Linear Alkylbenzene Sulphonate Concentration Research Articles

Seasonal variation and impact of linear alkyl sulphonate (LAS) toxicity on Nile tilapia, Oreochromis niloticus in two Nile Delta Lagoons, Egypt

ABSTRACT The aim of the present study is to assess the accumulation of detergents residues; linear alkylbenzene sulphonate (LAS) in Burullus and Edku lagoons water, sediments, and muscles of Oreochromis niloticus and investigate hazards effect on fish. The data revealed a significant accumulation of LAS in Burullus and Edku water, sediments, and fish muscle compared to those recorded in the Nile River as a reference site. The study showed seasonal changes in the serum concentrations of superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GSH) for fish tilapia. The ANOVA test displayed a significant difference between different seasons (p ≤ .001). The results of the current study exhibited the effect of increasing the concentration of LAS on the fishes of Burullus and Edku lagoons. The study showed low concentrations of serum activity, CAT, SOD and GSH in comparison with the values in the control fish (Nile River fish). It causes oxidative stress, severe disruption, followed by cytotoxicity. In excessive production of reactive oxygen species, the serum of SOD, CAT and GSH are exploited for detoxification. Alterations in histopathological structure were observed in both Burullus, and Edku fish liver and gills compared to those in the control fish.

Effect of Linear Alkylbenzene Sulphonate on Bacterial Population and Hydrocarbon Degradation in Crude-oil Polluted Soil

Aim: The aim of this study was to determine the concentrations of linear alkyl benzene sulphonate (LAS) that are non-toxic to bacteria in crude-oil polluted soil, and also effective in enhancing biodegradation of the hydrocarbons.
 Methodology: Seven concentrations (4, 8, 16, 32, 64, 128, and 256 mg/L) of LAS were prepared, and 50 ml of each were added to 500 g soils artificially polluted with crude-oil. Based on the quantity of soil used and the volume of LAS solutions added, the in-soil LAS concentrations were calculated to be 0.4 – 25.6 mg/Kg. A control was also set up were 50 ml sterile distilled water was used. The setups were maintained for seven days; on day 1, 3, and 7, the population of total heterotrophic bacteria (THB) were determined. Total hydrocarbon concentrations (THC) were determined on day 1 and 7.
 Results: The results obtained showed that the extent of hydrocarbon degradation increased with increase in LAS concentration from 35.9 to 61.4%, with the control having 10.9%. The THB population strength in all the setups increased from 106 to 107; in the setup treated with the highest concentration of LAS, the increase was from 106 to 108. Bacteria isolated from the setups included Bacillus, Micrococcus, Acinetobacter, Staphylococcus, and Pseudomonas sp, which are known hydrocarbon degraders.
 Conclusion: LAS concentration of up to 25.6 mg/Kg can lead to significant hydrocarbon biodegradation in crude-oil polluted soil with no adverse effect on bacteria present in the soil.

Spatial variability of ecosystem exposure to home and personal care chemicals in Asia

It is well recognized that there are currently limitations in the spatial and temporal resolution of environmental exposure models due to significant variabilities and uncertainties in model inputs and parameters. Here we present the updated Pangea multi-scale multimedia model based on the more spatially resolved, catchment-based hydrological HydroBASINS dataset covering the entire globe. We apply it to predict spatially-explicit exposure concentrations of linear alkylbenzene sulphonate (LAS) and triclosan (TCS) as two chemicals found in homecare (HC) and personal care (PC) products in river catchments across Asia, and test its potential for identifying/prioritizing catchments with higher exposure concentrations. In addition, we also identify the key parameters in the model framework driving higher concentrations and perform uncertainty analyses by applying Monte Carlo simulations on emissions and other non-spatial model inputs.The updated combination of Pangea with the HydroBASINS hydrological data represents a substantial improvement from the previous model with the gridded hydrological dataset (WWDRII) for modelling substance fate, with higher resolution and improved coverage in regions with lower flows, with the results demonstrating good agreement with monitored concentrations for TCS in both the freshwater (R2 = 0.55) and sediment (R2 = 0.81) compartments. The ranking of water basins by Predicted Environmental Concentrations (PECs) was similar for both TCS and LAS, with highest concentrations (Indus, Huang He, Cauvery, Huai He and Ganges) being one to two orders of magnitude greater than the water basins with lowest predicted PECs (Mekong and Brahmaputra). Emissions per unit volume of each catchment, chemical persistence, and river discharge were deemed to be the most influential factors on the variation of predicted PECs. Focusing on the Huang He (Yellow River) water basin, uncertainty confidence intervals (factor 31 for LAS and 6 for TCS) are much lower than the variability of predicted PECs across the Huang He catchments (factors 90,700 for LAS and 13,500 for TCS).

