Linear Alkylbenzene Research Articles

Fate of household and personal care chemicals in typical urban wastewater treatment plants indicate different seasonal patterns and removal mechanisms

Studies on the presence and fate of household and personal care chemicals (HPCCs) in wastewater treatment plants (WWTPs) are important due to their increasing consumption worldwide. The seasonal patterns and removal mechanisms of HPCCs are not well understood for WWTPs that apply different treatment technologies. To answer these questions, the sewage and sludge samples were taken from 10 typical WWTPs in Northeast China. Levels of UV filters in the influents in the warm season were significantly greater than that of the cold season (p < 0.05). Significant seasonal differences were found for the removals of many HPCCs. Results revealed that the highest removal efficiencies were found for linear alkylbenzene sulphonates with values ranging from 97.2% to 99.7%, and the values were 50.0%–99.9% for other HPCCs. The SimpleTreat model demonstrated that the studied WWTPs were operating with high efficiency at the time of sampling. The sorption of HPCCs to sludge can be strongly associated with their physicochemical parameters. Mass balance calculation suggested that sorption was the dominant mechanism for the removal of antimicrobials, while degradation and/or biotransformation were the other mechanisms for removing the most HPCCs in the WWTPs. This study real the factors influencing the seasonal patterns and removal mechanisms which imply the need for further studies to fully understands the plant and human health implications as sludge could be used in the municipal land application of biosolids.

Electrocoagulation Method Using Al/Graphite Electrode for Removal Surfactant LAS (Linear Alkylbenzene Sulfonate)

An increasing number of laundries have caused water contamination by surfactants. One commonly used surfactant is LAS (Linear Alkylbenzene Sulfonate), a material difficult to decompose, polluting the environment. Electrocoagulation was carried out using Al/Graphite electrode, applied to LAS surfactant artistic waste. This study aims to determine the functional ability of the Al/Graphite electrode in reducing surfactant through electrocoagulation. Various variations were carried out, on the voltage parameters (3,6,9,12) Volt; NaCl concentration (0;0.4;0.8;1.2;1.6;2) g/L; pH (3,5,7,9,11) and time (10,20,30,40,50) minutes. To analyze the changes in the sample before and after electrocoagulation, characterization was carried out using a UV-VIS spectrophotometer and FTIR. A kinetic study was conducted to determine the reaction order of electrocoagulation surfactant. Based on a study, removal at condition voltage 9 Volt, initial pH of the solution 9, electrocoagulation time 50 minute, and the addition of NaCl electrolyte 2 g/L, obtained surfactant concentration was 0,785 mg/L with removal efficiency 97,45%. UV-VIS spectra show a decreased absorption at a wavelength of 653 nm. FTIR spectra showed the presence of absorption on the same functional groups, which indicated that most of the surfactant pollutants could be separated from the wastewater through the electrocoagulation process. The second-order reaction was obtained in the surfactant electrocoagulation process.

Graywater treatment of emerging pollutant linear alkylbenzene sulfonate by adsorption with leather shave waste activated carbon.

The purpose of this research is to evaluate the use of leather shave waste activated carbon (ACLW) as an alternative for the treatment of wastewater containing linear alkylbenzene sulfonate (LAS). Batch adsorption tests were carried out (pH effect, isotherms, kinetics). The activated carbon was tested for its life cycle by desorption with solvent and it was further evaluated as real wastewater treatment for bath graywater. Under the optimum pH of 2.5, kinetic studies showed a better correlation with the pseudo-second order model, with an activation energy of 27.5kJmol-1. Equilibrium isotherms correlated better with the double layer model, indicating hemi-micelle formation and performing a high-affinity isotherm. Adsorption was shown to be endothermic (∆H0 = + 73.89kJmol-1), entropy driven (∆S0 = + 0.46kJmol-1K-1), and occurring spontaneously. The use of ethanol solution was effective for the regeneration of the adsorbent. Adsorption was applied in real wastewater, removing contaminants from bath graywater, especially anionic surfactants with up to 95% removal efficiency.

