C12H25O(CH2CH2O)9H) and different ionic surfactants was investigated. The two mixtures were AEO9/sodium dodecyl sulfate (SDS) and AEO9/cetyltrimethylammonium bromide (CTAB) at molar fraction of AEO9, αAEO9 =0.5. The surface properties of the surfactants, critical micelle concentration (CMC),effectiveness of surface tension reduction (γCMC), maximum surface excess concentration (Гmax) and minimum area per molecule at the air/solution interface (Amin) were determined for both individual surfactants and their mixtures. The significant deviations from ideal behavior (attractive interactions) of the nonionic/ionic surfactant mixtures were determined. Mixtures of both AEO9/SDS and AEO9/CTAB exhibited synergism in surface tension reduction efficiency and mixed micelle formation, but neither exhibited synergism in surface tension reduction effectiveness.

  12. Effect of alkyl length of cationic surfactants on desorption of Cs from contaminated clay

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bo Hyun; Park, Chan Woo; Yang, Hee Man; Seo, Bum Kyoung; Lee, Kune Woo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, So Jin [Chungnam National University, Daejeon (Korea, Republic of)

    2017-03-15

    In this study, desorption characteristics of Cs from clay according to the hydrophobic alkyl chain length of the cationic surfactant were investigated. Alkyltrimethylammonium bromide was used as a cationic surfactant, and the length of the hydrophobic alkyl chain of the cationic surfactant was varied from –octyl to –cetyl. The adsorbed amount of the cationic surfactant on montmorillonite increased with the length of the hydrophobic alkyl chain, and intercalation of the cationic surfactant into the clay interlayer increased the interlayer distances. The Cs removal efficiency was also enhanced with increasing alkyl chain length, and the cationic surfactant with the cetyl group showed a maximum Cs removal efficiency of 99±2.9%.

  13. Surfactant monitoring by foam generation

    Science.gov (United States)

    Mullen, Ken I.

    1997-01-01

    A device for monitoring the presence or absence of active surfactant or other surface active agents in a solution or flowing stream based on the formation of foam or bubbles is presented. The device detects the formation of foam with a light beam or conductivity measurement. The height or density of the foam can be correlated to the concentration of the active surfactant present.

  14. Surfactant adsorption kinetics in microfluidics

    Science.gov (United States)

    Riechers, Birte; Maes, Florine; Akoury, Elias; Semin, Benoît; Gruner, Philipp; Baret, Jean-Christophe

    2016-10-01

    Emulsions are metastable dispersions. Their lifetimes are directly related to the dynamics of surfactants. We design a microfluidic method to measure the kinetics of adsorption of surfactants to the droplet interface, a key process involved in foaming, emulsification, and droplet coarsening. The method is based on the pH decay in the droplet as a direct measurement of the adsorption of a carboxylic acid surfactant to the interface. From the kinetic measurement of the bulk equilibration of the pH, we fully determine the adsorption process of the surfactant. The small droplet size and the convection during the droplet flow ensure that the transport of surfactant through the bulk is not limiting the kinetics of adsorption. To validate our measurements, we show that the adsorption process determines the timescale required to stabilize droplets against coalescence, and we show that the interface should be covered at more than 90% to prevent coalescence. We therefore quantitatively link the process of adsorption/desorption, the stabilization of emulsions, and the kinetics of solute partitioning—here through ion exchange—unraveling the timescales governing these processes. Our method can be further generalized to other surfactants, including nonionic surfactants, by making use of fluorophore-surfactant interactions.

  15. Adsorptive removal of naphthalene induced by structurally different Gemini surfactants in a soil-water system.

    Science.gov (United States)

    Wei, Jia; Li, Jun; Huang, Guohe; Wang, Xiujie; Chen, Guanghui; Zhao, Baihang

    2016-09-01

    A new generation of surfactant, Gemini surfactants, have been synthesized and have attracted the attention of various industrial and academic research groups. This study focused on the use of symmetric and dissymmetric quaternary ammonium Gemini surfactants to immobilize naphthalene onto soil particles, and is used as an example of an innovative application to remove HOC in situ using the surfactant-enhanced sorption zone. The sorption capacity of modified soils by Gemini surfactant and natural soils was compared and the naphthalene sorption efficiency, in the absence and presence of Gemini surfactants with different alkyl chain lengths, was investigated in the soil-water system. The results have shown that the increased added Gemini surfactant formed admicelles at the interface of soil/water having superior capability to retard contaminant. Symmetric and dissymmetric Gemini surfactants have opposite effect on the aspect of removing of PAH attributing to their solubilization and sorption behavior in soil-water system. Compared with the natural soil, sorption of naphthalene by Gemini-modified soil is noticeably enhanced following the order of C12-2-16 < C12-2-12 < C12-2-8. However, the symmetric Gemini surfactant C12-2-12 is the optimized one for in situ barrier remediation, which is not only has relative high retention ability but also low dosage.

  16. Postdeposition dispersion of aerosol medications using surfactant carriers.

    Science.gov (United States)

    Marcinkowski, Amy L; Garoff, Stephen; Tilton, Robert D; Pilewski, Joseph M; Corcoran, Timothy E

    2008-12-01

    Inhaled aerosol drugs provide a means of directly treating the lungs; however, aerosol deposition and drug distribution can be nonuniform, especially in obstructive lung disease. We hypothesize that surfactant-based aerosol carriers will disperse medications over airway surfaces after deposition through surface tension driven flows, increasing dose uniformity and improving drug distribution into underventilated regions. We considered saline and surfactant aerosol delivery via cannula onto several model airway surfaces including porcine gastric mucus (PGM) and both cystic fibrosis (CF) and non-CF human bronchial epithelial cells (HBEs). Fluorescent dye and microspheres (d = 100 nm, 1 mum) were used to qualitatively and quantitatively assess postdeposition dispersion. Aerosol volume median diameters were in the 1-4 mum range. The tested surfactants included sodium dodecyl sulfate (SDS), cetyl trimethyl ammonium bromide (CTAB), tyloxapol, and calfactant. All surfactants tested on PGM (tyloxapol, calfactant, SDS, and CTAB) significantly increased dispersion area versus saline with all markers (2-20-fold increases; all p surfactants tested on CF HBEs (tyloxapol and calfactant) significantly increased dispersion area versus saline with all markers (1.6-4.1-fold increases; all p Surfactant carriers enhanced dispersion after aerosol deposition onto model airway surfaces, and may improve the efficacy of inhaled preparations such as inhaled antibiotics for cystic fibrosis.

  17. Inquiry and Aquifers.

    Science.gov (United States)

    Leuenberger, Ted; Shepardson, Daniel; Harbor, Jon; Bell, Cheryl; Meyer, Jason; Klagges, Hope; Burgess, Willie

    2001-01-01

    Presents inquiry-oriented activities that acquaint students with groundwater sources, movement of water through aquifers, and contamination of groundwater by pollution. In one activity, students use well log data from web-based resources to explore groundwater systems. Provides sample well log data for those not having access to local information.…

  18. Inquiry and Aquifers.

    Science.gov (United States)

    Leuenberger, Ted; Shepardson, Daniel; Harbor, Jon; Bell, Cheryl; Meyer, Jason; Klagges, Hope; Burgess, Willie

    2001-01-01

    Presents inquiry-oriented activities that acquaint students with groundwater sources, movement of water through aquifers, and contamination of groundwater by pollution. In one activity, students use well log data from web-based resources to explore groundwater systems. Provides sample well log data for those not having access to local information.…

  19. The use of surfactants to enhance the solubility and stability of the water-insoluble anticancer drug SN38 into liquid crystalline phase nanoparticles.

    Science.gov (United States)

    Ranneh, Abdul-Hackam; Iwao, Yasunori; Noguchi, Shuji; Oka, Toshihiko; Itai, Shigeru

    2016-12-30

    Cubosomes were used to increase the aqueous solubility of the water insoluble anticancer drug SN38. The results showed that the use of a common cubosome formulation consisting of phytantriol (PHYT) as the matrix amphiphile (PHYT-cubosome) led to a 6-fold increase in the solubility of SN38. However, mean hydrodynamic diameter (DH) and polydispersity index (PDI) of these PHYT-cubosome particles were 345±49nm and 0.37±0.05, respectively, making them unsuitable for intravenous applications. Several additives were investigated to increase the solubility of SN38 and reduce the DH and PDI values of the resulting particles. Charged additives such as didodecyldimethyl ammonium bromide (DDAB) and sodium dodecyl sulfate (SDS) led to improvements in the physiochemical properties of the cubosomes. Notably, the PHYT-DDAB and PHT-SDS cubosomes led to 15- and 14-fold increases in the aqueous solubility of SN38, respectively. Moreover, the SN38 loaded into the PHYT-DDAB and PHYT-SDS cubosomes was found to be highly stable, with very little hydrolysis to its inactive acid form. In summary, the addition of DDAB and SDS to PHYT-cubosome nanoparticle drug delivery systems not only led to considerable improvements in their physiochemical properties, but also enhanced the aqueous solubility of SN38 and increased its chemical stability. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Interaction of nonionic surfactant AEO9 with ionic surfactants*

    OpenAIRE

    2005-01-01

    The interaction in two mixtures of a nonionic surfactant AEO9 (C12H25O(CH2CH2O)9H) and different ionic surfactants was investigated. The two mixtures were AEO9/sodium dodecyl sulfate (SDS) and AEO9/cetyltrimethylammonium bromide (CTAB) at molar fraction of AEO9, α AEO9=0.5. The surface properties of the surfactants, critical micelle concentration (CMC), effectiveness of surface tension reduction (γ CMC), maximum surface excess concentration (Γ max) and minimum area per...

  1. MICROBIAL SURFACTANTS IN ENVIRONMENTAL TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    T. P. Pirog

    2015-08-01

    Full Text Available It was shown literature and own experimental data concerning the use of microbial surface active glycolipids (rhamno-, sophoro- and trehalose lipids and lipopeptides for water and soil purification from oil and other hydrocarbons, removing toxic heavy metals (Cu2+, Cd2+, Ni2+, Pb2+, degradation of complex pollution (oil and other hydrocarbons with heavy metals, and the role of microbial surfactants in phytoremediation processes. The factors that limit the use of microbial surfactants in environmental technologies are discussed. Thus, at certain concentrations biosurfactant can exhibit antimicrobial properties and inhibit microorganisms destructing xenobiotics. Microbial biodegradability of surfactants may also reduce the effectiveness of bioremediation. Development of effective technologies using microbial surfactants should include the following steps: monitoring of contaminated sites to determine the nature of pollution and analysis of the autochthonous microbiota; determining the mode of surfactant introduction (exogenous addition of stimulation of surfactant synthesis by autochthonous microbiota; establishing an optimal concentration of surfactant to prevent exhibition of antimicrobial properties and rapid biodegradation; research both in laboratory and field conditions.

  2. Electrokinetic investigation of surfactant adsorption.

    Science.gov (United States)

    Bellmann, C; Synytska, A; Caspari, A; Drechsler, A; Grundke, K

    2007-05-15

    Fuerstenau [D.W. Fuerstenau, in: M.L. Hair (Ed.), Dekker, New York, 1971, p. 143] has already discussed the role of hydrocarbon chain of surfactants, the effect of alkyl chain length, chain structure and the pH of the solution on the adsorption process of surfactants. Later Kosmulski [M. Kosmulski, Chemical Properties of Material Surfaces, Surfactant Science Series, vol. 102, Dekker, New York, Basel, 2001] included the effect of surfactant concentration, equilibration time, temperature and electrolyte in his approaches. Certainly, the character of the head groups of the surfactant and the properties of the adsorbent surface are the basis for the adsorption process. Different surfactants and adsorbents cause different adsorption mechanisms described firstly by Rosen [M.J. Rosen, Surfactants and Interfacial Phenomena, second ed., Wiley, New York, 1989]. These adsorption mechanisms and their influencing factors were studied by electrokinetic investigations. Here only changes of the charges at the surfaces could be detected. To control the results of electrokinetic investigations they were compared with results from ellipsometric measurements. In the case of surfactant adsorption the chain length was vitally important. It could be shown by the adsorption of alkyl trimethyl ammonium bromides onto polymer films spin coated at wafer surfaces. The influence of the chain length depending on surface properties of the polymer film was studied. Streaming potential measurements were applied for these investigations. The obtained results enabled us to calculate the molar cohesive free energy per mol of CH2-group in the alkaline chain of the surfactant if all other specific adsorption effects were neglected.

  3. Anaerobic Biodegradation of Detergent Surfactants

    Directory of Open Access Journals (Sweden)

    Erich Jelen

    2009-03-01

    Full Text Available Detergent surfactantscan be found in wastewater in relevant concentrations. Most of them are known as ready degradable under aerobic conditions, as required by European legislation. Far fewer surfactants have been tested so far for biodegradability under anaerobic conditions. The natural environment is predominantly aerobic, but there are some environmental compartments such as river sediments, sub-surface soil layer and anaerobic sludge digesters of wastewater treatment plants which have strictly anaerobic conditions. This review gives an overview on anaerobic biodegradation processes, the methods for testing anaerobic biodegradability, and the anaerobic biodegradability of different detergent surfactant types (anionic, nonionic, cationic, amphoteric surfactants.

  4. Transient exposure of pulmonary surfactant to hyaluronan promotes structural and compositional transformations into a highly active state.

    Science.gov (United States)

    Lopez-Rodriguez, Elena; Cruz, Antonio; Richter, Ralf P; Taeusch, H William; Pérez-Gil, Jesús

    2013-10-11

    Pulmonary surfactant is a lipid-protein complex that lowers surface tension at the respiratory air-liquid interface, stabilizing the lungs against physical forces tending to collapse alveoli. Dysfunction of surfactant is associated with respiratory pathologies such as acute respiratory distress syndrome or meconium aspiration syndrome where naturally occurring surfactant-inhibitory agents such as serum, meconium, or cholesterol reach the lung. We analyzed the effect of hyaluronan (HA) on the structure and surface behavior of pulmonary surfactant to understand the mechanism for HA-promoted surfactant protection in the presence of inhibitory agents. In particular, we found that HA affects structural properties such as the aggregation state of surfactant membranes and the size, distribution, and order/packing of phase-segregated lipid domains. These effects do not require a direct interaction between surfactant complexes and HA and are accompanied by a compositional reorganization of large surfactant complexes that become enriched with saturated phospholipid species. HA-exposed surfactant reaches very high efficiency in terms of rapid and spontaneous adsorption of surfactant phospholipids at the air-liquid interface and shows significantly improved resistance to inactivation by serum or cholesterol. We propose that physical effects pertaining to the formation of a meshwork of interpenetrating HA polymer chains are responsible for the changes in surfactant structure and composition that enhance surfactant function and, thus, resistance to inactivation. The higher resistance of HA-exposed surfactant to inactivation persists even after removal of the polymer, suggesting that transient exposure of surfactant to polymers like HA could be a promising strategy for the production of more efficient therapeutic surfactant preparations.

  5. 阴离子/非离子表面活性剂体系洗涤含油污泥%Experiment on enhanced washing of oily sludge by anionic/nonionic mixed surfactant

    Institute of Scientific and Technical Information of China (English)

    刁潘; 刘静; 张永奎; 刘瑾; 姚太平

    2014-01-01

    Preparation of complex detergent and experiments for the optimization of washing condition were conducted by treating the heavily oil-contaminated soil from an oilfield in Xinjiang. Orthogonal experiments were carried out to investigate the influence of concentrations of anionic surfactant, nonionic surfactant and the assistant washing agents (sodium silicate) on the residual oil content in the sample. It was found that there was a strong interaction between LAS and APEO,which enhanced washing effect and reduced the amount of detergent. The best detergent formulations were:sodium dodecyl benzene sulfonate (LAS) 2g/L,alkyl phenol ethoxylates (APEO) 3g/L,Na2SiO3 3g/L. The optimal liquid-solid ratio,temperature and washing time were 10∶1,70℃ and 1h. The oil content in sludge sample reduced from 26.07% to 1.21% by washing. The components removed by washing were analyzed by infrared spectroscopy (IR). It showed that most saturates,aromatics,resin, asphaltene in oily sludge were removed,which were considered as four main components in oil. Especially,saturates were removed obviously.%针对新疆某油田重度石油污染土壤,进行了洗涤剂的复配及洗脱条件的优化研究。考察了阴离子表面活性剂浓度、非离子表面活性剂浓度以及硅酸钠助剂浓度对残油量的影响。正交实验结果表明,十二烷基苯磺酸钠(LAS)与烷基酚聚氧乙烯醚(平平加,APEO)间存在着较强的交互协同作用;两者复配可以增强洗涤效果,并减少药剂用量。优化的复配洗涤剂配方为: LAS 2g/L,平平加3g/L,Na2SiO33g/L。复配洗涤剂洗涤含油污泥的最佳操作条件为:液固质量比10∶1、洗涤温度70℃、洗涤时间1h,在此条件下污泥含油量从26.07%降低至1.21%。对污泥洗涤前后的红外光谱检测表明该复配洗涤剂对于污泥中原油的饱和分、芳香分、胶质和沥青质都有洗涤效果,特别是对饱和分的去除效果尤为显著。

  6. Geochemical and isotopic composition of ground water with emphasis on sources of sulfate in the upper Floridan Aquifer and intermediate aquifer system in southwest Florida

    Science.gov (United States)

    Sacks, Laura A.; Tihansky, Ann B.

    1996-01-01

    has not dissolved significant amounts of gypsum compared to fresher water in the aquifer. This is consistent with a shallow seawater source for the saltwater, rather than a deeper source from the underlying middle confining unit or Lower Floridan aquifer, which would have elevated sulfate concentrations. Ion exchange and dolomitization may be important reactions for saltwater in the aquifer. According to geochemical modeling, the freshwater end member for water in the saltwater mixing zone in the southwestern part of the study area is not upgradient water from the Upper Floridan aquifer that dissolved gypsum. Instead, this water appears to be isolated from the regional freshwater flow system and may be part of a more localized flow system. The chemical and isotopic composition of water in the intermediate aquifer system is controlled by differences in extent of reactions with aquifer minerals, upward leakage from the Upper Floridan aquifer, and saltwater mixing. In inland areas, water generally is characterized by relatively low sulfate concentrations (less than 250 milligrams per liter) and differences in extent of carbonate mineral dissolution. Some inland waters have elevated chloride concentrations, which may be related to evaporation prior to recharge. In coastal Sarasota County and in isolated inland areas, water from the intermediate aquifer system has high sulfate concentrations characteristic of dedolomitization waters from the Upper Floridan aquifer. The chemical and isotopic composition of these waters is controlled by upward leakage from the Upper Floridan aquifer, which naturally occurs in the discharge area but may be locally enhanced by pumping or interconnection of wells open to both aquifer systems. In western Charlotte County, the waters are dominated by sodium and chloride, and their compositions are consistent with mixing between saltwater and inland intermediate aquifer system water that has not been influenced by discharge from the

  7. Small core flood experiments for foam EOR: screening surfactant applications

    NARCIS (Netherlands)

    Jones, S.A.; Van der Bent, V.; Farajzadeh, R.; Rossen, W.R.; Vincent-Bonnieu, S.

    2015-01-01

    Aqueous foams are a means of increasing the sweep efficiency of enhanced oil recovery processes. An understanding of how a foam behaves in the presence of oil is therefore of great importance when selecting suitable surfactants for EOR processes. The consensus is currently that the most reliable met

  8. Treatment with exogenous surfactant stimulates endogenous surfactant synthesis in premature infants with respiratory distress syndrome

    NARCIS (Netherlands)

    Bunt, JEH; Carnielli, VP; Janssen, DJ; Wattimena, JLD; Hop, WC; Sauer, PJ; Zimmermann, LJI

    2000-01-01

    Objective: Treatment of preterm infants with respiratory distress syndrome (RDS) with exogenous surfactant has greatly improved clinical outcome. Some infants require multiple doses, and it has not been studied whether these large amounts of exogenous surfactant disturb endogenous surfactant metabol

  9. Electrochemical Oscillations Induced by Surfactants

    Institute of Scientific and Technical Information of China (English)

    翟俊红; 贺占博

    2003-01-01

    A new type of electrochemical oscillation induced by surfactant was observed in experiments. The electrochemical system is a Daniell cell with a copper rod in CuSO4 aqueous and an aluminum rod in Al(NO3)3 aqueous as electrodes. The surfactants are CTAB, TX-100, SLS. The addition of trace surfactant solution by a micro-syringe made the original monotonously changing electrochemical system produce obvious periodic phenomena. At the mean time, the copper ion selective electrode and Hg2SO4 reference electrode were used to monitor the copper electrode reaction and determine its rate constant k of first order reaction. According to the experimental results of electrode reaction kinetics, the possible mechanism was found to be the polarization induced from the directional adsorption of trace surfactant on the electrode surface. That is the electrochemical oscillations.

  10. Characterization of Phase and Emulsion Behavior, Surfactant Retention, and Oil Recovery for Novel Alcohol Ethoxycarboxylate Surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Moeti, Lebone T.; Sampath, Ramanathan

    2002-03-13

    Electrical conductivity measurements for middle, bottom, and top phases, as well as bottom/middle, and middle/bottom conjugate pair phases of the NEODOX 23-4/dodecane/10mM water system were continued from the previous reporting period. Electrical conductivity of the mixture decreased as the fraction of volume of the middle phase was increased and vice versa. Also inversion phenomena was observed. Following this, more emulsion studies at various temperatures were progresses. A theoretical model to predict the conductivity measurements using Maxwell equations was developed and sensitivity analyses to test the performance of the model was completed. Surtek, Golden, CO, our industrial partner in this project, investigated the suitability of the surfactant for enhanced oil recovery employing coreflooding techniques and observed lower surfactant and hydrocarbon recovery for NEODOX 23-4.

  11. SOLUBILIZATION OF DODECANE, TETRACHLOROETHYLENE, AND 1,2-DICHLOROBENZENE IN MICELLAR SOLUTIONS OF ETHOXYLATED NONIONIC SURFACTANTS

    Science.gov (United States)

    Although surfactants have received considerable attention as a potential means for enhancing the recovery of organic compounds from the subsurface, only limited information is available regarding the micellar solubilization of common groundwater contaminants by nonionic surfactan...

  12. Effect of Y2(CO3)3 and Surfactants on Electrorheological Performance of SiO2 Particle Materials

    Institute of Scientific and Technical Information of China (English)

    许明远; 马淑珍; 李淑新; 李俊然; 张少华; 魏宸官; 高松

    2004-01-01

    The SiO2 particle material has weak electrorheological (ER) activity. The ER performance of the SiO2 particles can be ameliorated after adsorbing Y2(CO3)3. In this paper, the effect of Y2(CO3)3 and different surfactants on the ER performance of the SiO2 particle materials is investigated. The results show that anionic or cationic surfactants maybe enhance the ER activity of SiO2 material, and nonionic surfactants cannot when surfactants are added during the process of the SiO2 particle preparation, only the anionic surfactant, AES, can enhance markedly the ER performance of the material. The surface area, pore volume and pore diameter of the particles were measured. The effect of Y2(CO3)3 and the surfactants on the microstructure of SiO2 materials and the relationship between ER effect and the microstructure are described.

  13. Persurf, a New Method to Improve Surfactant Delivery: A Study in Surfactant Depleted Rats

    OpenAIRE

    2012-01-01

    PURPOSE: Exogenous surfactant is not very effective in adults with ARDS, since surfactant does not reach atelectatic alveoli. Perfluorocarbons (PFC) can recruit atelectatic areas but do not replace impaired endogenous surfactant. A surfactant-PFC-mixture could combine benefits of both therapies. The aim of the proof-of-principal-study was to produce a PFC-in-surfactant emulsion (Persurf) and to test in surfactant depleted Wistar rats whether Persurf achieves I.) a more homogenous pulmonary di...

  14. EPA Region 1 Sole Source Aquifers

    Data.gov (United States)

    U.S. Environmental Protection Agency — This coverage contains boundaries of EPA-approved sole source aquifers. Sole source aquifers are defined as an aquifer designated as the sole or principal source of...

  15. Sole Source Aquifers for NY and NJ

    Data.gov (United States)

    U.S. Environmental Protection Agency — This layer is the designated sole source aquifers of New York and New Jersey. A Sole Source Aquifer, is an aquifer that supplies 50% or more of the drinking water...