Surfactant biodegradation in batch reactors with aspergillus niger AN400

The wide production and use of the surfactant linear alkylbenzene sulphonate (LAS) has severe effects on the environment and, consequently on human health. This study sought to evaluate the efficiency of the species aspergillus niger AN400 on LAS removal, in reactors operated in batch mode. Three reactors were operated for 30 days with the following configuration: a control reactor without A. niger AN400 (CR) and two reactors with A. niger AN400, one of each supplemented with 1 mg L−1 of glucose (ANGR) and one without the co-substrate (ANR). LAS was tested in the concentrations of 15 and 30 mg L−1. LAS removal efficiencies 51% in ANR and 76% ANGR, for the initial concentration of LAS of 15 mg L−1, and 55% in ANR and 65% in ANGR, for 30 mg L−1 of LAS.

Membrane fouling control and performance enhancement of ultrafiltration of latex effluent

AbstractThe objective of the present study was to minimize membrane fouling of a latex solution either through improving the membrane surface charge or using a pretreated feed. Hydrophilic polysulphone (PSU) and Ultrafilic flat membranes, with a molecular weight cut‐off (MWCO) of 60 000 and 100 000 dalton, respectively, were implemented under a constant flow rate and cross‐flow mode in ultrafiltration of simulated latex effluent. Hydrophobic polyvinylidene difluoride membrane (PVDF) with a MWCO of 100 000 dalton was also tested. The influence of linear alkyl benzene sulphonate (LAS) on the ionic strength of the simulated latex effluent and the surface charge of latex particles at different LAS concentrations was investigated. LAS was also used, at different concentrations and various treatment times, to ensure the enhancement of the antifouling characteristics of the membrane surface. It was concluded that the LAS‐treated membrane surface is much more favourable than the pH‐changed feed pre‐treatment. As such, the total mass of fouling decreased by 44.00 % and 29.60 % in the cases of treated PVDF membrane surface with LAS at a concentration of 0.0001 g/L, and treated latex feed at pH 11, respectively. Nevertheless, LAS was considered to be an ineffective pre‐treatment for limiting the fouling propensity of latex solutions using hydrophilic membranes even at high concentrations and long treatment times.

Effect of laundry activities on in-stream concentrations of linear alkylbenzene sulfonate in a small rural South African river

In many parts of the world clothes are washed near to or in rivers and streams. Little information is available on resulting concentrations of detergent ingredients or on any potential effects caused. In this study, the fate of a commonly used anionic surfactant, linear alkylbenzene sulphonate (LAS) was investigated in a reach of the Balfour River (Eastern Cape Province, South Africa) which was regularly used as a site for laundry activity. Samples of river water were collected upstream of the main washing site and at a number of locations downstream on several occasions in winter and summer. Sediment samples were also collected and analysed. In addition, a household survey was conducted to ascertain the amount of detergent used and the distribution of washing practices. The results of the survey suggested that the use of riverside locations for laundry activities was seasonal. Most washing tended to be done at home during the winter with riverside sites used more frequently during the summer months. The monitoring data showed that LAS concentrations in water were very variable. They were occasionally high in the immediate vicinity of the laundry site (up to 342 µg L − 1 ) but were generally very low (< 11 µg L − 1 ) at downstream monitoring stations, suggesting that LAS was rapidly dissipated by a combination of degradation, hydrodynamic dispersion and dilution. Concentrations in the immediate vicinity of the washing site were lower than expected on the basis of the household survey because most waste water was disposed of on the river bank rather than directly in the river. No ecological effects are expected from LAS emissions at this site.

