Дисертації з теми "Adsorption of organic pollutants"

Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Adsorption of organic pollutants.

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Ознайомтеся з топ-50 дисертацій для дослідження на тему "Adsorption of organic pollutants".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.

1

Subramani, Arun. "ADSORPTION OF ORGANIC POLLUTANTS ONTO NATURAL ADSORBENTS." MSSTATE, 2002. http://sun.library.msstate.edu/ETD-db/theses/available/etd-08102002-210619/.

Повний текст джерела
Анотація:
In this research, the adsorptive capacities of kenaf, peat moss, hay, and peanut hulls were evaluated for the removal of TNT and 2,4-DCP from aqueous solutions. Adsorbent loading capacities determined by batch studies were verified by continuous column experiments. It was found that the adsorption capacity of the candidate adsorbents were significantly lower than granular activated carbon (GAC). The impact of surface modification techniques, such as surface oxidation, were evaluated to study the effect on adsorption capacity. At lower equilibrium concentrations of the adsorbate (less than 10 ppb), surface oxidation by ozone showed an increase in the adsorption capacity. The same trend was not observed with peroxone and ultrasound pretreatment. The adsorbent requirement for treating water contaminated with TNT and 2,4-DCP were calculated based on the adsorptive capacity of the adsorbents. Though the adsorbent requirements for the candidate adsorbents were considerably higher than granular activated carbon, the adsorbent requirement costs for most of the candidate adsorbents tested were competitive when compared to GAC costs.
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Ding, Chunli. "Organic cation-modified iron oxide-coated sand for adsorption of natural organic matter /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202009%20DING.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

JASPER, ANTHONY JOHN. "Impact of Nanoparticles and Natural Organic Matter on the Removal of Organic Pollutants by Activated Carbon Adsorption." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1218743967.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Hunter, Paige Holt. "Control of Volatile Organic Compound (VOC) Air Pollutants." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/38614.

Повний текст джерела
Анотація:
A variety of methods exist to remove volatile organic compound (VOC) air pollutants from contaminated gas streams. As regulatory and public opinion pressures increase, companies are searching for more effective methods to control these emissions. This document is intended as a guide to help determine if existing systems are adequate and to provide additional information to improve the efficiency of the systems. It explores conventional methods of controlling VOC emissions, as well as innovative technologies including membrane separation, plasma destruction, and ozone catalytic oxidation. The conventional technologies covered include condensation, adsorption, absorption (or scrubbing), thermal incineration, flaring, catalytic incineration, and biofiltration. Each chapter includes a description of the technology, a discussion of the types of systems available, notes on the design of the system, economic estimates, an explanation of potential problems, and a list of considerations for installation and maintenance concerns. The final chapter is dedicated to the preparation and characterization of metal catalysts which were developed to improve the reaction rate of VOCs using ozone as an oxidant.
Ph. D.
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Lladó, Valero Jordi. "Adsorption of organic and emerging pollutants on carbon materials in aqueous media : environmental implications." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/387438.

