Effect of an Anionic Surfactant on Hydraulic Conductivities of Sodium- and Calcium-Saturated Soils

The effect of sodium dodecylbenzenesulfonate (SDBS), an anionic surfactant used widely in household products and industrial processes, on saturated hydraulic conductivities (Ksat) of an Anthrosol saturated with sodium (Na-soil) or calcium (Ca-soil) was analyzed in a laboratory experiment using the constant head method, and adsorption and dispersion experiments were also conducted to infer the possible mechanisms of Ksat fluctuations. The results showed that SDBS was more intensely adsorbed in the Ca-soil than in the Na-soil. With an increase in the SDBS concentration, the stability of the Na-soil suspensions decreased when the SDBS concentration was less than 1.2 mmol L-1 and then above this concentration, increased markedly, while the stability of the Ca-soil suspensions increased gradually at all SDBS concentrations studied. With an increase in the SDBS concentration, the Ksat of the Na-soil increased, which resulted mainly from the increase of water channels in the soil because of the coagulation of the soil particles, while the Ksat of Ca-soil decreased mainly on account of the clogging of partial water channels by precipitated Ca(DBS)2 and the fine soil particles generated.

Phase Separation and Microstructure of Mixed Surfactants Solution Containing Cationic Geminis and Traditional Anionic Surfactant

The properties of aqueous two-phase system (ATPS) of mixed solution containing gemini cationic surfactant trimethylene-1,3-bis(dodecyldimethyl ammonium) bromide (12-3-12, 2Br-) and traditional anionic surfactant sodium dodecyl sulfate (SDS) with or without added salt have been studied. An ATPS is formed in a narrow region of the ternary phase diagram different from that of traditional aqueous cationic-anionic surfactant systems. In ATPS region, the lowest total concentration of surfactants varies with the mixing ratio of geminis to SDS. Photographs obtained from freeze-etching, negative-staining and transmission electron microscopy show that the microstructures of two phases are different from each other. Micelles and vesicles can coexist in a single phase. The addition of salts can change the phase diagram of ATPS. Furthermore, the added salts promote the aggregation of rod-like micelles to form coarse network structure that increase the viscosity of solutions. The negative ions of the added salts are the determining factor.

Synthesis and Characterization of Zirconia Nanocrystallites by Cationic Surfactant and Anionic Surfactant

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 nanocrystal size is around 15 nm 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.

Synthesis of Silica Hollow Spheres with Diameter Around 50 nm by Anionic Surfactant

Silica hollow spheres（SHSs） have attracted great attention because of their low toxicity, low density, large surface area, high chemical and thermal stability, and surface permeability. They can be widely applied in storage^[l], catalysis^[2], drug deli- very^[3,4], low-dielectric-constant materials^[5], low-refractive materials^[6-8], and so on. Up to now, there have been various methods to produce SHSs. Inorganic^[9] or organic particles^[10], such as polystyrene or calcium carbonate, were used as hard templates to create hollow cavities, However, the multistep synthetic process and the lack of structural robustness of the shells upon template removal process weaken their applica- tion. Soft templates, including oil-in-water emulsions^[11,12], vesicles^[13], micelle^[14,15] and gas bubbles^[16], are applied widely.

Theoretical and Experimental Studies on Interactions of Cationic-Anionic Surfactants

Typical cationic and anionic surfactants were chosen and their interactions were calculated by quantum chemical method. Interaction energies are -0.2378 kJ·mol-1, -3.3394kJ·mol-1 and 0.1204kJ·mol-1 for the molecular pairs with fluocarbon and hydrocarbon chain: C4H10/C5H12, C4F10/C5H12, and C4F10 /C5F12, respectively. When hydrophilic group with cationic and anionicions is introduced, interaction energies are -287.40kJ·mol-1, -311.18kJ·mol-1 and -345.83kJ·mol-1. The results show that there is strong static interaction between cationic and anionic surfactants. It has been predicted that mixed monolayer may be formed and surface activity is enhanced favorably, especially for mixtures of cationic and anionic surfactants with fluocarbon and hydrocarbon chains. The anionic surfactants, sodium octadecylbenzenesulfonate perfluopolyetherbenzenesulonate(ANF-I) was synthesized, mixture effects of ANF-I with sodium octadecylbenzenesulfonate or dodecyldimethyl benzylammonium bromide were studied. The results indicate that the efficiency of mixing increased and the theoretical prediction was testified. These results can provide useful information for the design of new surfactants.

