Linear Dodecylbenzene Sulfonate Research Articles

Insights into the preparation and mechanism of Non-Alkali viscosity reducer for enhancing heavy oil recovery under Low-Shear condition

Viscosity reducer flooding technology has been applied for enhanced oil recovery (EOR) in ordinary heavy oil reservoirs. However, the non-alkali viscosity reducer for heavy oil reservoir under low-shear condition has not been systematic studied. Thus, in terms of emulsifying ability and stability, oil–water interfacial tension and viscosity reduction performance, the non-alkali viscosity reducer was prepared under low-shear condition by the bottle inversion test method and shaker shaking method. Then the enhanced oil recovery ability of the non-alkali viscosity reducer was evaluated and the pore-scale EOR mechanism was investigated via microscopic visual flooding experiments. Results show that the non-alkali viscosity reducer consisting of C12-14 alkyl glucoside (APG1214) surfactant and sodium linear-dodecyl benzenesulfonate (LAS-30) surfactant was prepared with the oil–water interfacial tension of 0.15mN·m−1 and viscosity reduction rate of 97.9%. Compared with water flooding, the non-alkali viscosity reducer can significantly increase the sweep efficiency and the oil displacement efficiency and enhance oil recovery by 8.94% by the mechanism of emulsification, reducing interfacial tension and changing wettability.

Removal of LAS from water by activated carbon and resins in continuous process

In this study, Purolite resins and activated carbon (AC) were used to remove LAS (linear dodecyl benzene sulfonate) from water. In some cases the conventional filtration at constant pressure released a negligible amount of residual surfactant (< 0.1 mg L-1). Adsorption characteristics were investigated with anionic, cationic and mixed resins and activated carbon with different sizes. LAS adsorption onto the solid material was studied in a solution of low concentration (0.50 mg L-1). For comparison, some filters filled with resins and activated carbon were prepared, characterized and connected to the recipient bottom for filtration. The size of carbon particles really influenced the results, and the anionic resin exhibited better adsorption capacity than the others in this study. The ANOVA response surface analyses properly confirmed the experimental results. Keywords: resins; activated carbon; filtration; continuous process; adsorption.

Effect of Washing Conditions on Cleaning Action of Linear Alkylbenzene Sulfonate in Hard Water

Abstract The effects of water hardness on textile detergency in aqueous linear dodecylbenzene sulfonate (LAS) solutions were examined under various washing conditions. Plain-woven and towel cotton fabrics and plain-woven polyester fabric were soiled with a mixture of carbon black/oleic acid. The soiled fabrics were shake-washed in the LAS solution together with the original unsoiled fabrics. Surface reflectance measurements revealed that the soil removal and redeposition decreased and increased, respectively, with increasing water hardness. The identity of the mineral species (calcium or magnesium ions) in the hard water had no notable effect on the detergency. The addition of significant amounts of extra LAS did not fully compensate the reduction in detergency in hard water. Addition of softening agents and an alkali builder to the hard water limited the reduction in detergency, but the detergency was still lower than that in the absence of hardness salts. Moreover, a high wash temperature and repeated rinse procedure did not prevent the reduction in detergency in hard water. Finally, a washing test was carried out in hard water under the conditions considered to be effective for improving the detergent quality in hard water, based on the experimental results. The LAS detergency toward the cotton fabrics under these conditions was still poorer than that in the absence of hardness salts. We concluded that using soft wash water is the best choice for maximizing the cleaning power of detergents.

Effects of Water Hardness on Textile Detergency Performance in Aqueous Cleaning Systems.

The effects of water hardness on textile detergency in aqueous solutions were systematically investigated using four surfactants: sodium oleate (OLNa), linear dodecylbenzene sulfonate (LAS), sodium dodecyl sulfate (AS), and polyoxyethylene (10) dodecyl ether (AE). Water hardness was adjusted according to the standard procedure described in IEC 60734:2012. As expected, by adding hardness salts the surface tension of the OLNa solution increased. Surprisingly, the addition of hardness salts lowers the surface tension for the LAS and AS solutions. In the case of the AE solution, hardness salt did not affect the surface tension. A decrease in transmittance and foamability after adding hardness salts was observed for every anionic surfactant solution, indicating that anionic surfactants can combine with divalent ions to form insoluble precipitates. Detergency experiments were performed using cotton plain-woven and towel fabrics soiled with a carbon black and oleic acid mixture. One piece each of untreated and soiled fabric were stacked and placed horizontally in detergent solution with or without hardness salts. As a mechanical action of soil removal, the shaking of 190 spm was applied. Soil removal and redeposition due to washing were evaluated from changes in values of the Kubelka-Munk function for both fabrics. With increasing water hardness, soil removal decreased and redeposition increased. In order of decreasing detergency, the surfactants were as follows: LAS > OLNa ≈ AS > AE. The results indicate that precipitates, formed by reaction of LAS or AS with hardness salts, are strongly adsorbed on the water surface because of their hydrophobicity, but they have no detergency power. The field emission scanning electron microscopic observation and X-ray photoelectron spectroscopic analysis showed that Ca(LAS)2 precipitation clung to fiber surfaces, and remained on the surfaces after washing. Significant changes in the cotton fabric due to washing were observed in mechanical properties and water absorbency.