Biodegradation of Linear Alkylbenzene sulfonate-Anthracene Mixture by a Microbial Consortium isolated from Sediment

Linear alkylbenzene sulfonate and anthracene are chemical compounds which form pollutant mixtures with high toxic potential, causing damage to ecosystems. The process known as biodegradation is an effective, low-cost process carried out by microbial populations that reduces the toxic effect of linear alkylbenzene sulfonate and anthracene. In the present study, biodegradation was determined at different concentrations of linear alkylbenzene sulfonate, anthracene and the mixture of both compounds. The resulting reduction in toxicity produced by the mixture, the compounds separately and their biodegradation intermediaries was assessed using a microbial model. The ISO 9439 system was used to assess the biodegradation effect of a microbial consortium isolated from polluted sediment on 5, 10 and 20 mg/l of linear alkylbenzene sulfonate and the same concentrations of anthracene. Toxicity was determined by measuring inhibition of Bacillus cereus dehydrogenase activity produced by 0.25 ml aliquots of the linear alkylbenzene sulfonate, anthracene and the mixture of both compounds before and after they had been subjected to the biodegradation test. After 11 days, the linear alkylbenzene sulfonate -anthracene mixture was biodegraded to a greater degree than the compounds individually (3057.36 μmol CO2), but at a concentration of 20 mg/l of both compounds, a marked inhibition of biodegradation was observed. A reduction in toxicity produced by the biodegradation of linear alkylbenzene sulfonate and its mixture with anthracene at 5 and 10 mg/l respectively was observed.

Synthetic surfactants in Swiss sewage sludges: Analytical challenges, concentrations and per capita loads

Surfactants are high-production-volume chemicals that are among the most abundant organic pollutants in municipal wastewater. In this study, sewage sludge samples of 36 Swiss wastewater treatment plants (WWTPs), serving 32% of the country's population, were analyzed for major surfactant classes by liquid chromatography mass spectrometry (LC-MS). The analyses required a variety of complementary approaches due to different analytical challenges, including matrix effects (which can affect adduct ion formation) and the lack of reference standards. The most abundant contaminants were linear alkylbenzene sulfonates (LAS; weighted mean [WM] concentration of 3700 μg g−1 dry weight), followed by secondary alkane sulfonates (SAS; 190 μg g−1). Alcohol polyethoxylates (AEO; 8.3 μg g−1), nonylphenol polyethoxylates (NPEO; 16 μg g−1), nonylphenol (NP; 3.1 μg g−1), nonylphenol ethoxy carboxylates (NPEC; 0.35 μg g−1) and tert-octylphenol (tert-OP, 1.8 μg g−1) were present at much lower concentrations. This concentration pattern agrees with the production volumes of the surfactants and their fates in WWTPs. Branched AEO homologues dominated over linear homologues, probably due to higher persistence. Sludge concentrations of LAS, SAS, and NP were positively correlated with the residence time in the anaerobic digester. Derivation of the per capita loads successfully revealed potential industrial/commercial emission sources. Comparison of recent versus historic data showed a decrease in NPEO and NP levels by one or two orders of magnitude since their ban in the 1980s. By contrast, LAS still exhibit similar concentrations compared to 30 years ago.

Predictive Study of the Influence of the Position of the Sulfonate Substituent on the Chemical Stability of Some Linear Alkylbenzene Sulfonate Isomers

Molecules from industrial formulations are used as palliative solutions in the treatment and reuse of industrial waste, with very encouraging results in developing countries. However, the lack of knowledge of the physicochemical properties of these molecules constitutes a major obstacle in the search for an effective solution. To contribute to the characterization of their physicochemical properties, twenty molecules of linear alkyl benzenesulphonate isomers of C10 and C13 homologs and their parent structures were the subject of this study. The stability and overall reactivity parameters such as the energy gap (.∆E), the chemical potential (μ), the electrophilic index (ω) as well as the molecular dipole moment (μD) are determined by the DFT method with the level B3LYP / 6-311G (d, p) / (water; IEFPCM). The results showed that the meta position of the sulfonate substituent increases overall stability and reactivity and decreases the solubility of the more stable 2C10, 4C10, 2C13 and 3C13 homologues of linear alkylbenzene sulfonates. The parent molecules (2mC10, 4mC10, 2mC13 and 3mC13) obtained more stable and less soluble are in favor of the effects observed in the treatment of industrial waste.