  16. Cell-specific modulation of surfactant proteins by ambroxol treatment.

    Science.gov (United States)

    Seifart, Carola; Clostermann, Ursula; Seifart, Ulf; Müller, Bernd; Vogelmeier, Claus; von Wichert, Peter; Fehrenbach, Heinz

    2005-02-15

    Ambroxol [trans-4-(2-amino-3,5-dibromobenzylamino)-cyclohexanole hydrochloride], a mucolytic agent, was postulated to provide surfactant stimulatory properties and was previously used to prevent surfactant deficiency. Currently, the underlying mechanisms are not exactly clear. Because surfactant homeostasis is regulated by surfactant-specific proteins (SP), we analyzed protein amount and mRNA expression in whole lung tissue, isolated type II pneumocytes and bronchoalveolar lavage of Sprague-Dawley rats treated with ambroxol i.p. (75 mg/kg body weight, twice a day [every 12 h]). The methods used included competitive polymerase chain reaction (RT-PCR), Northern blotting, Western immunoblotting, and immunohistochemistry. In isolated type II pneumocytes of ambroxol-treated animals, SP-C protein and mRNA content were increased, whereas SP-A, -B and -D protein, mRNA, and immunoreactivity remained unaffected. However, ambroxol treatment resulted in a significant increase of SP-B and in a decrease of SP-D in whole lung tissue with enhanced immunostaining for SP-B in Clara Cells. SP-A and SP-D were significantly decreased in BAL fluid of ambroxol-treated animals. The data suggest that surfactant protein expression is modulated in a cell-specific manner by ambroxol, as type II pneumocytes exhibited an increase in SP-C, whereas Clara cells exhibited an increase in the immunoreactivity for SP-B accounting for the increased SP-B content of whole lung tissue. The results indicate that ambroxol may exert its positive effects, observed in the treatment of diseases related to surfactant deficiency, via modulation of surfactant protein expression.

  17. Surfactant damages on coastal vegetation in southern Italy

    Directory of Open Access Journals (Sweden)

    2005-01-01

    Full Text Available Coastal vegetation decline caused by seaspray has been reported to affect a variety of species in several countries: Australia, South of France, along the Italian Tyrrhenian coast, Spain and Tunisia. The most serious injury is due to the interaction between sea salt and surfactants, even if surfactants may cause direct damage on cell membranes. The salt uptake is enhanced by the durfactant-induced erosion of the epicuticular wax, which reduces the water surface tension. The symptoms are non-specific and consist in leaf discoloration and necrosis. In needles, necrosis begins from the apex; in leaves, from the edges. Directionality of crown damage is the main symptom for diagnosing the involvement of polluted seaspray. If an obstacle is placed between trees and sea wind, the trees do not show appreciable damage. In Italy, the tree decline caused by seaspray and surfactants has been investigated with special reference to the pinewoods of the San Rossore (Tuscany, Central Italy, or on the Tyrrhenian coastlands of Central Italy, such as the area around Castelporziano in Lazio. This research is aimed at a preliminary assessment of the extent of surfactant damage to the coastal vegetation in four regions in Southern Italy by: i field surveys and mapping of damage caused by surfactants; ii detecting the presence of surfactants on the tree crowns. The damages have been observed in a lot of zones in Apulia, Basilicata, Campania and Calabria, within 500 m inland from the sea, for a maximum length of 5500 m coastline, near the mouth of a river or stream, near the outlet of sewage canals and in any other coastal areas where the surface currents carry a surfactant load.

  18. Non-covalent bonding interaction of surfactants with functionalized carbon nanotubes in proton exchange membranes for fuel cell applications.

    Science.gov (United States)

    Sayeed, M Abu; Kim, Young Ho; Park, Younjin; Gopalan, A I; Lee, Kwang-Pill; Choi, Sang-June

    2013-11-01

    Dispersion of functionalized multiwalled carbon nanotubes (MWCNTs) in proton exchange membranes (PEMs) was conducted via non-covalent bonding between benzene rings of various surfactants and functionalized MWCNTs. In the solution casting method, dispersion of functionalized MWCNTs in PEMs such as Nafion membranes is a critical issue. In this study, 1 wt.% pristine MWCNTs (p-MWCNTs) and oxidized MWCNTs (ox-MWCNTs) were reinforced in Nafion membranes by adding 0.1-0.5 wt.% of a surfactant such as benzalkonium chloride (BKC) as a cationic surfactant with a benzene ring, Tween-80 as a nonanionic surfactant without a benzene ring, sodium dodecylsulfonate (SDS) as an anionic surfactant without a benzene ring, or sodium dodecylben-zenesulfonate (SDBS) as an anionic surfactant with a benzene ring and their effects on the dispersion of nanocomposites were then observed. Among these surfactants, those with benzene rings such as BKC and SDBS produced enhanced dispersion via non-covalent bonding interaction between CNTs and surfactants. Specifically, the surfactants were adsorbed onto the surface of functionalized MWCNTs, where they prevented re-aggregation of MWCNTs in the nanocomposites. Furthermore, the prepared CNTs reinforced nanocomposite membranes showed reduced methanol uptake values while the ion exchange capacity values were maintained. The enhanced properties, including thermal property of the CNTs reinforced PEMs with surfactants, could be applicable to fuel cell applications.

  19. Utilizing surfactants to control the sorption, desorption, and biodegradation of phenanthrene in soil-water system.

    Science.gov (United States)

    Jin, Haiwei; Zhou, Wenjun; Zhu, Lizhong

    2013-07-01

    An integrative technology including the surfactant enhanced sorption and subsequent desorption and biodegradation of phenanthrene in the soil-water system was introduced and tested. For slightly contaminated agricultural soils, cationic-nonionic mixed surfactant-enhanced sorption of organic contaminants onto soils could reduce their transfer to plants, therefore safe-guarding agricultural production. After planting, residual surfactants combined with added nonionic surfactant could also promote the desorption and biodegradation of residual phenanthrene, thus providing a cost-effective pollution remediation technology. Our results showed that the cationic-nonionic mixed surfactants dodecylpyridinium bromide (DDPB) and Triton X-100 (TX100) significantly enhanced soil retention of phenanthrene. The maximum sorption coefficient Kd of phenanthrene for contaminated soils treated by mixed surfactants was about 24.5 times that of soils without surfactant (Kd) and higher than the combined effects of DDPB and TX100 individually, which was about 16.7 and 1.5 times Kd, respectively. On the other hand, TX100 could effectively remove phenanthrene from contaminated soils treated by mixed surfactants, improving the bioavailability of organic pollutants. The desorption rates of phenanthrene from these treated soils were greater than 85% with TX100 concentration above 2000 mg/L and approached 100% with increasing TX100 concentration. The biodegradation rates of phenanthrene in the presence of surfactants reached over 95% in 30 days. The mixed surfactants promoted the biodegradation of phenanthrene to some extent in 10-22 days, and had no obvious impact on phenanthrene biodegradation at the end of the experiment. Results obtained from this study provide some insight for the production of safe agricultural products and a remediation scheme for soils slightly contaminated with organic pollutants.

  20. 单一和混合表面活性剂对硫丹的增溶作用研究%Water Solubility Enhancement of Endosulfan by Single and Mixed Surfactant Solutions

    Institute of Scientific and Technical Information of China (English)

    熊佰炼; 张进忠

    2015-01-01

    研究了添加和不添加Na2SiO3两种情况下,单一和非/阴离子混合表面活性剂对硫丹的增溶作用。结果表明,不添加Na2SiO3时,单一表面活性剂中硫丹溶解度顺序为Tween 80>Triton X-100>SDS,与临界胶束浓度(CMCs)呈负相关。非、阴离子表面活性剂的质量比大于或等于4:1时,混合表面Tween 80/SDS和Triton X-100/SDS均对硫丹起协同增溶作用,Tween 80/SDS对硫丹的增溶能力强于Triton X-100/SDS。混合表面活性剂Tween 80/SDS和Triton X-100/SDS对硫丹的质量增溶比(WSR)分别与对应的单一非离子表面活性剂Tween 80和Triton X-100相差不大。添加Na2SiO3可提高单一和混合表面活性剂的增溶能力。Na2SiO3浓度为1000 mg·L-1的Tween 80和Tween 80/SDS溶液是硫丹良好的增溶剂。%The solubilization of endosulfan by single non-ionic surfactants and mixed anionic/non-ionic surfactants in the presence or ab-sence of Na2SiO3 was studied. The results showed that, in the absence of Na2SiO3, the solubilities of endosulfan followed a decreasing order of Tween 80, Triton X-100 and SDS, which were negatively correlated with critical micelle concentrations (CMCs) of these sur-factants. When the mass ratio of anionic and nonionic surfactants was not less than 4:1, the mixed surfactants Tween 80/SDS and Triton X-100/SDS both could synergistically increase the solubility of endosulfan, and the solubilization capacity of the former was stronger than the latter. The weight solubilization ratio (WSR) of mixed surfactants, i.e. Tween 80/SDS and Triton X-100/SDS, were similar to those corresponding single non-ionic surfactant. The addition of Na2SiO3 could increase the solubility of endosulfan in mixed surfactant and single surfactants. Compared with other surfactants, Tween 80/SDS and Tween 80 in the presence of Na2SiO3 have good efficacies for the solubilization to endosulfan.

  1. Anomalous diffusion and stress relaxation in surfactant micelles

    Science.gov (United States)

    Dhakal, Subas; Sureshkumar, Radhakrishna

    2017-07-01

    We investigate the mechanisms of anomalous diffusion in cationic surfactant micelles using molecular dynamics simulations in the presence of explicit salt and solvent-mediated interactions. Simulations show that when the counterion density increases, saddle-shaped branched interfaces manifest. In experiments, branched structures exhibit lower viscosity as compared to linear and wormlike micelles. This has long been attributed to stress relaxation arising from the sliding motion of branches along the main chain. Our simulations reveal a mechanism of branch motion resulting from an enhanced counterion condensation at the branched interfaces and provide quantitative evidence of stress relaxation facilitated by branched sliding. Furthermore, depending on the surfactant and salt concentrations, which in turn determine the microstructure, we observe normal, subdiffusive, and superdiffusive motions of surfactants. Specifically, superdiffusive behavior is associated with branch sliding, breakage and recombination of micelle fragments, as well as constraint release in entangled systems.

  2. Biomimicry of surfactant protein C.

    Science.gov (United States)

    Brown, Nathan J; Johansson, Jan; Barron, Annelise E

    2008-10-01

    Since the widespread use of exogenous lung surfactant to treat neonatal respiratory distress syndrome, premature infant survival and respiratory morbidity have dramatically improved. Despite the effectiveness of the animal-derived surfactant preparations, there still remain some concerns and difficulties associated with their use. This has prompted investigation into the creation of synthetic surfactant preparations. However, to date, no clinically used synthetic formulation is as effective as the natural material. This is largely because the previous synthetic formulations lacked analogues of the hydrophobic proteins of the lung surfactant system, SP-B and SP-C, which are critical functional constituents. As a result, recent investigation has turned toward the development of a new generation of synthetic, biomimetic surfactants that contain synthetic phospholipids along with a mimic of the hydrophobic protein portion of lung surfactant. In this Account, we detail our efforts in creating accurate mimics of SP-C for use in a synthetic surfactant replacement therapy. Despite SP-C's seemingly simple structure, the predominantly helical protein is extraordinarily challenging to work with given its extreme hydrophobicity and structural instability, which greatly complicates the creation of an effective SP-C analogue. Drawing inspiration from Nature, two promising biomimetic approaches have led to the creation of rationally designed biopolymers that recapitulate many of SP-C's molecular features. The first approach utilizes detailed SP-C structure-activity relationships and amino acid folding propensities to create a peptide-based analogue, SP-C33. In SP-C33, the problematic and metastable polyvaline helix is replaced with a structurally stable polyleucine helix and includes a well-placed positive charge to prevent aggregation. SP-C33 is structurally stable and eliminates the association propensity of the native protein. The second approach follows the same design

  3. High Temperature Aquifer Storage

    Science.gov (United States)

    Ueckert, Martina; Niessner, Reinhard; Baumann, Thomas

    2016-04-01

    Combined heat and power generation (CHP) is highly efficient because excess heat is used for heating and/or process energy. However, the demand of heat energy varies considerably throughout the year while the demand for electrical energy is rather constant. It seems economically and ecologically highly beneficial for municipalities and large power consumers such as manufacturing plants to store excess heat in groundwater aquifers and to recuperate this energy at times of higher demand. Within the project High Temperature Aquifer Storage, scientists investigate storage and recuperation of excess heat energy into the bavarian Malm aquifer. Apart from high transmissivity and favorable pressure gradients, the hydrochemical conditions are crucial for long-term operation. An enormous technical challenge is the disruption of the carbonate equilibrium - modeling results indicated a carbonate precipitation of 10 - 50 kg/d in the heat exchangers. The test included five injection pulses of hot water (60 °C up to 110 °C) and four tracer pulses, each consisting of a reactive and a conservative fluorescent dye, into a depth of about 300 m b.s.l. resp. 470 m b.s.l. Injection and production rates were 15 L/s. To achieve the desired water temperatures, about 4 TJ of heat energy were necessary. Electrical conductivity, pH and temperature were recorded at a bypass where also samples were taken. A laboratory container at the drilling site was equipped for analysing the concentration of the dyes and the major cations at sampling intervals of down to 15 minutes. Additional water samples were taken and analysed in the laboratory. The disassembled heat exchanger prooved that precipitation was successfully prevented by adding CO2 to the water before heating. Nevertheless, hydrochemical data proved both, dissolution and precipitation processes in the aquifer. This was also suggested by the hydrochemical modelling with PhreeqC and is traced back to mixture dissolution and changing

  4. Evaporation of Sessile Droplets Laden with Particles and Insoluble Surfactants.

    Science.gov (United States)

    Karapetsas, George; Chandra Sahu, Kirti; Matar, Omar K

    2016-07-12

    We consider the flow dynamics of a thin evaporating droplet in the presence of an insoluble surfactant and noninteracting particles in the bulk. On the basis of lubrication theory, we derive a set of evolution equations for the film height, the interfacial surfactant, and bulk particle concentrations, taking into account the dependence of liquid viscosity on the local particle concentration. An important ingredient of our model is that it takes into account the fact that the surfactant adsorbed at the interface hinders evaporation. We perform a parametric study to investigate how the presence of surfactants affects the evaporation process as well as the flow dynamics with and without the presence of particles in the bulk. Our numerical calculations show that the droplet lifetime is affected significantly by the balance between the ability of the surfactant to enhance spreading, suppressing the effect of thermal Marangoni stresses-induced motion, and to hinder the evaporation flux through the reduction of the effective interfacial area of evaporation, which tend to accelerate and decelerate the evaporation process, respectively. For particle-laden droplets and in the case of dilute solutions, the droplet lifetime is found to be weakly dependent on the initial particle concentration. We also show that the particle deposition patterns are influenced strongly by the direct effect of the surfactant on the evaporative flux; in certain cases, the "coffee-stain" effect is enhanced significantly. A discussion of the delicate interplay between the effects of capillary pressure and solutal and thermal Marangoni stresses, which drive the liquid flow inside of the evaporating droplet giving rise to the observed results, is provided herein.

  5. Surfactant for pediatric acute lung injury.

    Science.gov (United States)

    Willson, Douglas F; Chess, Patricia R; Notter, Robert H

    2008-06-01

    This article reviews exogenous surfactant therapy and its use in mitigating acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS) in infants, children, and adults. Biophysical and animal research documenting surfactant dysfunction in ALI/ARDS is described, and the scientific rationale for treatment with exogenous surfactant is discussed. Major emphasis is placed on reviewing clinical studies of surfactant therapy in pediatric and adult patients who have ALI/ARDS. Particular advantages from surfactant therapy in direct pulmonary forms of these syndromes are described. Also discussed are additional factors affecting the efficacy of exogenous surfactants in ALI/ARDS.

  6. Specific yield, High Plains aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents specific-yield ranges in the High Plains aquifer of the United States. The High Plains aquifer underlies 112.6 million acres (176,000...

  7. Emulsification at the Liquid/Liquid Interface: Effects of Potential, Electrolytes and Surfactants.

    Science.gov (United States)

    Chowdhury, Mehrin; Kataky, Ritu

    2016-01-04

    Emulsification of oils at liquid/liquid interfaces is of fundamental importance across a range of applications, including detergency. Adsorption and partitioning of the anionic surface active ions at the interface between two immiscible solutions is known to cause predictable chaos at the transfer potential region of the surfactant. In this work, the phenomenon that leads to the chaotic behaviour shown by sodium dodecylbenzene sulfonate (SDBS) at the water/1,2-dichloroethane interface is applied to commercial surfactants and aqueous/glyceryl trioleate interface. Electrochemical methods, electrocapillary curves, optical microscopy and conductivity measurements demonstrated that at 1.5 mm of SDBS, surfactants are adsorbed at the interface and assemble into micelles, leading to interfacial instability. As the concentration of the anionic surfactant was enhanced to 8 and 13.4 mm, the Marangoni effect and the interfacial emulsification became more prominent. The chaotic behaviour was found to be dependent on the surfactant concentration and the electrolytes present.

  8. Alkali/Surfactant/Polymer Flooding in the Daqing Oilfield Class II Reservoirs Using Associating Polymer

    Directory of Open Access Journals (Sweden)

    Ru-Sen Feng

    2013-01-01

    Full Text Available Hydrophobically modified associating polyacrylamide (HAPAM has good compatibility with the Daqing heavy alkylbenzene sulfonate surfactant. The HAPAM alkali/surfactant/polymer (ASP system can generate ultralow interfacial tension in a wide range of alkali/surfactant concentrations and maintain stable viscosity and interfacial tension for 120 days. The HAPAM ASP system has good injectivity for the Daqing class II reservoirs (100–300 × 10−3 μm2 and can improve oil recovery by more than 25% on top of water flooding. In the presence of both the alkali and the surfactant, the surfactant interacts with the associating groups of the polymer to form more micelles, which can significantly enhance the viscosity of the ASP system. Compared with using HPAM (Mw = 2.5 MDa, using HAPAM can reduce the polymer use by more than 40%.

  9. SCREENING METHODS FOR SELECTION OF SURFACTANT FORMULATIONS FOR IOR FROM FRACTURED CARBONATE RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    William A. Goddard III; Yongchun Tang; Patrick Shuler; Mario Blanco; Yongfu Wu; Seung Soon Jang

    2005-07-01

    This topical report presents details of the laboratory work performed to complete Task 1 of this project; developing rapid screening methods to assess surfactant performance for IOR (Improved Oil Recovery) from fractured carbonate reservoirs. The desired outcome is to identify surfactant formulations that increase the rate and amount of aqueous phase imbibition into oil-rich, oil-wet carbonate reservoir rock. Changing the wettability from oil-wet to water-wet is one key to enhancing this water-phase imbibition process that in turn recovers additional oil from the matrix portion of a carbonate reservoir. The common laboratory test to evaluate candidate surfactant formulations is to measure directly the aqueous imbibition rate and oil recovery from small outcrop or reservoir cores, but this procedure typically requires several weeks. Two methods are presented here for the rapid screening of candidate surfactant formulations for their potential IOR performance in carbonate reservoirs. One promising surfactant screening protocol is based on the ability of a surfactant solution to remove aged crude oil that coats a clear calcite crystal (Iceland Spar). Good surfactant candidate solutions remove the most oil the quickest from the chips, plus change the apparent contact angle of the remaining oil droplets on the surface that thereby indicate increased water-wetting. The other fast surfactant screening method is based on the flotation behavior of powdered calcite in water. In this test protocol, first the calcite power is pre-treated to make the surface oil-wet. The next step is to add the pre-treated powder to a test tube and add a candidate aqueous surfactant formulation; the greater the percentage of the calcite that now sinks to the bottom rather than floats, the more effective the surfactant is in changing the solids to become now preferentially water-wet. Results from the screening test generally are consistent with surfactant performance reported in the literature.

  10. Electrodialytic remediation of polychlorinated biphenyls contaminated soil with iron nanoparticles and two different surfactants

    DEFF Research Database (Denmark)

    Gomes, Helena I.; Dias-Ferreira, Celia; Ottosen, Lisbeth M.

    2014-01-01

    nanoparticles (nZVI) could be a competitive alternative to the commonly adapted solutions of incineration or landfilling. Surfactants can enhance the PCB desorption, dechlorination, and the contaminated soil cleanup. In this work, two different surfactants (saponin and Tween 80) were tested to enhance PCB...... desorption and removal from a soil sampled at a polluted site, in a two-compartment cell where the soil was stirred in a slurry with 1% surfactant, 10mL of nZVI commercial suspension, and a voltage gradient of 1Vcm(-1). The highest PCB removal was obtained with saponin. Higher chlorinated PCB congeners...... (penta, hexa, hepta and octachlorobiphenyl) showed removal percentages between 9% and 96%, and the congeners with highest removal were PCB138, PCB153 and PCB180. The use of low level direct current enhanced PCB removal, especially with saponin. Electrodechlorination of PCB with surfactants and n...

  11. Single well surfactant test to evaluate surfactant floods using multi tracer method

    Science.gov (United States)

    Sheely, Clyde Q.

    1979-01-01

    Data useful for evaluating the effectiveness of or designing an enhanced recovery process said process involving mobilizing and moving hydrocarbons through a hydrocarbon bearing subterranean formation from an injection well to a production well by injecting a mobilizing fluid into the injection well, comprising (a) determining hydrocarbon saturation in a volume in the formation near a well bore penetrating formation, (b) injecting sufficient mobilizing fluid to mobilize and move hydrocarbons from a volume in the formation near the well bore, and (c) determining the hydrocarbon saturation in a volume including at least a part of the volume of (b) by an improved single well surfactant method comprising injecting 2 or more slugs of water containing the primary tracer separated by water slugs containing no primary tracer. Alternatively, the plurality of ester tracers can be injected in a single slug said tracers penetrating varying distances into the formation wherein the esters have different partition coefficients and essentially equal reaction times. The single well tracer method employed is disclosed in U.S. Pat. No. 3,623,842. This method designated the single well surfactant test (SWST) is useful for evaluating the effect of surfactant floods, polymer floods, carbon dioxide floods, micellar floods, caustic floods and the like in subterranean formations in much less time and at much reduced cost compared to conventional multiwell pilot tests.

  12. Desorption of two organophosphorous pesticides from soil with wastewater and surfactant solutions.

    Science.gov (United States)

    Hernández-Soriano, M C; Mingorance, M D; Peña, A

    2012-03-01

    A batch test was used to evaluate the extent of desorption of diazinon and dimethoate, preadsorbed on a calcareous agricultural soil, representative of the Mediterranean area. Urban wastewater from a secondary treatment and seven surfactant solutions, at concentrations ranging from 0.75 mg L(-1) to 10 gL(-1), were used. The surfactants assayed were cationic (hexadecyl trimethyl ammonium bromide (HD)), anionic (sodium dodecyl sulfate (SDS), Aerosol 22 (A22) and Biopower (BP)), and nonionic (Tween 80 (TW), Triton X 100 (TX) and Glucopon 600 (G600)). Desorption of dimethoate was either not affected or only slightly by the nonionic and anionic surfactants tested, while desorption of diazinon from the soil was only enhanced by A22, BP and TW. This desorption increase correlated significantly with the surfactant concentration of the solution used for desorption and with the concurrent increase in the supernatant of the dissolved organic carbon, in particular that originating from the surfactant. This parameter did not vary with the use of SDS, G600 and TX. The cationic surfactant HD was retained on the soil surface, as confirmed by an increase in soil organic carbon, resulting in a fall in desorption rate for both pesticides. Comparing treatment by wastewater with control water, there was no difference in desorption rate for either pesticide. Mixed TW/anionic surfactant solutions either did not modify or slightly increased desorption of both pesticides in comparison with individual surfactant solutions.

  13. Non-ionic surfactants do not consistently improve the enzymatic hydrolysis of pure cellulose.

    Science.gov (United States)

    Zhou, Yan; Chen, Hongmei; Qi, Feng; Zhao, Xuebing; Liu, Dehua

    2015-04-01

    Non-ionic surfactants have been frequently reported to improve the enzymatic hydrolysis of pretreated lignocellulosic biomass and pure cellulose. However, how the hydrolysis condition, substrate structure and cellulase formulation affect the beneficial action of surfactants has not been well elucidated. In this work, it was found that the enzymatic hydrolysis of pure cellulose was not consistently improved by surfactants. Contrarily, high surfactant concentration, e.g. 5 g/L, which greatly improved the hydrolysis of dilute acid pretreated substrates, actually showed notable inhibition to pure cellulose conversion in the late phase of hydrolysis. Under an optimal hydrolysis condition, the improvement by surfactant was limited, but under harsh conditions surfactant indeed could enhance cellulose conversion. It was proposed that non-ionic surfactants could interact with substrates and cellulases to impact the adsorption behaviors of cellulases. Therefore, the beneficial action of surfactants on pure cellulose hydrolysis is influenced by hydrolysis condition, cellulose structural features and cellulase formulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Anaerobic digestion of aircraft deicing fluid wastes: interactions and toxicity of corrosion inhibitors and surfactants.