Anionic Surfactants Levels in M’Koa Lake Water (Jacqueville, Cote d’Ivoire)

In this study, anionic surfactants concentrations and other physico-chemical parameters of surface water quality were assessed in the water of M’Koa Lake in the city of Jacqueville (C?te d’Ivoire). Three sampling campaigns were conducted at different seasons at six (6) sampling stations, identified in M’koa Lake by taking into account potential sources of pollution. The analyses of physico-chemical parameters were carried out using both the French AFNOR standard and the methods described by Rodier. The anionic surfactants concentrations were performed by using the methylene blue colorimetric method. The average concentrations of anionic surfactants in the water of M’koa Lake ranged from 0.23 ± 0.04 mg·L-1 to 1.43 ± 0.68 mg·L-1. They are high compared to both population density and socio-economic activities of Jacqueville’s town. These values can be explained by the characteristics of the studied Lake that do not allow enough dilution of the discharged effluent. The results indicate that M’koa Lake is subjected to harmful pollution by anionic surfactants. And among the physicochemical parameters studied, only turbidity and transparency values show water quality deterioration, favoured by wastewater discharge and direct human activities around the Lake.

Development and Prospect of China’s Anionic Surfactant Industry

The development process of anionic surfactants in China was reviewed.The current status of anionic surfactants in China was analyzed.The overall situation of sulfonation equipment was introduced,and the development trend of anionic surfactant industry in China was prospected.

Synergistic anionic/zwitterionic mixed surfactant system with high emulsification efficiency for enhanced oil recovery in low permeability reservoirs

Emulsification is one of the important mechanisms of surfactant flooding. To improve oil recovery for low permeability reservoirs, a highly efficient emulsification oil flooding system consisting of anionic surfactant sodium alkyl glucosyl hydroxypropyl sulfonate(APGSHS) and zwitterionic surfactant octadecyl betaine(BS-18) is proposed. The performance of APGSHS/BS-18 mixed surfactant system was evaluated in terms of interfacial tension, emulsification capability, emulsion size and distribution, wettability alteration, temperature-resistance and salt-resistance. The emulsification speed was used to evaluate the emulsification ability of surfactant systems, and the results show that mixed surfactant systems can completely emulsify the crude oil into emulsions droplets even under low energy conditions. Meanwhile,the system exhibits good temperature and salt resistance. Finally, the best oil recovery of 25.45% is achieved for low permeability core by the mixed surfactant system with a total concentration of 0.3 wt%while the molar ratio of APGSHS:BS-18 is 4:6. The current study indicates that the anionic/zwitterionic mixed surfactant system can improve the oil flooding efficiency and is potential candidate for application in low permeability reservoirs.

Evaluation of reusing alum sludge for the coagulation of industrial wastewater containing mixed anionic surfactants

A coagulation-flocculation process is typically employed to treat the industrial wastewater generated by the consumer products industry manufacturing detergents, soaps, and others. The expenditure of chemicals including coagulants and chemicals for pH adjustment is costly for treating this wastewater. The objective of this study was to evaluate the feasibility of reusing the aluminum sulfate （alum） sludge as a coagulant or as a coagulation aid so that the fresh alum dosage can be minimized or the removal efficiency can be enhanced. The experiments were conducted in a jar-test apparatus simulating the coagulation-flocculation process for simultaneous removals of organic matters, anionic surfactants, suspended solids, and turbidity. At the optimum initial pH value of 10 and the fresh alum concentration of 400 mg/L, the total suspended solids （TSS）, total chemical oxygen demand （TCOD）, total anionic surfactants, and turbidity removal efficiencies were 71.5%, 76.4%, 95.4%, and 98.2%, respectively. The addition of alum sludge as a coagulant alone without any fresh alum addition could significantly remove the turbidity, TCOD, and anionic surfactants. The TSS was left in the supernatants after the settling period, but would subsequently be removed by adding the fresh alum. The TSS, TCOD, and turbidity removal efficiencies were also enhanced when both the alum sludge and the fresh alum were employed. The TCOD removal efficiency over 80% has been accomplished, which has never fulfilled by using the fresh alum alone. It is concluded that the alum sludge could be reused for the treatment of industrial wastewater generated by the consumer products industry.

