Concentration Of Dodecylbenzene Sulfonate Research Articles

Precise estimation of dodecylbenzenesulfonate in aqueous solution containing dissolved organic matter extracted from soil using UV‐spectrometry

AbstractPrecise estimation of sodium dodecylbenzenesulfonate (DBS) is essential for understanding its adsorption in soils, transport, toxicity, fate, and its application in the remediation of contaminated soil and groundwater. DBS can be easily identified by its conjugated double bond systems of benzene rings under the ultraviolet (UV) spectrum of a spectrophotometer. However, benzene group components of dissolved organic matter (DOM) also absorb light in the UV spectrum, and this effect is responsible for the excess quantities of DBS that are falsely measured by spectrophotometers. This study was conducted to propose a method for accurately measuring the DBS concentration of a solution containing DOM. To elucidate the influence of DOM during the UV‐spectroscopic measurement of DBS in an aqueous solution, 222.5 nm UV and 400 nm UV–vis spectra were measured. The DOM was extracted from a highly humic non‐allophanic volcanic ash (Andosol) soil by using 1 mmol NaCl/L and 100 mmol NaCl/L solutions as the extractants. The absorbances at both 222.5 and 400 nm increased in proportion to the increase in the DOM concentration. The relationship between the absorbances at the two different wavelengths could be expressed as a linear relationship. On the other hand, the absorbance at 400 nm did not increase with the increase in the DBS concentration, whereas the absorbance at 222.5 nm increased with the increase in the DOM concentration. Therefore, we inferred that the influence of DOM on the absorbance value of the DBS–DOM complex solution at 222.5 nm could be eliminated by using the linear relationship between the two different absorbances of the DBS‐free DOM solution. This method makes it possible to easily measure the DBS concentration of a solution from soil water, streams or industrial effluents containing DOM, without using reagents.Highlights Dodecylbenzenesulfonate in a solution is overestimated in the presence of dissolved organic matter. Dodecylbenzenesulfonate becomes precisely detectable using 222.5 and 400 nm spectrophotometry. Our proposed method is simple, rapid, efficient, and requires no special reagent or recurring cost. This method can be used for precise DBS estimation in soil water, streams, or industrial effluents.

The Influence of Carbon Nanotubes on the Protective Properties of Polypyrrole Formed at Copper.

Protective polypyrrole films doped with dodecylbenzene sulfonate (DBS) were formed at copper, while carbon nanotubes (CNT) were incorporated within the polymer films with the DBS to give PPy-DBSCNT (polypyrrole films doped with DBS and incorporated CNT). The polymer films were deposited from a 0.05 M DBS solution at a pH of 6.0 at a thin polypyrrole film doped with tartrate, which served as a stable pre-layer. Low corrosion currents of 0.12 and 0.05 μA cm−2 were estimated using Tafel analysis for the PPy-DBS and PPy-DBSCNT films, respectively, while a significant reduction in the concentration of Cu2+ ions from the corroding copper was observed for the polymer-modified copper. The corrosion protection properties were attributed to the doping of the polymer by the large and immobile DBS anions and possibly, by the larger anionic micelles that are formed at a DBS concentration of 9.8 mM in the pyrrole-containing solution. These dopants give a negatively charged surface that repels chloride anions. The additional protective properties afforded by the CNTs appear to be related to the morphology of the CNT-modified polypyrrole coatings, while the functionalized CNTs also provide a negatively charged surface.

Polypyrrole doped with dodecylbenzene sulfonate as a protective coating for copper

Polypyrrole doped with dodecylbenzene sulfonate (DBS) was formed at copper, PPy–DBS, and at a thin coating of polypyrrole doped with tartrate to form a bilayer of PPy–Tar/PPy–DBS at copper. The two polymer coatings showed good protective properties. Breakdown potentials of 0.85 V and 0.93 V vs SCE were recorded in 0.1 M NaCl for the PPy–DBS and PPy–Tar/PPy–DBS bilayer, respectively. The more protective properties of the bilayer were explained in terms of an adherent thin polymer that was formed in the tartrate solution without significant dissolution of copper before the polymer was nucleated. The protective properties were also evident from open-circuit potential measurements where the potential adopted by the polymer coated copper remained constant and higher than the potential of the uncoated copper for several days. Furthermore, a decrease in the corrosion current density was observed from 1.95 μA cm−2 for copper to 0.12 μA cm−2 for the bilayer. The concentration of DBS had an influence on the properties of the polymer films with more protective films formed in 0.05 M DBS. The critical micelle concentration of DBS in 0.3 M pyrrole was measured as 9.8 mM, indicating a relatively high level of micelles in 0.05 M DBS. The protective properties of the coating were attributed to the large and immobile DBS anion, which gives the polymer cation exchange properties, minimising the uptake of chloride anions. In addition, the incorporation of anionic micelles may occur to repel further the chloride anions.