    Science.gov (United States)

    Gruden, Cyndee L; Hernandez, Mark

    2002-01-01

    Corrosion inhibitors and surfactants are present in aircraft deicing fluids (ADFs) at significant concentrations (> 1% w/w). The purpose of this research was to study the interactions of a common nonionic surfactant with the commercially significant corrosion inhibitors used in modern ADF (4- and 5-methylbenzotriazole [MeBT]), and to determine the effects of their mixture on the conventional anaerobic digestion process. In mesophilic anaerobic microcosms codigesting wastewater solids, propylene glycol, and MeBT, increasing surfactant levels resulted in enhanced MeBT sorption on digester solids. As judged by anaerobic toxicity assays, responses from digesters containing surfactant concentrations below their critical micelle concentration (CMC) suggested that low nonionic surfactant concentrations could facilitate a reduction in the apparent toxicity of MeBT. In microcosms exposed to surfactant concentrations above their CMC, no increase in MeBT solubility was observed, and the anaerobic toxicity response corresponded to control systems not containing surfactant. Direct microscopic measurements of digesting biomass using fluorescent phylogenetic probes (fluorescent in situ hybridization) revealed that members of the domain Bacteria were more sensitive to MeBT in the presence of surfactant than were members of the domain Archaea.

  15. Mobilization of arsenic from contaminated sediment by anionic and nonionic surfactants.

    Science.gov (United States)

    Liang, Chuan; Peng, Xianjia

    2017-06-01

    The increasing manufacture of surfactants and their wide application in industry, agriculture and household detergents have resulted in large amounts of surfactant residuals being discharged into water and distributed into sediment. Surfactants have the potential to enhance arsenic mobility, leading to risks to the environment and even human beings. In this study, batch and column experiments were conducted to investigate arsenic mobilization from contaminated sediment by the commercial anionic surfactants sodium dodecylbenzenesulfonate (SDBS), sodium dodecyl sulfate (SDS), sodium laureth sulfate (AES) and nonionic surfactants phenyl-polyethylene glycol (Triton X-100) and polyethylene glycol sorbitan monooleate (Tween-80). The ability of surfactants to mobilize arsenic followed the order AES>SDBS>SDS≈Triton X-100>Tween 80. Arsenic mobilization by AES and Triton X-100 increased greatly with the increase of surfactant concentration and pH, while arsenic release by SDBS, SDS and Tween-80 slightly increased. The divalent ion Ca(2+) caused greater reduction of arsenic mobilization than Na(+). Sequential extraction experiments showed that the main fraction of arsenic mobilized was the specifically adsorbed fraction. Solid phase extraction showed that arsenate (As(V)) was the main species mobilized by surfactants, accounting for 65.05%-77.68% of the total mobilized arsenic. The mobilization of arsenic was positively correlated with the mobilization of iron species. The main fraction of mobilized arsenic was the dissolved fraction, accounting for 70% of total mobilized arsenic. Copyright © 2016. Published by Elsevier B.V.

  16. Exposure to polymers reverses inhibition of pulmonary surfactant by serum, meconium, or cholesterol in the captive bubble surfactometer.

    Science.gov (United States)

    López-Rodríguez, Elena; Ospina, Olga Lucía; Echaide, Mercedes; Taeusch, H William; Pérez-Gil, Jesús

    2012-10-03

    Dysfunction of pulmonary surfactant in the lungs is associated with respiratory pathologies such as acute respiratory distress syndrome or meconium aspiration syndrome. Serum, cholesterol, and meconium have been described as inhibitory agents of surfactant's interfacial activity once these substances appear in alveolar spaces during lung injury and inflammation. The deleterious action of these agents has been only partly evaluated under physiologically relevant conditions. We have optimized a protocol to assess surfactant inhibition by serum, cholesterol, or meconium in the captive bubble surfactometer. Specific measures of surface activity before and after native surfactant was exposed to inhibitors included i), film formation, ii), readsorption of material from surface-associated reservoirs, and iii), interfacial film dynamics during compression-expansion cycling. Results show that serum creates a steric barrier that impedes surfactant reaching the interface. A mechanical perturbation of this barrier allows native surfactant to compete efficiently with serum to form a highly surface-active film. Exposure of native surfactant to cholesterol or meconium, on the other hand, modifies the compressibility of surfactant films though optimal compressibility properties recover on repetitive compression-expansion cycling. Addition of polymers like dextran or hyaluronic acid to surfactant fully reverses inhibition by serum. These polymers also prevent surfactant inhibition by cholesterol or meconium, suggesting that the protective action of polymers goes beyond the mere enhancement of interfacial adsorption as described by depletion force theories.

  17. Visualization of TCE recovery mechanisms using surfactant-polymer solutions in a two-dimensional heterogeneous sand model.

    Science.gov (United States)

    Robert, Thomas; Martel, Richard; Conrad, Stephen H; Lefebvre, René; Gabriel, Uta

    2006-06-30

    This research focused on the optimization of TCE dissolution in a physical two-dimensional model providing a realistic representation of a heterogeneous granular aquifer. TCE was infiltrated in the sand pack where it resided both in pools and in zones of residual saturation. Surfactant was initially injected at low concentration to minimize TCE remobilization at first contact but was incrementally increased later during the experiment. Xanthan gum was added to the injected surfactant solution to optimize the sweep efficiency through the heterogeneous medium. Photographs and digital image analysis illustrated the interactions between TCE and the injected fluids. During the polymer flood, the effects of heterogeneities inside the sand pack were greatly reduced by the increased fluid viscosity and the shear-thinning effects of the polymer. The polymer also improved the contact between the TCE ganglia and the surfactant-polymer solution, thereby promoting dissolution. Surfactants interacted with the polymer reducing the overall viscosity of the solution. At first contact with a 0.5%(mass) surfactant solution, the TCE pools drained and some remobilization occurred. However, no TCE bank was formed and TCE did not penetrate into any previously uncontaminated areas. As a result, TCE surface area was increased. Subsequent surfactant floods at higher surfactant concentrations did not trigger more remobilization. TCE was mainly dissolved by the solution with the highest surfactant concentration. Plugging from bacterial growth or microgel formation associated to the polymer at the inflow screen prevented the full completion of the experiment. However, more than 90% of TCE was recovered with the circulation of less than 6 pore volumes of surfactant-polymer solution.

  18. Surfactant recovery from water using foam fractionation

    Energy Technology Data Exchange (ETDEWEB)

    Tharapiwattananon, N.; Osuwan, S. [Chulalongkorn Univ., Bangkok (Thailand); Scamehorn, J.F. [Inst. of Oklahoma, Norman, OK (United States)] [and others

    1996-05-01

    The purpose of this study was to investigate the use of foam fractionation to recover surfactant from water. A simple continuous mode foam fractionation was used and three surfactants were studied (two anionic and one cationic). The effects of air flow rate, foam height, liquid height, liquid feed surfactant concentration, and sparger porosity were studied. This technique was shown to be effective in either surfactant recovery or the reduction of surfactant concentration in water to acceptable levels. As an example of the effectiveness of this technique, the cetylpyridinium chloride concentration in water can be reduced by 90% in one stage with a liquid residence time of 375 minutes. The surfactant concentration in the collapsed foam is 21.5 times the feed concentration. This cationic surfactant was easier to remove from water by foam fractionation than the anionic surfactants studied.

  19. Synthesis of carbohydrate-based surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Pemberton, Jeanne E.; Polt, Robin L.; Maier, Raina M.

    2016-11-22

    The present invention provides carbohydrate-based surfactants and methods for producing the same. Methods for producing carbohydrate-based surfactants include using a glycosylation promoter to link a carbohydrate or its derivative to a hydrophobic compound.

  20. Degradation of Surfactants in Hydroponic Wheat Root Zones

    Science.gov (United States)

    Monje, Oscar; McCoy, Lashelle; Flanagan, Aisling

    Hygiene water recycling in recirculating hydroponic systems can be enhanced by plant roots by providing a substrate and root exudates for bacterial growth. However, reduced plant growth can occur during batch mode additions of high concentrations of surfactant. An analog hygiene water stream containing surfactants (Steol CS330, Mirataine CB) was added to a hydroponically-grown wheat plant root zone. The plants were grown at 700 mol mol-1 CO2, a photosynthetic photon flux of 300 mol m-2 s-1, and a planting density of 380 plants m-2. Volumetric oxygen mass transfer coefficients were determined using the fermentative/dynamic outgassing method to maintain adequate oxygen mass transfer rates in the root zone. This analysis suggested an optimal flow rate of the hydroponic solution of 5 L min-1. The hydroponic system was inoculated with biofilm from a bioreactor and rates of surfactant degradation were measured daily based on reduction in chemical oxygen demand (COD). The COD decreased from 400 to 100 mg L-1 after 2 days following batch addition of the analog hygiene water to the hydroponic system. Measurements of dissolved oxygen concentration and solution temperature suggest that the root zone was provided adequate aeration to meet both oxygen demands from plant and microbial respiration during the degradation of the surfactant. Results from this study show that hydroponic systems can be used to enhance rates of hygiene water processing.

  1. Optimization of the Implementation of Managed Aquifer Recharge - Effects of Aquifer Heterogeneity

    Science.gov (United States)

    Maliva, Robert; Missimer, Thomas; Kneppers, Angeline

    2010-05-01

    Managed aquifer recharge (MAR) has become a key component of integrated water resources management, especially in water scarce regions. MAR can serve the dual role of increasing the supply of available water and improving the quality of recharged water through natural attenuation processes. The performance of MAR systems is highly dependent upon site-specific hydrogeological conditions. Aquifer heterogeneity, such as the presence of high-permeability preferential flow zones and dual or even the so-called triple-porosity conditions, has been responsible for the under performance or failure of some MAR systems. Aquifer heterogeneity can result in much more rapid and unpredictable movement and mixing of recharged water and the bypassing of natural attenuation processes. A critical element of MAR projects is a detailed aquifer characterization and the development of groundwater flow and solute transport models at the appropriate spatial and temporal scales that accurately simulate local heterogeneous flow systems. Geochemical modeling based on high-quality, site-specific mineralogical and water chemistry data can also be used to predict the potential for adverse water-rock interactions such as the leaching of arsenic and trace metals into recharged water. Hydrogeological conditions that could lead to poor system performance should be identified early in the project development before the investment is made to construct a full-scale system. Hydrogeological conditions that have lead to poor MAR system performance are typically identifiable at the exploratory well stage of projects. Early detection of adverse hydrogeological conditions provides an opportunity to either abandon a likely under-performing project, select an alternative site with more favorable conditions, or modify the system design to be more compatible with local hydrogeology. Advanced borehole geophysical techniques and workflow software can allow for enhanced aquifer characterization and thus allow for

  2. Effects of Concentration and Conformation of Surfactants on Phase Separation of Surfactant-Water-Oil Systems

    Institute of Scientific and Technical Information of China (English)

    袁银权; 邹宪武; 刘昊阳

    2004-01-01

    The effects of surfactants on the phase separation of surfactant-water-oil systems have been investigated by using discontinuous molecular dynamic simulations. The phase separation speed and equilibrium configuration are dependent on the surfactant concentration and conformation. The equilibrium concentration of surfactants at the interface remains constant. With the increasing surfactant concentration, the equilibrium configuration crosses over from the disperse phase to the bicontinuous one. The crossover concentration is estimated. The conformation of the surfactant has little effect on the equilibrium concentration of surfactants at the interface,while it affects the equilibrium configuration after phase separation.

  3. Complex Formation Between Polyelectrolytes and Ionic Surfactants

    OpenAIRE

    1998-01-01

    The interaction between polyelectrolyte and ionic surfactant is of great importance in different areas of chemistry and biology. In this paper we present a theory of polyelectrolyte ionic-surfactant solutions. The new theory successfully explains the cooperative transition observed experimentally, in which the condensed counterions are replaced by ionic-surfactants. The transition is found to occur at surfactant densities much lower than those for a similar transition in non-ionic polymer-sur...

  4. Vapour-liquid equilibrium relationship between toluene and mixed surfactants.

    Science.gov (United States)

    Tian, Senlin; Li, Yingjie; Mo, Hong; Ning, Ping

    2012-01-01

    Micellar partitioning of volatile organic compounds (VOCs) in surfactant solutions and its effects on vapour-liquid equilibrium is fundamental to the overall design and implementation ofsurfactant-enhanced remediation. Knowledge of the vapour-liquid equilibrium partitioning coefficients for VOCs, especially in contaminated soils and groundwater in which they exist, is required. Headspace experiments were performed to quantify the effect of three mixed surfactants, cetyltrimethyl ammonium bromide (CTMAB) with tetrabutylammonium bromide (TBAB), sodium dodecyl sulphate (SDS) with Triton X-405 (TX405), and CTMAB with Triton X-100 (TX100), on the apparent Henry's constants (Hc) of toluene at temperatures ranging from 25 degrees C to 40 degrees C. The Hc values were significantly reduced in the presence of all three mixed surfactants at concentrations above their critical micelle concentrations (CMC). Mixed micellar partitioning, showing effects on the vapour-liquid equilibrium of toluene, was primarily responsible for the significant reduction of Hc in their mixed systems. The mixed surfactants CTMAB-TX100 had the greatest effect on Hc above the CMC, followed by SDS-TX405, then CTMAB-TBAB. Mixed systems of CTMAB-TX100 decreased Hc at concentrations significantly lower than the SDS-TX405 and CTMAB-TBAB concentrations, because of to the lower CMC of CTMAB-TX100. Vapour-liquid equilibrium data were also tested against the model (Hc = H/(1 + K(X - CMC)) that described the partitioning of VOCs in vapour-water-micelle phases. The correlation of Hc with mixed surfactant concentrations (X) and CMC can be utilized as an effective tool to predict the Hc by mixed surfactants.

  5. Binding of cationic surfactants to humic substances

    NARCIS (Netherlands)

    Ishiguro, M.; Tan, W.; Koopal, L.K.

    2007-01-01

    Commercial surfactants are introduced into the environment either through waste products or site-specific contamination. The amphiphilic nature of both surfactants and humic substances (HS) leads to their mutual attraction especially when surfactant and HS are oppositely charged. Binding of the cati

  6. Surfactant adsorption to soil components and soils

    NARCIS (Netherlands)

    Ishiguro, Munehide; Koopal, Luuk K.

    2016-01-01

    Soils are complex and widely varying mixtures of organic matter and inorganic materials; adsorption of surfactants to soils is therefore related to the soil composition. We first discuss the properties of surfactants, including the critical micelle concentration (CMC) and surfactant adsorption on

  7. Effect of a commercial alcohol ethoxylate surfactant (C11-15E7) on biodegradation of phenanthrene in a saline water medium by Neptunomonas naphthovorans.

    Science.gov (United States)

    Li, Jing-Liang; Bai, Renbi

    2005-02-01

    Biodegradation of poorly soluble polycyclic aromatic hydrocarbons (PAHs) has been a challenge in bioremediation. In recent years, surfactant-enhanced bioremediation of PAH contaminants has attracted great attention in research. In this study, biodegradation of phenanthrene as a model PAHs solubilized in saline micellar solutions of a biodegradable commercial alcohol ethoxylate nonionic surfactant was investigated. The critical micelle concentration (CMC) of the surfactant and its solubilization capacity for phenanthrene were examined in an artificial saline water medium, and a type of marine bacteria, Neptunomonas naphthovorans, was studied for the biodegradation of phenanthrene solubilized in the surfactant micellar solutions of the saline medium. It is found that the solubility of phenanthrene in the surfactant micellar solutions increased linearly with the surfactant concentrations, but, at a fixed phenanthrene concentration, the biodegradability of phenanthrene in the micellar solutions decreased with the increase of the surfactant concentrations. This was attributed to the reduced bioavailability of phenanthrene, due to its increased solubilization extent in the micellar phase and possibly lowered mass transfer rate from the micellar phase into the aqueous phase or into the bacterial cells. In addition, an inhibitory effect of the surfactant on the bacterial growth at high surfactant concentrations may also play a role. It is concluded that the surfactant largely enhanced the solubilization of phenanthrene in the saline water medium, but excess existence of the surfactant in the medium should be minimized or avoided for the biodegradation of phenanthrene by Neptunomonas naphthovorans.

  8. Base of aquifer contours for the Northern High Plains aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Several pre-existing datasets that characterize portions of the Northern High Plains aquifer base were merged together in order to define the entire base of the...

  9. Contrasting definitions for the term `karst aquifer'

    Science.gov (United States)

    Worthington, Stephen R. H.; Jeannin, Pierre-Yves; Alexander, E. Calvin; Davies, Gareth J.; Schindel, Geary M.

    2017-08-01

    It is generally considered that karst aquifers have distinctly different properties from other bedrock aquifers. A search of the literature found five definitions that have been proposed to differentiate karst aquifers from non-karstic aquifers. The five definitions are based upon the presence of solution channel networks, hydraulic conductivities >10-6 m/s, karst landscapes, channels with turbulent flow, and caves. The percentage of unconfined carbonate aquifers that would classify as `karst' ranges from 50%.

  10. Influence of nonionic surfactant on the solubilization and biodegradation of phenanthrene

    Institute of Scientific and Technical Information of China (English)

    YANG Jian-gang; LIU Xiang; LONG Tao; YU Gang; PENG She; ZHENG Liu

    2003-01-01

    Phenanthrene was solubilized in two different nonionic surfactants, Tween80 and Triton X-100. The bioavailability of phenanthrene to the bacteria isolated from the petroleum contaminated soils was studied based on the rotary flasks experiments. The results showed that the concentration of nonionic surfactants above the critical micelle concentration(CMC) can increase the solubility of phenanthrene in water and were innoxious to the phenanthrene-degrading bacteria; phenanthrene solubilized in the micelles of Tween80 was bioavailable and biodegradable. The research demonstrated the potential of surfactant-enhanced bioremediation of soils contaminated by hydrophobic organic compounds( HOCs).

  11. Persurf, a new method to improve surfactant delivery: a study in surfactant depleted rats.

    Directory of Open Access Journals (Sweden)

    Wolfram Burkhardt

    Full Text Available PURPOSE: Exogenous surfactant is not very effective in adults with ARDS, since surfactant does not reach atelectatic alveoli. Perfluorocarbons (PFC can recruit atelectatic areas but do not replace impaired endogenous surfactant. A surfactant-PFC-mixture could combine benefits of both therapies. The aim of the proof-of-principal-study was to produce a PFC-in-surfactant emulsion (Persurf and to test in surfactant depleted Wistar rats whether Persurf achieves I. a more homogenous pulmonary distribution and II. a more homogenous recruitment of alveoli when compared with surfactant or PFC alone. METHODS: Three different PFC were mixed with surfactant and phospholipid concentration in the emulsion was measured. After surfactant depletion, animals either received 30 ml/kg of PF5080, 100 mg/kg of stained (green dye Curosurf™ or 30 ml/kg of Persurf. Lungs were fixated after 1 hour of ventilation and alveolar aeration and surfactant distribution was estimated by a stereological approach. RESULTS: Persurf contained 3 mg/ml phospholipids and was stable for more than 48 hours. Persurf-administration improved oxygenation. Histological evaluation revealed a more homogenous surfactant distribution and alveolar inflation when compared with surfactant treated animals. CONCLUSIONS: In surfactant depleted rats administration of PFC-in-surfactant emulsion leads to a more homogenous distribution and aeration of the lung than surfactant alone.

  12. [Strengthening Effects of Sodium Salts on Washing Kerosene Contaminated Soil with Surfactants].

    Science.gov (United States)

    Huang, Zhao-lu; Chen, Quan-yuan; Zhou, Juan; Xie, Mo-han

    2015-05-01

    The impact of sodium salt on kerosene contaminated soil washing with surfactants was investigated. The results indicated that sodium silicate greatly enhanced the washing efficiency of SDS. Sodium tartrate can largely enhance the washing efficiency of SDBS and Brij35. Sodium salts can enhance the washing efficiency on kerosene contaminated with TX-100. No significant differences were observed between different sodium salts. Sodium salt of humic acid and sodium silicate had similar enhancement on kerosene contaminated soil washing with saponin. Sodium humate can be a better choice since its application can also improve soil quality. The enhancement of sodium silicate on kerosene contaminated soil washing with Tw-80 increased with the increase of Tw-80 dosage. However, the impact of sodium chloride and sodium tartrate was opposite to sodium silicate. Sodium salts can reduce surface tension and critical micelle concentration of ionic surfactants to enhance the washing. Sodium salts can also reduce re-adsorption of oil to soil with nonionic surfactants to enhance the washing. Kerosene contamination can increase the contact angle of soil, which indicated the increase of hydrophilicity of soil. Washing with surfactants can reduce the hydrophilicitiy of soil according to contact angle measurement, which indicated that kerosene contaminated soil remediation with surfactant can also benefit nutrient and water transportation in the contaminated soil.

  13. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid isolated terrace aquifer covers...

  14. Digital data sets that describe aquifer characteristics of the Elk City aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries for the Elk City aquifer in western Oklahoma. The aquifer covers an area of approximately 193,000 acres and...

  15. Physical properties of botanical surfactants.

    Science.gov (United States)

    Müller, Lillian Espíndola; Schiedeck, Gustavo

    2017-08-24

    Some vegetal species have saponins in their composition with great potential to be used as natural surfactants in organic crops. This work aims to evaluate some surfactants physical properties of Quillaja brasiliensis and Agave angustifolia, based on different methods of preparation and concentration. The vegetal samples were prepared by drying and grinding, frozen and after chopped or used fresh and chopped. The neutral bar soap was used as a positive control. The drying and grinding of samples were the preparation method that resulted in higher foam column height in both species but Q. brasiliensis was superior to A. angustifolia in all comparisons and foam index was 2756 and 1017 respectively. Critical micelle concentration of Q. brasiliensis was 0.39% with the superficial tension of 54.40mNm(-1) while neutral bar soap was 0.15% with 34.96mNm(-1). Aspects such as genetic characteristics of the species, environmental conditions, and analytical methods make it difficult to compare the results with other studies, but Q. brasiliensis powder has potential to be explored as a natural surfactant in organic farming. Not only the surfactants physical properties of botanical saponins should be taken into account but also its effect on insects and diseases control when decided using them. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Interactions of Ovalbumin with Ionic Surfactants

    Institute of Scientific and Technical Information of China (English)

    GUO Xia; YAN Hui; GUO Rong

    2008-01-01

    The interactions of ovalbumin (OVA) with one anionic surfactant,sodium dodecyl sulfate (SDS),and two cationic surfactants,dodecyl trimethylammonium bromide (DTAB) and cetyl trimethylammonium bromide (CTAB),in water have been studied through fluorescence and UV-Vis spectroscopies and transmission electronic microscopy,combined with the measurement of conductivity.OVA can increase the critical micelle concentrations (cmc) of SDS and CTAB but has little effect on that of DTAB.The interaction between surfactant monomer and OVA is greater than that between surfactant micelles and OVA.Moreover,SDS can make OVA unfolded while cationic surfactants cannot.

  17. Surfactant gene polymorphisms and interstitial lung diseases

    Directory of Open Access Journals (Sweden)

    Pantelidis Panagiotis

    2001-11-01

    Full Text Available Abstract Pulmonary surfactant is a complex mixture of phospholipids and proteins, which is present in the alveolar lining fluid and is essential for normal lung function. Alterations in surfactant composition have been reported in several interstitial lung diseases (ILDs. Furthermore, a mutation in the surfactant protein C gene that results in complete absence of the protein has been shown to be associated with familial ILD. The role of surfactant in lung disease is therefore drawing increasing attention following the elucidation of the genetic basis underlying its surface expression and the proof of surfactant abnormalities in ILD.

  18. Tuning Polyelectrolyte-Surfactant Interactions: Modification of Poly(ethylenimine) with Propylene Oxide and Blocks of Ethylene Oxide.