Повний текст джерела
Анотація:
In the last two decades an increasing presence of organic substances such drugs, pesticides, etc. has been detected in water which may affect the health of the organisms and the environment. Some of these contaminants remain in the water after the usual treatment in sewage plants. This fact makes evident the need of introduction of the tertiary treatments that allow the complete elimination of these substances. This Doctoral Thesis researches for the elimination of different organic and emerging compounds present in water by means of the adsorption with new activated carbons. In particular, new carbon materials from different wastes, coal, synthetic materials, which have been produced and characterized, allow the adsorption of the organic compounds widely used in society. Different characteristics of the adsorbents (chemical composition, functional groups, texture, etc.) and of adsorbates (dimensions, hydrophobicity, pKa, functional groups, etc.) that influence on the adsorption process have been studied. Moreover, in this work, an analysis and kinetic model have been proposed. The analytic model allow, by chemometrics, enhancing the quantification of two or more organic compounds in solution by spectroscopy UV-vis. The kinetic model proposed provides a better comprehension and interpretation, as a better prediction of the different parameters on the adsorption process. In this sense, the following Thesis presents five works which have allowed a better comprehension of the adsorption process by means carbon materials from different origin. The first work, “highly microporous activated carbons from biocollagenic wastes as adsorbents or aromatic pollutants in water originating from industrial activities”, about the texture and chemical composition of activated carbon from biocollagenic wastes which have been studied in order to observe how these parameters affect on the adsorption of aromatic monosubstitued compounds. Moreover, different variables as temperature and activating agent are studied in the process of manufacture activated carbons. The second work, “Removal of pharmaceutical and Iodinated Contrast Media (ICM) compounds on carbon xerogels and activated carbons. NOM and textural properties influences”, shows the important role of pore size distribution in activated carbon which plays on the adsorption of different pharmaceuticals (salicylic acid, paracetamol, diclifenac, etc.) and iodinated contrast media (iohexol, iodixanol, iomeprol, etc) of different size. The influence of natural organic matter (NOM) in water is also studied in the adsorption of the all pollutants. The adsorption of paracetamol, phenol and salicylicacid in different coal-based activated carbon is showed in the contain of the work “Removal of pharmaceutical pollutants in water using coal-based activated carbons”. In this work, the chemical characteristics on the surface of activated carbons are studied in order to observe the influence in the adsorption of different organic compounds; and also the influence of the pH water. The results showed an increase of adsorption of salicylates due to the presence of sulphur on the surface of the adsorbent. The fourth work; “Multicomponent adsorption on coal-based activated carbons on aqueous media: new cross-correlation analysis method”, as a continuation of the previous work, shows a new chemometric technique that allows to analysis the binary and ternary solutions correctly by UV-vis spectroscopy. Moreover, the competitive effect between two or three molecules is studied on the adsorption process. In the last work, “Role of activated carbon properties in atrazine and paracetamol adsorption equilibrium and kinetics”, a new kinetic model is proposed for the adsorption of paracetamol and atrazine using activated carbon from sewage sludge and two, commercial, activated carbons.
En les darreres dues dècades s’ha detectat un increment de la presència de substàncies orgàniques com els fàrmacs, els pesticides,... en l’aigua que poden afectar la salut dels éssers vius i del medi ambient. Algun d'aquests contaminants romanen en les aigües després d’haver passat pels tractaments habituals en les plantes depuradores de tractament. Aquest fet fa evident la necessitat de la implantació de tractament terciaris que permetin la seva completa eliminació. La present Tesi doctoral estudia l’eliminació de diferents compostos orgànics i emergents presents en aigua mitjançant la tecnologia d’adsorció amb nous carbons activats. Concretament, s'han produït i caracteritzat nous materials carbonosos procedents de residus, carbó mineral, materials sintètics, ... que permeten adsorbir diferents compostos orgànics d'ampli us en la nostra societat. S'han estudiat les característiques dels adsorbents (composició química, grups funcionals, porositat) i dels adsorbats (dimensions, hidrofobicitat, pKa, grups funcionals...) que influeixen en el procés d’adsorció. A més a més, en aquest treball, s'han proposat dos nous models, un d'anàlisi i un altre cinètic. El model analític permet, mitjançant la quimiometria, millorar la quantificació de dos o més compostos orgànics presents en una mescla per espectroscòpia UV-vis. El model cinètic proposat proporciona una millor comprensió i interpretació, així com una millor predicció dels diferents paràmetres del procés d'adsorció. En aquest sentit, en la següent Tesi es presenten cinc treballs que han permès una millor comprensió del procés d’adsorció mitjançant materials carbonosos de diferents procedències. En el primer treball, “Highly microporous activated carbons from biocollagenic wastes as adsorbents or aromatic pollutants in water originating from industrial activities”, s'ha estudiat com afecta la textura i la composició química de carbons activats procedents de residus de pells en l'adsorció de compostos aromàtics monosubtituits. A més a més s’estudia com afecten diferents variables com temperatura i agent activant en el procés de fabricació dels carbons activats. El segon treball, “Removal of pharmaceutical and Iodinated Contrast Media (ICM) compounds on carbon xerogels and activated carbons. NOM and textural properties influences”, posa de manifest el rellevant paper que juga la distribució de porus d’un carbó activat en l’adsorció de diferents fàrmacs (àcid salicílic, paracetamol, diclofenac, ...) i agents de contrast (iohexol, iodixanol, iomeprol,...) de diferent mida. També, s’ha estudiat la influència de la matèria orgànica present en l’aigua en l’adsorció de tots els contaminants. L’estudi de l’adsorció de paracetamol, fenol i àcid salicílic en diferents carbons activats procedents de carbó mineral es reflexa en el treball “Removal of pharmaceutical pollutants im water using coal-based activated carbons”. En aquest treball s'estudia la influència de les característiques químiques de la superfície dels carbons activats en l’adsorció dels diferents compostos orgànics, així com la influència del pH de les aigües. Els resultats van mostrar un augment de l’adsorció de salicilats degut a la presència de sofre en l'adsorbent. El quart treball, “Multicomponent adsorption on coal-based activated carbons on aqueous media: new cross-correlation analysis method”, és una continuació del treball anterior. En aquest cas, es presenta un nova tècnica quimiomètrica que permet analitzar correctament mescles binàries i ternàries per espectroscòpia UV-vis. A més s’estudia l’efecte competitiu entre dues o tres molècules en el procés d'adsorció. El cinquè i últim treball, "Role of activated carbon properties in atrazine and paracetamol adsorption equilibrium and kinetics", planteja un nou model cinètic per a l’adsorció de paracetamol i atrazina mitjançant carbó activat procedent de fangs de depuradora i dos carbons comercials.
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Fei, Yingheng, and 费颖恒. "Adsorption of emerging environmental pollutants by marine sediment in relation to sediment organic diagensis." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B48329782.

Повний текст джерела
Анотація:
Ever-growing discharges of various emerging chemical contaminants are imposing a great threat of pollution to the coastal environment. Adsorption by sediment plays an essential role in the transport and fate of pollutants in the aquatic system. The sorption of emerging contaminants onto sediment is believed to be largely dependent on the sediment organic matter (SOM). In the present study, laboratory experiments were carried out on the changes of the adsorption behavior of sediment during the sediment aging and diagenesis process. A few EDCs and antibiotics were selected as the model emerging compounds for the adsorption tests. The results demonstrated that both the quantity and the quality of the SOM affected the adsorption of the model pollutants, such as 17α-ethinyl estradiol (EE2) and bisphenol A (BPA), onto the marine sediment collected from Victoria Harbour, Hong Kong. The adsorption isotherms can be well described by the linear partition model. Natural and artificial sediment with a high SOM content was incubated for 4-6 months to simulate the natural diagenesis process. The most rapid degradation of labile SOM occurred in the first 1 month or so and afterward, SOM reduction became slower. Microbial activity played an important role in SOM degradation and transformation. A rapid initial bacterial growth was observed in the sediment, followed by a slow endogenous decay. The dynamics of biomass growth and decay first transformed the labile SOM into biomass and microbial byproducts. After the exhaust of readily biodegradable SOM, the biomass decay produced humic-like substances, resulting in more refractory and condensed SOM residues in the sediment. More importantly, the degradation and transformation of SOM displayed a profound impact on the adsorption behavior of the sediment. For the selected EDCs and antibiotics, including BPA, EE2, nonylphenol (NP), phenanthrene (PHE) and tetracyclines (TCs), the adsorption capacity indicated by the partition coefficient, Kd, decreased at the beginning of SOM diagenesis. The Kd values for different chemicals recovered lately to different extents as the result of the SOM condensation and humification. All of the organic matter normalized partition coefficients, KOM, of the concerned pollutants increased considerably in the late phase of SOM diagenesis. Based on the experimental results, a general conceptual model was established to describe SOM diagenesis and its impact on chemical adsorption by the sediment. According to the model prediction, the SOM profile would become more dominated by the condensed and refractory fractions during sediment diagenesis with an increasing affinity and partition capacity for organic contaminants. Moreover, the release of adsorbed contaminants from marine sediment in the simulated digestive fluids was investigated. In general, the presence of gastric pepsin and bile salts helped the desorption of hydrophobic pollutants from the sediment into the digestive solutions. The influence of the SOM diagenetic status on chemical desorption from the sediment varied between EDCs of different chemical properties. It is apparent that aged sediment could bring more emerging pollutants into the digestive system of receiving organisms, imposing a potential risk to human health through the food chain.
published_or_final_version
Civil Engineering
Doctoral
Doctor of Philosophy
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Tasca, Andrea Luca. "Novel amorphous silica and silica xerogels for the adsorption of organic pollutants from water." Thesis, University of Strathclyde, 2017. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=28804.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Guan, Xiaohong. "Adsorption of phosphates and organic acids on aluminum hydroxide in aquatic environment : mechanisms and interactions /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202005%20GUAN.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Li, Chi-Wang. "Characterizing the properties and reactions of natural organic matter by UV spectroscopy : adsorption of NOM and formation of disinfection by-products /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/10150.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Odem, Wilbert Irwin. "COMPETITIVE ADSORPTION OF VOLATILE ORGANIC COMPOUNDS ONTO NATURAL AND SYNTHETIC ADSORBENTS (TRICHLOROETHYLENE, 1,4-DICHLOROBENZENE, TETRACHLOROETHYLENE, CARBON TETRACHLORIDE, PREDICTIVE MODELS)." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275458.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
11