Ordered-Mesoporous-Carbon-Bonded Cobalt Phthalocyanine: A Bioinspired Catalytic System for Controllable Hydrogen Peroxide Activation

The chemistry of enzymes presents a key to understanding the catalysis in the world. In the pursuit of controllable catalytic oxidation, researchers make extensive efforts to discover and develop functional materials that exhibit various properties intrinsic to enzymes. Here we describe a bioinspired catalytic system using ordered-mesoporous-carbon (OMC)-bonded cobalt tetraaminophthalocyanine (CoTAPc-OMC) as a catalyst that could mimic the space environment and reactive processes of metalloporphyrin-based heme enzymes and employing linear dodecylbenzenesulfonate as the fifth ligands to control the activation of H2O2 toward the peroxidase-like oxidation. The generation of nonselective free hydroxyl radicals was obviously inhibited. In addition, functional modification of OMC has been achieved by a moderate method, which can reduce excessive damage to the structure of OMC. Because of its favorable and tunable pore texture, CoTAPc-OMC provides a suitable interface and environment for the accessibility and oxidation of C.I. Acid Red 1, the model compound, and exhibits significantly enhanced catalytic activity and sufficient stability for H2O2 activation. The high-valent cobalt oxo intermediates with high oxidizing ability have been predicted as the acceptable active species, which have been corroborated by the results from the semiempirical quantum-chemical PM6 calculations.

Dissipation pathways of organic pollutants during the composting of organic wastes

The organic pollutants (OPs) present in compostable organic residues can be recovered in the final composts leading to environmental impacts related to their use in agriculture. However, the composting process may contribute to their partial dissipation that is classically evaluated through the concentration decrease in extractable OPs, without identification of the responsible mechanisms as mineralization or stabilization of OP as non-extractable residues (NER) or bound residues. The dissipation of four 14C-labeled OPs (fluoranthene; 4-n-nonylphenol, NP; sodium linear dodecylbenzene sulfonate, LAS; glyphosate) was assessed during composting of sewage sludge and green waste. The dissipation of LAS largely resulted from its mineralization (51% of initial LAS), whereas mineralization was intermediate for NP (29%) and glyphosate (24%), and negligible for fluoranthene. The NER pathway mostly concerned NP and glyphosate, with 45% and 37% of the recovered 14C being found as NER at the end of composting, respectively. In the final composts, the proportions of water soluble residues of OPs considered as readily available were <11% of recovered 14C-OPs. However, most fluoranthene remained solvent extractable (72%) and potentially available, whereas only 18% of glyphosate and less than 7% of both NP and LAS remained solvent extractable in the final compost.

Sorption and mineralization of organic pollutants during different stages of composting

The organic pollutant (OP) content is a key factor when determining compost quality. The OPs present in feedstock materials may either be degraded during composting or stabilized in the compost by sorption interactions with organic matter (OM), which may reduce the availability of OP to microorganism degradation. It is particularly important to identify the key stages during composting that are involved in OP mineralization so as to be able to optimize the composting process and determine whether OP sorption on OM is a limiting factor to OP mineralization. Four 14C-labeled OPs were used during the study: a polycyclic aromatic hydrocarbon (fluoranthene), two surfactants (4-n-nonylphenol – NP and sodium linear dodecylbenzene sulfonate – LAS) and a herbicide (glyphosate). The potential for compost microflora to degrade OP, and compost sorption properties, were characterized at different stages of composting. The highest levels of LAS and glyphosate mineralization were found during the thermophilic stage, at the beginning of maturation for NP and at the end of maturation for fluoranthene. A specific microflora was probably involved in the biodegradation of fluoranthene while NP, LAS and glyphosate mineralization were linked to total microbial activity. OP sorption on compost was linked to their hydrophobicity, decreasing in the order: fluoranthene > NP > LAS > glyphosate. Moreover, sorption decreased as compost maturity increased, except for glyphosate. The sorption coefficients were positively correlated to mineralization kinetics parameters for NP, LAS and glyphosate, suggesting a positive effect of sorption on increasing mineralization rates.