    Science.gov (United States)

    Penfold, J; Thomas, R K; Li, P; Batchelor, S N; Tucker, I M; Burley, A W

    2016-02-02

    Significantly enhanced adsorption at the air-water interface arises in polyelectrolyte/ionic surfactant mixtures, such as poly(ethylenimine)/sodium dodecyl sulfate (PEI/SDS), down to relatively low surfactant concentrations due to a strong surface interaction between the polyelectrolyte and surfactant. In the region of charge neutralization this can result in precipitation or coacervation and give rise to undesirable properties in many applications. Ethoxylation of the PEI can avoid precipitation, but can also considerably weaken the interaction. Localization of the ethoxylation can overcome these shortcomings. Further manipulation of the polyelectrolyte-surfactant interaction can be achieved by selective ethoxylation and propoxylation of the PEI amine groups. Neutron reflectivity and surface tension data are presented here which show how the polyelectrolyte-surfactant interaction can be manipulated by tuning the PEI structure. Using deuterium labeled surfactant and polymer the neutron reflectivity measurements provide details of the surface composition and structure of the adsorbed layer. The general pattern of behavior is that at low surfactant concentrations there is enhanced surfactant adsorption due to the strong surface interaction; whereas around the region of the SDS critical micellar concentration, cmc, the surface is partially depleted of surfactant in favor bulk aggregate structures. The results presented here show how these characteristic features of the adsorption are affected by the degree of ethoxylation and propoxylation. Increasing the degree of propoxylation enhances the surfactant adsorption, whereas varying the degree of ethoxylation has a less pronounced effect. In the region of surfactant surface depletion increasing both the degree of ethoxylation and propoxylation result in an increased surface depletion.

  19. Mississippi River Valley alluvial aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Mississippi River Valley alluvial aquifer in the states of Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and...

  20. Region 9 Sole Source Aquifers

    Data.gov (United States)

    U.S. Environmental Protection Agency — There are 7 polygons representing 6 individual sole source aquifer boundaries and one streamflow source area in California, Arizona, and Nevada. Various efforts were...

  1. Southeastern Coastal Plain aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Southeastern Coastal Plain aquifer system in Kentucky, Tennessee, Mississippi, Alabama, Georgia, and South Carolina.

  2. Contaminants retention in soils as a complementary water treatment method: application in soil-aquifer treatment processes

    OpenAIRE

    Martins, Tiago André Nunes

    2016-01-01

    Tese de mestrado, Geologia Aplicada (Hidrogeologia), Universidade de Lisboa, Faculdade de Ciências, 2016 Soil-Aquifer Treatment (SAT) is a well-established Managed Aquifer Recharge (MAR) complementary method which main purpose is to increase water availability in aquifers by enhancing the quality of the injected water. SAT-MAR methods are an important way of addressing water scarcity challenges by reusing water of impaired quality, such as wastewater, converting it into a reliable resource...

  3. Managed aquifer recharge by using spreading basin methods on alluvial fans: a general overview of the situation in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Hida, N.

    2009-07-01

    In this paper, the author reviews the present situation of managed aquifer recharge (MAR) by using basin method as of 2009 in Japan. Most of the MAR basin is carried in the area of alluvial fans. The enhancing groundwater resources in the Rokugo alluvial aquifer has resulted in sustain ability for the groundwater environment, especially in the distal fan. As a recent tendency, the MAR basin contributes to sustainable aquifer management in alluvium and is spreading in Japan. (Author)

  4. Microbial Enhanced Oil Recovery - Advanced Reservoir Simulation

    DEFF Research Database (Denmark)

    Nielsen, Sidsel Marie

    In this project, a generic model has been set up to include the two main mechanisms in the microbial enhanced oil recovery (MEOR) process; reduction of the interfacial tension (IFT) due to surfactant production, and microscopic fluid diversion as a part of the overall fluid diversion mechanism due......, bacterial growth, substrate consumption, and surfactant production in one dimension. The system comprises oil, water, bacteria, substrate, and surfactant. There are two flowing phases: Water and oil. We introduce the partition of surfactant between these two phases determined by a partitioning constant......, the curve levels off. Partitioning of surfactant between the oil and water phase is a novel effect in the context of microbial enhanced oil recovery. The partitioning coefficient determines the time lag before the surfactant effect can be seen. The surfactant partitioning does not change final recovery...

  5. Enhanced Remedial Amendment Delivery to Subsurface Using Shear Thinning Fluid and Aqueous Foam

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Lirong; Szecsody, James E.; Oostrom, Martinus; Truex, Michael J.; Shen, Xin; Li, Xiqing

    2011-04-23

    A major issue with in situ subsurface remediation is the ability to achieve an even spatial distribution of remedial amendments to the contamination zones in an aquifer or vadose zone. Delivery of amendment to the aquifer using shear thinning fluid and to the vadose zone using aqueous foam has the potential to enhance the amendment distribution into desired locations and improve the remediation. 2-D saturated flow cell experiments were conducted to evaluate the enhanced sweeping, contaminant removal, and amendment persistence achieved by shear thinning fluid delivery. Bio-polymer xanthan gum solution was used as the shear thinning fluid. Unsaturated 1-D column and 2-D flow cell experiments were conducted to evaluate the mitigation of contaminant mobilization, amendment uniform distribution enhancement, and lateral delivery improvement by foam delivery. Surfactant sodium lauryl ether sulfate was used as the foaming agent. It was demonstrated that the shear thinning fluid injection enhanced the fluid sweeping over a heterogeneous system and increased the delivery of remedial amendment into low-permeability zones. The persistence of the amendment distributed into the low-perm zones by the shear thinning fluid was prolonged compared to that of amendment distributed by water injection. Foam delivery of amendment was shown to mitigate the mobilization of highly mobile contaminant from sediments under vadose zone conditions. Foam delivery also achieved more uniform amendment distribution in a heterogeneous unsaturated system, and demonstrated remarkable increasing in lateral distribution of the injected liquid compared to direct liquid injection.

  6. Microbial dynamics in natural aquifers

    OpenAIRE

    Bajracharya, Bijendra Man

    2016-01-01

    Microorganisms in groundwater form ecosystems that can transform chemical compounds. Quantitatively understanding microbial dynamics in soils and groundwater is thus essential for pollutant dynamics and biogeochemistry in the subsurface. This dissertation addresses three factors influencing microbial dynamics in aquifers and soils, namely: (1) the influence of grazing on bacteria in eutrophic aquifers, posing the question whether the carrying capacity of bacteria, which has been observed i...

  7. Effect of anionic-nonionic mixed surfactant on ryegrass uptake of phenanthrene and pyrene from water

    Institute of Scientific and Technical Information of China (English)

    SUN Lu; ZHU LiZhong

    2009-01-01

    The effect of anionic-nonionic mixed surfactant (SDBS-TX100) on the uptake of phenanthrene and pyrene by ryegrass in a hydroponic system was studied, and the influence factors including the com-positions and concentrations of mixed surfactants and the compounds properties were also discussed. The results showed that SDBS-TX100 mixtures with certain compositions and concentrations could enhance the uptake of phenanthrene and pyrene by ryegrass, which could be attributed to the im-proved uptake capacity of ryegrass roots for phenanthrene and pyrene. SDBS-TX100 can enhance the uptake of phenanthrene and pyrene by ryegrass in a wider range of surfactant concentrations (0-0.8 mmol/L) in comparison with corresponding single surfactants, and the maximal contents of phenan-threne and pyrene in ryegrass roots were obtained with the concentrations of SDBS-TX100 around the corresponding critical micelle concentrations. The uptake of phenanthrene and pyrene by ryegrass increased with the increasing mole fraction of SDBS in mixed surfactant solutions, and SDBS-TX100 mixture with a mole ratio of SDBS to TX100 at 9:1 had the greatest capacity in enhancing the uptake of phenanthrene and pyrene, at which the corresponding maximal concentrations of phenanthrene and pyrene in ryegrass roots were 216 and 8.16 times those without surfactants, respectively. Results from this study indicate that the anionic-nonionic mixed surfactants (SDBS-TX100) would be a preferred selection for the application of surfactant-enhanced phytoremediation technology to contaminated soils.

  8. Solubilization of trichloroethylene by polyelectrolyte/surfactant complexes

    Energy Technology Data Exchange (ETDEWEB)

    Uchiyama, Hirotaka; Christian, S.D.; Tucker, E.E.; Scamehorn, J.F. (Univ. of Oklahoma, Norman, OK (United States))

    1994-12-01

    An automated vapor pressure method is used to obtain solubilization isotherms for trichloroethylene (TCE) in polyelectrolyte/surfactant complexes throughout a wide range of solute activities at 20 and 25 C. The polyelectrolyte chosen is sodium poly(styrenesulfonate), PSS< and the surfactant is cetylpyridinium chloride or N-hexadecylpyridinium chloride, CPC. Data are fitted to the quadratic equation K = K[sub 0](1[minus][alpha]X + [beta]X[sup 2]), which correlates the solubilization equilibrium constant (K) with the mole fraction of TCE (X) in the micelles or complexes at each temperature. Activity coefficients are also obtained for TCE in the PSS/CPC complexes as a function of X. The general solubilization of TCE in PSS/CPC complexes resembles that of TCE in CPC micelles, as well as that of benzene or toluene in CPC micelles, suggesting that TCE solubilizes in ionic micelles both within the hydrocarbon micellar interior and near the micellar surface. The presence of the polyelectrolyte causes a small decrease in the ability of the cationic surfactant to solubilize TCE, while greatly reducing the concentration of the surfactant present in monomeric form. PSS/CPC complexes may be useful in colloid-enhanced ultrafiltration processes to purify organic-contaminated water.

  9. Photocatalytic Degradation of Diethyl Phthalate with Surfactant Addition

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tianyong; HU Juan; ZHANG Youlan; LI Bin; FEI Xuening

    2006-01-01

    This paper studies the adsorption of diethyl phthalate (DEP,an environmental hormone) on the surface of nanoscale TiO2, effects of pH value of solutions, initial concentrations of DEP and additive surfactant on photocatalytic degradation and dynamics of DEP. Under ultra violet illumination, the interaction between DEP and surfactants including DBS (sodium dodecylbenzenesulfonate), CTAB (cetyltrimethylammonium bromide), and OP-10 (nonylphenol polyoxyethylene ether)was exploited from the perspective of degradation speed calculated by the data of high pressure liquid chromatography (HPLC) and UV-Vis spectra, respectively. Photocatalytic degradation of DEP followed pseudo first-order reaction kinetics. DEP as substrate degraded fast when its initial concentration was 130 mg/L. TiO2 had certain adsorption ability of DEP. TiO2 could adsorb the most DEP at the approximately neutral pH of 6.91. Degradation of DEP was not affected obviously by ad ditives OP-10 and JBS. Degradation rate of DEP was not enhanced greatly in the presence of surfactants, but degradation of DBS was sped up. Degradation rate of DEP was depressed in the presence of additive CTAB. The more CTAB was added, the less DEP was degraded. Degradation rate of CTAB became slow with the increase of initial CTAB concentration. The possible adsorption models among TiO2, DEP and surfactants were given.

  10. A study of polymer-surfactant interactions by neutron reflectivity

    CERN Document Server

    Warren, N

    1999-01-01

    surfactants and their relative levels of interaction with the polymer. The surface behaviour of these systems was observed to be in many ways more remarkable than that of the bulk solution. In the high total surfactant concentration range, once all polymer molecules were associated with bound micelles, the extent of adsorption at the air-liquid interface was found to be dominated largely, as might be expected, by the solution monomer concentrations of the two surfactants. Prior to this, however, adsorption was dominated by the presence of a very surface active polymer-SDS complex which gave rise to enhanced SDS adsorption and low surface tensions compared with those found in polymer-free systems. The origin of this effect, being the stabilisation of the adsorbed SDS monolayer due to a reduction in the inter-headgroup repulsions through screening, by the charged polymer segments, suggests that this may be a characteristic feature of systems continuing a polyelectrolyte and an oppositely charged surfactant. In ...

  11. Ogallala Bedrock Data Enhancement

    Data.gov (United States)

    Kansas Data Access and Support Center — This data set provides an enhanced estimate of the bedrock elevation of the Ogallala Aquifer in Kansas based on lithologic logs from a variety of sources. The data...

  12. Some aspects of surfactant action mechanism in the organic reagents - metal ions systems

    Energy Technology Data Exchange (ETDEWEB)

    Chernova, R.K.; Shtykov, S.N.; Beloliptseva, G.M.; Sukhova, L.K.; Amelin, V.G.; Kulapina, E.G. (Saratovskij Gosudarstvennyj Univ. (USSR))

    1984-06-01

    Results are reviewed of investigations into the interaction of ions of Mo(6), W, Zr, Be, Sc, Nb, Ta, J, rare earths, a. o. with organic reagents of triphenylmethane class in the 8M H/sub 2/SO/sub 4/-pH14 acidity range and the 1x10/sup -3/-5x10/sup -6/ M concentration range both in the presence and absence of different surfactant type (cetylpyridine, methyltrimethylammonium, synthanols, etc). Three types of effects, determining enhancement of the sensitivity and selectivity of reactions jn the Me-R-surfactant systems, were determined: an increase in the number of coordinated ligands, the activating effect of cation surfactants resulting in a potential complexing in acid media, multicenter interaction of polydentate ligands both via chelating groups and auxochrome groups in the presence of cation surfactants. Protolytic and flotation properties of ionic associates are considered. The observed effects are explained from the viewpoint of electrostatic and hydrophobic interactions in the R-surfactant systems, observed by the methods of NMR, polarography amperometry, conductometry. A possible use of the investigated M-R-surfactant systems as complexonometric indicators was evaluated. A possibility was shown of using them for direct titrimetric determination of hundredth milligram portions of Cu, Ga, In and Sc at a titrant concentratjon of less than 0.01 M. It follows from the estimation of basic optical parameters of the Me-R-surfactant systems that detection.

  13. Characterising aquifer treatment for pathogens in managed aquifer recharge.

    Science.gov (United States)

    Page, D; Dillon, P; Toze, S; Sidhu, J P S

    2010-01-01

    In this study the value of subsurface treatment of urban stormwater during Aquifer Storage Transfer Recovery (ASTR) is characterised using quantitative microbial risk assessment (QMRA) methodology. The ASTR project utilizes a multi-barrier treatment train to treat urban stormwater but to date the role of the aquifer has not been quantified. In this study it was estimated that the aquifer barrier provided 1.4, 2.6, >6.0 log(10) removals for rotavirus, Cryptosporidium and Campylobacter respectively based on pathogen diffusion chamber results. The aquifer treatment barrier was found to vary in importance vis-à-vis the pre-treatment via a constructed wetland and potential post-treatment options of UV-disinfection and chlorination for the reference pathogens. The risk assessment demonstrated that the human health risk associated with potable reuse of stormwater can be mitigated (disability adjusted life years, DALYs aquifer is integrated with suitable post treatment options into a treatment train to attenuate pathogens and protect human health.

  14. Adsorption of dimeric surfactants in lamellar silicates

    Energy Technology Data Exchange (ETDEWEB)

    Balcerzak, Mateusz; Pietralik, Zuzanna [Department of Macromolecular Physics, Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Domka, Ludwik [Department of Metalorganic Chemistry, Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań (Poland); Skrzypczak, Andrzej [Institute of Chemical Technology, Poznań University of Technology, Berdychowo 4, 60-965 Poznań (Poland); Kozak, Maciej, E-mail: mkozak@amu.edu.pl [Department of Macromolecular Physics, Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland)

    2015-12-01

    Highlights: • The intercalation of dimeric surfactants changed the morphology of MMT samples. • XRD indicated structures formed by surfactant molecules in interlayer space. • The four-step thermal decomposition of dimeric surfactant, confirms intercalation. - Abstract: The adsorption of different types of cationic surfactants in lamellar silicates changes their surface character from hydrophilic to hydrophobic. This study was undertaken to obtain lamellar silicates modified by a series of novel dimeric (gemini) surfactants of different length alkyl chains and to characterise these organophilised materials. Synthetic sodium montmorillonite SOMASIF® ME 100 (M) and enriched bentonite of natural origin (Nanoclay – hydrophilic bentonite®) were organophilised with dimeric (gemini) surfactants (1,1′-(1,4-butanediyl)bis(alkoxymethyl)imidazolium dichlorides). As a result of surfactant molecule adsorption in interlamellar space, the d-spacing (d{sub 001}) increased from 0.97 nm (for the anhydrous structure) to 2.04 nm. A Fourier transform infrared spectroscopy (FTIR) analysis of the modified systems reveals bands assigned to the stretching vibrations of the CH{sub 2} and CH{sub 3} groups and the scissoring vibrations of the NH group from the structure of the dimeric surfactants. Thermogravimetric (TG) and derivative thermogravimetric (DTG) studies imply a four-stage process of surfactant decomposition. Scanning electron microscopy (SEM) images provide information on the influence of dimeric surfactant intercalation into the silicate structures. Particles of the modified systems show a tendency toward the formation of irregularly shaped agglomerates.

  15. LOWER COST METHODS FOR IMPROVED OIL RECOVERY (IOR) VIA SURFACTANT FLOODING

    Energy Technology Data Exchange (ETDEWEB)

    William A. Goddard III; Yongchun Tang; Patrick Shuler; Mario Blanco; Seung Soon Jang; Shiang-Tai Lin; Prabal Maiti; Yongfu Wu; Stefan Iglauer; Xiaohang Zhang

    2004-09-01

    salinity reservoirs. Alkylpropoxy sulfate surfactants are not yet available as large volume commercial products. The results presented herein can provide the needed industrial impetus for extending application (alkyl polyglycoside) or scaling up (alkylpropoxy sulfates) of these two promising surfactants for enhanced oil recovery. Furthermore, the advanced simulations tools presented here can be used to continue to uncover new types of surfactants with promising properties such as inherent low IFT and biodegradability.

  16. Arsenic release from Floridan Aquifer rock during incubations simulating aquifer storage and recovery operations.

    Science.gov (United States)

    Jin, Jin; Zimmerman, Andrew R; Norton, Stuart B; Annable, Michael D; Harris, Willie G

    2016-05-01

    While aquifer storage and recovery (ASR) is becoming widely accepted as a way to address water supply shortages, there are concerns that it may lead to release of harmful trace elements such as arsenic (As). Thus, mechanisms of As release from limestone during ASR operations were investigated using 110-day laboratory incubations of core material collected from the Floridan Aquifer, with treatment additions of labile or refractory dissolved organic matter (DOM) or microbes. During the first experimental phase, core materials were equilibrated with native groundwater lacking in DO to simulate initial non-perturbed anaerobic aquifer conditions. Then, ASR was simulated by replacing the native groundwater in the incubations vessels with DO-rich ASR source water, with DOM or microbes added to some treatments. Finally, the vessels were opened to the atmosphere to mimic oxidizing conditions during later stages of ASR. Arsenic was released from aquifer materials, mainly during transitional periods at the beginning of each incubation stage. Most As released was during the initial anaerobic experimental phase via reductive dissolution of Fe oxides in the core materials, some or all of which may have formed during the core storage or sample preparation period. Oxidation of As-bearing Fe sulfides released smaller amounts of As during the start of later aerobic experimental phases. Additions of labile DOM fueled microbially-mediated reactions that mobilized As, while the addition of refractory DOM did not, probably due to mineral sorption of DOM that made it unavailable for microbial utilization or metal chelation. The results suggest that oscillations of groundwater redox conditions, such as might be expected to occur during an ASR operation, are the underlying cause of enhanced As release in these systems. Further, ASR operations using DOM-rich surface waters may not necessarily lead to additional As releases.

  17. Surfactants in tribology, v.3

    CERN Document Server

    Biresaw, Girma

    2013-01-01

    The manufacture and use of almost every consumer and industrial product rely on application of advanced knowledge in surface science and tribology. These two disciplines are of critical importance in major economic sectors, such as mining, agriculture, manufacturing (including metals, plastics, wood, computers, MEMS, NEMS, appliances), construction, transportation, and medical instruments, transplants, and diagnostic devices. An up-to-date reference with contributions by experts in surface science and tribology, Surfactants in Tribology, Volume 3 discusses some of the underlying tribological a

  18. Anaerobic Biodegradation of Detergent Surfactants

    OpenAIRE

    Erich Jelen; Ute Merrettig-Bruns

    2009-01-01

    Detergent surfactantscan be found in wastewater in relevant concentrations. Most of them are known as ready degradable under aerobic conditions, as required by European legislation. Far fewer surfactants have been tested so far for biodegradability under anaerobic conditions. The natural environment is predominantly aerobic, but there are some environmental compartments such as river sediments, sub-surface soil layer and anaerobic sludge digesters of wastewater treatment plants which have str...

  19. A rotating disk apparatus for assessing the biodegradation of polycyclic aromatic hydrocarbons transferring from a non-aqueous phase liquid to solutions of surfactant Brij 35

    OpenAIRE

    Bernardez, Letícia Alonso

    2009-01-01

    Texto completo: acesso restrito. p. 415-424 A rotating disk apparatus was used to investigate the biodegradation of PAHs from non-aqueous phase liquids to solutions of Brij 35. The mass transfer of PAHs in absence of surfactant solution was not large enough to replenish the degraded PAHs. The addition of surfactant resulted in an overall enhancement of biodegradation rates compared to that observed in pure aqueous solution. This is because surfactant partition significant amount of PAHs in...

  20. Caractérisation des solutions de tensio-actif utilisées en récupération assistée Characterization of Surfactant Solutions Used in Enhanced Recovery

    Directory of Open Access Journals (Sweden)

    Moulu J. C.

    2006-11-01

    Full Text Available Des solutions de tensio-actif sont étudiées en vue de déterminer celles qui doivent être les plus efficaces pour le déplacement d'huile résiduelle en milieu poreux. Selon les propriétés de ces solutions au moment de leur injection, un banc d'huile se forme rapidement et progresse au niveau du front de tensio-actif, ou au contraire, les globules d'huile sont entraînés avec une vitesse faible dans l'ensemble du bouchon, les échanges entre les phases peuvent alors être importants. On a donc cherché à évaluer les caractéristiques des solutions en tenant compte des échanges qu'elles ont pu avoir avec l'huile et en particulier dans les deux cas extrêmes : solutions aqueuses sans huile et solutions équilibrées avec un grand volume d'huile. Pour ces deux états des solutions aqueuses, on a mis en évidence des comportements rhéologiques et interfaciaux très différents, dus à la migration d'alcool et d'huile entre les phases en présence. Ces propriétés des solutions de tensio-actif ont par ailleurs été reliées à la présence de structures cristallines et à leur transformation au cours des échanges qui se produisent. Research is being done on surfactant solutions to determine the ones that should be the most efficient for driving residual oil in porous media. Depending on the properties of these solutions at the time of their injection, an oil bank is formed quickly and progresses at the level of the surfactant front or, on the contrary, the oil ganglia are displaced slowly in the slug as a whole, and exchanges between the phases may then be great. Therefore, an effort was made to assess the characteristics of solutions while considering the exchanges they may have had with the oil, and particularly in the two extreme cases, i. e. aqueous solutions without oil and equilibrated solutions with a large volume of oil. For these two states of aqueous solutions, very different rheological and interfacial behaviors were found as

  1. Surfactant inhibition in acute respiratory failure : consequences for exogenous surfactant therapy

    NARCIS (Netherlands)

    E.P. Eijking (Eric)

    1993-01-01

    textabstractThe neonatal respiratory distress syndrome (RDS) is characterized by immaturity of the lung, resulting in relative or absolute absence of pulmonary surfactant. Worldwide, neonates suffering from RDS have been treated successfully with exogenous surfactant preparations. Currently, exogeno

  2. Bio-inspired pulmonary surfactant-modified nanogels: A promising siRNA delivery system.

    Science.gov (United States)

    De Backer, Lynn; Braeckmans, Kevin; Stuart, Marc C A; Demeester, Jo; De Smedt, Stefaan C; Raemdonck, Koen

    2015-05-28

    Inhalation therapy with small interfering RNA (siRNA) is a promising approach in the treatment of pulmonary disorders. However, clinical translation is severely limited by the lack of suitable delivery platforms. In this study, we aim to address this limitation by designing a novel bioinspired hybrid nanoparticle with a core-shell nanoarchitecture, consisting of a siRNA-loaded dextran nanogel (siNG) core and a pulmonary surfactant (Curosurf®) outer shell. The decoration of siNGs with a surfactant shell enhances the colloidal stability and prevents siRNA release in the presence of competing polyanions, which are abundantly present in biofluids. Additionally, the impact of the surfactant shell on the biological efficacy of the siNGs is determined in lung cancer cells. The presence of the surfactants substantially reduces the cellular uptake of siNGs. Remarkably, the lowered intracellular dose does not impede the gene silencing effect, suggesting a crucial role of the pulmonary surfactant in the intracellular processing of the nanoparticles. In order to surmount the observed reduction in cellular dose, folate is incorporated as a targeting ligand in the pulmonary surfactant shell to incite receptor-mediated endocytosis. The latter substantially enhances both cellular uptake and gene silencing potential, achieving efficient knockdown at siRNA concentrations in the low nanomolar range.