A Review in Linear Alkylbenzene (LAB) Production Processes in the Petrochemical Industry

Linear alkylbenzene (LAB) is a cost-effective and biodegradable intermediate in the production of detergents and surfactants. Recently, due to the spread of the Coronavirus and the high global need for detergent, the production of LAB is essential. Kerosene is the raw material of linear paraffin with high purity, which are finally converted to linear olefins by dehydrogenation. The linear mono-olefins react with benzene in the existence of the catalyst to produce LAB which is used to produce linear alkylbenzene sulfonate (LAS), as a biodegradable detergent. The main methods for the production of LAB, including HF and Detal processes were studied and compared with each other. In Detal method, many compounds such as zeolites and metal oxides have been used to make solid catalysts with selectivity, long life, economic efficiency and high safety. Nowadays, most LAB production units have used the Detal process. In this review, the production of LAB was investigated, the influential factors and the advantages, disadvantages and limitations of each method were also investigated. The product quality, process economics, sales market, and the quantitative and qualitative properties of LAB have also been investigated. Also, the exact mechanism of LAB production by HF acid was described.

Histopathological effects of detergent, Linear Alkyl benzene sulphonate on hepatopancreas of freshwater prawn, Macrobrachium lamarrei (Crustacea-Decapoda)

Freshwater prawns, Macrobrachium lamarrei (Crustacea-Decapoda) were subjected to static subacute exposure (0.755 mg/l) of detergent, Linear Alkyl Benzene Sulphonate (LAS) (25% of 96h LC50) for 10,20 & 30 days. Hepatopancreas showed pronounced changes like vacuolization, hypertrophy, hyperplasia and degenerative changes leading to almost complete loss of histoarchitecture after 30 days exposure. Peculiar cell shedding in tubules was noticed after 10 day exposure while heavy increase in wandering cell population was recorded after 20 day exposure. R&B cells were found most effected throughout the hepatopancreas. Histopathological effects were found duration dependent. Underlying mechanism of detergent toxicity and role of histopathology as biomarker has been discussed.

Monitoring of linear alkyl benzenes (LABs) in riverine and estuarine sediments in Malaysia.

The aim of this a pioneering research is to investigate linear alkylbenzenes (LABs) as biomarkers of sewage pollution in sediments collected from four rivers and estuaries of the south and east of Peninsular Malaysia. The sediment samples went through soxhlet extraction, two-step column chromatography purification, fractionation and gas chromatography-mass spectrometry (GC-MS) analysis. Principal component analysis (PCA) with multivariate linear regression (MLR) was used as well for source apportionment of LABs. The results of this study showed that total LAB concentration was 36-1196ngg-1dw. The internal to external isomer ratios (I/E ratio) of LABs were from 0.56 to 3.12 indicated release of raw sewage and primary and secondary effluents into the environment of south and east of Peninsular Malaysia. Our research supported that continuous monitoring of sewage pollution to limit the environmental pollution in riverine and estuarine ecosystem.

Organic contaminants in marine environment - Let us not forget the shallow areas

The evaluation of anthropogenic pressures in marine environments commonly involves sediments, water and marine biota. However, the evaluation of the quality of the beach sediment and sediments from shallow areas are scarce compared to sediments from deeper areas in environmental assessment studies. In this study polycyclic aromatic hydrocarbons and linear alkylbenzenes were assessed in sediments from shallow areas of the São Sebastião channel, southeastern Brazil. The channel is part of the Marine Protected Area of the Northern Coast of São Paulo State besides holds the largest petroleum terminal in South America further than three sewage outfalls. Despite the concentrations of these contaminants in the sediments were relatively low compared to those found in the sediments from deeper areas of the channel, suggesting low toxicity of the beach sediments, the contamination reflected the pattern of the sediments of the São Sebastião channel.