Mechanism and behavior of surfactant adsorption onto resins with different matrices

The recovery of surfactant from wastewater utilizing polymeric adsorbent is important not only in the protection of the environment from pollution, but also in the effective use of raw materials. Mechanism and behavior of surfactant (linear dodecyl-benzene sulfonate, LAS) adsorption onto styrene resin XAD-4 and acrylic ester resin was studied in high concentration solution (several thousand mg/L). For comparison, a series of acrylic ester resins had been prepared, characterized and used along with commercial resins XAD-7 and HP2MG. Y-50 resin, one of the resins, exhibits better adsorption capacity than the other acrylic ester resins in this study. The experimental equilibrium data were fitted to Langmuir model, and the model was found to provide very good fits for all of acrylic ester resins over the temperature range, whereas fitted results for the styrene resin XAD-4 were less accurate. Adsorption kinetics and elution processes were also investigated to study different mechanism and behavior of surfactant adsorption onto resins. The observation indicates that the cooperation of hydrophobic interactions and electrostatic attraction impels the adsorption process as well as the formation of monolayer and bi-layer.

Extraction Condition and Efficiency of Some Hazardous Organic Chemicals from Aqueous Solutions Using a Thermoresponsive Polymer System

The extraction behavior of β-estradiol, bisphenol A and triclosan observed in a thermoresponsive poly (vinylmethyl) ether precipitate system were investigated. The three toxicants were extracted from aqueous solutions into a gum-like precipitate, which formed by aggregation when the solution was heated to a temperature higher than the lower critical solution temperature of the polymer (ca. 305 K) . An anionic surfactant, linear dodecylbenzenesulfonate was found to decrease the efficiency in formation of the precipitate and in extraction of the target chemicals. However, no such effect was found by addition of a kind of nonionic surfactant polyethyleneglycol tert-octylphenyl ether or humic acid, which are typical coexisting organic materials in environmental waters. More than 90 % of the β-estradiol and bisphenol A was extracted with 3 gl-1 of the polymer, and only 0.3 gl-1 was needed to extract more than 90% of the triclosan. The extraction capacity of the polymer precipitate for the three chemicals was around 10-4 mol per 1 g of the precipitate.

Anaerobic degradation of linear alkylbenzene sulfonate

Linear alkylbenzene sulfonate (LAS) found in wastewater is removed in the wastewater treatment facilities by sorption and aerobic biodegradation. The anaerobic digestion of sewage sludge has not been shown to contribute to the removal. The concentration of LAS based on dry matter typically increases during anaerobic stabilization due to transformation of easily degradable organic matter. Hence, LAS is regarded as resistant to biodegradation under anaerobic conditions. We present data from a lab-scale semi-continuously stirred tank reactor (CSTR) spiked with linear dodecylbenzene sulfonate (C12 LAS), which show that C12 LAS was biodegradable under methanogenic conditions. Sorption of C12 LAS on sewage sludge was described with a Freundlich isotherm. The C12 LAS sorption was determined with different concentrations of total solids (TS). In the semi-continuously stirred tank reactor, 18% of the added C12 LAS was bioavailable and 20% was biotransformed when spiking with 100 mg/L of C12 LAS and a TS concentration of 14.2 mg/L. Enhanced bioavailability of C12 LAS was obtained in an upflow anaerobic sludge blanket (UASB) reactor inoculated with granular sludge and sewage sludge. Biodegradation under thermophilic conditions was 37% with LAS as sole carbon source. Benzaldehyde was produced in the UASB reactor during LAS transformation.