Differences in Adsorption of Anionic Surfactant AOT by Calcium Oxalate： Effect of Crystal Size and Crystalline Phase

The adsorption of anionic surfactant sodium diisooctyl sulfosuccinate（AOT） onto calcium oxalate mono- hydrate（COM） and dihydrate（COD） with sizes of 50, 100 nm, 1, 3 and 10 μm was comparatively studied to simulate the interaction between urinary crystallites and urine components. The adsorption quantity of different concentrations of AOT onto COD and COM with different sizes was detected using a UV-Vis spectrophotometer. The crystalline phase transition of COM and COD before and after adsorption was analyzed by X-ray powder diffraction and Fourier transform infrared spectrometry. The zeta potential of the crystal surface after adsorption of different concentrations of AOT was measured using a zeta potential analyzer. The adsorption quantity of AOT on COM and COD with different sizes was ranked in the following order： 50 nm〉100 nm〉1μm〉3 μm〉10 μm. The adsorption quantity of COM was greater than that of COD with the same size because the density of the positive charges on the COM surface was higher than that on COD surface. With the increase of AOT concentration, the adsorption curves of the large-sized COM and COD（3 and 10μm） were S-type, whereas the adsorption curves of the small-sized COM and COD（50 nm, 100 nm and 1μm） were linear. The adsorption capacities of small-sized COM and COD were much greater than those of the 3 and 10μm crystals. On the basis of the above results, we proposed a molecular model to summarize the absorption of AOT onto COM and COD crystals. Small crystals exhibit a large specific surface area and high surface energy. Thus, the adsorption capacities of them are stronger than those of large crystals. Overall, this study implies that small crystals can easily absorb anionic molecules in urine and may easily adhere to a negatively charged cell surface, thereby increasing the severity of cell injury.

High Selective Determination of Anionic Surfactant Using Its Parallel Catalytic Hydrogen Wave

A faradaic response of anionic surfactants (AS),such as linear alkylbenzene sulfonate (LAS),dodecyl benzene sulfonate and dodecyl sulfate,was observed in weak acidic medium. The faradaic response of AS includes (1) a catalytic hydrogen wave of AS in HAc/NaAc buffer that was attributed to the reduction of proton associated with the sulfo-group of AS,and (2) a parallel catalytic hydrogen wave of AS in the presence of hydrogen peroxide,which was due to the catalysis of the catalytic hydrogen wave of AS by hydroxyl radical ·OH electrogenerated in the reduction of hydrogen peroxide. The parallel catalytic hydrogen wave is about 50 times as sensitive as the catalytic hydrogen wave. Based on the parallel catalytic hydrogen wave,a high selective method for the determination of AS was developed. In 0.1 mol/L HAc/NaAc (pH=6.2±0.1)/1.0×10 -3 mol/L H_2O_2 supporting electrolyte,the second-order derivative peak current of the parallel catalytic hydrogen wave located at -1.33 V (vs. SCE) was rectilinear to AS concentration in the range of 3.0×10 -6 —2.5×10 -4 mol/L,without the interference of other surfactants. The proposed method was evaluated by quantitative analysis of AS in environmental wastewater.

Determination of trace inorganic anions in anionic surfactants by single-pump column-switching ion chromatography

An ion chromatography method has been proposed for the determination of three common inorganic anions（chloride,nitrate and sulfate） in anionic surfactants using a single pump system.The new system consists of an ion exclusion column,a concentrator column,and an anion exchange column connected in series via two 6-ports valves in a Dionex ICS-2000 ion chromatograph.The valves were switched several times for removing surfactants,concentrating and separating the three anions.The chromatographic conditions were optimized.Detection limits（S/N = 3） were in the range of 0.10-0.68μg/L.The relative standard deviations（RSDs） of peak area were less than 4.6%.The recoveries were in the range of 84.1-112.6%.

Overview of Simple Test for Determination of Surfactants by Adhesion Method

A simple, sensitive, and rapid analytical method is reported for the determination of surfactants. This is based on the use of an oppositely charged dye as the ion pair to form an ionic associate with the surfactant in a vessel, thus affording ion-associated adhesion on the inner wall of the vessel. After the adhesion, the remaining solution in the vessel is removed, and the ionic associate is dissolved in a suitable solvent. The absorbance of the resulting solution is measured spectrophotometrically to determine the concentration of the surfactant. Further, the mechanism of adhesion is elucidated.