GAMAGE, M. G. D. S. "Reduction of organic micro-pollutants in sewage water - a structure-adsorption relationship study and detailed characterization of natural adsorbent." Thesis, Umeå universitet, Kemiska institutionen, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-130409.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
12

Navarro, Amador Ricardo. "Synthesis and characterization of metal organic frameworks for energy and environmental applications." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT174.

Повний текст джерела
Анотація:
La pollution de l'environnement, sa remédiation et l'obtention de sources d'énergie plus propres et plus efficaces sont des problématiques difficiles auxquels les humains sont confrontés. Parmi les nombreux matériaux développés par les scientifiques, les polymères de coordination cristallins type MOFs sont de plus en plus développés dans plusieurs domaines, du fait de la facilité et la versatilité de leur synthèse. La recherche sur ces matériaux est récente, mais les possibilités qu’offrent ces matériaux pour différentes applications sont énormes.C'est dans ce cadre que nous avons travaillé sur la conception et la synthèse de différents MOF pour la récupération, le recyclage et/ou la dégradation de certains polluants. En utilisant différentes approches de synthèse, nous avons obtenu des matériaux efficaces pour les diffèrent applications ciblées de ces matériaux. Nous pensons que les MOF ont le potentiel pour solutionner certains problèmes cruciaux comme la décontamination de l'environnement
The pollution of the environment, its remediation and to obtain a cleaner and more efficient energy sources are some of the most challenging topics that humans are now facing. Among the several materials that scientists have developed, Metal Organic Frameworks (MOFs) are gaining a lot of attention on several fields due to the easiness and the versatility in which these materials can be designed, synthesized and used. Even when research on these materials is still young, the possibilities that they offer are enormous.It is on this frame that our work group has worked on the design and the synthesis of different MOFs for the recovery, the recycling and/or the degradation of some pollutants of interest. By using different synthesis approaches we have tested the versatility in the synthesis and the possible applications of these materials. We believe that MOFs hold the potential to solve some crucial issues in the recovery of the environment
Стилі APA, Harvard, Vancouver, ISO та ін.
13

Imwer, Serge Mapan. "Adsorption of perfluorinated water contaminants on Agave sisalana activated carbon fibre." Thesis, Cape Peninsula University of Technology, 2014. http://hdl.handle.net/20.500.11838/867.

Повний текст джерела
Анотація:
Thesis submitted in fulfilment of the requirements for the degree Magister Technologiae: Chemical Engineering in the Faculty of Engineering at the Cape Peninsula University of Technology 2014
An awareness campaign on the harmful effects of Perfluorinated compounds (PFCs), especially Perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonate (PFOS) has been conducted to inform the general public about the impact of these organic compounds on hu-mans and biota. These compounds have been shown to be potential carcinogens, as indi-cated by the United States Environmental Protection Agency (USEPA) and the Organization for Economic Co-operation and Development . A major concern about these chemicals is that they have been widely used in consumer products and have been detected in food and drinking water. They have been determined to be resistant to biological degradation, owing to their unique chemical and physical properties (fluorine atoms that have substituted hydrogen atoms in their chemical structure). Owing to their characteristics of being highly soluble in water, they cannot be removed from water using ordinary purification processes. Studies have been conducted to evaluate the removal of PFOA and PFOS from water using different methods. Among these methods, it has been proved that adsorption is a suitable method with the best adsorbent identified as activated carbon (AC). AC can be found in many forms, including as a fibre. The use of AC for the removal of PCFs can be augmented with sonica-tion and electro-chemical methods for rapid absorption of these compounds. The aim of this study was to remove these contaminants using a microporous AC fibre (ACF) made from an indigenous plant, Agave sisalana, which is widely available across sub-Saharan Africa, by using electro-physico-chemical methods. ACF has the following advantages when compared with granulated and/or powdered AC: it has a slightly larger reactive surface area; small quantities can be used; it is easily handled; it retains its shape under stress, thus does not require additional filtration to remove particulate residue; and can be regenerated easily. The manufacturing process of the ACF was done in several steps: 1) harvesting of the A. sisalana leaves, stripping them to obtain wet fibre by scrapping using traditional meth-ods, 2) chemical activation using NaOH, KOH, ZnCl2 and H3PO4, employing a spraying method instead of soaking, which was followed by drying, and 3) carbonisation in a furnace at the required temperature. The use of activation reagents involved the determination of an appropriate concentration, with optimum concentrations determined as 0.54M, 0.625M, 1.59M and 0.73M for NaOH, KOH, ZnCl2 and H3PO4, respectively. Apart from the fibre acti-vation, temperature and activation time were also important parameters that were optimised. A response surface methodology was used to design a set of experiments that provided the optimum temperature and activation time. From the input variables, the Expert design soft- ware generated experimental runs (n = 13) for each fibre activation reagent used with a tem-perature range of 450°C to 933°C being assessed for carbonisation time of between 17 to 208 minutes. ACF activated with KOH (0.54 M) and characterised by micropores with the highest surface area achieved being 1285.8 m2/g in comparison with Granular activated car-bon (Ounas et al., 2009) with an average surface area range of 1000 to 1100 m2/g. This sur-face area was measured using Dubinin-Astakhov isotherm with CO2 at 273 K. The physical characteristics of the ACF were analysed using a Scanning Electron Microscope to ascertain the integrity of the fibres. PFOA and PFOS were analysed using a solid phase extraction (SPE) method fol-lowed by analysis using a liquid chromatography/tandem mass spectrometer (SPE-LC/MS/MS). The water sample volume used for extraction was 60 mL. The instrument used was an HPLC - Ultimate 3000 Dionex HPLC system and MS model - Amazon SL Ion Trap, with the following MS/MS operational conditions and ion mode: MS Interface → ESI; dry temp → 350C; nebulising pressure → 60 psi; dry gas flow → 10 L/min; ionisation mode → negative; capillary voltage → +4500V; end plate offset → −500V, while the separation col-umn was a Waters Sunfire C18, 5 μm, 4.6 × 150 mm column (supplier: Waters, Dublin, Ire-land), with an operational temperature of 30C. Initially, adsorption studies (n = 48) using sonication (20 kHz) in batch systems indi-cated efficient removal of PFOA and PFOS within 120 min, with numerous samples (n = 14) achieving complete removal for both PFOA and PFOS. The minimum removal rates ob-served were 65.55% for PFOA and 95.92% for PFOS. From the ACF samples in which high-est removal rates were achieved, a number (n = 3) of the ACF samples were selected for surface characterisation. Based on the sonication in the previous experiments, an electro-physico-chemical adsorption regime was designed, to facilitate the rapid adsorption of PFOS and PFOA from contaminated drinking water in an electrolytic cell. In these experiments, si-multaneous sonication and electrolysis were used. A comparison was made between ACF produced in this study and the commercial activated carbon. The result revealed that adsorp-tion of PFOA and PFOS on ACF was a monolayer adsorption type phenomenon and had the best fit using a Freundlich isotherm compared with the Langmuir isotherm. Adsorption of PFOA and PFOS on the commercial AC presented a multilayer adsorption type of isotherm fit with the Langmuir isotherm having the best fit compared with the Freundlich isotherm.
Стилі APA, Harvard, Vancouver, ISO та ін.
14

