Characteristics and environmental fate of the anionic surfactant sodium lauryl ether sulphate (SLES) used as the main component in foaming agents for mechanized tunnelling

2017 ◽  
Vol 226 ◽  
pp. 94-103 ◽  
Author(s):  
Anna Barra Caracciolo ◽  
Martina Cardoni ◽  
Tanita Pescatore ◽  
Luisa Patrolecco
Keyword(s):  
Anionic Surfactant ◽  
Environmental Fate ◽  
Foaming Agents ◽  
Lauryl Ether ◽  
Mechanized Tunnelling ◽  
Main Component

scholarly journals Environmental Fate and Effects of Foaming Agents Containing Sodium Lauryl Ether Sulphate in Soil Debris from Mechanized Tunneling

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2074
Author(s):  
Luisa Patrolecco ◽  
Tanita Pescatore ◽  
Livia Mariani ◽  
Ludovica Rolando ◽  
Paola Grenni ◽  
...  
Keyword(s):  
Environmental Fate ◽  
Vibrio Fischeri ◽  
Lepidium Sativum ◽  
Eisenia Foetida ◽  
Site Specific ◽  
Foaming Agents ◽  
Mechanized Tunneling ◽  
Lauryl Ether ◽  
Set Up ◽  
Main Component

A wide use of foaming agents as lubricants is required in mechanized tunneling. Their main component, the anionic surfactant sodium lauryl ether sulphate (SLES), can remain in residual concentrations in soil debris, influencing their potential reuse as by-product. This study aimed at evaluating the environmental fate and effects of a foaming product used for conditioning soils collected from real excavation sites, in the presence/absence of an anti-clogging polymer, both containing SLES. Soil microcosm experiments were set-up and incubated for 28 days. Over time, soils and their water extracts (elutriates) were collected to perform both ecotoxicological tests (Vibrio fischeri, Lepidium sativum, Eisenia foetida, Hetereocypris incongruens, Danio rerio) and SLES analysis. The results showed that, just after conditioning, SLES did not exert any hazardous effect on the organisms tested except for the bacterium V. fischeri, which was the most sensitive to its presence. However, from day seven the toxic effect on the bacterium was never observed thanks to the SLES decrease in the elutriates (<2 mg/L). SLES degraded in soils (half-lives from 9 to 25 days) with higher disappearance rates corresponding to higher values of microbial abundances. This study highlights the importance of site-specific studies for assessing the environmental reuse of spoil materials.

Assessment of biodegradation of the anionic surfactant sodium lauryl ether sulphate used in two foaming agents for mechanized tunnelling excavation

2019 ◽  
Vol 365 ◽  
pp. 538-545 ◽  
Author(s):  
A. Barra Caracciolo ◽  
N. Ademollo ◽  
M. Cardoni ◽  
A. Di Giulio ◽  
P. Grenni ◽  
...  
Keyword(s):  
Anionic Surfactant ◽  
Foaming Agents ◽  
Lauryl Ether ◽  
Mechanized Tunnelling

scholarly journals Germination, root elongation, and photosynthetic performance of plants exposed to sodium lauryl ether sulfate (SLES): an emerging contaminant

2021 ◽  
Author(s):  
Elisabetta Salvatori ◽  
Jasmin Rauseo ◽  
Luisa Patrolecco ◽  
Anna Barra Caracciolo ◽  
Francesca Spataro ◽  
...  
Keyword(s):  
Root Elongation ◽  
Photosynthetic Performance ◽  
Emerging Contaminant ◽  
Terrestrial Plants ◽  
Foaming Agents ◽  
Soil Microbial ◽  
Sodium Lauryl Ether Sulfate ◽  
Ether Sulfate ◽  
Lauryl Ether ◽  
Main Component

