Anionic surfactants are wildly used in many industrial and household applications. Because anionic surfactants are used so widely, significant attention has focused on the removal of these contaminants from wastewater. Among various treatment techniques, biofiltration, such as trickling filter technologies, has been employed in many wastewater treatment plants (WWPTs) to remove anionic surfactants. However, current knowledge of the efficacy of trickling filter to remove anionic surfactants from wastewaters is limited. The present study characterized the performance of a high rate (i.e. roughing) trickling filter to remove anionic surfactants both at lab-scale and pilot-scale. Lab-scale tests investigated the biodegradation of anionic surfactants under controllable conditions were compared with those from previous studies by others. Pilot-scale tests investigated the efficacy of a trickling filter at removing anionic surfactants from a wastewater over an extended period of time. The data from the pilot-scale tests were used to model the performance of trickling filter at removing anionic surfactants from the wastewater, using first order and modified Velz models. The lab-scale tests indicated that high molecular weight anionic surfactants degrade faster than the low molecular weight surfactants. The biodegradation rates observed in the present study were similar to those from pervious studies by others. The pilot-scale tests indicated that roughing trickling filter could remove 11% to 29% of anionic surfactants and 4% to 22% of COD from the wastewater. Higher molecular weight anionic surfactants were more degradable. The experimental data could be accurately modeled using the modified Velz model (R² value more than 0.9). The degradation rates of modified Velz model for total anionic surfactants, high molecular weight anionic surfactants and COD were 0.053±0.0057, 0.088±0.0048 and 0.119±0.0111 (mIs)0.5 respectively. The pilot-scale test results indicated that a high rate (i.e., roughing) trickling filter was not capable of effectively removing anionic surfactants in the primary effluent at Lions Gate WWTP because a relatively large trickling filter area would be required to achieve the required surfactant removal efficiency. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Les nuages sont essentiels dans le cycle de l'eau et dans le budget climatique mais certains aspects de leur formation sont encore incompris. La théorie de Köhler prédit que les surfactants devraient favoriser l'activation des particules en goutte de nuage alors que les modèles actuels les considèrent comme négligeables. Au début de ce travail de thèse, quelques études commençaient à démontrer le contraire mais des preuves du rôle de ces composés dans l'atmosphère étaient encore manquantes, d'où l'objectif de ce travail de thèse. Le développement d'une méthode pour déterminer la concentration en surfactants dans les aérosols a conduit aux premières courbes de tension de surface de surfactants atmosphériques dans des aérosols PM2.5 côtiers (Suède), et à l'identification du ratio C/CMC comme paramètre clé contrôlant l'efficacité des aérosols à former des nuages. Une seconde étude a révélé des corrélations fortes entre la présence de nuages et les propriétés intrinsèques des surfactants dans des aérosols PM1 boréaux (Finlande), démontrant pour la première fois le rôle des surfactants dans la formation des gouttes de nuage à partir d'observations directes dans l'atmosphère. Les résultats prédisent un nombre de noyaux de condensation en moyenne quatre fois plus important que lorsque les effets des surfactants étaient négligés, montrant l‘importance d'inclure l'effet des surfactants dans les modèles prédictifs. Cette importance a été confirmée en laboratoire par des expériences sur des gouttes individuelles microniques par l'augmentation de leur taille en présence de surfactants. Enfin, les observations à partir des différentes études indiquent une origine biologique des surfactants dans les aérosols atmosphériques / Clouds are essential components of the Earth’s hydrological system and climate but some aspects of their formation are still not completely understood. In particular, although Köhler theory predicts that surfactants should enhance cloud droplet activation, current models consider this role negligible. At the time of this PhD work, a few studies had started to demonstrate the contrary but atmospheric evidence for the role of these compounds was still missing and very little was known about their atmospheric concentrations, sources, and mechanism of action. The objective of this PhD work was to investigate these aspects. A method was developed to quantify surfactant concentrations in aerosols. Its application led to the first absolute atmospheric surfactants’ surface tension curves, in coastal PM2.5 aerosols in Sweden, and to the identification of the ratio C/CMC as the key parameter controlling the cloud-forming efficiency of aerosols. A second study revealed strong correlations between cloud occurrence and intrinsic surfactant properties in boreal PM1 aerosols in Finland, demonstrating for the first time the role of surfactants in cloud formation from direct atmospheric observations. The results predicted Cloud Condensation Nuclei numbers four times larger on average than when neglecting surfactant effects, showing the importance of including surfactant effects in cloud predictions models. The role of surfactants inferred from macroscopic measurements was confirmed by laboratory experiments on individual micron-sized droplets showing an increase of droplet growth in the presence of surfactants. Finally, observations from the different field studies indicated a biological origin for the surfactants present in atmospheric aerosols