Shukla, Pradeep. "Combined adsorption and oxidation technique for waste water treatment: potential application in permeable reactive barrier." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/212.

Повний текст джерела
Анотація:
This dissertation explores a combined adsorption and advanced oxidation technology for trapping and destruction of organic pollutants in waste water. The adsorbed/immobilized pollutant onto the surface of metal supported catalyst is oxidized via advanced oxidation technology. The advanced oxidation process is carried out using Co[superscript]2+/KHSO[subscript]5 (Cobalt/peroxymonosulphate) reagent to generate highly active sulphate radical (SO[subscript]4*), which can readily attack and oxidize the organic pollutants in waste water. The reaction mechanism of Co[superscript]2+/KHSO[subscript]5 reagent follows similarly to the Fenton reagent (Fe[superscript]2+/H[subscript]2O[subscript]2) which is used to generate hydroxyl radical (OH*). Co[superscript]2+/KHSO[subscript]5 reagent has been successfully utilized for bleaching applications and oxidation of organic contaminants. Compared to hydroxyl radical, the sulphate radical is highly potent to oxidize contaminants even at basic pH. However the biggest disadvantage of using Co[superscript]2+/KHSO[subscript]5 reagent is the dissolution of Co[superscript]2+ ion into the water which poses a severe environmental hazard. In the current study, cobalt ion is incorporated into supporting media and utilized for advanced oxidation.Very few studies have so far explored the heterogeneous oxidation technology based on Co[superscript]2+/KHSO[subscript]5 for the treatment of organic contaminants in water. With this research focus, various support media have been utilized to load cobalt ions, which included Zeolite A, Zeolite X, ZSM-5, SBA-15, Silica and Activated Carbon. Cobalt metal was incorporated into commercial Zeolites by ion exchange technique whereas in-situ cobalt loading was carried out during the synthesis of SBA-15. Cobalt loading was done into Silica and Activated Carbon by conventional impregnation technique. The choice of cobalt loading technique inherently determines the oxidation state of cobalt species loaded into the sample which in turn determines the oxidation efficiency. Furthermore, the choice of cobalt precursor significantly affects the metal-support bonding which has been investigated by loading on silica support with different types of cobalt precursor such as cobalt chloride, cobalt acetate and cobalt nitrate. Many of these supports such as Zeolite ZSM-5 and Activated Carbon have never been tested before for cobalt loading and oxidation via sulphate based oxidant and demonstrate efficient oxidation of phenolic pollutants.The investigation of organic oxidation using sulphate based oxidants was further extended into photocatalytic reactions. Photo degradation was carried out using artificial solar light and germicidal UV radiation in the presence of ZnO and oxidants such as peroxymonosulphate, peroxidisulphate and hydrogen peroxide. The comparison of photochemical and photocatalytic oxidation was carried out and their synergy of combination was explored.The thesis provides a thorough exploration of heterogeneous oxidation via sulphate based oxidant for the treatment of organic pollutants. The supported catalysts investigated here can be further improved and utilized as a PRB media for groundwater remediation. A final chapter discusses about the mathematical modeling of a column test to mimic a lab scale PRB in order to investigate the process parameters affecting the PRB design. The column modeling also directs towards a development of a novel “Reactive Adsorber” for the treatment of industrial waste by combined adsorption and oxidation.
Стилі APA, Harvard, Vancouver, ISO та ін.
15

Pirilä, M. (Minna). "Adsorption and photocatalysis in water treatment:active, abundant and inexpensive materials and methods." Doctoral thesis, Oulun yliopisto, 2015. http://urn.fi/urn:isbn:9789526207629.