Validation of Analytical Method Determination of Sodium Dodecyl Benzene Sulfonate (DBS) in Catfish (Clarias batrachus L.) by Spectrophotometric Using Methylene Blue

A spectrophotometric method for analysis of DBS anionic surfactant in Clarias batracus has been validated. The method of analysis was divided into two phases. Extraction with solid-liquid extraction using Soxhlet and analysis of DBS. The extraction was performed using solvent of n-hexane and methanol for 9 and 6 hours, respectively. The analysis was performed using Spectrophotometer UV-Vis based on the complex formation of DBS-methylene blue (DBS-MB). This methods is applied to the determination of DBS in local catfish after DBS exposure and that of obtained in markets. The results showed that the parameters of validation methods have high acceptability as linierity (R2 = 0.99), limit of detection (LOD) and limit of quantification (LOQ ) (2.93 mg/g and 9.75 mg/g), sensitivity (e = 2.44 x 105 L mol-1 cm-1), precision (RSD = 0.14-1.38%) and accuracy (% recovery in a range 82-110 %). The results of analysis of DBS in catfish with 2.5; 5; 10; 15 mg/L of DBS concentration exposure are 0.87; 1.67; 8.50 and 18.10 mg/kg, respectively and catfish from markets in a range 8.5-61 mg/kg. The result showed that the method of analysis of DBS anionic surfactant using MB could be applied for catfish samples. Keywords: Validation methode, extraction, catfish, Clarias batrachus, dodecyl benzene sulfonate, methylene blue.

Adsorption of sodium dodecylbenzene sulfonate (DBS) by c-3,4-di-methoxyphenylcalix [4]resorcinarene triphenylphosphonium chloride

Surfactants have been widely used in many industries, one of them is sodium dodecylbenzene sulfonate (DBS) which is a major component used in the manufacture of detergents and considered as toxic material. Various methods have been undertaken to reduce DBS content in water. One of them is adsorption, which is known as the most effective and environmentally friendly method so far. Our previous study has successfully synthesized an adsorbent C–3,4–dimethoxyphenylcalix[4]resorcinarene triphenylphosphonium chloride (CRP). The aim of this study is to investigate the adsorption of DBS by CRP. Adsorption studies were carried out using the batch methods at different acidity, contact time, and initial DBS concentration and analyzed using UV–Visible, FTIR, and SEM–EDX spectrophotometer. The results showed the optimum condition of DBS adsorption was at pH 8, contact time 120 min, and DBS concentration 40 mg/L. The maximum capacity for the adsorption process was 12.93 mg/g. The rate of adsorption was found to follow the pseudo second–order kinetic model and the Langmuir adsorption isotherm. The mechanism was a chemisorption that occur in monolayer (G ads = –24.87 kJ/mol).

New Biosorbent Based on Al2O3Modified Lignocellulosic Biomass (Lagenaria vulgaris): Characterization and Application

A new biosorbent, obtained by chemical modification of lignocellulosic biomass with Al2O3, was tested for removal of anionic surfactant sodium dodecylbenzenesulfonate (DBS) from aqueous solution in batch conditions. As a basic lignocellulosic material for chemical modification by Al2O3 was used Lagenaria vulgaris shell (LVB). Biosorbent characterization was performed by Fourier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy, and X-ray diffraction analysis. Obtained matter showed significant improvement of removal efficiency compared with unmodified biomass. Effect of initial pH value, biosorbent dosage, and initial concentration of DBS on the sorption process was studied. Sorption of DBS onto LVB-Al2O3 was highly pH dependent. Complete DBS removal was attained at lower pHs; as pH increased up to 9, DBS removal rapidly decreased. Optimal sorbent dosage was 2 g/dm3. Sorption kinetics followed pseudosecond-order, intraparticle diffusion and Chrastil's models, suggesting that both surface reaction and diffusion were rate-limiting steps. Equilibria experimental results were best fit by Langmuir sorption isotherm models. Maximum sorption capacity of LVB-Al2O3 for DBS was found to be 513.28 mg/g. The present study suggests that the chemically modified L. vulgaris shell with Al2O3 could be used effectively for the removal of DBS from aqueous solution.