Cytotoxicity of surfactants to the FHM-sp cell line

: Cytotoxicity of eight surfactants was determined by the neutral red assay with the fathead minnow (FHM)-sp cell line, a cell line in suspension culture from fish. The toxicity ranking of the surfactants was benzalkonium chloride > benzethonium chloride > sodium linear-dodecylbenzene–sulfonate (LAS) > potassium laurate > sodium dodecylsulfate > polyoxyethylene(20)sorbitan monolaurate > polyoxyethylene(20)sorbitan monooleate > betaine. The toxicity ranking of the surfactants classified into four groups based on the ion of the hydrophilic group was cationic surfactants > anionic surfactants > non-ionic surfactants > amphipathic surfactants. The FHM-sp cells, as well as the chinook salmon embryo (CHSE)-sp cells, could be inoculated directly to the microplate wells without dispersion by trypsin treatment of cell sheets at room temperature. Therefore, the cytotoxicity assay of the surfactants could be carried out quickly by using the FHM-sp cell line. The FHM-sp cell line had similar or higher sensitivity to sodium dodecylsulfate compared with several cell lines from mammals. The cytotoxicity assay could be shortened by the procedure exposing the surfactants to the FHM-sp cells before the cell monolayer formation in the microplate wells. To use the FHM-sp cell line as a screening tool prior to in vivo testing, studies on the correlation between in vivo data and in vitro data on the toxicity of surfactants are necessary.

FEASIBILITY OF IN SITU NAPL-CONTAMINATED AQUIFER BIOREMEDIATION BY BIODEGRADABLE NUTRIENT–SURFACTANT MIX

Entrapped non-aqueous liquid phase (NAPL) pollutants (e.g., fuels) constitute one of the biggest current problems in the bioremediation efforts of contaminated soil and aquifers worldwide. On site, in situ surfactant-enhanced bioremediation, in the presence of sufficient nutrients and dissolved oxygen, has the potential of becoming the remediation method of choice in terms of both technological and economical feasibility. This approach was applied in our lab-scale column-based flow system with the aid of which an optimized, below CMC, of biodegradable surfactant-nutrient surfactant mix has been established for the best solubilization/mobilization of NAPL (hexane, toluene, kerosene and their mixtures as “representatives”) in sandy matrix. For kerosene, the highest f values (the enhancement factors) were obtained for the systems containing either the amphoteric cocoamphodiacetate or the anionic linear dodecylbenzene sulfonate (0.1–0.3 g/L) with one or both the nutrient-surfactants L and B (0.05 g/L).

Decomposition of linear dodecylbenzenesulfonate by simultaneous treatment with ozone and ultraviolet irradiation: rapid disappearance of formed mutagens.

The decomposition products and mutagenic activity in Salmonella typhimurium strains TA98, TA100 and TA104 in the presence and absence of S9 mix of linear dodecylbenzenesulfonate (DBS) in aqueous solution after ozone treatment alone or simultaneous treatment with ozone and ultraviolet (UV) irradiation (ozone/UV treatment) were investigated. The decomposed DBS solutions after these treatments for 4 h were mutagenic for strains TA98, TA100 and TA104 both with and without S9 mix, but this mutagenicity disappeared rapidly during further ozone/UV treatment. Mutagenicity of the decomposed solution of DBS, however, was not substantially decreased by treatment with ozone alone. Formaldehyde and glyoxal were identified as the decomposition products of DBS in water by high-performance liquid chromatography after treatment with 2,4-dinitrophenylhydrazine. Although these two compounds were mutagenic for strain TA104 both with and without S9 mix, they disappeared after further ozone/UV treatment but not after ozone treatment alone. These results indicate that ozone/UV treatment is an effective procedure for purifying drinking water.

Decomposition of linear dodecylbenzene sulfonate by simultaneous treatment with ozone and UV irradiation and rapid disappearance of the formed mutagens

Decomposition of linear dodecylbenzene sulfonate by simultaneous treatment with ozone and UV irradiation and rapid disappearance of the formed mutagens

Relationship of structure to properties of surfactants. 15 Isomeric sulfated polyoxyethylenated Guerbet alcohols