Повний текст джерела
Анотація:
Abstract Water contamination is a global problem and the growing utilization of limited water resources creates a need for efficient purification methods. Industrial effluents are polluting the natural waters, e.g. uncontrolled mining activities in developing countries have created numerous environmental hazards and different types of pollutants. This study focuses on novel adsorbents and photocatalytic materials in order to reach the aim of more efficient and affordable water treatment. This thesis aimed at making active, efficient, and viable adsorbents out of waste materials, as well as using photocatalysis in water treatment for organic pollutants originating from different types of industries. Local Peruvian agro-waste was used as a precursor for activated carbon that was used in adsorption studies for single (As(V) and methylene blue, MB), and multicomponent mixtures (As(V)/Pb/Cd), and real polluted river water. An industrial intermediate product, hydrous TiO2, was used for As(III)/As(V) removal. Photocatalytic materials included a commercial photoactive TiO2 (P25), and tailor-made TiO2 based nanofibers (NF) decorated with Pt/Pd. The results show that the agro-waste based activated carbons show high potential as adsorbents (e.g. ~100% As(V) removal in 2 h). With the multicomponent solution there is evidently competition for the adsorption sites; Pb was removed most efficiently. The specific surface area and pore size distribution play an important role in MB adsorption, as with As(V) the ash content is the most influential parameter. The industrial intermediate product has a high adsorption capacity towards both As(III) and As(V) (over 96% removals in 4 h), and is promising for use in natural and wastewater treatment due to its adsorption properties, availability, low cost, and non-toxicity. Photocatalysis was found to be an efficient removal method for the pollutants tested, also in the diluted industrial wastewater matrix, e.g. diuron was removed 99% in 1 h. The NFs are promising for the efficient photocatalytic degradation of organic effluents in aqueous streams such as wastewaters originating from e.g. biofuel production or fine chemicals and pharmaceutical industry. This study provides new and valuable knowledge for the purification of waters, especially when aiming at developing inexpensive water treatment materials and methods for different applications
Tiivistelmä Puhtaan veden puute on maailman laajuinen ongelma, ja raskasmetallien ja orgaanisten haitta-aineiden päätymistä ympäristöön ja luonnonvesiin voidaan vähentää hyvällä ja tehokkaalla teollisuuden jätevesien käsittelyllä. Uusia ja tehokkaita, ympäristön kannalta suotuisia ja kestäviä vedenpuhdistustekniikoita tarvitaan erityisesti kehitysmaissa, joissa esim. kontrolloimaton kaivostoiminta aiheuttaa ympäristö- ja terveyshaittoja. Työn kokeellisessa osassa valmistettiin perulaisesta maatalousjätteistä aktiivihiiltä kemiallisella aktivoinnilla, ja seurattiin niiden kykyä adsorboida haitta-aineita (As(V), Pb, Cd, metyleenisini) yksi- ja monikomponenttiliuoksista ja saastuneesta luonnonvedestä (Puyango-Tumbesjoki, Peru). Lisäksi tutkittiin teollisuuden välituotteen (TiO2) aktiivisuutta arseenin, As(III) ja As(V), adsorptiossa. Viimeisessä osiossa tutkittiin valokatalyysiä orgaanisten haitta-aineiden poistossa vesiliuoksista sekä kaupallisella TiO2 P25 -katalyytillä että kokeellisilla Pd/Pt-dopatuilla TiO2 -nanokuiduilla. Tulokset osoittavat, että paikallisesta raaka-aineesta valmistetut aktiivihiilet ovat hyvin potentiaalisia vedenpuhdistusmateriaaleja saavuttaen jopa 100% As(V) poistuman (2h). Adsorboitavien ionien välillä on nähtävissä kilpailua monikomponettiadsorptiossa; lyijyn havaittiin poistuvan tehokkaimmin tutkituissa olosuhteissa. Adsorbentin ominaispinta-ala ja huokoskokojakauma ovat tärkeitä tekijöitä metyleenisinin adsorptiossa, kun taas tuhkapitoisuudella on arseenin adsorptioon suurempi vaikutus. Teollisuuden TiO2-välituotteella havaittiin olevan korkea adsorptiokapasiteetti sekä As(III)- että As(V)-spesieksiä kohtaan saavuttaen yli 96% poistumat (4h). Se on lupaava materiaali edelleen kehitettäväksi ja käytettäväksi esimerkiksi luonnonvesien ja jätevesien puhdistuksessa johtuen sen hyvistä adsorptio-ominaisuuksista, saatavuudesta, edullisuudesta ja myrkyttömyydestä. Valokatalyysin havaittiin olevan toimiva menetelmä orgaanisten molekyylien hajottamiseen, myös laimeasta teollisuuden jätevesimatriisista, esim. diuroni poistui 99% tunnissa. Nanokuitujen tapauksessa aktiivinen metalli vaikutti merkittävämmin reaktion tehokkuuteen kuin ominaispinta-ala. Tämä työ tarjoaa uutta ja tärkeää tietoa vesien puhdistukseen kun tavoitteena on löytää tehokas ja edullinen menetelmä erityyppisiin sovelluksiin
Стилі APA, Harvard, Vancouver, ISO та ін.
16

Zietzschmann, Frederik [Verfasser], Martin [Akademischer Betreuer] Jekel, Martin [Gutachter] Jekel, and Eckhard [Gutachter] Worch. "Impacts of background organic matter on organic micro-pollutant adsorption onto activated carbon / Frederik Zietzschmann ; Gutachter: Martin Jekel, Eckhard Worch ; Betreuer: Martin Jekel." Berlin : Technische Universität Berlin, 2016. http://d-nb.info/1156181232/34.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
17

Cosseron, Anne-Flore. "Evaluation et traitement des polluants émis par un moteur thermique fonctionnant avec des biocarburants." Phd thesis, Université de Haute Alsace - Mulhouse, 2012. http://tel.archives-ouvertes.fr/tel-00860233.