Experiments to Evaluate Swelling Inhibition of Coal with High Salinity by Sodium Dodecyl Benzene Sulfonate Concentration

Experiments to Evaluate Swelling Inhibition of Coal with High Salinity by Sodium Dodecyl Benzene Sulfonate Concentration

Influence of organic matter on the adsorption of sodium dodecylbenzene sulfonate on volcanic ash soil

Sodium dodecylbenzene sulfonate (DBS), an anionic surfactant, is used as an important content of detergent. Its discharge without treatment causes environmental problem and its adsorptive behavior in soils is not fully understood. In this study, the adsorption behavior of DBS of linear carbon chain on volcanic ash soil was investigated before and after removing most of the organic matter from the soil. The soil used in the experiment is highly humic non- allophanic Andisol soil. Non-allophanic Andisol and DBS have negative charge, which helped to observe the negative-negative soil-surfactant interaction. The adsorption isotherm amount was measured at the electrolyte concentration of 100 mmol L-1 NaCl in order to get the smooth adsorption isotherm and to shorten the diffuse double layer. The adsorption amounts were increased by increasing the concentration of DBS in both soils. The soil having organic matter showed the more adsorption compared to the soil after removing most of the organic matter at different pH conditions. It was also observed that adsorption amount was higher at lower pH. These results indicate that organic matter has increased the adsorption of DBS on volcanic ash soil at all pH condition. Key words: Sodium dodecylbenzene sulfonate (DBS), adsorption isotherm, anionic surfactant, electrolyte, volcanic ash soil.

Liquid phase deposition of tungsten doped TiO 2 films for visible light photoelectrocatalytic degradation of dodecyl-benzenesulfonate

The technique of liquid phase deposition (LPD) was developed for the preparation of tungsten doped TiO 2 (W-TiO 2) films in this study. The doped films were characterized with scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The UV–vis spectra showed that the films extended the absorption wavelength into visible light range after being doped with 1–7% (at.%) content of W. Under the illumination of visible light, the W-TiO 2 film showed a sensitive photocurrent response. Accordingly, the visible light photocatalytic degradation of dodecyl-benzenesulfonate (DBS) was tested and 5% W-TiO 2 film showed the highest degradation efficiency up to 84.8% after 4-h treatment. When +1.0 V anodic bias potential and visible light were simultaneously applied, the degradation efficiency of DBS over the 5% W-TiO 2 film was significantly improved to 92% after 90 min. The effects of anodic bias potential, initial pH value, and initial concentration of DBS on the PEC degradation of DBS were investigated.

Sodium Dodecylbenzene Sulfonate 수용액의 분해반응에서 초음파 효과

계면활성제 중 sodium dodecylbenzene sulfonate(DBS) 수용액에 초음파(200 W, 6 <TEX>$W/cm^2$</TEX>)를 조사하여 주파수, 용존가스 및 농도에 따른 분해경향을 조사하였다. 주파수에 따른 초음파 분해속도는 50 kHz와 600 kHz보다 200 kHz에서 가장 빠른 것으로 나타났다. 200 kHz의 초음파를 이용한 DBS의 분해반응에서는 산소를 이용하였을 때 가장 빠른 분해속도를 나타내었으며, 질소의 경우가 가장 늦은 분해속도를 나타내 초음파반응에 사용된 용존가스(산소, 공기, 질소, 아르곤, 헬륨)의 물리적성질과 활성라디칼의 생성에 의해 분해속도가 달라졌음을 알 수 있다. DBS의 농도에 따른 초음파분해 경향을 보면, 1 mM 까지 분해속도의 감소가 뚜렷하게 나타났으며, DBS의 critical micelle concentration(3 mM) 부근을 기준으로 분해속도의 변화가 거의 나타나지 않아 계면활성제의 미셀형성이 초음파에 의해 유도되는 라디칼에 의한 산화반응과 버블계면에서의 열분해반응에 영향을 미치는 것으로 생각된다. The influence of ultrasound frequency, dissolved gases, and initial concentration on the decomposition of sodium dodecylbenzene sulfonate(DBS) aqueous solution was investigated using ultrasound generator with 200 W ultrasound power. The decomposition rates at three frequencies(50, 200, and 600 kHz) examined under argon atmosphere were highest at 200 kHz. The highest observed decomposition rate at 200 kHz occurred in the presence of oxygen followed by air and argon, helium, and nitrogen. The effect of initial concentration of DBS on the ultrasonic decomposition was decreased with increasing initial concentration and would depend upon the formation of micelle in aqueous solution. It appears that the ultrasound frequency, dissolved gases, and initial concentration play an important role on the sonolysis of DBS. Sonolysis of DBS mainly take place at the interfacial region of cavitation bubbles by both OH radical attack and pyrolysis to alkyl chain, aromatic ring, and headgroup.