Iron Bearing Minerals Flotation from Silica Sand Using Hydroxyl Surfactants

A technological clayey sandstone sample from Wadi Qena locality, Eastern Desert of Egypt, was directed to processing. Fine kaolin and clean silica sand were produced after intensive attrition scrubbing of the sample. To increase the quality of the produced silica, it was subjected to reverse anionic flotation to minimize its iron content. In this respect, conventional flotation tests using three anionic oxyhydryl surfactants namely: sodium dodecyl benzene sulphonate, sodium naphtha sulphonate, and sodium dodecyl sulphate, were tried. Results showed a privilege action for sodium dodecyl sulphate to remove most of the iron oxide content of the sample. A statistical Box-Behnken design was constructed to optimize the process efficiency. It was shown that from a flotation feed contained 360 ppm Fe2O3 and 1190 ppm Al2O3, sand concentrate contained 29 ppm Fe2O3 and 564 ppm Al2O3, was produced. The optimum flotation conditions were 3.86 kg/t sodium dodecyl sulphate dose, 3.22 flotation pulp pH, 1226 rpm impeller speed, and 22.24 L/min airflow rate. Variables interaction effects results showed that flotation separation efficiency was significantly influenced by air flow rate and cell impeller speed of the process.

Pilot test of polymer microsphere alternate surfactant flood(PMAS)with mixtures of anionic-cationic surfactants under harsh conditions in a sandstone reservoir

The first pilot test of polyacrylamide microsphere alternate surfactant flood(PMAS)with mixtures of anionic-cationic surfactants(Sa/c)was carried out for a high-temperature,high-salinity,and highhardness sandstone reservoir to demonstrate the potential of this novel technique to improve oil recovery.A critical micelle concentration(CMC)of 4.82 mg/L,an ultralow interfacial tension(IFT)of 8104 mN/m,and a high oil solubilization of 22 were obtained.Static and dynamic adsorptions of Sa/c on natural core containing 15 wt%clay were reduced to about 2.20 and 0.30 mg/g-core,respectively,with the addition of adsorption inhibitor(AI).Since June 2014,the pilot test of PMAS was carried out in a Sinopec reservoir with a temperature of 87C,a salinity of 260,393 mg/L,and a hardness of 6,401 mg/L.Twelve cycles of alternative injection of 0.0125 PV Sa/c with a concentration of 0.1%and 0.0125 PV polyacrylamide microsphere with a concentration of 0.2%were conducted at an injection rate of 0.1 PV/yr,for a total of 0.3 PV chemical injection.As a result,the net daily oil production increased from 0 t to 6.5 t,and the water cut decreased from 96.3%to 93.8%,leading to an ultimate improved oil recovery of 6.3%original oil-in-place.

Evaluating the potential of surface-modified silica nanoparticles using internal olefin sulfonate for enhanced oil recovery

Recently,nanoparticles have proven to enhance oil recovery on the core-flood scale in challenging high-pressure high-temperature reservoirs.Nanomaterials generally appear to improve oil production through wettability alteration and reduction in interfacial tension between oil and water phases.Besides,they are environmentally friendly and cost-effective enhanced oil recovery techniques.Studying the rheological properties of nanoparticles is critical for field applications.The instability of nanoparticle dispersion due to aggregation is considered as an unfavorable phenomenon in nanofluid flooding while conducting an EOR process.In this study,wettability behavior and rheological properties of surface-treated silica nanoparticles using internal olefins sulfonates(IOS20–24 and IOS19–23),anionic surfactants were investigated.Surface modification effect on the stability of the colloidal solution in porous media and oil recovery was inspected.The rheology of pure and surfacetreated silica nanoparticles was investigated using a HPHT rheometer.Morphology and particle size distributions of pure and coated silica nanoparticles were studied using a field emission scanning electron microscope.A series of core-flood runs was conducted to evaluate the oil recovery factor.The coated silica nanoparticles were found to alter rheological properties and exhibited a shear-thinning behavior as the stability of the coated silica nanoparticles could be improved considerably.At low shear rates,the viscosity slightly increases,and the opposite happens at higher shear rates.Furthermore,the surfacemodified silica nanoparticles were found to alter the wettability of the aqueous phase into strongly water-wet by changing the contact angle from 80°to 3°measured against glass slides representing sandstone rocks.Oil–water IFT results showed that the surface treatment by surfactant lowered the oil–water IFT by 30%.Also,the viscosity of brine increased from 0.001 to 0.008 Pa s by introducing SiO2 nanoparticles to the aqueous phase for better displacement efficiency during chemicalassisted EOR.The core-flood experiments revealed that the ultimate oil recovery is increased by approximately 13%with a surfactant-coated silica nanofluid flood after the conventional waterflooding that proves the potential of smart nanofluids for enhancing oil recovery.The experimental results imply that the use of surfactant-coated nanoparticles in tertiary oil recovery could facilitate the displacement efficiency,alter the wettability toward more water-wet and avoid viscous fingering for stable flood front and additional oil recovery.