Повний текст джерела
Анотація:
Les biocarburants présentent une alternative prometteuse à l'utilisation de carburants fossiles. Cependant, l'augmentation de la quantité de biocarburants introduite dans les carburants nécessite de connaître leur impact sur les émissions de polluants. Le travail réalisé lors de cette thèse peut être décrit en deux parties : La première traite de l'évaluation des émissions de polluants réglementés et non réglementés émis par la combustion de biocarburants dans un moteur diesel. Différents biocarburants ont été testés : des esters méthyliques d'huile de soja et de colza, des esters éthyliques d'huile usagée et un carburant de référence exempt de tout biocarburant. Les résultats montrent que la nature des biocarburants ainsi que leur teneur ont un impact sur les polluants émis. Par exemple, une diminution de la taille des particules émises a été observée avec l'utilisation des esters méthyliques d'huile de soja. Le deuxième objectif de cette thèse concerne le piégeage des polluants Diesel, notamment des composés organiques volatils par des zéolithes. Plusieurs zéolithes ont été synthétisées puis caractérisées. Des tests d'adsorption par thermogravimétrie ont ensuite été réalisés au laboratoire avec différentes molécules sondes représentatives des polluants émis par les moteurs Diesel (le n-hexane, le p-xylène et l'acétone). Certaines zéolithes comme les zéolithes faujasite présentent des capacités d'adsorption intéressantes. Toutefois, la plupart des résultats montrent une diminution de la capacité d'adsorption avec l'augmentation de la température. Ces zéolithes ont ensuite été placées en sortie d'échappement d'un moteur diesel afin d'étudier leur capacité d'adsorption.
Стилі APA, Harvard, Vancouver, ISO та ін.
18

Martins, Bianca Fernandes. "Aerogéis de hidroxipropil metilcelulose: síntese, caracterização e aplicação como adsorventes para 17α-etinilestradiol." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-11042018-135443/.

Повний текст джерела
Анотація:
Aerogéis de hidroxipropil metilcelulose (HPMC) com diferentes graus de substituição por grupos metila (DS) e hidroxipropila (MS) foram preparados por liofilização utilizando diferentes ácidos como agentes de reticulação, a saber: ácido cítrico, ácido oxálico e ácido tereftálico. Nanocristais de celulose bacteriana (BCN) neutros e negativamente carregados foram utilizados como carga de reforço nas concentrações de 5% (m/m) e 15% (m/m) em relação à massa da matriz. Os resultados indicaram que HPMCs com menores valores de DS e maiores valores de MS resultam em aerogéis com maior eficiência na reticulação. Além disso, agentes de reticulação insolúveis em água minimizaram a capacidade de reticulação, enquanto agentes de reticulação com uma maior quantidade de grupos funcionais ácidos aumentaram a probabilidade e a eficiência da reação de reticulação das cadeias de HPMC. Os aerogéis apresentaram alta estabilidade em água, solventes orgânicos e meio ácido, além de apresentar resiliência quanto à deformação em meio aquoso. Os aerogéis apresentaram porosidade de ~98%, densidade média variando de 0,021 à 0,026 (± 0,002) g.cm-3, módulo de Young variando de 101 à 150 (± 19) kPa e capacidade média de absorção de água de 18 g de água/g de aerogel. A adição de carga de reforço resultou em um aumento de até 13% na densidade aparente do aerogel e um aumento médio de 20% no módulo de Young dos materiais. A morfologia dos poros dos aerogéis sintetizados é irregular, com ampla faixa de distribuição de tamanho de poros, podendo variar cerca de 5 µm a 500 µm. Nos aerogéis reforçados, as BCNs encontram-se preferencialmente no interior das paredes dos aerogéis, onde o reforço mecânico é mais eficiente. Isotermas de adsorção de 17α-etinilestradiol (EE) foram realizadas, resultando em capacidades de remoção de até 90%, com possibilidade de reciclo. As isotermas indicam que a matriz HPMC J5MS possui maior afinidade para adsorção de EE e que a adição de BCNs aumenta a afinidade das moléculas pelo substrato. As isotermas foram melhor ajustadas com o modelo de Freundlich, indicando que a adição de 5% de BCNs aumenta a capacidade de adsorção do aerogel, enquanto a adição de 15% de BCNs provoca uma diminuição nesta propriedade.
Aerogels of Hydroxypropyl methylcellulose (HPMC), with different degrees of substitution for methyl groups (MS) and hydroxypropyl groups (DS) were prepared by freeze-drying. The HPMCs were combined with three organic acids as crosslinking agents: citric acid, oxalic acid and terephthalic acid. Bacterial cellulose nanocrystals (BCN) neutral and negatively charged were used as reinforcement particles from 5% to 15% m/m in relation to the polymer mass. The results indicated that HPMC with lower DS and higher MS levels result in aerogels with higher crosslink efficiency. Besides that, crosslinking agents that are water insoluble minimized the crosslinking capacity, while crosslinking agents with more functional acid groups presented higher probability and efficiency in the crosslinking reaction. The aerogels presented high stability in water, organic solvents and acid media, and presented mechanical resilience in aqueous media. The resulting aerogels presented porosity of ~98%, average density of 0.021 to 0.026 (± 0.002) g.cm-3, Young modulus of 101 to 150 (± 19) kPa and an average capacity of water absorption of 18 g of water/g of aerogel. The addition of reinforcement particles resulted in an increase in density up to 13% and an average increase in the Young modulus of 20%. The morphology of the aerogels was irregular, with a wide pore size distribution, varying between de 5 µm a 500 µm. In the reinforced aerogels, the BCNs were found preferably inside the aerogels walls, were the mechanical reinforcement is more efficient. Adsorption isotherms of 17 ethinyl estradiol (EE) revealed removal capacity up to 90% and possibility of adsorbent recycling. The isotherms indicated that the HPMC J5MS has higher affinity for EE molecules and that the use of BCNs increases aerogels affinity. The isotherms were well fitted with the Freundlich model, indicating that the addition of 5% BCN increases the adsorption capacity of the aerogels, while the addition of 15 % BCN results in a decrease in this property.
Стилі APA, Harvard, Vancouver, ISO та ін.
19

Guedidi, Hanen. "Préparation et modification de carbones activés pour l'adsorption de polluants organiques émergents : molécules pharmaceutiques et liquides ioniques." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAA003/document.