Fluorescence enhancement method for measuring anionic surfactants with a hydrophobic cyanine dye

A novel fluorimetric method based on use of a hydrophobic cationic cyanine dye has been developed for determination of the anionic surfactant sodium dodecylbenzenesulfonate (DBS). The method is based on the enhancement effect of DBS on the fluorescence of the hydrophobic cyanine dye 2-[-4'-chloro-7'-(1"-ethyl-3",3"-dimethylindolin-2"-ylidene)-3',5'-(propane-1"',3"'-diyl)-1',3',5'-heptatrien-1'-yl]-1-ethyl-3,3-dimethyl-3 H-indolium iodide. Under the optimum conditions the extent of fluorescence enhancement is proportional to the concentration of DBS in the range 0.05-5.0 mg L(-1); the detection limit is 0.014 mg L(-1). The relative standard deviation for 0.35 mg L(-1) DBS was 1.1% (n=10). The proposed method, which avoided use of toxic solvents and tedious solvent-extraction, and was applied to the determination of DBS in natural water with recoveries between 99.9 and 107%. Preliminary research shows that the fluorescence enhancement is due to the formation of a dye aggregate facilitated by DBS.

Photocatalytic decomposition of the sodium dodecylbenzene sulfonate surfactant in aqueous titania suspensions exposed to highly concentrated solar radiation and effects of additives

The sodium dodecylbenzene sulfonate (DBS) surfactant photodegrades in aqueous titanium dioxide (TiO2) dispersions under highly concentrated solar light exposure (ca. 70 suns) via apparent first-order kinetics with accumulated light energy as the experimental variable. The choice of optimal experimental parameters for the photodegradation of DBS with a concentrated solar illumination device is explored: optimal circulation flow rate, 8.3lmin−1; pH, 5.0; and TiO2 loading, 5gl−1. Foaming action of the DBS–TiO2 suspension increased with increase in increments of the flow rate. The foam produced at the higher TiO2 loadings exhibited greater stability than in the absence of TiO2. The increase in surface tension is faster than the temporal decrease of the concentration of DBS, which followed the typical. Langmuir–Hinshelwood (LH) model: LH apparent rate constant, kLH=0.184mMkJ−1; LH adsorption constant, KLH=0.527mM−1. The relative photonic efficiency, ξrel; against phenol; kapp) of DBS is 0.53. The rate of removal of total organic carbon (TOC) of DBS was improved by a combination of TiO2 loading and added K2S2O8 additive; i.e. at pH 5.0 and TiO2 loading of 0.2gl−1, or pH 8.4 and TiO2 loading of 5.0gl−1. However, at pH 5.0 and TiO2 loading 5.0gl−1, the rate of TOC removal was not enhanced in the presence of K2S2O8 as the oxidizing agent and electron scavenger. The results are explained by contributions from the photochemical oxidation with K2S2O8 and from the K2S2O8-assisted photocatalytic oxidation of DBS.

Self-assembly of poly( p-phenylene vinylene) using long chain counter-ion: a new process for fabrication of multilayer thin films heterostructures

Layer-by-layer thin films of sulfoniun poly(p-phenylene vinylene) (PPV) precursor have been processed using the long chain dodecylbenzenesulfonate (DBS) anion. Here we adopted the alternative approach consisting of the controlled substitution of the chloride counterion of a water-soluble PPV precursor by DBS. The internal layer structure of these films is therefore likely to be different from conventional layer-by-layer films, since DBS ions are expected to be incorporated into the PPV precursor chain. The main advantage of this novel procedure is that thermal conversion through the elimination of DBS may be realized at considerably lower temperatures (80-100 °C) in a few minutes, with enhanced optical properties. Using this new conversion procedure, the conjugation length can also be varied along the deposition direction by controlling the immersion time or DBS concentration in the film. This opens up a number of new possibilities to realize molecularly band-gap engineered structures such as asymmetric ladder type or V-type structures along the film.