AbstractThe anionic surfactant SLES (sodium lauryl ether sulfate) is an emerging contaminant, being the main component of foaming agents that are increasingly used by the tunnel construction industry. To fill the gap of knowledge about the potential SLES toxicity on plants, acute and chronic effects were assessed under controlled conditions. The acute ecotoxicological test was performed on Lepidum sativum L. (cress) and Zea mays L. (maize). Germination of both species was not affected by SLES in soil, even at concentrations (1200 mg kg−1) more than twice higher than the maximum realistic values found in contaminated debris, thus confirming the low acute SLES toxicity on terrestrial plants. The root elongation of the more sensitive species (cress) was instead reduced at the highest SLES concentration. In the chronic phytotoxicity experiment, photosynthesis of maize was downregulated, and the photosynthetic performance (PITOT) significantly reduced already under realistic exposures (360 mg kg−1), owing to the SLES ability to interfere with water and/or nutrients uptake by roots. However, such reduction was transient, likely due to the rapid biodegradation of the surfactant by the soil microbial community. Indeed, SLES amount decreased in soil more than 90% of the initial concentration in only 11 days. A significant reduction of the maximum photosynthetic capacity (Pnmax) was still evident at the end of the experiment, suggesting the persistence of negative SLES effects on plant growth and productivity. Overall results, although confirming the low phytotoxicity and high biodegradability of SLES in natural soils, highlight the importance of considering both acute and nonlethal stress effects to evaluate the environmental compatibility of soil containing SLES residues.

scholarly journals Interaction of guar gum galactomannans with the anionic surfactant sodium lauryl ether sulphate

2020 ◽  
Vol 165 ◽  
pp. 713-721
Author(s):  
Carlos H. de Seixas-Junior ◽  
Mariana M. de Carvalho ◽  
Joslaine Jacumazo ◽  
Rodolfo D. Piazza ◽  
Gabriela P. Parchen ◽  
...  
Keyword(s):  
Anionic Surfactant ◽  
Guar Gum ◽  
Lauryl Ether

Co-presence of the anionic surfactant sodium lauryl ether sulphate and the pesticide chlorpyrifos and effects on a natural soil microbial community

2020 ◽  
Vol 27 (25) ◽  
pp. 30987-30997 ◽  
Author(s):  
Tanita Pescatore ◽  
Luisa Patrolecco ◽  
Ludovica Rolando ◽  
Francesca Spataro ◽  
Jasmin Rauseo ◽  
...  
Keyword(s):  
Microbial Community ◽  
Anionic Surfactant ◽  
Soil Microbial Community ◽  
Natural Soil ◽  
Soil Microbial ◽  
Lauryl Ether

scholarly journals Bioaugmentation With a Consortium of Bacterial Sodium Lauryl Ether Sulfate-Degraders for Remediation of Contaminated Soils

2021 ◽  
Vol 12 ◽  
Author(s):  
Ludovica Rolando ◽  
Anna Barra Caracciolo ◽  
Paola Grenni ◽  
Livia Mariani ◽  
Jasmin Rauseo ◽  
...  
Keyword(s):  
Contaminated Soils ◽  
Earth Pressure ◽  
Bacterial Consortium ◽  
Pressure Balance ◽  
Soil Extracts ◽  
Foaming Agents ◽  
Sodium Lauryl Ether Sulfate ◽  
Ether Sulfate ◽  
Lauryl Ether ◽  
Boring Machines