Growth Response and Feed Utilization in the Cichlid, Tilapia zilli Exposed to Sublethal Concentrations of Linear Alkylbenzene Sulphonate (LAS) Detergent

Fingerlings of the cichlid Tilapia zilli, were exposed to various sublethal concentrations of linear alkylbenzene sulphonate (LAS) detergent, a toxicant, and the effects on growth response indices and feed utilization were recorded using biostatic assays. Water quality was also monitored. The fish were exposed in aerated tanks for 12 weeks, at concentrations of 1.56, 0.39, 0.196, 0.098 and 0.00 (control) mgL-1. No mortality occurred in the exposed fish or in the control group. The toxicant led to significant depression in weight gain in direct proportion to concentrations of the toxicant. Feed utilization was significantly reduced. The environmental impacts on fish of detergents in an ecosystem are discussed.

Derivation of predicted no effect concentrations (PNEC) for marine environmental risk assessment: Application of different approaches to the model contaminant Linear Alkylbenzene Sulphonates (LAS) in a site-specific environment

Four sediment-dwelling marine organisms were exposed to sediments spiked with increasing concentrations of Linear Alkylbenzene Sulphonate (LAS). The selected endpoint mortality was reported daily and acute LC 50 (96 h), as well as final LC 10 values were calculated for the derivation of environmentally safe predicted no effect concentrations (PNEC) for the sediment compartment. PNECs were estimated by both application of assessment factors (AF) and the equilibrium partitioning method (EPM) as proposed by the EU TGD. Finally, environmental risk assessment in a site-specific environment, the Sancti Petri Channel, South Iberian Peninsula, was carried out at three different sampling stations with known environmental LAS concentrations. PNECs obtained by the assessment factor approach with acute toxicity data were one to two orders of magnitude lower than those from the equilibrium partitioning method. On the other hand, when applying lower AFs to the estimated LC 10 values, the PNECs obtained by both approaches were more similar. Environmental risk assessment carried out with the estimated PNECs in a site specific environment with known sediment LAS concentrations revealed that PNECs obtained with acute toxicity data were over conservative whereas those obtained with AF = 10 on LC 10 data and EPM produced more realistic results in accordance with field observations carried out in the study area.

Predicting diffuse-source transfers of surfactants to surface waters using SWAT

Chemicals present in domestic wastewater can adsorb to solid phase materials during sewage treatment. If biosolids (or sewage sludge) are applied to land, these chemicals can be transferred to soil. Under some circumstances they can also be transferred to surface waters during storm events either in solution or attached to sediment. In this paper we describe the utility of the SWAT 2000 model to estimate diffuse-source surface water exposure to “down-the-drain” chemicals. The model was applied hypothetically to predict the behaviour of linear alkylbenzene sulphonate (LAS), an anionic surfactant commonly used in household detergents, in a small catchment in Bedfordshire, UK, where it has previously been successfully validated for stream flow, sediments and pesticides. LAS transfers were estimated for two scenarios: (1) realistic and (2) reasonable worst case, based on assumptions on sludge application rates and the concentration of LAS in sludge. In addition, the sensitivity of the model output to the proportion of the catchment to which sludge is applied was established. Soil wetness and the total quantity of biosolids applied were the biggest determinants of chemical transport from the catchment. The potential of SWAT as a higher-tier tool in environmental risk assessments is discussed.

Sources of priority substances entering an urban wastewater catchment—trace organic chemicals

The implementation of new legislation such as the Water Framework Directive (WFD) requires Member States to gain a better understanding of priority substances entering surface waters. This will include inputs from wastewater treatment works as well as from other urban, industrial and agricultural sources. There is currently a lack of available data regarding the magnitude and sources of organic priority substances entering treatment works. As a consequence the concentrations of organic priority substances including PAHs, surfactants, polybrominated diphenylethers (PBDEs), diethylhexyl phthalate (DEHP), pesticides and solvents were determined in the wastewater from an urban catchment located in the UK, as part of a project undertaken for UK Water Industry Research (UKWIR). Most organic priority substances were detected in the μg/l range. Significant variations in the concentration of linear alkylbenzene sulphonate (LAS), DEHP, PBDEs and nonylphenol ethoxylates (NPEOs), in particular, were observed for the different sources. The greatest differences were evident between new and older domestic discharges. Solvent levels varied considerably reflecting use and production within the catchment. Chloroform levels were highest in domestic effluent, while trichloroethene and tetrachloroethene were detected only in commercial samples.