Photoassisted Degradation of Dye Pollutants. 3. Degradation of the Cationic Dye Rhodamine B in Aqueous Anionic Surfactant/TiO2 Dispersions under Visible Light Irradiation: Evidence for the Need of Substrate Adsorption on TiO2 Particles

The TiO2 photoassisted degradation of the cationic dye rhodamine B (RhB) has been examined in aqueous dispersions under visible light irradiation at wavelengths longer than 470 nm in the presence and absence of the anionic surfactant sodium dodecylbenzenesulfonate (DBS). RhB degrades slowly via a pH-independent process in TiO2 dispersions containing no DBS. The surfactant DBS adsorbs strongly on the TiO2 particles and significantly accelerates RhB degradation with initial rates reaching maximal values at the critical micelle concentration of DBS (cmc = 1.2 mM). In the presence of DBS, rates decrease with increase in pH, an effect directly attributable to variations in the extent of adsorption of RhB with changes in the surface charge of TiO2 particles. The zeta (ζ)-potentials of TiO2 particles in RhB/DBS/TiO2 dispersions (pH 2.1) show that DBS significantly enhances RhB adsorption and correlates with an enhancement in the rate of photodegradation of RhB. The results confirm the heretofore presumed but val...

Photocatalytic oxidation of organic pollutants in water

The primary photo-oxidation at pollutant level concentration of dodecylbenzene sulfonate (DBS), azynphos-methyl and dimethoate in water has been studied in homogeneous and heterogeneous media by using a 400 W lamp with a solar spectral distribution, and TiO 2 and FeCl 3 as catalysts. Two different geometries of differential batch-recycled reactors were used: first, a concentric tubular reactor with the lamp placed at the tube axis and second, a flow through parallel-plate reactor. An incidence radial model and a linear source spherical emission (LSSE) model with a Monte-Carlo approach to account for scattering of light have been used for the light intensity distribution. Data showed a molar concentration reduction of 30% for DBS in 150 min with light and TiO 2. When FeCl 3 was used as photocatalyst, concentration of DBS was reduced by 70%. Similar behavior found for azynphos-methyl was reduced to 85% in 20 min after irradiation with FeCl 3; 100% in 20 min with TiO 2 and 100% in 2 min with TiO 2 and FeCl 3. Approximately the same performance obtained for dimethoate was completely oxidized in 20 min after irradiation of slurry solution of TiO 2 with FeCl 3. From these data kinetic equations were obtained by assuming a free-radical mechanism for oxidation of hydrocarbons. Pollutants present no activity to solar light, but when FeCl 3 or TiO 2 were used, pollutants were decomposed; being the value of kinetic constant of order 10 4 cm 2/einst. When the solution was irradiated with a FeCl 3 and TiO 2 together, the rate increased about 10 times more. Also, deactivation of catalyst was studied by X-ray diffraction, TG and DTA methods.

Photodegradation of dyes with poor solubility in an aqueous surfactant/TiO2 dispersion under visible light irradiation

The photodegradation of a cationic dye, Malachite Green (MG), is examined both in an anionic surfactant sodium dodecylbenzene sulfonate (DBS)/TiO2 dispersion and in a cationic surfactant hexadecytrimethylammonium bromide (HTAB)/TiO2 dispersion under visible irradiation (λ>470 nm). In the absence of surfactants, MG is difficult to degrade in aqueous TiO2 dispersion, owing to its poor solubility in water and low adsorption on the surface of TiO2 particles. Addition of surfactants enhances the solubility and adsorption ability of MG and hence accelerates significantly the MG degradation rate in aqueous TiO2 dispersions. The MG degradation rate reaches a maximum when the concentration of DBS added is at its c.m.c. According to the adsorption characteristics of the ionic surfactant molecules, the degradation rate of MG decreases with increases in the pH of DBS/TiO2 dispersions, while the degradation of MG is more rapid at higher pH ranges in HTAB/TiO2 dispersions. These results confirm and reinforce that the adsorption of dyes molecules upon the TiO2 particle surface is a prerequisite for TiO2-assisted photodegradation under visible irradiation and the degradation takes place at the TiO2 particle surface, rather than in the bulk solution. The photodegradation kinetics of the dyes in surfactant/TiO2 dispersions under visible irradiation obeys the Langmuir–Hinshelwood model. Evidence for the generation of active OH radicals is obtained using spin-trapping (DMPO) EPR spectroscopy.

Removal of dodecylbenzenesulfonate by a system based on poly(butadiene–maleic anhydride)

Poly(butadiene–maleic anhydride) was aminated with methoxypropylamine. Although this reaction product (APBM) was easily soluble in water, when APBM was supported on activated alumina, APBM/alumina hybrid materials (HM) removed dodecylbenzenesulfonate (DBS) solutes in water. The effects of the supported amounts and of the initial concentrations of DBS on the removed amounts were studied.