Metagenomic assembly deciphered the type-dependent effects of surfactants on the fates of antibiotics resistance genes during sludge fermentation and the underlying mechanisms

Waste activated sludge (WAS) is an important reservoir of antibiotic resistance genes (ARGs). However, the interactive effects of co-existed substances in WAS on ARGs fates have yet to be disclosed. This study demonstrated the type-dependent effects of surfactants (potentially effective chemicals for WAS disposal) on the reduction of ARGs during WAS fermentation, which followed the order of linear alkylbenzene sulphonates (LAS) > alkyl polyglucoside (APG) > hexadecyl trimethyl ammonium bromide (HTAB). Interestingly, the ratio of ARGs affiliated to efflux pump showed an upward trend in the surfactant-treated reactor. Mechanistic investigations revealed that the extracellular polymeric substances (EPS) destruction induced by surfactants increased the permeability of bacterial cells and caused the ARGs being released and susceptible for subsequent elimination. Besides, the surfactants significantly altered the microbial community, resulting in the ARGs reduction via changing the potential hosts. Also, the metabolic pathways participated in the dissemination of ARGs were remarkably down-regulated, thereby resulting in the reduction of ARGs abundances. This work broadened the understanding of ARGs fates during WAS fermentation and provided insights on the interactive functions of exogenous chemicals in multiple matrics.

Adsorption mechanism on surfactant removal using eggshell waste and rice straw as economically biosorbent

Adsorption is an effective process to remove organic compounds, including surfactants. In this research, rice straw (JP) and eggshell waste (CT) would be tested as economically adsorbents of surfactant. This research aims to determine the effect of pH, adsorbent dose, initial concentration, and particle size on adsorption effectivity, find out kinetics, removal efficiency and desorption ability of adsorbents. Anionic surfactant Linear Alkylbenzene Sulfonate (LAS) was determined by using MBAS method. A preliminary test was conducted to examine which adsorbent is the potential to be used in the main experiment. Adsorbent selected from the preliminary test was CT2 and JP1. Surfactant removal at an acidic solution was better than in an alkaline solution. The particle size of adsorbent was not influencing much at removal of surfactant. As increasing dosage, removal efficiency increases. Removal efficiency decreases as initial concentration is increased. Isotherm D-R fitted well for both adsorption and desorption using JP; therefore Langmuir isotherm fitted well for CT. Removal efficiency of LAS adsorption was better using JP than CT adsorbent. Desorption release at CT was 9.68-20.94%, while for JP was 8.51-12.20%. Pseudo-second order and second-order models fitted data well for adsorption kinetics. Physisorption was dominant in the adsorption process.

Microscopic Diffusion Characteristics of Linear Alkylbenzene Sulfonates on the Surface of Anthracite: The Influence of Different Attachment Sites of Benzene Ring in the Backbone

In order to explore the effect of the attachment site of the benzene ring in the backbone of the surfactant on its diffusion characteristics on the surface of anthracite, the molecular dynamics simulation method was used, and the four isomers (m-C16, m = 2,4,6,8; m represents the attachment site of the benzene ring in the backbone) of sodium hexadecyl benzene sulfonate (SHS) were selected. Binary models of surfactant/anthracite, surfactant/graphene modified by oxygen-containing functional groups, and a ternary model of water/surfactant/anthracite were constructed. By analyzing a series of properties such as interaction energy, contact surface area, relative concentration distribution, radial distribution function, hydrophobic tail chain order parameter, etc., it is concluded that the adsorption strength of 4-C16 on the surface of anthracite is the highest; the reason is that 4-C16 has the highest degree of aggregation near the oxygen-containing functional groups on the surface of anthracite. Further investigations find that 4-C16 can be densely covered on the ketone group, and the longer branch chain of 4-C16 has the highest degree of order in the Z-axis direction.

Removal kinetics of linear alkylbenzene sulfonate in a batch-operated oxygen based membrane biofilm reactor treating greywater: Quantitative differentiation of adsorption and biodegradation

Oxygen-based membrane biofilm reactor (O2-MBfR) is a unique technique for high linear alkylbenzene sulfonate (LAS)-containing greywater (GW) treatment. Despite the efficient removal of LAS, the dynamics of how it is taken up and the quantitative differentiation of adsorption and biodegradation are largely undefined. In this study, we tracked the fate of LAS, chemical oxygen demand and nitrogen in various systems: GW, GW with inactivated sludge (InAS) and GW with activated sludge (AS). We determined the distribution of biodegraded-, free-, and extracellular polymeric substances (EPS)-attached LAS, and we also developed a model to simulate all the steps. Results showed that AS exhibited high live cells proportion and microbial activity, but the opposite trend for GW and InAS. Both of nitrogen and organics could be simultaneously and efficiently removed in the AS inoculated system. The two-step model for LAS uptake and biodegradation represented the experimental results well. EPS adsorption led to the fast LAS accumulation in biofilm, and biodegradation led to the continuous removal of LAS in the system. After operated for 24 h, biodegradation and EPS accumulation of LAS were 94% and 4%, respectively, and the residual soluble LAS was lower than 1%. This work lays the foundation for using O2-MBfR to treat GW and other types of wastewater, and understanding the key roles of EPS and the mathematical model of LAS removal in the system.