The anionic surfactant sodium lauryl ether sulfate (SLES) is the main component of most commercial foaming agents (FAs) used in the excavation of highway and railway tunnels with Earth pressure balance-tunnel boring machines (EPB-TBMs). Several hundreds of millions of tons of spoil material, consisting of soil mixed with FAs, are produced worldwide, raising the issue of their handling and safe disposal. Reducing waste production and reusing by-products are the primary objectives of the “circular economy,” and in this context, the biodegradation of SLES becomes a key question in reclaiming excavated soils, especially at construction sites where SLES degradation on the spot is not possible because of lack of space for temporary spoil material storage. The aim of the present work was to apply a bacterial consortium (BC) of SLES degraders to spoil material excavated with an EPB-TBM and coming from a real construction site. For this purpose, the BC capability to accelerate SLES degradation was tested. Preliminary BC growth, degradation tests, and ecotoxicological evaluations were performed on a selected FA. Subsequently, a bioaugmentation experiment was conducted; and the microbial abundance, viability, and SLES concentrations in spoil material were evaluated over the experimental time (0.5, 3, 6, 24, 48, and 144 h). Moreover, the corresponding aqueous elutriates were extracted from all the soil samples and analyzed for SLES concentration and ecotoxicological evaluations with the bacterium Aliivibrio fischeri. The preliminary experiments showed the BC capability to grow under 14 different concentrations of the FA. The maximum BC growth rates and degradation efficiency (100%) were achieved with initial SLES concentrations of 125, 250, and 500 mg/L. The subsequent bioaugmentation of the spoil material with BC significantly (sixfold) improved the degradation time of SLES (DT50 1 day) compared with natural attenuation (DT50 6 days). In line with this result, neither SLES residues nor toxicity was recorded in the soil extracts showing the spoil material as a by-product promptly usable. The bioaugmentation with BC can be a very useful for cleaning spoil material produced in underground construction where its temporary storage (for SLES natural biodegradation) is not possible.

Total etch dentin bonding systems: scanning electron microscopy of the resin-dentin hybrid layer

1992 ◽  
Vol 50 (2) ◽  
pp. 1092-1093
Author(s):  
Jorge Perdigao
Keyword(s):  
Composite Resin ◽  
Mechanical Interlocking ◽  
Hybrid Layer ◽  
Agent Based ◽  
Dentin Bonding ◽  
Acid Agent ◽  
Bond Strengths ◽  
Main Component ◽  
Bonding Systems ◽  
New Generation

In 1955, Buonocore introduced the etching of enamel with phosphoric acid. Bonding to enamel was created by mechanical interlocking of resin tags with enamel prisms. Enamel is an inert tissue whose main component is hydroxyapatite (98% by weight). Conversely, dentin is a wet living tissue crossed by tubules containing cellular extensions of the dental pulp. Dentin consists of 18% of organic material, primarily collagen. Several generations of dentin bonding systems (DBS) have been studied in the last 20 years. The dentin bond strengths associated with these DBS have been constantly lower than the enamel bond strengths. Recently, a new generation of DBS has been described. They are applied in three steps: an acid agent on enamel and dentin (total etch technique), two mixed primers and a bonding agent based on a methacrylate resin. They are supposed to bond composite resin to wet dentin through dentin organic component, forming a peculiar blended structure that is part tooth and part resin: the hybrid layer.

Functional surfaces produced by foam coating

TAPPI Journal ◽  
2016 ◽  
Vol 15 (8) ◽  
pp. 515-521 ◽  
Author(s):  
EIJA KENTTÄ ◽  
HANNA KOSKELA ◽  
SARA PAUNONEN ◽  
KARITA KINNUNEN-RAUDASKOSKI ◽  
TUOMO HJELT
Keyword(s):  
Life Time ◽  
Silica Coating ◽  
Foaming Properties ◽  
Coated Paper ◽  
Paper Properties ◽  
Foaming Agent ◽  
Foaming Agents ◽  
Size Stability ◽  
Stability Measurement ◽  
Standard Paper

This paper reports experiments on silica coating formulations that are suitable for application as a thin pigment layer with foam coating technique on a paper web. To understand the foaming properties of nanosilica dispersions, the critical micelle concentration, foam half-life time, and foam bubble size stability were determined with three different foaming agents. The results indicate that the bubble stability measurement is a useful characterization method for foam coating purposes. Pilot foam coating trials were done and the effects of the chosen foaming agents were studied on the properties of the nanosilica-coated paper. The surface hydrophilicity of silica coated paper was related not only to silica pigment, but also to the chemical nature of the foaming agent. Standard paper properties were not affected by the thin silica coating.

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