AbstractThe properties at 25°C in aqueous 0.1M NaCl at the aqueous solution/air, aqueous solution/hexadecane, and aqueous solution/hydrophobic solid interfaces of two isomeric Guerbet alcohol‐derived surfactants C8H17CH(C6H13)CH2(OC2H4)5SO4Na, one in which the octyl and hexyl groups are both linear (L isomer), the other in which they are both highly branched (B isomer), have been investigated and compared in some cases with commercial sodium linear dodecylbenzene‐sulfonate (LAS). The cmc value increases, the pC20 value decreases, and the ΔGoad value becomes less negative in the order: L isomer—B isomer—LAS. The minimum area/molecule at the aqueous solution/air interface increases in the order: LAS≪L isomer&lt;B isomer.The L isomer is slightly more hydrophobic than the B isomer, and both are considerably more surface‐active than LAS. The greater steric inhibition to micellization in the B isomer results in the lowest minimum surface tension. Both isomers have similar minimum interfacial tension values against hexadecane. Unusually small minimum area/molecule values for the two isomers at the aqueous solution/hydrophobic solid interface may indicate multilayer adsorption there. Both isomers are more efficient at reducing the contact angle than LAS. Mixtures of the B isomer with the corresponding unsulfated Guerbet alcohol show only weak interaction between the two. No synergism in surface (or interfacial) tension reduction efficiency or micelle formation exists at either the aqueous solution/air or aqueous solution interface but the mixture does show synergism in surface (or interfacial) tension reduction effectiveness, yielding a surface tension value of 28.2 dynes/cm, and an interfacial tension value of 0.1 dyne/cm against hexadecane. Draves wetting times increase in the order: B isomer&lt;LAS&lt;L isomer, and Ross‐Miles initial foam heights decrease in the order B isomer ≈LAS&gt;L isomer.

Decomposition of dodecylbenzenesulfonate in river water by simultaneous treatment with ozone and UV irradiation.

A procedure for decomposition of contaminants in environmental water by simultaneous treatment with ozone and UV irradiation (ozone/UV treatment) was applied to linear dodecylbenzenesulfonate (DBS) in river water. Total organic carbon in the river water was decreased by this, though the reduction was not total and some persistent substances remained. When various river waters supplemented with DBS were treated with both ozone and UV, DBS was completely decomposed into inorganic carbons, while the decomposition was incomplete with ozone treatment alone. These results suggest that ozone/UV treatment is an effective procedure for purifying wastewater containing DBS.

Synergism in binary mixtures of surfactants: 9. N-alkyl-2-pyrrolidone-anionic mixtures

The interactions of a series of N-alkylpyrrolidones—N-2-ethylhexyl-(C2,6P), N-octyl-(C8P), N-decyl-(C10P), and N-dodecyl-(C12P) 2-pyrrolidone—with sodium dodecanesulfonate (C12SNa) and commercial sodium linear dodecylbenzenesulfonate (LAS) were investigated. Molecular interaction parameters were consistent with those obtained previously on mixtures of moderately interacting zwitterionic and anionic surfactants. Mixtures of well-purified C8P and C12SNa showed synergism in surface or interfacial tension reduction efficiency at the aqueous/air, aqueous/Parafilm, aqueous/Teflon, and aqueous/hexadecane interfaces, both in pure water and in 0.1 M NaCl. C2,6P, C8P, and C10P exhibited synergism in surface tension reduction efficiency at the aqueous/air interface when mixed with LAS.

Primary biodegradation of linear alkyltoluene and alkylbenzene sulfonates

Studies on the primary biodegradation of linear dodecylbenzene sulfonate, linear dodecyltoluene sulfonate, linear C 10–14 benzene sulfonate, linear C 10–14 toluene sulfonate, commercial samples of linear C 10–14 benzene sulfonate and branched dodecylbenzene sulfonate (DDBS) were carried out using a microbial culture developed from garden soil. Results show that linear alkyl toluene (LAT) is as degradable as linear alkylbenzene (LAB) in 7 days. However, a slower rate of degradation was noted with LAT. Various distributions of the positional isomers of the phenyl ring in the alkane chain of C 10–14 LAB showed no change in the pattern of primary biodegradation.

Acetoacetic acid as a potential trihalomethane precursor in the biodegradation intermediates produced by sewage bacteria

When sodium linear dodecylbenzenesulfonate (LAS), sodium dodecylsulfate (AS) and glucose were incubated with sewage bacteria, a high level of chloroform was produced on chlorination in the course of biodegradation. In addition to LAS, AS and glucose, the primary biodegradation intermediates of LAS and AS were not able to produce high level of chloroform. Acetoacetic acid was found to produce a large quantity of chloroform on chlorination amounting to 55.5% on a molar basis. The formation of acetoacetic acid in the course of biodegradation was determined and it was found that from 51 to 87% of the total chloroform produced could be explained to be derived from acetoacetic acid. These results indicate that acetoacetic acid functions as a potential chloroform precursor in the biodegradation of organic materials by sewage bacteria.

Determination of sodium linear dodecyl benzene sulfonate and sodium cumene sulfonate in mixtures by liquid chromatography

Determination of sodium linear dodecyl benzene sulfonate and sodium cumene sulfonate in mixtures by liquid chromatography