Influence of cosubstrate and hydraulic retention time on the removal of drugs and hygiene products in sanitary sewage in an anaerobic Expanded Granular Sludge Bed reactor

Diclofenac (DCF), ibuprofen (IBU), propranolol (PRO), triclosan (TCS) and linear alkylbenzene sulfonate (LAS) can be recalcitrant in Wastewater Treatment Plants (WWTP). The removal of these compounds was investigated in scale-up (69 L) Expanded Granular Sludge Bed (EGSB) reactor, fed with sanitary sewage from the São Carlos-SP (Brazil) WWTP and 200 mg L−1 of ethanol. The EGSB was operated in three phases: (I) hydraulic retention time (HRT) of 36±4 h; (II) HRT of 20±2 h and (III) HRT of 20±2 h with ethanol. Phases I and II showed no significant difference in the removal of LAS (63 ± 11–65 ± 12 %), DCF (37 ± 18–35 ± 11 %), IBU (43 ± 18–44 ± 16 %) and PRO (46 ± 25–51 ± 23 %) for 13±2–15 ± 2 mg L−1, 106 ± 32–462 ± 294 μg L−1, 166 ± 55–462 ± 213 μg L−1 and 201 ± 113–250 ± 141 μg L−1 influent, respectively. Higher TCS removal was obtained in phase I (72 ± 17 % for 127 ± 120 μg L−1 influent) when compared to phase II (51 ± 13 % for 135 ± 119 μg L−1 influent). This was due to its greater adsorption (40 %) in the initial phase. Phase III had higher removal of DCF (42 ± 10 % for 107 ± 26 μg L−1 influent), IBU (50 ± 15 % for 164 ± 47 μg L−1 influent) and TCS (85 ± 15 % for 185 ± 148 μg L−1 influent) and lower removal of LAS (35 ± 14 % for 12 ± 3 mg L−1 influent) and PRO (−142 ± 177 % for 188 ± 88 μg L−1 influent). Bacteria similar to Syntrophobacter, Smithella, Macellibacteroides, Syntrophus, Blvii28_wastewater-sludge_group and Bacteroides were identified in phase I with relative abundance of 3.1 %–4.7 %. Syntrophobacter was more abundant (15.4 %) in phase II, while in phase III, it was Smithella (12.7 %) and Caldisericum (15.1 %). Regarding the Archaea Domain, Methanosaeta was more abundant in phases I (84 %) and II (67 %), while in phase III it was Methanobacterium (86 %).

Primary, secondary screening and evaluation of LAS degrading potential of soil bacteria isolated from Vidya Pratishthan’s college area

Inefficiency of use of soap in hard water popularized the use of anionic surfactants namely, branched alkylbenzene sulphonates (BAS) and Linear alkyl benzene sulphonates (LAS) in detergents. The low cost and superior solubility in hard water had made them popular and first choice of many household care-products. However, the disadvantage associated with their use was formation of stable foam over waterbodies which is detrimental for both the aquatic plants and animals. The current study involves primary and secondary screening of LAS degrading organisms and evaluates their potential. The three isolates screened isolate 1 can degrade LAS to the tune of 66% in 5 days, isolate 2 and isolate 3 degrade 72.16% and 68.25% respectively in 4 days.

Bacillus licheniformis SMIA-2 protease used as an additive in detergent formulations

Microbial proteases, especially from Bacillus spp., have been widely exploited for a broad variety of applications, such as the improvement of the cleaning efficiency of conventional detergents. In this work, the statistical design of the experiment was used to optimize the concentrations of a three-component mixture: Bacillus licheniformis SMIA-2 protease, Linear Alkylbenzene Sulphate and hydrogen peroxide, in an attempt to prepare an environmentally correct cleaning formulation. The results demonstrated that the combination of 1% (w/v) protease with 1.5% (w/v) LAS and 1% (w/v) H2O2 was effective in removing blood from cloth pieces and that a protease concentration decrease from 1.0% to 0.5% (w/v) would not have a significant impact on percent blood removal if LAS concentrations between 1.5-2.0% (w/v) in combination with lower (&lt;0.5%, w/v) concentrations of H2O2 were used. Thus, the protease from Bacillus licheniformis SMIA-2 can be effectively incorporated into cleaning formulations together with LAS and hydrogen peroxide to formulate more sustainable detergents.