  3. Chemical Behavior of Cadmium in Purple Soil as Affected by Surfactants and EDTA

    Institute of Scientific and Technical Information of China (English)

    CHEN Yu-Cheng; XIONG Zhi-Ting; DONG Shan-Yan

    2006-01-01

    A soil batch experiment was conducted to investigate both separate and compound effects of three types of surfactants:anionic dodecylbenzene sulfonic acid sodiumsalt (DBSS), cationic cetyltrimethylammonium bromide (CTAB), and nonionic nonyl phenol polyethyleneoxy ether (TX-100), as well as ethylenediaminetetraacetic acid (EDTA) on cadmium solubility, sorption kinetics, and sorption-desorption behavior in purple soil. The results indicated that both individual application of the three types of surfactants and surfactants combined with EDTA could stimulate Cd extraction from the soil with a general effectiveness ranking of EDTA/TX-100 > EDTA/DBSS > EDTA/CTAB > EDTA > TX-100 >DBSS > CTAB. Further study showed that the compound application of surfactants and EDTA had stronger (P < 0.05)effects on Cd solubility than those added individually. The application of surfactants and EDTA to purple soil (P < 0.05)decreased the proportion of Cd sorbed, while their effectiveness ranking was similar to that of enhanced solubilization. The sorption kinetics of Cd in purple soil was best described by the double-constant equation, while the Freundlich equation gave an excellent fit to the sorption isotherm curves. Therefore, surfactant-enhanced remediation of Cd contaminated soil is feasible and further research should be conducted.

  4. Rheologycal properties of sodium carboxymethylcellulose in the presence of electrolyte and mixed micelle of surfactants

    Directory of Open Access Journals (Sweden)

    Sovilj Verica J.

    2003-01-01

    Full Text Available One of the most significant aspects of polymer-surfactant interaction, from the practical point of view, is that of rheology control and viscosity enhancement. In the oppositely charged polyelectrolyte-surfactant system strong ionic interaction often leads to precipitation of the formed complex yielding serious problems. In this paper the interaction between anionic polyelectrolyte - sodium carboxymethylcellulose (NaCMC and cationic surfactant - cethyltrimethylammonium bromide (CTMAB has been investigated by rheological measurements. Addition of electrolyte NaBr and nonionic surfactant - Tween 80 reduced the binding strength, prevented the precipitation of the complex and increased the viscosity of the system. It was found that rheological properties are strong influenced by NaCMC-CTMAB interaction and the system exhibits either pseudoplastic or thixotropic or rheopectic behavior according to the intensity of interaction.

  5. REMEDIATION OF SOILS CONTAMINATED WITH MOTOR OIL BY HIGHLY BIODEGRADABLE SURFACTANTS

    Directory of Open Access Journals (Sweden)

    Ignacio Moya-Ramírez

    2014-06-01

    Full Text Available The remediation of a sandy soil contaminated with motor oil was studied by applying two different washing procedures: one discontinuous and the other continuous. In addition the capacity of three highly biodegradable surfactants, two synthetic (Glucopon 600 and Findet 1214N/23 and a biosurfactant from Bacillus subtilis, to enhance oil removal was tested. The results obtained with the continuous procedure were much better than those achieved with the discontinuous one, even in experiments conducted with distilled water. Both the addition of surfactants and the rise in temperature significantly increased the removal of the pollutant in experiments conducted with the discontinuous procedure, but the biosurfactant showed a higher capacity for soil remediation than the synthetic surfactants at concentrations close to its CMC. Conversely, when the continuous method was used, surfactant concentration seems to have a lower effect on motor oil removal, at least below the CMC.

  6. Surfactant and nonlinear drop dynamics in microgravity

    Science.gov (United States)

    Jankovsky, Joseph Charles

    2000-11-01

    Large amplitude drop dynamics in microgravity were conducted during the second United States Microgravity Laboratory mission carried onboard the Space Shuttle Columbia (20 October-5 November 1995). Centimeter- sized drops were statically deformed by acoustic radiation pressure and released to oscillate freely about a spherical equilibrium. Initial aspect ratios of up to 2.0 were achieved. Experiments using pure water and varying aqueous concentrations of Triton-X 100 and bovine serum albumin (BSA) were performed. The axisymmetric drop shape oscillations were fit using the degenerate spherical shape modes. The frequency and decay values of the fundamental quadrupole and fourth order shape mode were analyzed. Several large amplitude nonlinear oscillation dynamics were observed. Shape entrainment of the higher modes by the fundamental quadrupole mode occurred. Amplitude- dependent effects were observed. The nonlinear frequency shift, where the oscillation frequency is found to decrease with larger amplitudes, was largely unaffected by the presence of surfactants. The percentage of time spent in the prolate shape over one oscillation cycle was found to increase with oscillation amplitude. This prolate shape bias was also unaffected by the addition of surfactants. These amplitude-dependent effects indicate that the nonlinearities are a function of the bulk properties and not the surface properties. BSA was found to greatly enhance the surface viscoelastic properties by increasing the total damping of the oscillation, while Triton had only a small influence on damping. The surface concentration of BSA was found to be diffusion-controlled over the time of the experiments, while the Triton diffusion rate was very rapid. Using the experimental frequency and decay values, the suface viscoelastic properties of surface dilatational viscosity ( ks ) and surface shear viscosity ( ms ) were found for varying surfactant concentrations using the transcendental equation of Lu

  7. Use of surfactants as plasticizers in preparing solid dispersions of poorly soluble API: selection of polymer-surfactant combinations using solubility parameters and testing the processability.

    Science.gov (United States)

    Ghebremeskel, Alazar N; Vemavarapu, Chandra; Lodaya, Mayur

    2007-01-10

    Formation of solid dispersions as a means to enhance the dissolution rate of poorly soluble Active pharmaceutical ingredients (APIs) typically employs hydrophilic polymer systems and surfactants. While the utility of the surfactant systems in solubilization is well known, the secondary effects of the same on processing and subsequent physical stability of the solid dispersions needs to be studied further. Physical blends of the poorly soluble API and hydrophilic polymers such as PVP-K30, Plasdone-S630, HPMC-E5, HPMCAS, and Eudragit L100 with mass ratio 1:1 were prepared. The surfactants tested in this study included Tween-80, Docusate sodium, Myrj-52, Pluronic-F68 and SLS. Thermal analysis of the API-polymer-surfactant blends suggested that the surfactants caused solvation/plasticization, manifesting in reduction of (i) the melting (T(m)) of API (ii) T(g) of the polymers and (iii) the combined T(g) of the solid dispersion formed from quench cooling. Explanation of these effects of surfactants is attempted based on their physical state (at the temperature of interest), HLB values and similarity of their solubility parameter values with respect to drug-polymer systems. Furthermore, extruded matrices containing different API-polymer (PVP-K30, Plasdone-S630, and HPMC-E5) mixtures prepared with and without surfactants, were produced by feeding the powder blend through a hot-melt extruder. The melt viscosity of the polymer blends was assessed by torque rheometry using a Haake Rheomix. The physicochemical properties of the extruded API-polymer-surfactant were characterized by differential scanning calorimetry, X-ray diffraction, Raman spectroscopy, and polarized microscopy. The results demonstrated that the glass transition temperature of the carrier polymers decreased as direct result of the surfactants in the extrudate, due to an increase in the chain mobility of polymers. A decrease in the melt viscosity was seen due to a plasticization of the polymer. The drug release

  8. Photoactivation and perturbation of photoluminescent properties of aqueous ZnS nanoparticles: Probing the surfactant-semiconductor interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Mehta, S.K., E-mail: skmehta@pu.ac.in [Department of Chemistry and Centre for Advanced Studies in Chemistry, Panjab University, Chandigarh 160014 (India); Kumar, Sanjay [Department of Chemistry, Government College, Chowari, Chamba, H.P. 176302 (India)

    2011-12-15

    Graphical abstract: The variation in PL emission intensity of growing ZnS NPs during first hour of their growth depends upon the nature of surfactants used for their stabilization. Highlights: Black-Right-Pointing-Pointer Photoluminescence (PL) intensity of growing ZnS NPs increases linearly with time. Black-Right-Pointing-Pointer Significant PL enhancement in anionic surfactant stabilized ZnS NPs on irradiation. Black-Right-Pointing-Pointer PL decay with delay time after removing from UV-irradiation in all the surfactants. Black-Right-Pointing-Pointer Better PL stability of ZnS NPs stabilized in anionic surfactants than cationic ones. - Abstract: The in situ photochemistry of aqueous colloidal ZnS has been studied in relation to variety of the surfactants as surface passivating agents. The photoluminescence (PL) intensity of ZnS nanoparticles (NPs) has been drastically enhanced as compared to their bare counterparts due to surface passivation by surfactants depending upon their molecular structure. Cationic surfactants of alkyltrimethylammonium bromide series with different chain lengths (C{sub 16}, C{sub 14} and C{sub 12}) have been tested. The PL emission of ZnS NPs decreases with decrease in chain length because of ineffective stabilization and passivation of surface because the larger sized NPs were produced in the surfactant with smaller chain length. On the other hand, three anionic surfactants with C{sub 12} chain length with different head groups have been capable of comparatively effective passivation to produce stable NPs with better luminescence. The changing nature of surface states during growth and long time ripening of ZnS NPs has also been monitored by comparing time evolution PL emission in different surfactants. The influence of UV-light irradiation in enhancing the PL emission has been found to be surfactant structure dependent with maximum enhancement observed with the surfactants having {pi}-electrons in their head group functionalities. The

  9. ANALYTICAL ELEMENT MODELING OF COASTAL AQUIFERS

    Science.gov (United States)

    Four topics were studied concerning the modeling of groundwater flow in coastal aquifers with analytic elements: (1) practical experience was obtained by constructing a groundwater model of the shallow aquifers below the Delmarva Peninsula USA using the commercial program MVAEM; ...

  10. Saturated thickness, High Plains aquifer, 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents the saturated thickness of the High Plains aquifer of the United States, 2009, in feet. The High Plains aquifer underlies...

  11. ANALYTICAL ELEMENT MODELING OF COASTAL AQUIFERS

    Science.gov (United States)

    Four topics were studied concerning the modeling of groundwater flow in coastal aquifers with analytic elements: (1) practical experience was obtained by constructing a groundwater model of the shallow aquifers below the Delmarva Peninsula USA using the commercial program MVAEM; ...

  12. National Sole Source Aquifer GIS Layer

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data set contains indexes and Esri shape files of boundaries of the designated sole source aquifers and related aquifer boundaries. Data provide a vector...

  13. Cationic versus anionic surfactant in tuning the structure and interaction of nanoparticle, protein, and surfactant complexes.

    Science.gov (United States)

    Mehan, Sumit; Aswal, Vinod K; Kohlbrecher, Joachim

    2014-08-26

    The structure and interaction in complexes of anionic Ludox HS40 silica nanoparticle, anionic bovine serum albumin (BSA) protein, and cationic dodecyl trimethylammonium bromide (DTAB) surfactant have been studied using small-angle neutron scattering (SANS). The results are compared with similar complexes having anionic sodium dodecyl sulfate (SDS) surfactant (Mehan, S; Chinchalikar, A. J.; Kumar, S.; Aswal, V. K.; Schweins, R. Langmuir 2013, 29, 11290). In both cases (DTAB and SDS), the structure in nanoparticle-protein-surfactant complexes is predominantly determined by the interactions of the individual two-component systems. The nanoparticle-surfactant (mediated through protein-surfactant complex) and protein-surfactant interactions for DTAB, but nanoparticle-protein (mediated through protein-surfactant complex) and protein-surfactant interactions for SDS, are found to be responsible for the resultant structure of nanoparticle-protein-surfactant complexes. Irrespective of the charge on the surfactant, the cooperative binding of surfactant with protein leads to micellelike clusters of surfactant formed along the unfolded protein chain. The adsorption of these protein-surfactant complexes for DTAB on oppositely charged nanoparticles gives rise to the protein-surfactant complex-mediated aggregation of nanoparticles (similar to that of DTAB surfactant). It is unlike that of depletion-induced aggregation of nanoparticles with nonadsorption of protein-surfactant complexes for SDS in similarly charged nanoparticle systems (similar to that of protein alone). The modifications in nanoparticle aggregation as well as unfolding of protein in these systems as compared to the corresponding two-component systems have also been examined by selectively contrast matching the constituents.

  14. Arsenic retention and transport behavior in the presence of typical anionic and nonionic surfactants.

    Science.gov (United States)

    Liang, Chuan; Wang, Xianliang; Peng, Xianjia

    2016-01-01

    The massive production and wide use of surfactants have resulted in a large amount of surfactant residuals being discharged into the environment, which could have an impact on arsenic behavior. In the present study, the influence of the anionic surfactant sodium dodecyl benzene sulfonate (SDBS) and nonionic surfactant polyethylene glycol octylphenyl ether (Triton X-100) on arsenic behavior was investigated in batch and column tests. The presence of SDBS and Triton X-100 reduced arsenic retention onto ferrihydrite (FH), enhanced arsenic transport through FH coated sand (FH-sand) columns and promoted arsenic release from the FH surface. With coexisting surfactants in solution, the equilibrium adsorbed amount of arsenic on FH decreased by up to 29.7% and the adsorption rate decreased by up to 52.3%. Pre-coating with surfactants caused a decrease in the adsorbed amount and adsorption rate of arsenic by up to 15.1% and 58.3%, respectively. Because of the adsorption attenuation caused by surfactants, breakthrough of As(V) and As(III) with SDBS in columns packed with FH-sand was 23.8% and 14.3% faster than that in those without SDBS, respectively. In columns packed with SDBS-coated FH-sand, transport of arsenic was enhanced to a greater extent. Breakthrough of As(V) and As(III) was 52.4% and 43.8% faster and the cumulative retention amount was 44.5% and 57.3% less than that in pure FH-sand column systems, respectively. Mobilization of arsenic by surfactants increased with the increase of the initial adsorbed amount of arsenic. The cumulative release amount of As(V) and As(III) from the packed column reached 10.8% and 36.0%, respectively.

  15. Solubilization of Hydrophobic Dyes in Surfactant Solutions

    Directory of Open Access Journals (Sweden)

    Ali Reza Tehrani-Bagha

    2013-02-01

    Full Text Available In this paper, the use of surfactants for solubilization of hydrophobic organic dyes (mainly solvent and disperse dyes has been reviewed. The effect of parameters such as the chemical structures of the surfactant and the dye, addition of salt and of polyelectrolytes, pH, and temperature on dye solubilization has been discussed. Surfactant self-assemble into micelles in aqueous solution and below the concentration where this occurs—the critical micelle concentration (CMC—there is no solubilization. Above the CMC, the amount of solubilized dye increases linearly with the increase in surfactant concentration. It is demonstrated that different surfactants work best for different dyes. In general, nonionic surfactants have higher solubilization power than anionic and cationic surfactants. It is likely that the reason for the good performance of nonionic surfactants is that they allow dyes to be accommodated not only in the inner, hydrocarbon part of the micelle but also in the headgroup shell. It is demonstrated that the location of a dye in a surfactant micelle can be assessed from the absorption spectrum of the dye-containing micellar solution.

  16. Using biologically soft surfactants for dust suppression

    Energy Technology Data Exchange (ETDEWEB)

    Tkachenko, N.G.; Kolodiichak, V.K.; Motrii, A.E.; Severin, V.D.

    1982-07-01

    This article discusses environmental aspects of using surfactants in coal mines for dust suppression. Surfactants for underground black coal mines in the USSR are divided into three classes: so-called soft surfactants with a decomposition period from 1 to 3 days, hard surfactants with decomposition exceeding a month and an intermediary group. The decomposition process is analyzed; the role played by fermentation is stressed. Environmental effects of surfactant decomposition are evaluated. Selected surfactants tested in Soviet laboratories are described. The results of experimental use of diethanolamide as a surfactant for water injection in coal seams are evaluated. Wetting time amounts to 1 s when a 0.2% concentration is used. When surfactant concentration in water is reduced to 0.05% wetting time does not change; when concentration decreases to 0.025% wetting time increases to 3 s. Surfactant efficiency is investigated under operational conditions in a Donbass mine. Specifications of the working face, mining system and air pollution caused by a shearer loader are discussed. When diethanolamide is used dust suppression efficiency ranges from 86.4 to 90.4%. During the tests diethanolamide concentration in water was 0.05%.

  17. Remediation using trace element humate surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Riddle, Catherine Lynn; Taylor, Steven Cheney; Bruhn, Debra Fox

    2016-08-30

    A method of remediation at a remediation site having one or more undesirable conditions in which one or more soil characteristics, preferably soil pH and/or elemental concentrations, are measured at a remediation site. A trace element humate surfactant composition is prepared comprising a humate solution, element solution and at least one surfactant. The prepared trace element humate surfactant composition is then dispensed onto the remediation site whereby the trace element humate surfactant composition will reduce the amount of undesirable compounds by promoting growth of native species activity. By promoting native species activity, remediation occurs quickly and environmental impact is minimal.

  18. Surfactant nebulisation : lung function, surfactant distribution and pulmonary blood flow distribution in lung lavaged rabbits

    NARCIS (Netherlands)

    Dijk, Peter H.; Heikamp, A; Bambang Oetomo, Sidarto

    1997-01-01

    Objective: Surfactant nebulisation is a promising alternative to surfactant instillation in newborns with the respiratory distress syndrome. Although less surfactant is deposited in the lung, it improves gas exchange, probably due to a superior distribution. We hypothesize that a more uniform distri

  19. Biophysical inhibition of pulmonary surfactant function by polymeric nanoparticles: role of surfactant protein B and C.

    Science.gov (United States)

    Beck-Broichsitter, Moritz; Ruppert, Clemens; Schmehl, Thomas; Günther, Andreas; Seeger, Werner

    2014-11-01

    The current study investigated the mechanisms involved in the process of biophysical inhibition of pulmonary surfactant by polymeric nanoparticles (NP). The minimal surface tension of diverse synthetic surfactants was monitored in the presence of bare and surface-decorated (i.e. poloxamer 407) sub-100 nm poly(lactide) NP. Moreover, the influence of NP on surfactant composition (i.e. surfactant protein (SP) content) was studied. Dose-elevations of SP advanced the biophysical activity of the tested surfactant preparation. Surfactant-associated protein C supplemented phospholipid mixtures (PLM-C) were shown to be more susceptible to biophysical inactivation by bare NP than phospholipid mixture supplemented with surfactant protein B (PLM-B) and PLM-B/C. Surfactant function was hindered owing to a drastic depletion of the SP content upon contact with bare NP. By contrast, surface-modified NP were capable of circumventing unwanted surfactant inhibition. Surfactant constitution influences the extent of biophysical inhibition by polymeric NP. Steric shielding of the NP surface minimizes unwanted NP-surfactant interactions, which represents an option for the development of surfactant-compatible nanomedicines.

  20. Surfactant nebulisation : lung function, surfactant distribution and pulmonary blood flow distribution in lung lavaged rabbits

    NARCIS (Netherlands)

    Dijk, Peter H.; Heikamp, A; Bambang Oetomo, Sidarto

    1997-01-01

    Objective: Surfactant nebulisation is a promising alternative to surfactant instillation in newborns with the respiratory distress syndrome. Although less surfactant is deposited in the lung, it improves gas exchange, probably due to a superior distribution. We hypothesize that a more uniform distri

  1. Determination of methylene blue biosorption by Rhizopus arrhizus in the presence of surfactants with different chemical structures.

    Science.gov (United States)

    Karatay, Sevgi Ertuğrul; Gül, Ulküye Dudu; Dönmez, Gönül

    2014-10-03

    Methylene blue (MB) biosorption properties of Rhizopus arrhizus were investigated in the presence of surfactants. The effects of cationic and anionic surfactants on MB removal by dead biomass (1 g L(-1)) were determined. MB removal was tested as a function of initial pH (2-12), contact time (5-1440 min), and dye (37.4-944.7 mg L(-1)) and surfactant (0-10 mM) concentrations. The opposite charged anionic surfactant dodecylbenzenesulfonic acid sodium salt (DBS) enhanced sorption of cationic MB by biomass dramatically. Maximum biosorption capacity was 471.5 mg g(-1) at pH 8 with 0.5 mM DBS at 944.7 mg L(-1) MB concentration. The surfactant-stimulated fungal decolorization method may provide a highly efficient, inexpensive, and time-saving procedure in biological wastewater treatment technologies.

  2. Characterization of Ni–P coating on AZ91D magnesium alloy with surfactants and nano-additives

    Directory of Open Access Journals (Sweden)

    Mohammed Sahal

    2014-12-01

    Full Text Available Direct electroless Ni–P plating was done on AZ91D magnesium alloy by immersing magnesium AZ91D samples into a bath containing Nickel sulphate. The nucleation mechanism of Ni–P deposits on the AZ91D magnesium alloy in the presence of surfactants and nano-additives was studied by using SEM. The electroless Ni–P deposits were preferentially nucleated on the βMg17Al12 phase of AZ91D magnesium alloy. Ni–P coating was coated uniformly in the presence of surfactants. Effect of surfactant C-Tab with varying quantities was studied. Addition of surfactant C-Tab homogenized the Ni–P deposition on AZ91D magnesium alloy surface. The effect produced by surfactant C-Tab was maximum with minimum addition (1 g/l of surfactant C-Tab further increase in the surfactant C-Tab quantity did not brought much changes in morphology. Effect of surfactant SLS was studied using SEM. Surfactant SLS when incorporated in small amounts (6 g/l and 12 g/l only exerted a slight influence in Ni–P deposition on AZ91D alloy surface. However Ni–P deposition was more uniform and spread throughout the surface with the addition of SLS surfactant (18 g/l. Effect of nano additives Al2O3, ZnO, SiO2 were studied. Nano additive Al2O3 enhanced the deposition of Ni–P on AZ91D alloy when added in 0.6 g/l quantity. SiO2 addition also gave the same results. ZnO addition influenced the Ni–P deposition on AZ91D alloy positively. Ni–P surface coating was coated more uniform and spread throughout the surface with the addition of surfactants and nano-additives.