Повний текст джерела
Анотація:
Dans ce travail, nous avons modifié deux carbones activés (grain AC et tissu T0) par divers traitements chimique (H2O2, NaOCl et un traitement thermique sous azote) et par des traitements ultrasonores à 20 et 500 kHz en présence de différents solvants (eau ultrapure, peroxyde d'hydrogène et acide formique). Ces carbones (bruts et modifiés) ont été caractérisés du point de vue de leur chimie de surface et de leur texture. Nous avons étudié l'adsorption d'ibuprofène (IBP) aux différents pH et températures. Le processus d'adsorption de l'IBP sur (AC ou T0) est avéré endothermique à pH 3. L'oxydation par NaOCl crée des groupes phénoliques qui défavorisent l'adsorption d'IBP tandis que l'oxydation par H2O2 augmente la teneur en groupe carbonyles et carboxyles responsable d'une contribution à l'adsorption de l'IBP. Le traitement ultrasonore de AC a augmenté son adsorption d'IBP par rapport au charbon brut. La cinétique d'adsorption de deux liquides ioniques synthétisés (LI1 : bromure de 4-tertiobutyl-1-propylpyridinium et LI2 : bromure de 4-tertiobutyl-1(2-carboxy-ethyl)pyridinium ) sur T0 est beaucoup plus rapide que la cinétique d'adsorption de l'IBP à pH 7,5. La compétition d'adsorption sur T0 entre les trois molécules (IBP et les deux liquides ioniques) a montré que l'IBP s'adsorbe en plus grande quantité sur le T0 que le LI1 et le LI2
In this work, two activated carbons (granular AC and fabric T0) were modified either by chemical treatment (H2O2, NaOCl and thermal treatment under N2) or by ultrasonic irradiation at 20 kHz or 500 kHz in different solvents (UHQ water, H2O2 and HCOOH). The raw and modified materials were characterized by different methods. We studied the ibuprofen (IBP) adsorption at different pH and temperatures. The adsorption of IBP by (AC or T0) was an endothermic process at pH 3. Oxidation with NaOCl creates phenol groups that led to a decrease of the adsorption uptake while oxidation by H2O2 increases the carbonyl group content and carboxyl that induce an increase in the adsorption of IBP. The ultrasonic treatment of AC increases the adsorption capacity of ibuprofen in comparison with the raw AC. The adsorption of the two ionic liquids (LI1 : the 4(tert-butyl)-1propylpyridinium bromide and LI2 : 4(tert-butyl)-1(2-carboxy-ethyl)pyridinium bromide ) onto T0 was found much faster than the adsorption kinetic of IBP at pH 7.5. The competitive adsorption of mixture of IBP and the two ionic liquids showed that IBP is the most adsorbed by T0
Стилі APA, Harvard, Vancouver, ISO та ін.
20

Maja, Lončarski. "Uticaj fizičko-hemijskih svojstava mikroplastike i odabranih perzistentnih organskih polutanata na interakcije u vodenom matriksu." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2020. https://www.cris.uns.ac.rs/record.jsf?recordId=114925&source=NDLTD&language=en.