The identification and performance assessment of dominant bacterial species during linear alkylbenzene sulfonate (LAS)-biodegradation in a bioelectrochemical system.

The anionic surfactant linear alkylbenzene sulfonate (LAS) is a major chemical constituent of detergent formulation. Regarding the recalcitrant nature of sulfonoaromatic compounds, discharging these substances into wastewater collection systems is a real environmental issue. A study on LAS biodegradation based on bioelectrochemical treatment and in the form of developing a single-chamber microbial fuel cell with air cathode is reported in the present work. Pretreatment study showed LAS concentration of 60ppm resulted in the highest anaerobic LAS removal of 57%; so, this concentration was chosen to run the MFC. After the sustained anodic biofilm was formed, LAS degradation rate during 4days in MFC was roughly 76% higher than that in the serum bottle, which indicated the role of the bioelectrochemical process in improving anaerobic LAS removal. Additionally, through 16S rRNA gene sequencing, the dominant bacterial species in the biofilm was identified as Pseudomonas zhaodongensis NEAU-ST5-21(T) with about 98.9% phylogenetic similarity and then a pathway was proposed for LAS anaerobic biodegradation. The MFC characteristics were assessed by pH monitoring as well as scanning electron microscopy and current density evolution.

Highly Efficient Degradation of Linear Alkylbenzene Sulfonate Surfactant by MIL‐53 (Fe) Metal Organic Framework Derived Electro‐Fenton Applicable in Water Treatments

AbstractMIL‐53 (Fe) Metal‐organic framework (MOF) was synthesized by a hydrothermal method and characterized by SEM, XRD, FT‐IR, and Brunauer‐Emmett‐Teller techniques. The synthesized MOF was successfully applied as an efficient catalyst in Electro‐Fenton degradation of linear alkylbenzene sulfonate (LAS) surfactant, so that degradation rate constant, Kapp, for LAS degradation showed significantly higher amounts in presence of Fe MOF. Effect of experimental parameters on Electro‐Fenton degradation including pH, MOF amount, applied current, Fe (II) concentration, and electrodes distance were investigated and optimized amounts were found. Applying of MOF caused efficient removal of LAS in compared to when MOF was not applied. Catalytic electrochemical degradation in this work showed removal of more than 98 % of initial surfactant in 150 min which was completely satisfying for LAS removal.

Spatial modeling framework for aquatic exposure assessments of chemicals disposed down the drain: Case studies for China and Japan.

A modeling framework was created for the development of spatially explicit aquatic exposure models for any region or country of interest for chemicals disposed of down the drain. The framework relies on globally available data sets for river flow and population, and locally available data sets for wastewater treatment infrastructure and domestic water use, and leverages the iSTREEM® chemical routing algorithm. The framework was applied to China and Japan as case study countries. Spatially explicit population data were obtained from WorldPop. River flows covering the spatial extent of the two countries were derived from a high-resolution surface runoff gridded data set that was based on the Curve Number approach and combined with the hydrology network for catchments and rivers from HydroBASINS and HydroSHEDS data sets. Publicly available data from government sources were used for estimating per capita water use and wastewater treatment infrastructure. To demonstrate the framework, the China model was used to predict the levels of the antifungal agent climbazole in rivers across the country, and the Japan model was used to predict river concentrations of linear alkylbenzene sulfonate. For both chemicals, the comparison of measured to modeled values showed good agreement, using linear regression analysis (R2 ≥ 0.96). The framework presented in this study provides a systematic and robust approach to develop spatially resolved exposure models that can be extrapolated to any country or region, allowing more accurate risk assessment of chemicals disposed down the drain by leveraging concentration distributions generated by the model. Integr Environ Assess Manag 2022;18:722-733. © 2021 SETAC.