Effect of SDBS on interfacial electron transfer at the liquid/liquid interface by thin layer method

The effect of an adsorbed anionic surfactant sodium dodecyl benzene sulfonate （SDBS） on electron transfer （ET） reaction between ferricyanide aqueous solution and decamethylferrocene （DMFc） located on the adjacent organic phase was investigated for the first time by thin layer method. The adsorption of SDBS at the interface resulted in a decay in the cathodic plateau current of bimolecular reaction with increasing concentrations of SDBS in aqueous phase. However, the rate constant of electron transfer （ket） increased monotonically as the SDBS concentrations increased from 0 to 200 p, moFL. The experimental results showed that SDBS formed patches on the interface and influenced the structure of electrical double layer. 2009 Xiao Quan Lu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Preparation of Alizarin Dye Dispersion Solution and Dyeing of Cotton Fabric

Alizarin,extracted from rubia cordifolia,is a green natural dye.However,its application has been limited by its poor water solubility and pH sensitivity.In this study,linear sulfonic anionic surfactant(LAS)had been studied as a new dispersant,which promoted the dyeing of alizarin on fabrics under mild conditions.Ultraviolet visible(UV-vis)spectra and Fourier transform infrared(FTIR)spectra confirmed appropriate bonding between alizarin and LAS,and the nano particle size analysis showed that LAS could promote the dispersion of alizarin in aqueous solution.Under the optimized condition of alizarin 4.8%on mass of fabric(omf)and LAS solution 2×10^(-2)mol/L,the fabrics were dyed with alizarin at room temperature and pH neutral conditions.The dyed fabrics had good washing fastness and ironing fastness.

Linear Alkylbenzene Sulfonates in the Groundwater and Surface Waters： Ergene Basin Case Study

Ergene Basin is one of the most important industrial centers due to the geographical location in Turkey. Uncontrolled and rapidly increasing industrialization brings together a large number of environmental problems in the basin. In this study, pollution was investigated in the water samples taken at time intervals and different parts of groundwater and surface water resources located within Ergene Basin by methylene blue anionic surfactants （MBAS） analysis method. Turbidity, temperature, pH, electrical conductivity （EC）, concentrations of total P and linear alkylbenzene sulfonates （LAS） were simultaneously determined in the investigated water resources. The results were compared with the Turkish Water Pollution Control Regulation specified in the Quality Criteria of the Inland Water Resources according to their class. The total P and LAS concentrations of surface waters are generally higher than groundwater. In terms of LAS concentrations, the groundwater is Ⅰ-Ⅱ class and the surface water is Ⅱ-Ⅳ class.

Synthesis of Monoglycerides with Cinnamomum Burmannii Seeds Oil and Its Application in Moisturizing Cream

Synthesis of monoglycerides with Cinnamomum burmannii seeds oil and its application in moisturizing cream were studied. The results showed that the optimal transesterification conditions of synthesis of monoglycerides with Cinnamomum burmannii seeds oil were as follows： the glycerol to oil molar ratio of 3 ： 1 ; NaOH catalyst dosage of 0.8% of the oil mass; reaction temperature of 180 ℃ for 3 hours; and the yield reached 62.6% . The crude product was purified by molecular distillation and the purity of the final product achieved 92.8%. Physicochemical properties of moisturizing cream prepared by using the final product can meet the requirements of China National Standard and the cosmetic product displayed good performance in application.