  3. BEHAVIOR OF SURFACTANT MIXTURES AT SOLID/LIQUID AND OIL/LIQUID INTERFACES IN CHEMICAL FLOODING SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Prof. P. Somasundaran

    2002-09-30

    The aim of the project is to develop and evaluate efficient novel surfactant mixtures for enhanced oil recovery. Surfactant loss by adsorption or precipitation depends to a great extent on the type of surfactant complexes and aggregates formed. Such information as well as techniques to generate the information is lacking currently particularly for surfactant mixtures and surfactant/polymer systems. A novel analytical centrifuge application is explored during the last period to generate information on structures-performance relationship for different surfactant aggregates in solution and, in turn, at interfaces. To use analytical untracentrifuge for surfactant mixtures, information on partial specific volumes of single surfactants and their mixtures is required. Towards this purpose, surface tension and density measurements were performed to determine critical micellar concentrations (cmc), partial specific volumes of n-dodecyl-{beta}-Dmaltoside (DM), nonyl phenol ethoxylated decyl ether (NP-10) and their 1:1 mixtures at 25 C. Durchschlag's theoretical calculation method was adopted to calculate the partial specific volumes. Effects of temperature and mixing, as well as methods used for estimation on micellization and partial specific volumes were studied during the current period. Surface tension results revealed no interaction between the two surfactants in mixed micelles. Partial specific volume measurements also indicated no interaction in mixed micelles. Maximum adsorption density, area per molecule and free energy of micellization were also calculated. Partial specific volumes were estimated by two experimental methods: d{sub {rho}}/dc and V{sub {sigma}}. The difference between the results of using the two methods is within 0.5% deviation. It was found that the partial specific volume is concentration dependent and sensitive to changes in temperature. The information generated in this study will be used for the study of surfactant aggregate mass

  4. Role of the charge, carbon chain length, and content of surfactant on the skin penetration of meloxicam-loaded liposomes

    Directory of Open Access Journals (Sweden)

    Duangjit S

    2014-04-01

    Full Text Available Sureewan Duangjit,1,2 Boonnada Pamornpathomkul,1 Praneet Opanasopit,1 Theerasak Rojanarata,1 Yasuko Obata,2 Kozo Takayama,2 Tanasait Ngawhirunpat11Faculty of Pharmacy, Silpakorn University, Nakhon Pathom, Thailand; 2Department of Pharmaceutics, Hoshi University, Shinagawa-ku, Tokyo, JapanAbstract: The objective of this study was to investigate the influence of surfactant charge, surfactant carbon chain length, and surfactant content on the physicochemical characteristics (ie, vesicle size, zeta potential, elasticity, and entrapment efficiency, morphology, stability, and in vitro skin permeability of meloxicam (MX-loaded liposome. Moreover, the mechanism for the liposome-enhanced skin permeation of MX was determined by Fourier transform infrared spectroscopy and differential scanning calorimetry. The model formulation used in this study was obtained using a response surface method incorporating multivariate spline interpolation (RSM-S. Liposome formulations with varying surfactant charge (anionic, neutral, and cationic, surfactant carbon chain length (C4, C12, and C16, and surfactant content (10%, 20%, and 29% were prepared. The formulation comprising 29% cationic surfactant with a C16 chain length was found to be the optimal liposome for the transdermal delivery of MX. The skin permeation flux of the optimal formulation was 2.69-fold higher than that of a conventional liposome formulation. Our study revealed that surfactants affected the physicochemical characteristics, stability, and skin permeability of MX-loaded liposomes. These findings provide important fundamental information for the development of liposomes as transdermal drug delivery systems.Keywords: optimal liposome, optimization, transdermal drug delivery, surfactant charge, surfactant carbon chain length, surfactant content

  5. MINERAL-SURFACTANT INTERACTIONS FOR MINIMUM REAGENTS PRECIPITATION AND ADSORPTION FOR IMPROVED OIL RECOVERY

    Energy Technology Data Exchange (ETDEWEB)

    P. Somasundaran

    2005-04-30

    The aim of this project is to delineate the role of mineralogy of reservoir rocks in determining interactions between reservoir minerals and externally added reagents (surfactants/polymers) and its effect on critical solid-liquid and liquid-liquid interfacial properties such as adsorption, wettability and interfacial tension in systems relevant to reservoir conditions. Previous studies have suggested that significant surfactant loss by precipitation or adsorption on reservoir minerals can cause chemical schemes to be less than satisfactory for enhanced oil recovery. Both macroscopic adsorption, wettability and microscopic orientation and conformation studies for various surfactant/polymer mixtures/reservoir rocks systems were conducted to explore the cause of chemical loss by means of precipitation or adsorption, and the effect of rock mineralogy on the chemical loss. During this period, the adsorption of mixed system of n-dodecyl-{beta}-D-maltoside (DM) and dodecyl sulfonate (C{sub 12}SO{sub 3}Na) has been studied. The effects of solution pH, surfactant mixing ratio and different salts on surfactant adsorption on alumina have been investigated in detail. Along with these adsorption studies, changes in mineral wettability due to the adsorption of the mixtures were determined under relevant conditions to identify the nano-structure of the adsorbed layers. Solution properties of C{sub 12}SO{sub 3}Na/DM mixtures were also studied to identify surfactant interactions that affect the mixed aggregate formation in solution. Adsorption of SDS on gypsum and limestone suggested stronger surfactant/mineral interaction than on alumina, due to the precipitation of surfactant by dissolved calcium ions. The effects of different salts such as sodium nitrate, sodium sulfite and sodium chloride on DM adsorption on alumina have also been determined. As surfactant hemimicelles at interface and micelles in solution have drastic effects on oil recovery processes, their microstructures in

  6. Hemolysis by surfactants--A review.

    Science.gov (United States)

    Manaargadoo-Catin, Magalie; Ali-Cherif, Anaïs; Pougnas, Jean-Luc; Perrin, Catherine

    2016-02-01

    An overview of the use of surfactants for erythrocyte lysis and their cell membrane action mechanisms is given. Erythrocyte membrane characteristics and its association with the cell cytoskeleton are presented in order to complete understanding of the erythrocyte membrane distortion. Cell homeostasis disturbances caused by surfactants might induce changes starting from shape modification to cell lysis. Two main mechanisms are hypothesized in literature which are osmotic lysis and lysis by solubilization even if the boundary between them is not clearly defined. Another specific mechanism based on the formation of membrane pores is suggested in the particular case of saponins. The lytic potency of a surfactant is related to its affinity for the membrane and the modification of the lipid membrane curvature. This is to be related to the surfactant shape defined by its hydrophobic and hydrophilic moieties but also by experimental conditions. As a consequence, prediction of the hemolytic potency of a given surfactant is challenging. Several studies are focused on the relation between surfactant erythrolytic potency and their physico-chemical parameters such as the critical micellar concentration (CMC), the hydrophile-lipophile balance (HLB), the surfactant membrane/water partition coefficient (K) or the packing parameter (P). The CMC is one of the most important factors considered even if a lytic activity cut-off effect points out that the only consideration of CMC not enough predictive. The relation K.CMC must be considered in addition to the CMC to predict the surfactant lytic capacity within the same family of non ionic surfactant. Those surfactant structure/lytic activity studies demonstrate the requirement to take into account a combination of physico-chemical parameters to understand and foresee surfactant lytic potency.

  7. Partition behavior of surfactants, butanol, and salt during application of density-modified displacement of dense non-aqueous phase liquids

    Energy Technology Data Exchange (ETDEWEB)

    Damrongsiri, S. [Center of Excellence on Hazardous Substance Management (HSM), Chulalongkorn University, Phaya-Thai Rd., Bangkok (Thailand); Tongcumpou, C., E-mail: tchantra@chula.ac.th [Center of Excellence on Hazardous Substance Management (HSM), Chulalongkorn University, Phaya-Thai Rd., Bangkok (Thailand); Environmental Research Institute, Chulalongkorn University (Thailand); Sabatini, D.A. [School of Civil Engineering and Environmental Science, The University of Oklahoma, Oklahoma (United States)

    2013-03-15

    Highlights: ► Aqueous surfactant increases the partition of butanol aqueous phase. ► Water partition to NAPL phase via butanol and surfactant in NAPL phase. ► PCE partition to aqueous phase by solubilization into micelles. ► Surfactants cause the dramatically partition of water to NAPL phase. ► Aqueous salt dispels surfactant to NAPL phase. -- Abstract: Density-modified displacement (DMD) is a recent approach for removal of trapped dense NAPL (DNAPL). In this study, butanol and surfactant are contacted with the DNAPL to both reduce the density as well as release the trapped DNAPL (perchloroethylene: PCE). The objective of the study was to determine the distribution of each component (e.g., butanol, surfactant, water, PCE) between the original aqueous and PCE phases during the application of DMD. The results indicated that the presence of the surfactant increased the amount of n-butanol required to make the NAPL phase reach its desired density. In addition, water and anionic surfactant were found to partition along with the BuOH into the PCE phase. The water also found partitioned to reverse micelles in the modified phase. Addition of salt was seen to increase partitioning of surfactant to BuOH containing PCE phase. Subsequently, a large amount of water was solubilized into reverse micelles which lead to significantly increase in volume of the PCE phase. This work thus demonstrates the role of each component and the implications for the operation design of an aquifer treatment using the DMD technique.

  8. Structured fluids polymers, colloids, surfactants

    CERN Document Server

    Witten, Thomas A

    2010-01-01

    Over the last thirty years, the study of liquids containing polymers, surfactants, or colloidal particles has developed from a loose assembly of facts into a coherent discipline with substantial predictive power. These liquids expand our conception of what condensed matter can do. Such structured-fluid phenomena dominate the physical environment within living cells. This book teaches how to think of these fluids from a unified point of view showing the far-reaching effects ofthermal fluctuations in producing forces and motions. Keeping mathematics to a minimum, the book seeks the simplest expl

  9. Innovation in surfactant therapy I: surfactant lavage and surfactant administration by fluid bolus using minimally invasive techniques.

    Science.gov (United States)

    Dargaville, Peter A

    2012-01-01

    Innovation in the field of exogenous surfactant therapy continues more than two decades after the drug became commercially available. One such innovation, lung lavage using dilute surfactant, has been investigated in both laboratory and clinical settings as a treatment for meconium aspiration syndrome (MAS). Studies in animal models of MAS have affirmed that dilute surfactant lavage can remove meconium from the lung, with resultant improvement in lung function. In human infants both non-randomised studies and two randomised controlled trials have demonstrated a potential benefit of dilute surfactant lavage over standard care. The largest clinical trial, performed by our research group in infants with severe MAS, found that lung lavage using two 15-ml/kg aliquots of dilute surfactant did not reduce the duration of respiratory support, but did appear to reduce the composite outcome of death or need for extracorporeal membrane oxygenation. A further trial of lavage therapy is planned to more precisely define the effect on survival. Innovative approaches to surfactant therapy have also extended to the preterm infant, for whom the more widespread use of continuous positive airway pressure (CPAP) has meant delaying or avoiding administration of surfactant. In an effort to circumvent this problem, less invasive techniques of bolus surfactant therapy have been trialled, including instillation directly into the pharynx, via laryngeal mask and via brief tracheal catheterisation. In a recent clinical trial, instillation of surfactant into the trachea using a flexible feeding tube was found to reduce the need for subsequent intubation. We have developed an alternative method of brief tracheal catheterisation in which surfactant is delivered via a semi-rigid vascular catheter inserted through the vocal cords under direct vision. In studies to date, this technique has been relatively easy to perform, and resulted in rapid improvement in lung function and reduced need for

  10. 液固比对土壤洗涤去除多环芳烃效果的影响%Influence of Operating Parameters on Surfactant-enhanced Washing to Remedy PAHs Contaminated Soil

    Institute of Scientific and Technical Information of China (English)

    吴威; 姜林; 陈家军; 彭胜

    2012-01-01

    液固比是影响土壤洗涤污染物去除率的重要因素.以Triton X-100和Tween-80为洗涤剂,采用洗涤去除率(R)、吸附损失率(Vs)和新定义的指标增溶百分比(SP)分析液固比对土壤洗涤去除目标多环芳烃效果的影响.结果表明,液固比对土壤洗涤去除多环芳烃效果影响显著.R随液固比增加呈非线性形式增大,液固比10∶1后R增长变缓.同一液固比时,洗涤去除率Triton X-100〉Tween-80.Vs随液固比增加显著减少,液固比10∶1后逐渐变缓.同一液固比时,吸附损失率Triton X-100%Liquid/solid ratio(L/S) is an important influencing factor on contaminant removal in soil washing.The impact of different liquid/solid ratio on washing performance with Triton X-100 and Tween-80 was studied respectively and evaluated through removal ratio(R),surfactant adsorption loss ratio(Vs) and solubilization percent(SP).The results presented that the performance of washing to remove PAHs in soil was significantly affected by liquid/solid ratio.PAH removal ratio was gradually increased with liquid/solid ratio increasing in the non-linear form,R presented nonlinear increasing until L/S=10∶1.Surfactant adsorption loss ratio was insignificantly decreased.At the same liquid/solid ratio,removal ratio of Triton X-100 is more than that of Tween-80.Vs presented drastic decreasing until L/S=10∶1,adsorption loss ratio of Triton X-100 is less than that of Tween-80.SP was decreased after maximum value is occurred at L/S=10∶1.Combining with R,Vsand SP,L/S=10∶1 should be an effective washing point,Triton X-100 should be a reasonable washing solution and SP is a more effective index to chose liquid/solid ratio.When Triton X-100 is as washing solution and L/S=10∶1,R,Vsand SP is 74.7%,23.47% and 48.99%,respectively.

  11. Surfactant Adsorption: A Revised Physical Chemistry Lab

    Science.gov (United States)

    Bresler, Marc R.; Hagen, John P.

    2008-01-01

    Many physical chemistry lab courses include an experiment in which students measure surface tension as a function of surfactant concentration. In the traditional experiment, the data are fit to the Gibbs isotherm to determine the molar area for the surfactant, and the critical micelle concentration is used to calculate the Gibbs energy of micelle…

  12. Surfactant effects on soil aggregate tensile strength

    Science.gov (United States)

    Little is known regarding a soil aggregate's tensile strength response to surfactants that may be applied to alleviate soil water repellency. Two laboratory investigations were performed to determine surfactant effects on the tensile strength of 1) Ap horizons of nine wettable, agricultural soils co...

  13. Modelling karst aquifer evolution in fractured, porous rocks

    Science.gov (United States)

    Kaufmann, Georg

    2016-12-01

    The removal of material in soluble rocks by physical and chemical dissolution is an important process enhancing the secondary porosity of soluble rocks. Depending on the history of the soluble rock, dissolution can occur either along fractures and bedding partings of the rock in the case of a telogenetic origin, or within the interconnected pore space in the case of eogenetic origin. In soluble rocks characterised by both fractures and pore space, dissolution in both flow compartments is possible. We investigate the dissolution of calcite both along fractures and within the pore space of a limestone rock by numerical modelling. The limestone rock is treated as fractured, porous aquifer, in which the hydraulic conductivity increases with time both for the fractures and the pore spaces. We show that enlargement of pore space by dissolution will accelerate the development of a classical fracture-dominated telogenetic karst aquifer, breakthrough occurs faster. In the case of a pore-controlled aquifer as in eogenetic rocks, enlargement of pores results in a front of enlarged pore spaces migrating into the karst aquifer, with more homogeneous enlargement around this dissolution front, and later breakthrough.

  14. Influence of microbial and synthetic surfactant on the biodegradation of atrazine.

    Science.gov (United States)

    Singh, Anil Kumar; Cameotra, Swaranjit Singh

    2014-02-01

    The present study reports the effect of surfactants (rhamnolipids and triton X-100) on biodegradation of atrazine herbicide by strain A6, belonging to the genus Acinetobacter. The strain A6 was able to degrade nearly 80 % of the 250-ppm atrazine after 6 days of growth. The bacterium degraded atrazine by de-alkylation process. Bacterial cell surface hydrophobicity as well as atrazine solubility increased in the presence of surfactant. However, addition of surfactant to the mineral salt media reduced the rate and extent of atrazine degradation by decreasing the bioavailability of herbicide. On the contrary, addition of surfactant to atrazine-contaminated soil increased the rate and extent of biodegradation by increasing the bioavailability of herbicide. As compared to triton X-100, rhamnolipids were more efficient in enhancing microbial degradation of atrazine as a significant amount of atrazine was removed from the soil by rhamnolipids. Surfactants added for the purpose of hastening microbial degradation may have an unintended inhibitory effect on herbicide degradation depending upon contiguous condition, thus highlighting the fact that surfactant must be judiciously used in bioremediation of herbicides.

  15. Emulsion electrospinning of polycaprolactone: influence of surfactant type towards the scaffold properties.

    Science.gov (United States)

    Hu, Jue; Prabhakaran, Molamma P; Ding, Xin; Ramakrishna, Seeram

    2015-01-01

    Producing uniform nanofibers in high quality by electrospinning remains a huge challenge, especially using low concentrated polymer solutions. However, emulsion electrospinning assists to produce nanofibers from less concentrated polymer solutions compared to the traditional electrospinning process. The influence of individual surfactants towards the morphology of the emulsion electrospun poly (ɛ-caprolactone)/bovine serum albumin (PCL/BSA) nanofibers were investigated by using (i) non-ionic surfactant sorbitane monooleate (Span80); (ii) anionic sodium dodecyl sulfate (SDS); and (iii) cationic benzyltriethylammonium chloride, and poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer Pluronic F108 of different concentrations. The morphology, along with the chemical and mechanical properties of the fibers, was evaluated by field emission scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, differential scanning calorimetry, water contact angle, and tensile tester. With the addition of surfactants, the electrospinnability of dilute PCL solution was enhanced, with either branched or uniform fibers were obtained. Electrospinning of an emulsion containing 0.4% (w/v) SDS produced the smallest and the most uniform nanofibers (167 ± 39 nm), which was attributed to the high conductivity of the solution. Analysis revealed that the emulsion electrospun nanofibers containing different surfactants and surfactant concentrations differ in fiber morphology and mechanical properties. Results suggest that surfactants have the ability to modulate the fiber morphology via electrostatic and hydrogen bonding, depending on their chemical structure.

  16. Joint influence of surfactants and humic matter on PAH solubility. Are mixed micelles formed?

    Energy Technology Data Exchange (ETDEWEB)

    Lippold, H.; Gottschalch, U.; Kupsch, H. [Inst. of Interdisziplinare Isotopeforschung, Leipzig (Germany)

    2008-02-15

    Mobilization of polycyclic aromatic hydrocarbons (PAH) by surfactants, present at contaminated sites or deliberately introduced for remediation purposes, is inevitably associated with the influence of humic substances, which are ubiquitous in natural systems. Therefore, the solubilizing effects of anthropogenic and natural amphiphiles must be considered in their combined action since synergistic or antagonistic effects may be expected, for instance, as a consequence of mixed micellization. In this paper, solubilization of {sup 14}C-labeled pyrene in single-component and mixed solutions of surfactants and humic acid (coal-derived) was investigated up to the micellar concentration range. At low concentrations, antagonistic effects were observed for systems with cationic as well as anionic surfactants. Solubility enhancements in the presence of humic acid were canceled on addition of a cationic surfactant (DTAB) since charge compensation at humic colloids entailed precipitation. Solubility was also found to be decreased in the presence of an anionic surfactant (SDS), which was attributed to a competitive effect in respect of pyrene-humic interaction. This explanation is based on octanol-water partitioning experiments with radiolabeled humic acid, yielding evidence of different interaction modes between humic colloids and cationic/anionic surfactants. At higher concentrations, the effects of humic acid and SIDS were found to be additive. Thus, a formation of mixed micelles is very unlikely, which was confirmed by size exclusion chromatography of mixed systems. It can be concluded that remediation measures on the basis of micellar solubilization are not significantly affected by the presence of natural amphiphilic compounds.

  17. Characteristics of sugar surfactants in stabilizing proteins during freeze-thawing and freeze-drying.

    Science.gov (United States)

    Imamura, Koreyoshi; Murai, Katsuyuki; Korehisa, Tamayo; Shimizu, Noriyuki; Yamahira, Ryo; Matsuura, Tsutashi; Tada, Hiroko; Imanaka, Hiroyuki; Ishida, Naoyuki; Nakanishi, Kazuhiro

    2014-06-01

    Sugar surfactants with different alkyl chain lengths and sugar head groups were compared for their protein-stabilizing effect during freeze-thawing and freeze-drying. Six enzymes, different in terms of tolerance against inactivation because of freeze-thawing and freeze-drying, were used as model proteins. The enzyme activities that remained after freeze-thawing and freeze-drying in the presence of a sugar surfactant were measured for different types and concentrations of sugar surfactants. Sugar surfactants stabilized all of the tested enzymes both during freeze-thawing and freeze-drying, and a one or two order higher amount of added sugar surfactant was required for achieving protein stabilization during freeze-drying than for the cryoprotection. The comprehensive comparison showed that the C10-C12 esters of sucrose or trehalose were the most effective through the freeze-drying process: the remaining enzyme activities after freeze-thawing and freeze-drying increased at the sugar ester concentrations of 1-10 and 10-100 μM, respectively, and increased to a greater extent than for the other surfactants at higher concentrations. Results also indicate that, when a decent amount of sugar was also added, the protein-stabilizing effect of a small amount of sugar ester through the freeze-drying process could be enhanced. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  18. Surfactant induced complex formation and their effects on the interfacial properties of seawater.

    Science.gov (United States)

    Guzmán, Eduardo; Santini, Eva; Benedetti, Alessandro; Ravera, Francesca; Ferrari, Michele; Liggieri, Libero

    2014-11-01

    The effect of a cationic surfactant, hexadecyltrimethylammonium bromide (CTAB), on the interfacial properties of seawater has been studied by dynamic and equilibrium surface tension and by dilational rheology essays. Important modifications of the surface tension and dilational rheology response have been observed already at the very low CTAB concentrations, where the effects due to the high ionic strength are negligible. The comparison with the effects of CTAB in different seawater models, or in natural seawater fractions, points out the establishment of strong interactions between the surfactant molecules and the lipophilic fraction of organic material dispersed/dissolved in seawater, affecting the interfacial activity of the molecules. Considering the biochemical richness of seawater, these results can be explained assuming interaction mechanisms and adsorption schemes similar to those speculated for protein and other macromolecules in the presence of surfactants, which in fact show similar features. Thus already at the low concentrations the surfactant molecules form highly surface-active complexes with part of the organic fraction of seawater. At the larger surfactant concentrations these complexes compete for adsorption with an excess of free CTAB molecules which, according to the thermodynamic conditions, are most favoured to occupy the liquid interface. The results of this study underline the important role of the sea organic content in enhancing the surface-activity of surfactants, which is relevant for a deeper understand of the direct and indirect effects of these types of pollutants on the physico-chemical environment in the sea coastal areas and develop mitigation strategies.

  19. Microbial surfactant activities from a petrochemical landfarm in a humid tropical region of Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Maciel, B.M.; Dias, J.C.T.; Santos, A.C.F.; Argolo-Filho, R.C.; Fontana, R.; Loguercio, L.L.; Rezende, R.P. [Univ. Estadual de Santa Cruz, Santa Cruz (Brazil). Dept. de Ciencias Biologicas

    2007-08-15

    Studies have suggested that biosurfactants can enhance the biodegradation of almost insoluble organics by increasing cell uptake availability. In this study, micro-organisms were isolated from a soil sample from a Brazilian petrochemical waste landfarm and grown in petroleum as a carbon source in order to assess their surfactant potential. Isolated colonies were inoculated into tubes, and a drop-collapse method was used to select micro-organisms with surfactant activity. Surfactant activity of the isolates was assessed when the activity was detected for the first time in each culture. The supernatant of each micro-organism was then diluted. The surfactant activity of each dilution was then observed via micelles formation. DNA was then extracted from the samples. A total of 60 microbial strains were selected. Results showed that a variety of petroleum-grown micro-organisms obtained from the landfarm soil showed surfactant activity. Results showed that the micro-organisms were able to use petroleum as a sole carbon source. The production of surfactant compounds occurred during the declining stages of microbial culture curves, which suggested that the nutritional stress achieved on the fourth day of the culture induced the synthesis and secretion of biosurfactants by the isolates. It was concluded that micro-organisms derived from soils polluted with hydrocarbons can be used in bioremediation processes. 21 refs., 1 tab., 3 figs.

  20. Surfactant protein A and surfactant protein D variation in pulmonary disease

    DEFF Research Database (Denmark)

    Sørensen, Grith Lykke; Husby, Steffen; Holmskov, Uffe

    2007-01-01

    Surfactant proteins A (SP-A) and D (SP-D) have been implicated in pulmonary innate immunity. The proteins are host defense lectins, belonging to the collectin family which also includes mannan-binding lectin (MBL). SP-A and SP-D are pattern-recognition molecules with the lectin domains binding...... molecules present on immune cells leading to enhanced microbial clearance and modulation of inflammation. SP-A and SP-D also modulate the functions of cells of the adaptive immune system including dendritic cells and T cells. Studies on SP-A and SP-D polymorphisms and protein levels in bronchoalveolar...... preferentially to sugars on a broad spectrum of pathogen surfaces and thereby facilitating immune functions including viral neutralization, clearance of bacteria, fungi and apoptotic and necrotic cells, modulation of allergic reactions, and resolution of inflammation. SP-A and SP-D can interact with receptor...

  1. Metathesis depolymerization for removable surfactant templates.

    Energy Technology Data Exchange (ETDEWEB)

    Zifer, Thomas (Sandia National Laboratories, Livermore, CA); Wheeler, David Roger; Rahimian, Kamayar; McElhanon, James Ross (Sandia National Laboratories, Livermore, CA); Long, Timothy Michael; Jamison, Gregory Marks; Loy, Douglas Anson (Los Alamos National Laboratories, Los Alamos, NM); Kline, Steven R. (National Institute of Standards and Technology, Gaithersburg, MD); Simmons, Blake Alexander (Sandia National Laboratories, Livermore, CA)

    2005-03-01

    Current methodologies for the production of meso- and nanoporous materials include the use of a surfactant to produce a self-assembled template around which the material is formed. However, post-production surfactant removal often requires centrifugation, calcination, and/or solvent washing which can damage the initially formed material architecture(s). Surfactants that can be disassembled into easily removable fragments following material preparation would minimize processing damage to the material structure, facilitating formation of templated hybrid architectures. Herein, we describe the design and synthesis of novel cationic and anionic surfactants with regularly spaced unsaturation in their hydrophobic hydrocarbon tails and the first application of ring closing metathesis depolymerization to surfactant degradation resulting in the mild, facile decomposition of these new compounds to produce relatively volatile nonsurface active remnants.