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Orientador: Marcos Akira D'Ávila / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-28T14:33:17Z (GMT). No. of bitstreams: 1 Segundo_JoaodeDeusPereiradeMoraes_M.pdf: 7452357 bytes, checksum: ad3c155a2b3b137e6642655d1af1ef0f (MD5) Previous issue date: 2015 / Resumo: A eletrofiação é uma das principais técnicas para produzir fibras poliméricas ultrafinas na escala nano e submicrométrica. A poli ('épsilon'-caprolactona) (PCL) é um polímero sintético biodegradável bastante utilizado na área médica. Fibras de PCL obtidas por eletrofiação formam mantas porosas propícias para aplicações biomédicas como na engenharia tecidual. Em algumas aplicações as fibras alinhadas de PCL são de interesse, pois conferem melhorias em determinadas propriedades quando comparadas com fibras aleatórias. A PCL é considerada um polímero moderadamente hidrofóbico e a eletrofiação aumenta a hidrofobicidade das mantas. Os surfactantes têm a capacidade de modificar a superfície das fibras poliméricas aumentando a sua molhabilidade. Este trabalho versa sobre a influência da adição de surfactantes catiônico (CTAB), aniônico (SDS) e não-iônico (Triton X-100) na morfologia e no alto alinhamento de fibras de PCL obtidas por eletrofiação com coletor rotativo. Preparou-se solução de PCL contendo clorofórmio e acetona como solventes. As concentrações em massa de surfactantes utilizadas foram: 0,05; 0,1; 0,5; 1,0 e 1,5 wt%. As soluções foram caracterizadas através de medições de tensão superficial, condutividade elétrica e reologia. As morfologias das fibras foram analisadas com Microscópio Eletrônico de Varredura (MEV) juntamente com o software imageJ e o plugin OrientationJ. As fibras foram caracterizadas quanto às propriedades térmicas (DSC), análise química (FTIR) e molhabilidade (ângulo de contato). Através dos resultados obtidos, observou-se que a condutividade elétrica das soluções foi aumentada de acordo com o tipo de surfactante. A reologia foi alterada com os tipos e as concentrações, enquanto a tensão superficial não apresentou mudança significativa com a adição dos surfactantes. Os surfactantes CTAB e SDS alteraram o alinhamento das fibras de PCL e, dependendo da concentração, melhoraram a uniformidade dos diâmetros das fibras. Os surfactantes foram capazes de melhorar a molhabilidade das mantas, enquanto as propriedades térmicas foram mantidas / Abstract: The electrospinning is one of the main techniques to produce ultrafine polymeric fibers in the nano and submicron scale. Poly ('épsilon'-caprolactone) (PCL) is a biodegradable synthetic polymer widely used in the medical field. Electrospun PCL fibers form porous mats favorable for biomedical applications such as in tissue engineering. PCL aligned fibers are of interest since it expand the applications of these fibers and confer improvements in certain properties when compared with random fibers. PCL considered a moderately hydrophobic polymer and the electrospinning increases the hydrophobicity of the mats. Surfactants have the ability to modify the surface of polymeric fibers increasing its wettability. This work is concerned with the study of the effects of adding cationic (CTAB), anionic (SDS) and nonionic (Triton X-100) surfactants in the morphology and alignment PCL fibers obtained by electrospinning used a rotating collector. Poly ('épsilon'-caprolactone) (PCL) solutions with chloroform and acetone as solvent were prepared and different concentrations of surfactants were used: 0.05; 0.1; 0.5; 1.0; and 1,5 wt% in mass. Solutions characterized by measurements of surface tension, electric conductivity and viscosity. The morphology of the fibers analyzed by Scanning Electron Microscopy (SEM) together with the ImageJ software and OrientationJ plugin. The fibers characterized by differential scanning calorimetry (DSC), infrared spectroscopy (FTIR) and wettability (contact angle). Through the results obtained, the electrical conductivity of the solutions increased according to the type of surfactant. The rheology changed with the types and concentrations, while the surface tension did not change significantly with the addition of surfactants. The presence of surfactants CTAB and SDS influence the alignment of the PCL fibers, and depending on the concentration, improve the uniformity of fiber diameters. The surfactants were able to improve the wettability of mats, while the thermal properties maintained / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

archives@tulane.edu / 1 / Olakunle Francis Ojo

This thesis studies the lifetime of the PE pipes materials. For determination of the lifetime one of the standard accelerated tests (Full Notch Creep test) was used. The main goal is to assess the influence of different types of detergents on lifetime. Specimen preparation and measurement procedure corresponding to the relevant ISO standard (ISO 16770: Plastics - Determination of environmental stress cracking (ESC) of Polyethylene (PE) - Full Notch Creep Test (FNCT)). Air, distilled water, Arkopal N 090 and Arkopal N 110 were used as detergents.

