44 research outputs found
Oznaczanie poziomów zawartości surfaktantów w próbkach środowiskowych. Część 3. Niejonowe związki
Non-ionic surface active agents are a diverse group of chemicals which have an uncharged polar head
and a non-polar tail. They have different properties due to amphiphilic structure of their molecules. Commercial
available non-ionic surfactants consist of the broadest spectrum of compounds in comparison with other types of
such agents. Typically, non-ionic compounds found applications in households and industry during formulation
of cleaning products, cosmetics, paints, preservative coatings, resins, textiles, pulp and paper, petroleum products
or pesticides. Their are one of the most common use class of surfactants which can be potential pollution sources
of the different compartment of environment (because of they widely application or discharging treated
wastewaters to surface water and sludge in agricultural). It is important to investigate the behavior, environmental
fate of non-ionic surfactants and their impact on living organisms (they are toxic and/or can disrupt endocrine
functions). To solve such problems should be applied appropriated analytical tools. Sample preparation step is one
of the most critical part of analytical procedures in determination of different compounds in environmental
matrices. Traditional extraction techniques (LLE - for liquid samples; SLE - for solid samples) are time and
solvent-consuming. Developments in this field result in improving isolation efficiency and decreasing solvent
consumption (eg SPE and SPME - liquid samples or PLE, SFE and MAE - solid samples). At final determination
step can be applied spectrophotometric technique, potentiometric titrametration or tensammetry (determination
total concentration of non-ionic surfactants) or chromatographic techniques coupled with appropriated detection
techniques (individual analytes). The literature data concerning the concentrations of non-ionic surfactants in the
different compartments of the environment can give general view that various ecosystems are polluted by those
compounds
Oznaczanie poziomów zawartości surfaktantów w próbkach środowiskowych. Część 2. Związki anionowe
Surface active agents (SAA) with negative charge of polar group are named as anionic compounds.
They are the main constituent of most products containing synthetic surfactants. The linear alkylbenzene
sulfonates (LAS), alkyl ethoxysulfates (AES) and alkyl sulfates (AS) are typically applied from this class of
compounds. Those surfactants are ingredients of household detergents and cleaners, laundry detergents, cosmetic
etc. Moreover they can be applied in the paper, textile and tanning industry as optical brighteners, dispersant,
wetting and suspending agents. They can be substrates in the formulation of different products like dyes,
pigments, pesticides, exchange resins, plasticizers and pharmaceuticals. Anionic surfactants after use are passed
into sewage-treatment plants, where they are partially degraded and adsorbed to sewage sludge (applied in
agriculture fields). Finally, the anionic SAA or their degradation products are discharged into surface waters and
onto bottom sediments, soils or living organisms. Therefore, it is important (widely application, bioaccumulation,
toxicity for living organisms) to investigate the environmental fate of those class of compounds in more details.
This research involves determination the concentration of anionic surfactants with use appropriated analytical
techniques in environmental samples The official methodology for determination of anionic SAA in liquid
samples is based on the ion-pair reaction of these analytes compounds with methylene blue (MB) and an
extraction with toxic solvent chloroform. During isolation step of anionic compounds from solid samples are
employed Soxhlet and ultrasonic-assisted extraction techniques with use of methanol or mixture of other organic
solvents as extraction medium. To overcome disadvantages of those traditional techniques were applied following
techniques at sample preparation step from liquid and solid matrices: solid-phase extraction (SPE) and
solid-phases microextraction (SPME); accelerated solvent extraction (ASE), microwave-assisted extraction
(MAE), supercritical fluid extraction (SFE), respectively. For estimate total concentration of anionic analytes in
extracts the spectrophotometric technique is used (as official regulation). For determination concentration of
individual analytes were applied gas (derivatization step requires) and liquid chromatography mainly with mass
spectrometry technique. The presence of anionic surface active agents was confirmed in various ecosystems
(liquid and solid environmental samples)
Organization of the highway strip repair process
The article presents the possibilities of advance development of detailed organization-technical plans for the repair of Highway Strips, which will enable their effective use, particularly during combat operations – while maintaining the required time and technical standards at the same time. The main objectives of Highway Strips were presented; their role in securing military aviation activities and historical conditions for their creation. The concept of HS (Highway Strip) was defined along with the modern principles for their construction, modernization and renovation. Based on a selected example, the principles for evaluating the technical condition of their pavement and the repair possibility assessment were presented. At the same time, typical damage to HSs and factors affecting such damage were presented. Next, the methods and technologies for repairing various types of bituminous pavement damage repairs were discussed, with particular emphasis on the methods of repairing cracks, surface damage, deep damage and asphalt renovation. A schedule for the “Wielbark” highway strip was also developed, and the necessary calculations of the repair times, as well as the resources and resources for securing these operations were made. The article is concluded with a short summary and a proposal for further work, aimed at inhibiting the destructive processes of Highway Strips in Poland