  2. Summer/winter variability of the surfactants in aerosols from Grenoble, France

    Science.gov (United States)

    Baduel, Christine; Nozière, Barbara; Jaffrezo, Jean-Luc

    2012-02-01

    Many atmospheric aerosols seem to contain strong organic surfactants likely to enhance their cloud-forming properties. Yet, few techniques allow for the identification and characterization of these compounds. Recently, we introduced a double extraction method to isolate the surfactant fraction of atmospheric aerosol samples, and evidenced their very low surface tension (≤30 mN m -1). In this work, this analytical procedure was further optimized. In addition to an optimized extraction and a reduction of the analytical time, the improved method led to a high reproducibility in the surface tension curves obtained (shapes and minimal values), illustrated by the low uncertainties on the values, ±10% or less. The improved method was applied to PM 10 aerosols from the urban area of Grenoble, France collected from June 2009 to January 2010. Significant variability was observed between the samples. The minimum surface tension obtained from the summer samples was systematically lower (30 mN m -1) than that of the winter samples (35-45 mN m -1). Sharp transitions in the curves together with the very low surface tensions suggested that the dominating surfactants in the summer samples were biosurfactants, which would be consistent with the high biogenic activity in that season. One group of samples from the winter also displayed sharp transitions, which, together with the slightly higher surface tension, suggested the presence of weaker, possibly man-made, surfactants. A second group of curves from the winter did not display any clear transition but were similar to those of macromolecular surfactants such as polysaccharides or humic substances from wood burning. These surfactants are thus likely to originate from wood burning, the dominating source for aerosols in Grenoble in winter. These observations thus confirm the presence of surfactants from combustion processes in urban aerosols reported by other groups and illustrates the ability of our method to distinguish between

  3. Characterization of flow dynamics and vulnerability in a coastal aquifer system.

    Science.gov (United States)

    Murgulet, Dorina; Tick, Geoffrey R

    2013-01-01

    Traditional aquifer vulnerability techniques primarily rely on spatial property data for a region and are limited by their ability to directly or indirectly assess flow and transport processes occurring from the surface to depth within an aquifer system. The main objective of this study was to investigate groundwater vulnerability in terms of aquifer interconnectivity and flow dynamics. A combination of stable isotopes, groundwater age-dating (radiocarbon), and geomorphic/geogenic spatial analyses was applied to a regional, highly developed coastal aquifer to explain the presence of nitrate at depth. The average δ(13) C value (-17.3 ± 2‰ VPDB, n = 27) is characteristic of groundwater originating from locally infiltrated precipitation through extensively cultivated soils. The average δ(18) O and δD values (-4.0 ± 0.1‰ VSMOW, n = 27; δD: -19.3 ± 1‰ VSMOW, n = 27, respectively) are similar to precipitation water derived from maritime sources feeding the region's surface water and groundwater. Stable and radioactive isotopes reveal significant mixing between shallow and deep aquifers due to high velocities, hydraulic connection, and input of local recharge water to depths. Groundwater overdevelopment enhances deeper and faster modern water downward flux, amplifying aquifer vulnerability. Therefore, aquifer vulnerability is a variable, dependent on the type and degree of stress conditions experienced by a groundwater system as well as the geospatial properties at the near surface.

  4. Groundwater response to tidal fluctuations in wedge-shaped confined aquifers

    Science.gov (United States)

    Cuello, Julián E.; Guarracino, Luis; Monachesi, Leonardo B.

    2017-08-01

    Most of the analytical solutions to describe tide-induced head fluctuations assume that the coastal aquifer has a constant thickness. These solutions have been applied in many practical problems ignoring possible changes in aquifer thickness, which may lead to wrong estimates of the hydraulic parameters. In this study, a new analytical solution to describe tide-induced head fluctuations in a wedge-shaped coastal aquifer is presented. The proposed model assumes that the aquifer thickness decreases with the distance from the coastline. A closed-form analytical solution is obtained by solving a boundary-value problem with both a separation of variables method and a change of variables method. The analytical solution indicates that wedging significantly enhances the amplitude of the induced heads in the aquifer. However, the effect on time lag is almost negligible, particularly near the coast. The slope factor, which quantifies the degree of heterogeneity of the aquifer, is obtained and analyzed for a number of hypothetical scenarios. The slope factor provides a simple criterion to detect a possible wedging of the coastal aquifer.

  5. Effects of altered groundwater chemistry upon the pH-dependency and magnitude of bacterial attachment during transport within an organically contaminated sandy aquifer

    Science.gov (United States)

    Harvey, Ronald W.; Metge, David W.; Barber, Larry B.; Aiken, George R.

    2010-01-01

    The effects of a dilute (ionic strength = 5 ?? 10-3 M) plume of treated sewage, with elevated levels (3.9 mg/L) of dissolved organic carbon (DOC), upon the pH-dependency and magnitude of bacterial transport through an iron-laden, quartz sand aquifer (Cape Cod, MA) were evaluated using sets of replicate, static minicolumns. Compared with uncontaminated groundwater, the plume chemistry diminished bacterial attachment under mildly acidic (pH 5.0-6.5) in-situ conditions, in spite of the 5-fold increase in ionic strength and substantively enhanced attachment under more alkaline conditions. The effects of the hydrophobic neutral and total fractions of the plume DOC; modest concentrations of fulvic and humic acids (1.5 mg/L); linear alkyl benzene sulfonate (LAS) (25 mg/L); Imbentin (200 ??g/L), a model nonionic surfactant; sulfate (28 mg/L); and calcium (20 mg/L) varied sharply in response to relatively small changes in pH, although the plume constituents collectively decreased the pH-dependency of bacterial attachment. LAS and other hydrophobic neutrals (collectively representing only ???3% of the plume DOC) had a disproportionately large effect upon bacterial attachment, as did the elevated concentrations of sulfate within the plume. The findings further suggest that the roles of organic plume constituents in transport or bacteria through acidic aquifer sediments can be very different than would be predicted from column studies performed at circumneutral pH and that the inorganic constituents within the plume cannot be ignored.

  6. Effects of altered groundwater chemistry upon the pH-dependency and magnitude of bacterial attachment during transport within an organically contaminated sandy aquifer.

    Science.gov (United States)

    Harvey, Ronald W; Metge, David W; Barber, L B; Aiken, George R

    2010-02-01

    The effects of a dilute (ionic strength=5x10(-3)M) plume of treated sewage, with elevated levels (3.9 mg/L) of dissolved organic carbon (DOC), upon the pH-dependency and magnitude of bacterial transport through an iron-laden, quartz sand aquifer (Cape Cod, MA) were evaluated using sets of replicate, static minicolumns. Compared with uncontaminated groundwater, the plume chemistry diminished bacterial attachment under mildly acidic (pH 5.0-6.5) in-situ conditions, in spite of the 5-fold increase in ionic strength and substantively enhanced attachment under more alkaline conditions. The effects of the hydrophobic neutral and total fractions of the plume DOC; modest concentrations of fulvic and humic acids (1.5 mg/L); linear alkyl benzene sulfonate (LAS) (25 mg/L); Imbentin (200 microg/L), a model nonionic surfactant; sulfate (28 mg/L); and calcium (20 mg/L) varied sharply in response to relatively small changes in pH, although the plume constituents collectively decreased the pH-dependency of bacterial attachment. LAS and other hydrophobic neutrals (collectively representing only approximately 3% of the plume DOC) had a disproportionately large effect upon bacterial attachment, as did the elevated concentrations of sulfate within the plume. The findings further suggest that the roles of organic plume constituents in transport or bacteria through acidic aquifer sediments can be very different than would be predicted from column studies performed at circumneutral pH and that the inorganic constituents within the plume cannot be ignored.

  7. Fibrinogen stability under surfactant interaction.

    Science.gov (United States)

    Hassan, Natalia; Barbosa, Leandro R S; Itri, Rosangela; Ruso, Juan M

    2011-10-01

    Differential scanning calorimetry (DSC), circular dichroism (CD), difference spectroscopy (UV-vis), Raman spectroscopy, and small-angle X-ray scattering (SAXS) measurements have been performed in the present work to provide a quantitatively comprehensive physicochemical description of the complexation between bovine fibrinogen and the sodium perfluorooctanoate, sodium octanoate, and sodium dodecanoate in glycine buffer (pH 8.5). It has been found that sodium octanoate and dodecanoate act as fibrinogen destabilizer. Meanwhile, sodium perfluorooctanoate acts as a structure stabilizer at low molar concentration and as a destabilizer at high molar concentration. Fibrinogen's secondary structure is affected by all three studied surfactants (decrease in α-helix and an increase in β-sheet content) to a different extent. DSC and UV-vis revealed the existence of intermediate states in the thermal unfolding process of fibrinogen. In addition, SAXS data analysis showed that pure fibrinogen adopts a paired-dimer structure in solution. Such a structure is unaltered by sodium octanoate and perfluoroctanoate. However, interaction of sodium dodecanoate with the fibrinogen affects the protein conformation leading to a complex formation. Taken together, all results evidence that both surfactant hydrophobicity and tail length mediate the fibrinogen stability upon interaction. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Effect of nonionic surfactant addition on Pyrex glass ablation using water-assisted CO2 laser processing

    Science.gov (United States)

    Chung, C. K.; Liao, M. W.; Lin, S. L.

    2010-04-01

    Pyrex glass etching using laser ablation is an important technology for the microfluid application to lab-on-a-chip devices but suffers from the formation of surface crack. In this article, the addition of nonionic surfactant to water for glass ablation using water-assisted CO2 laser processing (WACLAP) has been investigated to enhance ablation rate and to eliminate conventional surface defects of cracks in air. WACLAP for Pyrex glass ablation can reduce thermal-stress-induced crack with water cooling and hydrophilic nonionic surfactant to water can enhance ablation performance. Compared to pure water, the 15% weight percent Lauramidopropyl Betaine surfactant solutions for WACLAP can enhance ablation rate from 13.6 to 25 μm/pass of Pyrex glass ablation at a linear laser energy density of 2.11 J/cm, i.e., 24 W power, 114 mm/s scanning speed, and obtain through-wafer etching at 3.16 J/cm for 20 passes without cracks on the surface. Effect of surfactant concentration and linear energy density on WACLAP was also examined. The possible mechanism of surfactant-enhanced phenomenon was discussed by the Newton’s law of viscosity of surfactant solution.

  9. Facile Fabrication of Large Area Polystyrene Colloidal Crystal Monolayer via Surfactant-free Langmuir-Blodgett Technique

    Institute of Scientific and Technical Information of China (English)

    RUAN Wei-dong; L(U) Zhi-cheng; JI Nan; WANG Chun-xu; ZHAO Bing; ZHANG Jun-hu

    2007-01-01

    A facile and novel method for the production of a large area of well-ordered polystyrene(PS) colloidal crystal monolayer was established using the surfactant-free Langmuir-Blodgett (LB) technique. The hydrophobic property(film-forming ability) of PS spheres was improved by a thermo-rheology treatment before LB assembly, and a large film was obtained. In contrast to the traditional LB technique, no surfactant was needed in this method, which could eliminate the additional contamination of surfactants in the preparation process and provided the products with versatile applications in nanosphere lithography(NSL) for biosensor, surface plasmon resonance, and surface enhanced Raman spectroscopy.

  10. Surfactant replacement therapy--economic impact.

    Science.gov (United States)

    Pejaver, R K; al Hifzi, I; Aldussari, S

    2001-06-01

    Surfactant replacement is an effective treatment for neonatal respiratory distress syndrome. (RDS). As widespread use of surfactant is becoming a reality, it is important to assess the economic implications of this new form of therapy. A comparison study was carried out at the Neonatal Intensive Care Unit (NICU) of Northwest Armed Forces Hospital, Saudi Arabia. Among 75 infants who received surfactant for RDS and similar number who were managed during time period just before the surfactant was available, but by set criteria would have made them eligible for surfactant. All other management modalities except surfactant were the same for all these babies. Based on the intensity of monitoring and nursing care required by the baby, the level of care was divided as: Level IIIA, IIIB, Level II, Level I. The cost per day per bed for each level was calculated, taking into account the use of hospital immovable equipment, personal salaries of nursing, medical, ancillary staff, overheads and maintenance, depreciation and replacement costs. Medications used, procedures done, TPN, oxygen, were all added to individual patient's total expenditure. 75 infants in the Surfactant group had 62 survivors. They spent a total of 4300 days in hospital. (av 69.35) Out of which 970 d (av 15.65 per patient) were ventilated days. There were 56 survivors in the non-surfactant group of 75. They had spent a total of 5023 days in the hospital (av 89.69/patient) out of which 1490 were ventilated days (av 26.60 d). Including the cost of surfactant (two doses), cost of hospital stay for each infant taking the average figures of stay would be SR 118, 009.75 per surfactant treated baby and SR 164, 070.70 per non-surfactant treated baby. The difference of 46,061 SR is 39.03% more in non-surfactant group. One Saudi rial = 8 Rs (approx at the time study was carried out.) Medical care cost varies from place to place. However, it is definitely cost-effective where surfactant is concerned. Quality adjusted

  11. Different effects of surfactant proteins B and C - implications for development of synthetic surfactants.

    Science.gov (United States)

    Curstedt, Tore; Johansson, Jan

    2010-06-01

    Treatment of premature newborn rabbits with synthetic surfactants containing a surfactant protein C analogue in a simple phospholipid mixture gives similar tidal volumes as treatment with poractant alfa (Curosurf(R)) but ventilation with a positive end-expiratory pressure (PEEP) is needed for this synthetic surfactant to stabilize the alveoli at end-expiration. The effect on lung gas volumes seems to depend on the structure of the peptide since treatment with a synthetic surfactant containing the 21-residue peptide (LysLeu(4))(4)Lys (KL(4)) gives low lung gas volumes in experiments also performed with PEEP. Surfactant preparations containing both surfactant proteins B and C or their analogues prevent alveolar collapse at end-expiration even if ventilated without PEEP. Treatment of premature newborn rabbits with different natural surfactants indicates that both the lipid composition and the proteins are important in order to stabilize the alveoli at end-expiration. Synthetic surfactants containing two peptides may be able to replace natural surfactants within the near future but more trials need to be performed before any conclusion can be drawn about the ideal composition of this new generation of synthetic surfactants.

  12. Exogenous Pulmonary Surfactant as a Vehicle for Antimicrobials: Assessment of Surfactant-Antibacterial Interactions In Vitro

    Directory of Open Access Journals (Sweden)

    Alexei Birkun

    2014-01-01

    Full Text Available Owing to its unique surface-active properties, an exogenous pulmonary surfactant may become a promising drug delivery agent, in particular, acting as a vehicle for antibiotics in topical treatment of pneumonia. The purpose of this study was to assess a mutual influence of natural surfactant preparation and three antibiotics (amikacin, cefepime, and colistimethate sodium in vitro and to identify appropriate combination(s for subsequent in vivo investigations of experimental surfactant/antibiotic mixtures. Influence of antibiotics on surface-active properties of exogenous surfactant was assessed using the modified Pattle method. Effects of exogenous surfactant on antibacterial activity of antimicrobials against Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa were evaluated using conventional microbiologic procedures. Addition of amikacin or cefepime to surfactant had no significant influence on surface-active properties of the latter. Obvious reduction of surface-active properties was confirmed for surfactant/colistimethate composition. When suspended with antibiotics, surfactant either had no impact on their antimicrobial activity (amikacin or exerted mild to moderate influence (reduction of cefepime bactericidal activity and increase of colistimethate bacteriostatic activity against S. aureus and P. aeruginosa. Considering favorable compatibility profile, the surfactant/amikacin combination is advisable for subsequent investigation of joint surfactant/antibacterial therapy in animals with bacterial pneumonia.

  13. BEHAVIOR OF SURFACTANT MIXTURES AT SOLID/LIQUID AND OIL/LIQUID INTERFACES IN CHEMICAL FLOODING SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Prof. P. Somasundaran

    2003-03-31

    The aim of the project is to develop a knowledge base to help with the design of enhanced process for mobilizing and extracting untrapped oil. We emphasize on evaluating novel surfactant mixtures and on obtaining optimum combinations of the surfactants in chemical flooding EOR process. An understanding of the micellar shape and size is crucial since these physical properties directly determine the crude oil removal efficiency. Analytical ultracentrifugation experiments were used to test the multi-micelle model proposed earlier and formulate the relationships between mixed micelle formation and the surfactant structure. Information on partial specific volume of surfactants and their mixtures is required to treat analytical ultracentrifuge data. In the last report, it was noted that the partial specific volumes of the sugar-based surfactants obtained experimentally did not agree with those from theoretical calculations. A scrutiny of partial specific volumes of the four sugar-based surfactants revealed that conformational changes upon micelle formation are responsible for the large deviation. From sedimentation equilibrium experiments, two types of micelles were identified for the nonionic polyethylene surfactant and its mixtures with the sugar-based surfactant, dodecyl maltoside. The average aggregation numbers of n-dodecyl-{beta}-D-maltoside and nonyl phenol ethoxylated decyl ether agreed with those reported in literature using other techniques. Our study displayed, for the first time, that small micelles might coexist with large micelles at high concentrations due to unique structures of the surfactant although classical thermodynamic theory supports only one type of micelle. Initial dynamic light scattering results support the results for the same mixed surfactant system from analytical ultracentrifuge equilibrium technique. The implication of this finding lies in the fact that efficiency of oil recovery will be improved due to the large micellar size, its

  14. Effects of surfactant on properties of MIM feedstock

    Institute of Scientific and Technical Information of China (English)

    LI Yi-min; LIU Xiang-quan; LUO Feng-hua; YUE Jian-ling

    2007-01-01

    Effects of the surfactant for improving the properties of MIM feedstock were investigated. Feedstocks were prepared by 17-4PH stainless steel(SS) powder and paraffin wax-based binder containing different contents of stearic acid(SA) as the surfactant. The viscosity of the feedstock decreases significantly when the SA is added. Besides, the wetting angle of the binder against the 17-4PH SS powder decreases greatly and the critical solid loading increases with the adding of the SA. Fourier transformation infrared spectroscopy(FTIR) analysis was used to prove the interaction between the SA and the 17-4PH SS powder. Chemical bonding is found on the surface of 17-4PH SS powder after mixing and it helps a lot to enhance the interacting force between the binder and the powder. Then an adsorbing model was adopted to estimate the least content of the surfactant that formed a monolayer adsorption on the mono-sized spherical powder (with smooth surface). The least content of the surfactant is calculated to be 0.19%. Whereas, the experiments indicate that about 5% is the optimal value to improve the properties of the feedstock. The reason may come from two aspects: firstly, the powders used in current experiment are not all mono-sized spheres and the coarse surface of the powder has a great effect on the adsorptive capacity of the powder; secondly, multilayer adsorption is likely to occur on the powder surface, which will also increase the adsorptive capacity.

  15. Combination of surfactant solubilization with permanganate oxidation for DNAPL remediation.

    Science.gov (United States)

    Li, Zhaohui; Hanlie, Hong

    2008-02-01

    A combination of surfactant solubilization with permanganate oxidation of trichloroethylene (TCE) was studied in batch, flow-through column, and three-dimensional (3-D) tank tests. Batch results showed that chloride production, an indication of TCE degradation, followed a pseudo-first-order reaction kinetics with respect to KMnO4 in the presence of free-phase TCE. A higher chloride production rate was achieved when anionic surfactants were present. The observed pseudo-first-order reaction rate constant increased as the concentrations of anionic surfactants Ninate 411 and Calfax increased from 0% to 0.1%, 0.3%, and 1.0%. Column experiments on TCE reduction by permanganate in the presence and absence of surfactants were carried out using well-sorted coarse Ottawa sand. The peak effluent TCE concentration reached 1700 mg/L due to enhanced solubilization when both sodium dodecyl sulfate (SDS) and permanganate were used, in contrast to less than 300 mg/L when only permanganate solution was used. In addition, the effluent TCE concentration decreased much faster when SDS was present in the permanganate solution, compared with the case when SDS was absent. With an initial 1 mL of TCE emplaced in the columns, the effluent TCE concentration dropped to breakthrough occurred after 21-25 h of injection when SDS was present compared with 45-70 h later when SDS was absent. A slightly higher chloride concentration was observed in the earlier stage of the column experiment and the chloride concentration decreased quickly once KMnO4 was seen in the effluent. The 3-D tank test showed that the MnO2 precipitation front formed more quickly when 1% SDS was present, which further confirmed the observation from the column study.

  16. Identifying the influential aquifer heterogeneity factor on nitrate reduction processes by numerical simulation

    Science.gov (United States)

    Jang, E.; He, W.; Savoy, H.; Dietrich, P.; Kolditz, O.; Rubin, Y.; Schüth, C.; Kalbacher, T.

    2017-01-01

    Nitrate reduction reactions in groundwater systems are strongly influenced by various aquifer heterogeneity factors that affect the transport of chemical species, spatial distribution of redox reactive substances and, as a result, the overall nitrate reduction efficiency. In this study, we investigated the influence of physical and chemical aquifer heterogeneity, with a focus on nitrate transport and redox transformation processes. A numerical modeling study for simulating coupled hydrological-geochemical aquifer heterogeneity was conducted in order to improve our understanding of the influence of the aquifer heterogeneity on the nitrate reduction reactions and to identify the most influential aquifer heterogeneity factors throughout the simulation. Results show that the most influential aquifer heterogeneity factors could change over time. With abundant presence of electron donors in the high permeable zones (initial stage), physical aquifer heterogeneity significantly influences the nitrate reduction since it enables the preferential transport of nitrate to these zones and enhances mixing of reactive partners. Chemical aquifer heterogeneity plays a comparatively minor role. Increasing the spatial variability of the hydraulic conductivity also increases the nitrate removal efficiency of the system. However, ignoring chemical aquifer heterogeneity can lead to an underestimation of nitrate removals in long-term behavior. With the increase of the spatial variability of the electron donor, i.e. chemical heterogeneity, the number of the "hot spots" i.e. zones with comparably higher reactivity, should also increase. Hence, nitrate removal efficiencies will also be spatially variable but overall removal efficiency will be sustained if longer time scales are considered and nitrate fronts reach these high reactivity zones.

  17. Fluorescence emission of pyrene in surfactant solutions.

    Science.gov (United States)

    Piñeiro, Lucas; Novo, Mercedes; Al-Soufi, Wajih

    2015-01-01

    The systematic description of the complex photophysical behaviour of pyrene in surfactant solutions in combination with a quantitative model for the surfactant concentrations reproduces with high accuracy the steady-state and the time resolved fluorescence intensity of pyrene in surfactant solutions near the cmc, both in the monomer and in the excimer emission bands. We present concise model equations that can be used for the analysis of the pyrene fluorescence intensity in order to estimate fundamental parameters of the pyrene-surfactant system, such as the binding equilibrium constant K of pyrene to a given surfactant micelle, the rate constant of excimer formation in micelles, and the equilibrium constant of pyrene-surfactant quenching. The values of the binding equilibrium constant K(TX100)=3300·10³ M⁻¹ and K(SDS)=190·10³ M⁻¹ for Triton X-100 (TX100) and SDS micelles, respectively, show that the partition of pyrene between bulk water and micelles cannot be ignored, even at relatively high surfactant concentrations above the cmc. We apply the model to the determination of the cmc from the pyrene fluorescence intensity, especially from the intensity ratio at two vibronic bands in the monomer emission or from the ratio of excimer to monomer emission intensity. We relate the finite width of the transition region below and above the cmc with the observed changes in the pyrene fluorescence in this region.

  18. A study of surfactant-assisted waterflooding

    Energy Technology Data Exchange (ETDEWEB)

    Scamehorn, J F; Harwell, J H

    1990-09-01

    In surfactant-assisted waterflooding, a surfactant slug is injected into a reservoir, followed by a brine spacer, followed by second surfactant slug. The charge on the surfactant in the first slug has opposite sign to that in the second slug. When the two slugs mix in the reservoir, a precipitate or coacervate is formed which plugs the permeable region of the reservoir. Subsequently injected water or brine is forced through the low permeability region of the reservoir, increasing sweep efficiency of the waterflood, compared to a waterflood not using surfactants. In this part of the work, two major tasks are performed. First, core floods are performed with oil present to demonstrate the improvement in incremental oil production, as well as permeability modification. Second, a reservoir simulation model will be proposed to further delineate the optimum strategy for implementation of the surfactant-assisted waterflooding, as well as indicate the reservoir types for which it would be most effective. Surfactants utilized were sodium dodecyl sulfate and dodecyl pyridinium chloride. 44 refs., 17 figs., 3 tabs.