The dynamic development of industry and the constant production of new substances affecting the environment is currently one of the priorities of the interests of the human population. This thesis is focused on the ecotoxicological evaluation of selected extinguishing agent which are applied in case of fire. They must effectively extinguish fire because a live protection and material resources in any case very important, but Theky should be also environmentally friendly. In this work were tested surfactants, which are the main component of foaming extinguishing agent with the following commercial names: STAMEX F-15, F-15 EXPYROL, MOUSOL APS F-15, FINIFLAM F-15 and PYROCOOL B. Since surfactants have a negative impact mainly on aquatic ecosystem assessment were mainly used ecotoxicity tests using aquatic organisms. Test organisms were aquatic crustacean Daphnia magna and Thamnocephalus platyurus aquatic dicotyledons plant Lemna minor and terrestrial monocotyledons plant Sinapis alba. Based on the results of the tests were values of LC50, EC50 and IC50 for the tested substances determined and their ecotoxicity compared.

The surfactants have become a common part of everyday human life. For their properties they are used as aditive components of foam extinguishers used in large quantities for area fires fighting. This thesis deals with the ecotoxicological evaluation of commercially available fire-fighting agents Sthamex F 15, Moussol APS F 15, Finiflam F 15, Expyrol F 15 and Pyrocool B, which are made on the basis of surfactants. In the framework of this thesis the ecotoxicological effects of selected extinquishing agents were assessed through aquatic ecotoxicity tests with organisms Thamnocephalus platyurus, Daphnia magna, dicotyledonous plants Lemna minor and white mustard seeds Sinapis alba. Via tests of contaminated soils leachate the effect of soil sorption complex on the ecotoxicological effects was evaluated. Extinguishing agents were further considered in terms of acute ecotoxicity for soil organism via ecotoxicological tests in the contact arrangement using earthworm Eisenia fetida and lettuce seeds Lactuca sativa. To assess the influence of biodegradation under different conditions on ecotoxicological effects the seed germination tests of L. sativa were conducted with hindsight. According to the results of the individual tests this work discuss the need for further evaluation of the negative influence of selected agents, while paying special attention to legislative measures.

Surfactant-mediated intercalation of aliphatic fatty acids into a commercial,layered double hydroxide (LDH) with the approximate composition of [Mg0.689Al0.311(OH2)] (CO3)0.1569nH2O was explored. The reactions were conducted at elevated temperatures with the LDH powder suspended in a fatty acid oil-water emulsion. The acidic fatty acid, e.g. stearic acid, reacts with the basic carbonate anions from LDH-CO3. In the process, CO2 is released as a gas and the fatty acids are intercalated as a bilayer. A high concentration of anionic or non-ionic surfactants, i.e. sodium dodecylsulphate or Tween 60, facilitates the intercalation process by emulsifying the molten fatty acids and dispersing the LDH particles. The presence of carboxylate anions in the interlayer region was confirmed by the carboxylate absorption peaks observed in the region 1700–1000 cm-1 on Fouriertransform infrared spectroscopy (FT-IR). Several bands were observed, i.e. ionised and non-ionised. An increase in the d-spacing of the d003 plane of the brucite-like LDH layers was observed on X-ray diffraction (XRD) analysis of all the LDH intercalates. The d-spacing increased linearly with the length of the carboxylic acid chain. Sharp reflection peaks were obtained on XRD, showing the high crystallinity of the LDH intercalates. The thermal decomposition of these materials was explored on thermogravimetric or differential thermogravimetric analysis (TGA/DTA) and temperature-scanned XRD. The mole ratio of Mg to Al was obtained by XRF and the morphology by scanning electron microscopy (SEM). The present method works well with long-chain aliphatic fatty acids at temperatures above or at the melting point of the desired acid. Temperature proved to be the most important parameter to control during the preparation process, i.e. at low temperatures incomplete reactions were obtained. The method is convenient, economical and environmentally friendly. It employs the readily available carbonate form of LDH as a starting reagent, water is used as medium rather than organic solvents, there are no high-temperature calcinations, and an inert atmosphere is not required. Copyright / Dissertation (MSc)--University of Pretoria, 2008. / Chemistry / unrestricted

The influence of a chiral surfactant and a polymer-supported chiral additive on reduction of ketones using sodium borohydride will be described. Initial preparations involved methylation of (S)-leucinol to give (2S)-N,N-dimethyl-2-amino-4-methyl-1-pentanol (1) (67%). The chiral surfactant (2) was synthesized by reacting (1) with bromohexadecane (71%). The functionalized styrene for the polymer-supported chiral additive (5) was synthesized by reacting (1) with 4-vinylbenzyl chloride. Polymerization was carried out with 10% of the functionalized monomer (4), 5% cross-linking agent divinylbenzene, and 85% styrene with AIBN as the initiator. The activity of the chiral surfactant and polymeric additive were examined by using them as additives in a standard reduction of 2-pentanone with sodium borohydride to yield (R)- and (S)-2-pentanol (3) (20%). The resulting alcohol was analyzed by polarimetry (ee 9.5%) and also esterified with (2S)-methylbutyric acid prior to characterization by NMR. 13C NMR indicated an enantiomeric excess of 5.2% when the chiral surfactant was used, and 7% when the polymeric additive was used.