UK monitoring study on the removal of linear alkylbenzene sulphonate in trickling filter type sewage treatment plants. Contribution to GREAT-ER project # 2

The results of a linear alkylbenzene sulphonate (LAS) monitoring exercise carried out during August and September, at six different trickling filter sewage treatment plants in the Aire and Calder catchments in the UK are described. The average LAS concentration in flow proportional, composite, crude sewage was 3.25 mg l −1 and ranged from 1.10 to 5.58 mg l −1. Based on consumer usage data and boron measurements these results indicate that up to 60% of the LAS was removed in the sewers prior to reaching the sewage treatment plants. The concentration of LAS in flow proportional, composite final effluents from well-operated plants ranged from 4 to 460 μg l −1, with an average value of 240 μg l −1. Removal through the plants ranged from 70–99% with mean values of 90.7, 93.4, 93.0, 74.6, 97.3 and 92.4% for the six plants. A simple model is described which can be used to accurately predict the diel variation in LAS concentrations in the final effluent when measured influent concentrations, flow and settling tank volumes are known.

Fate and Effect of Detergent Chemicals in the Marine and Estuarine Environment

Detergents are high-volume consumer products which are discharged directly into domestic sewage after their use. They are removed in the treatment of domestic sewage and via instream removal mechanisms in surface waters. Important removal mechanisms are biological degradation, adsorption to sediments, etc. The degree of removal mainly depends on the physico-chemical and environmental properties of the chemical and on the type of sewage treatment. The continuous removal processes, combined with the continuous discharge to surface waters via treated or untreated sewage effluents, results in the presence of detergent chemicals in surface waters, where they can further biodegrade. Detergent chemicals can thus, ultimately, enter the marine environment. Data are presented on the discharged amounts of detergent ingredients, such as surfactants and phosphates, to surface waters and to the North Sea. Furthermore, the fate and effects of a typical surfactant in the marine and estuarine environment are described. Monitoring data for one of the major anionic surfactants, Linear Alkylbenzene Sulphonate (LAS), are presented. A comparison of the measured concentrations of LAS with the concentrations, predicted on the basis of a measured dilution of the river water with sea water, shows that this surfactant continues to biodegrade under marine conditions.

Reduction by a surfactant of olfactory mediated attraction between juveniles of arctic charr, Salvelinus alpinus (L.)

The effect of sublethal concentrations of linear alkylbenzene sulphonate (LAS) on attraction to conspecific compounds was studied in juvenile Arctic charr, Salvelinus alpinus. In a fluviarium single fish were observed over nine consecutive 90-min test periods in darkness choosing between two flows, the one containing charr odour, the other not. After each 90-min period the flows were exchanged. Sixty-three subjects were tested. Four different types of test were run: control test; attraction test; attraction test after 96 h pre-exposure of test fish to 1–2 ppm LAS; attraction test with LAS distributed to all parts of the test area during four of the test periods. Intact charr always showed strong and steady attraction to water conditioned by conspecifics. Pre-exposure to 1–2 ppm LAS significantly reduced chemo-attraction. Simultaneous supply of 0.02 or 0.2 ppm LAS to the test area significantly decreased attraction, while 1.0 ppm LAS completely quenched the attraction. Chemo-attraction was still significantly reduced during the test period immediately after the supply of 0.02 or 1.0 ppm LAS was stopped. Locomotor activity was affected only during supply of 1.0 ppm LAS into the test area. The chemo-attraction studied in Arctic charr may possibly be used in behavioural-toxicity testing of xenobiotics in sublethal concentrations.