  19. Surfactants tailored by the class Actinobacteria

    Directory of Open Access Journals (Sweden)

    Johannes H Kügler

    2015-03-01

    Full Text Available Gloablly, the drive towards the establishment of a bio-based economy has resulted in an increased need for bio-based applications. This, in turn, has served as a driving force for the discovery and application of novel biosurfactants. The class Actinobacteria represents a vast group of microorganisms with the ability to produce a diverse range of secondary metabolites, including surfactants. Understanding the extensive nature of the biosurfactants produced by actinobacterial strains can assist in finding novel biosurfactants with new potential applications. This review therefore presents a comprehensive overview of the knowledge available on actinobacterial surfactants, the chemical structures that have been completely or partly elucidated, as well as the identity of the biosurfactant-producing strains. Producer strains of not yet elucidated compounds are discussed, as well as the original habitats of all the producer strains, which seems to indicate that biosurfactant production is environmentally driven. Methodology applied in the isolation, purification and structural elucidation of the different types of surface active compounds, as well as surfactant activity tests, are also discussed. Overall, actinobacterial surfactants can be summarized to include the dominantly occurring trehalose-comprising surfactants, other non-trehalose containing glycolipids, lipopeptides and the more rare actinobacterial surfactants. The lack of structural information on a large proportion of actinobacterial surfactants should be considered as a driving force to further explore the abundance and diversity of these compounds. This would allow for a better understanding of actinobacterial surface active compounds and their potential for biotechnological application.

  20. Compatible solutes: ectoine and hydroxyectoine improve functional nanostructures in artificial lung surfactants.

    Science.gov (United States)

    Harishchandra, Rakesh Kumar; Sachan, Amit Kumar; Kerth, Andreas; Lentzen, Georg; Neuhaus, Thorsten; Galla, Hans-Joachim

    2011-12-01

    Ectoine and hydroxyectoine belong to the family of compatible solutes and are among the most abundant osmolytes in nature. These compatible solutes protect biomolecules from extreme conditions and maintain their native function. In the present study, we have investigated the effect of ectoine and hydroxyectoine on the domain structures of artificial lung surfactant films consisting of dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylglycerol (DPPG) and the lung surfactant specific surfactant protein C (SP-C) in a molar ratio of 80:20:0.4. The pressure-area isotherms are found to be almost unchanged by both compatible solutes. The topology of the fluid domains shown by scanning force microscopy, which is thought to be responsible for the biophysical behavior under compression, however, is modified giving rise to the assumption that ectoine and hydroxyectoine are favorable for a proper lung surfactant function. This is further evidenced by the analysis of the insertion kinetics of lipid vesicles into the lipid-peptide monolayer, which is clearly enhanced in the presence of both compatible solutes. Thus, we could show that ectoine and hydroxyectoine enhance the function of lung surfactant in a simple model system, which might provide an additional rationale to inhalative therapy.

  1. Digital data sets that describe aquifer characteristics of the Central Oklahoma aquifer in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries created for a previously published report about the Central Oklahoma aquifer in central Oklahoma. This area...

  2. Digital data sets that describe aquifer characteristics of the Rush Springs aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries for the Rush Springs aquifer in western Oklahoma. This area encompasses all or part of Blaine, Caddo,...

  3. Digital data sets that describe aquifer characteristics of the Elk City aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant hydraulic conductivity values for the Elk City aquifer in western Oklahoma. The aquifer covers an area of...

  4. Digital data sets that describe aquifer characteristics of the Elk City aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant recharge values for the Elk City aquifer in western Oklahoma. The aquifer covers an area of approximately...

  5. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid isolated terrace aquifer...

  6. Digital data sets that describe aquifer characteristics of the Antlers aquifer in southeastern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries of the Antlers aquifer in southeastern Oklahoma. The Early Cretaceous-age Antlers Sandstone is an important...

  7. Digital data sets that describe aquifer characteristics of the Elk City aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the Elk City aquifer in western Oklahoma. The aquifer covers an area of approximately 193,000...

  8. Digital data sets that describe aquifer characteristics of the High Plains aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the High Plains aquifer in western Oklahoma. This area encompasses the panhandle counties of Cimarron,...

  9. Surfactant-Assisted Coal Liquefaction

    Science.gov (United States)

    Hickey, Gregory S.; Sharma, Pramod K.

    1993-01-01

    Obtaining liquid fuels from coal which are economically competitive with those obtained from petroleum based sources is a significant challenge for the researcher as well as the chemical industry. Presently, the economics of coal liquefaction are not favorable because of relatively intense processing conditions (temperatures of 430 degrees C and pressures of 2200 psig), use of a costly catalyst, and a low quality product slate of relatively high boiling fractions. The economics could be made more favorable by achieving adequate coal conversions at less intense processing conditions and improving the product slate. A study has been carried out to examine the effect of a surfactant in reducing particle agglomeration and improving hydrodynamics in the coal liquefaction reactor to increase coal conversions...

  10. Gemini surfactants from natural amino acids.

    Science.gov (United States)

    Pérez, Lourdes; Pinazo, Aurora; Pons, Ramon; Infante, Mrosa

    2014-03-01

    In this review, we report the most important contributions in the structure, synthesis, physicochemical (surface adsorption, aggregation and phase behaviour) and biological properties (toxicity, antimicrobial activity and biodegradation) of Gemini natural amino acid-based surfactants, and some potential applications, with an emphasis on the use of these surfactants as non-viral delivery system agents. Gemini surfactants derived from basic (Arg, Lys), neutral (Ser, Ala, Sar), acid (Asp) and sulphur containing amino acids (Cys) as polar head groups, and Geminis with amino acids/peptides in the spacer chain are reviewed.

  11. Synthesis and Characterization of Zirconia Nanocrystallites by Cationic Surfactant and Anionic Surfactant

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Study on nanomaterials has attracted great interests in recent years. In this article,zirconia nanocrystallites of different structures have been successfully synthesized via hydrothermal methods with cationic surfactant (CTAB) and anionic surfactant (SDS), respectively. Differential Scanning Calorimeter (DSC-TG), X-ray Diffractometer (XRD), Transmission Electron Microscope (TEM), Ultraviolet-Visible (UV-vis) and N2 adsorption-desorption analyses are used for their structure characteristics. The results show that the cationic surfactant has a distinctive direction effect on the formation of zirconia nanocrystallites, while the anionic surfactant has a self-assembly synergistic effect on them. The sample synthesized with the cationic surfactant presents good dispersion with the main phase of tetragonal zirconia, and the average nanocryst al size is around 15nm after calcination at 500 ℃. While the sample synthesized with the anionic surfactant exhibits a worm-like mesoporous structure with pure tetragonal phase after calcination at 500 ℃ and with good thermal stability.

  12. Studies on the electrocapillary curves of anionic surfactants in presence of non-ionic surfactants.

    Science.gov (United States)

    Bembi, R; Goyal, R N; Malik, W U

    1976-09-01

    Polyoxyethylated non-ionic surfactants such as Tween 20, Tween 40, Nonidet P40 and Nonex 501 have been supposed to be associated with cationic characteristics. Studies on the effect of these surfactants on the electrocapillary curves of the anionic surfactants Aerosol IB, Manaxol OT and sodium lauryl sulphate (SLS), show that the electrocapillary maxima shift towards positive potentials. The order of adsorption of the anionic surfactants is SLS > Manaxol OT > Aerosol IB while the shift in maxima is in the order Aerosol IB ~ Manaxol OT > SLS which confirms association of cationic characteristics with the micelles of these non-ionic surfactants. The magnitude of the shift in electrocapillary maxima is Nonex 501 > Nonidet P40 > Tween 20 > Tween 40 which may be the order of magnitude of the positive charge carried by these non-ionic surfactants.

  13. Biodegradable surfactant stabilized nanoscale zero-valent iron for in situ treatment of vinyl chloride and 1,2-dichloroethane

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Yu-Ting; Wu, Shian-chee; Yang, Shi-Wei; Che, Choi-Hong [Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, Taiwan, ROC (China); Lien, Hsing-Lung, E-mail: lien.sam@nuk.edu.tw [Department of Civil and Environmental Engineering, National University of Kaohsiung, Kaohsiung, Taiwan, ROC (China); Huang, De-Huang [Chinese Petroleum Corporation, Kaohsiung, Taiwan, ROC (China)

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Biodegradable surfactant stabilized nanoscale zero-valent iron (NZVI) is tested. Black-Right-Pointing-Pointer Vinyl chloride and 1,2-dichloroethane are remediated by NZVI in the field. Black-Right-Pointing-Pointer Multiple functions of biodegradable surfactants are confirmed. Black-Right-Pointing-Pointer Biodegradable surfactants stabilize NZVI and facilitate the bioremediation. Black-Right-Pointing-Pointer NZVI creates reducing conditions beneficial to an anaerobic bioremediation. - Abstract: Nanoscale zero-valent iron (NZVI) stabilized with dispersants is a promising technology for the remediation of contaminated groundwater. In this study, we demonstrated the use of biodegradable surfactant stabilized NZVI slurry for successful treatment of vinyl chloride (VC) and 1,2-dichloroethane (1,2-DCA) in a contaminated site in Taiwan. The biodegradable surfactant stabilized NZVI was coated with palladium and synthesized on-site. From monitoring the iron concentration breakthrough and distribution, it was found that the stabilized NZVI is capable of transporting in the aquifer at the test plot (200 m{sup 2}). VC was effectively degraded by NZVI while the 1,2-DCA degradation was relatively sluggish during the 3-month field test. Nevertheless, as 1,2-DCA is known to resist abiotic reduction by NZVI, the observation of 1,2-DCA degradation and hydrocarbon production suggested a bioremediation took place. ORP and pH results revealed that a reducing condition was achieved at the testing area facilitating the biodegradation of chlorinated organic hydrocarbons. The bioremediation may be attributed to the production of hydrogen gas as electron donor from the corrosion of NZVI in the presence of water or the added biodegradable surfactant serving as the carbon source as well as electron donor to stimulate microbial growth.

  14. Filtration of Pathogenic Parasites Using Surfactant-Modified Zeolites

    Science.gov (United States)

    Lehner, T.; Schulze-Makuch, D.; Bowman, R.

    2003-12-01

    Migration of pathogenic microorganisms, specifically Cryptosporidium parvum and Giardia lamblia, in groundwater due to sewage effluent and mismanaged wastewater has become an increased concern for human health in many regions. Cryptosporididosis and Giardiasis produces moderate to severe intestinal illness for many weeks and is a serious threat for immunodeficient persons. Previous studies by Schulze-Makuch et al. (2002) indicated that surfactant-modified zeolites (SMZ) removed all of the bacteria and most viruses in laboratory experiments. This study focuses on the efficiency of the SMZ to prevent migration of the protozoan spores in groundwater. Adsorption of the spores involves interactions between the surface properties of the spores and the SMZ. The efficiency of removal is tested simulating natural conditions. Laboratory experiments are conducted in a plexiglass model aquifer and pathogen removal is measured by taking water samples from strategically placed piezometers in the model. Since C. parvum and G. lamblia are hazardous to humans and move primarily in spore state through groundwater, polystyrene microspheres of similar sizes and Bacillus subtilis, a sporulating bacterium, are used as analogues for the protozoa. Preliminary results show a significant decrease in concentration of the B. subtilis spores down-gradient of the barrier.

  15. A comparative research of different ensemble surrogate models based on set pair analysis for the DNAPL-contaminated aquifer remediation strategy optimization

    Science.gov (United States)

    Hou, Zeyu; Lu, Wenxi; Xue, Haibo; Lin, Jin

    2017-08-01

    Surrogate-based simulation-optimization technique is an effective approach for optimizing the surfactant enhanced aquifer remediation (SEAR) strategy for clearing DNAPLs. The performance of the surrogate model, which is used to replace the simulation model for the aim of reducing computation burden, is the key of corresponding researches. However, previous researches are generally based on a stand-alone surrogate model, and rarely make efforts to improve the approximation accuracy of the surrogate model to the simulation model sufficiently by combining various methods. In this regard, we present set pair analysis (SPA) as a new method to build ensemble surrogate (ES) model, and conducted a comparative research to select a better ES modeling pattern for the SEAR strategy optimization problems. Surrogate models were developed using radial basis function artificial neural network (RBFANN), support vector regression (SVR), and Kriging. One ES model is assembling RBFANN model, SVR model, and Kriging model using set pair weights according their performance, and the other is assembling several Kriging (the best surrogate modeling method of three) models built with different training sample datasets. Finally, an optimization model, in which the ES model was embedded, was established to obtain the optimal remediation strategy. The results showed the residuals of the outputs between the best ES model and simulation model for 100 testing samples were lower than 1.5%. Using an ES model instead of the simulation model was critical for considerably reducing the computation time of simulation-optimization process and maintaining high computation accuracy simultaneously.

  16. Synthesis of novel quaternary ammonium surfactants containing adamantane

    Institute of Scientific and Technical Information of China (English)

    Jian Wei Guo; Xing Zhong; Hua Zhu; Li Juan Feng; Ying De Cui

    2012-01-01

    A series of novel quaternary ammonium surfactants containing adamantane were designed and synthesized from 1-adamantanecarboxylic acid.The structures of target surfactants were confirmed by 1H NMR,elements analysis and FTIR.Surface properties of these surfactants were investigated.Due to the lipophilicity of adamantane,the critical micelle concentration (CMC) and C20 values of the synthesized quaternary ammonium surfactants are lower than that of conventional quaternary ammonium surfactants.

  17. Lung surfactant levels are regulated by Ig-Hepta/GPR116 by monitoring surfactant protein D.

    Directory of Open Access Journals (Sweden)

    Taku Fukuzawa

    Full Text Available Lung surfactant is a complex mixture of lipids and proteins, which is secreted from the alveolar type II epithelial cell and coats the surface of alveoli as a thin layer. It plays a crucial role in the prevention of alveolar collapse through its ability to reduce surface tension. Under normal conditions, surfactant homeostasis is maintained by balancing its release and the uptake by the type II cell for recycling and the internalization by alveolar macrophages for degradation. Little is known about how the surfactant pool is monitored and regulated. Here we show, by an analysis of gene-targeted mice exhibiting massive accumulation of surfactant, that Ig-Hepta/GPR116, an orphan receptor, is expressed on the type II cell and sensing the amount of surfactant by monitoring one of its protein components, surfactant protein D, and its deletion results in a pulmonary alveolar proteinosis and emphysema-like pathology. By a coexpression experiment with Sp-D and the extracellular region of Ig-Hepta/GPR116 followed by immunoprecipitation, we identified Sp-D as the ligand of Ig-Hepta/GPR116. Analyses of surfactant metabolism in Ig-Hepta(+/+ and Ig-Hepta(-/- mice by using radioactive tracers indicated that the Ig-Hepta/GPR116 signaling system exerts attenuating effects on (i balanced synthesis of surfactant lipids and proteins and (ii surfactant secretion, and (iii a stimulating effect on recycling (uptake in response to elevated levels of Sp-D in alveolar space.

  18. Lung surfactant levels are regulated by Ig-Hepta/GPR116 by monitoring surfactant protein D.

    Science.gov (United States)

    Fukuzawa, Taku; Ishida, Junji; Kato, Akira; Ichinose, Taro; Ariestanti, Donna Maretta; Takahashi, Tomoya; Ito, Kunitoshi; Abe, Jumpei; Suzuki, Tomohiro; Wakana, Shigeharu; Fukamizu, Akiyoshi; Nakamura, Nobuhiro; Hirose, Shigehisa

    2013-01-01

    Lung surfactant is a complex mixture of lipids and proteins, which is secreted from the alveolar type II epithelial cell and coats the surface of alveoli as a thin layer. It plays a crucial role in the prevention of alveolar collapse through its ability to reduce surface tension. Under normal conditions, surfactant homeostasis is maintained by balancing its release and the uptake by the type II cell for recycling and the internalization by alveolar macrophages for degradation. Little is known about how the surfactant pool is monitored and regulated. Here we show, by an analysis of gene-targeted mice exhibiting massive accumulation of surfactant, that Ig-Hepta/GPR116, an orphan receptor, is expressed on the type II cell and sensing the amount of surfactant by monitoring one of its protein components, surfactant protein D, and its deletion results in a pulmonary alveolar proteinosis and emphysema-like pathology. By a coexpression experiment with Sp-D and the extracellular region of Ig-Hepta/GPR116 followed by immunoprecipitation, we identified Sp-D as the ligand of Ig-Hepta/GPR116. Analyses of surfactant metabolism in Ig-Hepta(+/+) and Ig-Hepta(-/-) mice by using radioactive tracers indicated that the Ig-Hepta/GPR116 signaling system exerts attenuating effects on (i) balanced synthesis of surfactant lipids and proteins and (ii) surfactant secretion, and (iii) a stimulating effect on recycling (uptake) in response to elevated levels of Sp-D in alveolar space.

  19. Molecular-thermodynamic theory of micellization of multicomponent surfactant mixtures: 2. pH-sensitive surfactants.

    Science.gov (United States)

    Goldsipe, Arthur; Blankschtein, Daniel

    2007-05-22

    In article 1 of this series, we developed a molecular-thermodynamic (MT) theory to model the micellization of mixtures containing an arbitrary number of conventional (pH-insensitive) surfactants. In this article, we extend the MT theory to model mixtures containing a pH-sensitive surfactant. The MT theory was validated by examining mixtures containing both a pH-sensitive surfactant and a conventional surfactant, which effectively behave like ternary surfactant mixtures. We first compared the predicted micellar titration data to experimental micellar titration data that we obtained for varying compositions of mixed micelles containing the pH-sensitive surfactant dodecyldimethylamine oxide (C12DAO) mixed with either a cationic surfactant (dodecyltrimethylammonium bromide, C12TAB), a nonionic surfactant (dodecyl octa(ethylene oxide), C12E8), or an anionic surfactant (sodium dodecyl sulfate, SDS) surfactant. The MT theory accurately modeled the titration behavior of C12DAO mixed with C12E8. However, C12DAO was observed to interact more favorably with SDS and with C12TAB than was predicted by the MT theory. We also compared predictions to data from the literature for mixtures of C12DAO and SDS. Although the pH values of solutions with no added acid were modeled with only qualitative accuracy, the MT theory resulted in quantitatively accurate predictions of solution pH for mixtures containing added acid. In addition, the predicted degree of counterion binding yielded a lower bound to the experimentally measured value. Finally, we predicted the critical micelle concentration (cmc) of solutions of two pH-sensitive surfactants, tetradecyldimethylamine oxide (C14DAO) and hexadecyldimethyl betaine (C16Bet), at varying solution pH and surfactant composition. However, at the pH values considered, the pH sensitivity of C16Bet could be neglected, and it was equivalently modeled as a zwitterionic surfactant. The cmc's predicted using the MT theory agreed well with the experimental

  20. Effects of Interactions Among Surfactants,Water and Oil on Equilibrium Configuration of Surfactant-Water-Oil Systems

    Institute of Scientific and Technical Information of China (English)

    YUAN Yin-quan; SUN Zhi-bo; XIE Yun; ZOU Xian-wu

    2004-01-01

    The distribution and configuration of surfactants at interface in surfactant-water-oil systems have been investigated using discontinuous molecular dynamic simulations. There exists a certain equilibrium concentration of surfactants at interface for the systems with certain interactions among surfactant, water and oil. The interface length and equilibrium morphology of the systems are dependent on the equilibrium concentration of surfactants at interface and the total amount of surfactants. The interaction strengths among surfactant, water and oil determine the equilibrium concentration of surfactants at interface. Three typical configurations of surfactants at interface have been observed: ① surfactant molecules are perpendicular to the interface and arranged closely; ② perpendicular to the interface and arranged at interval of two particles; ③ lie down in the interface partly.

  1. Effects of selected surfactants on nutrient uptake in corn (Zea mays L.)

    Science.gov (United States)

    Surfactants with solvent and wetting abilities are used in the formulation of herbicides to enhance spraying capabilities. These chemicals eventually enter into the soil and may disrupt different chemical, physical and biological processes. The aim of this study was to examine the effects on nutrien...

  2. The Use of Biobased Surfactant Obtained by Enzymatic Syntheses for Wax Deposition Inhibition and Drag Reduction in Crude Oil Pipelines

    Directory of Open Access Journals (Sweden)

    Zhihua Wang

    2016-04-01

    Full Text Available Crude oil plays an important role in providing the energy supply of the world, and pipelines have long been recognized as the safest and most efficient means of transporting oil and its products. However, the transportation process also faces the challenges of asphaltene-paraffin structural interactions, pipeline pressure losses and energy consumption. In order to determine the role of drag-reducing surfactant additives in the transportation of crude oils, experiments of wax deposition inhibition and drag reduction of different oil in pipelines with a biobased surfactant obtained by enzymatic syntheses were carried out. The results indicated that heavy oil transportation in the pipeline is remarkably enhanced by creating stable oil-in-water (O/W emulsion with the surfactant additive. The wax appearance temperature (WAT and pour point were modified, and the formation of a space-filling network of interlocking wax crystals was prevented at low temperature by adding a small concentration of the surfactant additive. A maximum viscosity reduction of 70% and a drag reduction of 40% for light crude oil flows in pipelines were obtained with the surfactant additive at a concentration of 100 mg/L. Furthermore, a successful field application of the drag-reducing surfactant in a light crude oil pipeline in Daqing Oilfield was demonstrated. Hence, the use of biobased surfactant obtained by enzymatic syntheses in oil transportation is a potential method to address the current challenges, which could result in a significant energy savings and a considerable reduction of the operating cost.

  3. Adsorption of Anionic, Cationic and Nonionic Surfactants on Carbonate Rock in Presence of ZrO 2 Nanoparticles

    Science.gov (United States)

    Esmaeilzadeh, Pouriya; Bahramian, Alireza; Fakhroueian, Zahra

    The adsorption of surfactants at the solid-water interface is important for the control of wetting, lubrication, detergency and in mineral flotation.We have studied the adsorptions of different types of surfactants, cationic (Dodecyl trimethylammonium bromide, DTAB), anionic (sodium dodecyl sulfate, SDS) and non-anionic (lauryl alcohol-7 mole ethoxylate, LA7) on carbonate rock in presence of zirconium oxide spherical nanoparticles (17-19 nm). ZrO2 nanoparticles with tetrahedral structure have significant effect on adsorption of surfactants on the carbonate rock. We have used the measured conductivities to determine the rate of adsorption of surfactants at rock-water interfaces. The conductivity of DTAB in aqueous solutions containing calcite powder decreases more than the other surfactants in contact with ZrO2 nanoparticles. We have also investigated the adsorption of surfactants at the air-water interface. The presence of nanoparticles, as demonstrated by our experiments, enhances the surface activity and surface adsorption of the surfactants through electrostatic forces or formation of nanostructures. Dynamic light structuring data shows similar aggregation number of nanoparticles in presence of nanoparticles.

  4. Aggregation of sulfosuccinate surfactants in water

    Energy Technology Data Exchange (ETDEWEB)

    Magid, L.J.; Daus, K.A.; Butler, P.D.; Quincy, R.B.

    1983-12-22

    The aggregation of sodium di-n-alkyl sulfosuccinates in water (H/sub 2/O and D/sub 2/O at 45/sup 0/C) has been investigated. A self-consistent picture of the dependence of sodium ion binding on surfactant concentration is obtained from emf measurements, conductimetry, and small-angle neutron scattering (SANS) measurements. The concentration dependence of the micellar agregation number for the sulfosuccinates and related double-tailed surfactants depends markedly on surfactant solubility. A sphere-to-disk transition in micellar shape, which might have been expected as a precursor to formation of a lamellar mesophase, was not observed as the surfactant concentration was increased. 8 figures, 2 tables.

  5. Investigation of a polyether trisiloxane surfactant

    OpenAIRE

    Michel, Amandine

    2016-01-01

    Thanks to their adaptability and high efficiency compared to traditional carbon based surfactants, silicone surfactants are a success in many different applications, from pesticides to cosmetics, polyurethane foam, textile and car care products. In spite of those numerous applications, no analytical method existed for their trace determination in environmental samples and no data have been available regarding their environmental occurrence and fate. An analytical method for the trace ana...