Повний текст джерела
Анотація:
Mikroplastika  je  sveprisutna  u  vodenom  ekosistemu  pri  čemu  se  čestoističe značaj ispitivanja njihovog uticaja na ponašanje drugih jedinjenja u vodi.Pod pojmom mikroplastika podrazumevaju se plastične čestice manje od 5 mm.Imajući u vidu potrebu za unapređenjem znanja o štetnom uticaju mikroplastikeu životnoj sredini u ovom radu sproveden je set eksperimenata u kom je ispitivanmehanizam  interakcija  koje  se  uspostavljaju  prilikom  adsorpcije  hlorovanihfenola,  derivata  benzena  i  policikličnih  aromatičnih  ugljovodonika  na mikroplastici  u  vodenom  matriksu.  Kako  bi  se  što  detaljnije  razumeo  uticaj mikroplastike  i  osobina  vodenog  matriksa  na  ponašanje  organskih  polutanata, laboratorijska ispitivanja su sprovedena u sintetičkom i realnom vodenommatriksu.  Takođe  je  sprovedena  optimizacija  izolovanja  i  karakterizacije mikroplastike iz kozmetičkih sredstava u cilju procene uticaja osobina primarne mikroplastike na uspostavljanje interakcija sa organskim polutantima. Na  osnovu  dobijenih  rezultata  istraživanja  može  se  zaključiti  da  se optimalna metoda izolovanja mikroplastike iz kozmetičkih sredstava zasniva na dodatnom  tretiranju  osušenog  materijala  30%  vodonik-peroksidom,  nakon ekstrakcije  sredstva  u  destilovanoj  vodi,  u  cilju  dobijanja  čistijih  uzoraka mikroplastike. Promena brzine mešanja ima znčajan uticaj na promenu stepena adsorpcije ispitivanih grupa organskih jedinjenja.  Uticaj se ogleda u povećanju stepena adsorpcije sa porastom brzine mešanja, a maksimalni procenat adsorpcije postignut  je  pri  brzini  mešanja  od  150  o/min.  Dodatno,  disperzija  praškastih materijala u vodi nema značajan uticaj na promenu stepena adsorpcije hlorovanih fenola,  derivata  benzena  i  policikličnih  aromatičnih  ugljovodonika  na mikroplastici.Ravnotežno  stanje  između  koncentracije  hlorovanih  fenola,  derivatabenzena  i  policikličnih  aromatičnih  ugljovodonika  u  vodi  i  odabranih predstavnika  mikroplastike  (PEp,  PE_PCPs_1,  PE_PCPs_2,  PEg,  PET,  PP  i PLA) uspostavlja se nakon 24 i 48 h kontakta u zavisnosti od vrste jedinjenja. Na promenu  adsorpcionog  afiniteta  hlorovanih  fenola,  derivata  benzena  i policikličnih aromatičnih ugljovodonika prema mikroplastici utiču kako fizičkohemijske  osobine  jedinjenja  tako  i  karakteristike  mikroplastike.  Na  osnovu kinetičkih  eksperimenata, najveći adsorpcioni afinitet ka mikroplastici  ispoljili su  derivati  benzena  (qt=103-350  µg/g),  dok  je  najmanji  uočen  kod  hlorovanih fenola  (qt=25-225  µg/g).  Dobijeni  rezultati  adsorpcije  derivata  benzena  na ispitivanim  česticama  mikroplastike  takođe  su  ukazali  na  veći  afinitet  ovih jedinjenja  ka  mikroplastici,  u  poređenju  sa  jedinjenjima  iz  grupe  policikličnih aromatičnih  ugljovodonika  i  hlorovanih  fenola  sličnih  logKow  vrednosti. Dodatno,  uticaj  vodenog  matriksa  na  adsorpciju  hlorovanih  fenola,  derivata benzena  i  policikličnih  aromatičnih  ugljovodonika  na  mikroplastici  zavisi  od same grupe jedinjenja kao i od vrste mikroplastike pri čemu je najmanje izražen u  slučaju  ispitivanih  policikličnih  aromatičnih  ugljovodonika,  a  najviše  kod hlorovanih fenola.Visoke  vrednosti  koeficijenta  determinacije  kinetičkog  modela  pseudodrugog  reda  za  adsorpciju  hlorovanih  fenola,  derivata  benzena  i  policikličnih aromatičnih ugljovodonika na čestice mikroplastike ukazjuju da je hemisorpcija mogući  mehanizam.  Pored  visokih  vrednosti  koeficijenata  determinacije  u slučaju svih odabranih organskih jedninjenja dobijena konstanta brzine drugog reda  bila  je  manja  od  po četne  brzine  adsorpcije  što  ukazuje  na  znatno  brže odvijanje  adsorpcije  pri  kraćim  vremenima  kontakta  (12-24  h)  nakon  čega  jedolazilo do usporavanja procesa adsorpcije.Mehanizam adsorpcije hlorovanih fenola, derivata benzena i policikličnih aromatičnih ugljovodonika  ispitivan  je primenom Freundlich-ovog, Langmuirovog,  Redlich-Peterson-ovog  i  Dubinine-Radusckevich-evog  adsorpcionog modela. Vrednosti Freundlich-ovog eksponenta za adsorpciju hlorovanih fenola, derivata benzena i  policikličnih aromatičnih ugljovodonika bile su manje od 1,što ukazuje na to da je slobodna energije adsorpcije na mikroplastci opadala sa povećanjem  inicijalne  koncetracije  ispitivanih  polutanata.  Vrednosti maksimalnog adsorpcionog kapaciteta dobijene za  adsorpcione procese PAH  na česticama mikroplastike bile su u opsegu od 29,7-2596,5 µg/g. Visoke vrednosti maksimalnih adsorpcionih kapaciteta dobijene su takođe za adsorpciju derivata benzena na ispitivanim vrstama mikroplastike  39,3-2010,1 µg/g. S druge strane, uočeno  je  različito  adsorpciono  ponšanje  hlorovanih  fenola  u  zavisnosti  od vodenog metriksa u kom su eksperimenti sprovedeni pri čemu su  qmax  vrednosti iznosile 20,00-205,6 µg/g. Značajan uticaj  pH vrednosti vodenog matriksa  utvrđen je  za adsorpciju hlorovanih  fenola  na  mikroplastici,  dok  u  slučaju  derivata  benzena  i  PAH promena pH vrednosti vodenog matriksa nije pokazala značajan uticaj. Rezultati dobijeni  za  adsorpciju  hlorovanih  fenola  na  mikroplastici  ukazuju  na  nižu tendenciju  ka  formiranju  interakcija  hlorovanih  fenola  sa  česticama mikroplastike pri pH 4 i pH 10, pri čemu se stepen adsorpcije kretao u opsegu od 8-35% i 15-35%, respektivno, u odnosu na pH 7 (55-65%). Najniži  adsorpcioni  afinitet  uočava  se  pri  adsorpciji  ispitivanih  grupa jedinjenja na PLA. Može se pretpostaviti da će se organski polutanti,   ukoliko ova vrsta mikroplastike dospe u vodene sisteme, slabo vezivati na ovaj materijal pri čemu će značajno manje uticati na njihov trasport kroz životnu sredinu, u odnosuna druge ispitivane vrste mikroplastike. Na  osnovu  dobijenih  rezultata  istraživanja  može  se  zaključiti  da  na adsorpciju ispitivanih grupa organskih jedinjenja i mikroplastike značajan uticaj imaju  fizičko-hemijske  osobine  ispitivanih  jedinjenja  kao  što  su  kiselinska konstanta, veličina molekula, hidrofobnost, stukturni raspored i dr. Pored toga, karakteristike vodenog matriksa, među kojima je najvažnija pH vrednost, imaju značajan  uticaj  na  adsorpcioni  afinitet  jedinjenja  ka  mikroplastici.  Dodatno,struktura  i  poreklo  polimera  ima  veliki  uticaj  na  formiranje  interakcija  saispitivanim grupama organskih polutanata. Dobijeni rezultati takođe ukazuju nanemogućnost  određivanje  unifomnog  mehanizma  adsorpcije  organskihjedinjenja na česticama mikroplastike u vodi.
Microplastics  are  ubiquitous  in  aquatic  ecosystems,  so  it  is  essential  to study their  impact on the behaviour of other compounds which are commonly present in water. The term microplastics refers to all plastic particles smaller than 5 mm. In order  to address knowledge gaps relating to the potential harmful effects of microplastics in the environment, the experiments conducted during this thesis were designed to investigate the adsorption mechanism of chlorinated phenols, benzene derivatives, and polycyclic aromatic hydrocarbons on microplastics in water.  To  provide  a  more  detailed  understanding  of  the  influence  of  different water  matrices  on  adsorption  properties  of  microplastics,  experiments  were conducted in both synthetic and real water matrices. In the course of this work, methods were optimised for the isolation and characterization of microplastifrom personal care products, in order to allow investigation  of the influence of the  properties  of  primary  microplastics  on  their  interactions  with  organic pollutants.Base on the obtained results, it can be concluded that the optimal method of isolating microplastics from personal care products is based  on treating already dried  material  with  30%  hydrogen  peroxide,  after  extraction  of  the  agent  in distilled water, in order to obtain cleaner microplastic samples. The mixing rate was  found  to  have  a  significant  effect  on  the  degree  of  adsorption  of  the investigated  organic  compounds.  Increasing  the  mixing  speed  led  to  a  higherdegree  of  adsorption,  with  the  maximum  adsorption  percentage  reached  at  amixing speed of 150 rpm. In addition, the dispersion of powdered materials in the  water  had  no  significant  effect  on the  degree  of  adsorption  of  chlorinated phenols,  benzene  derivatives,  and  polycyclic  aromatic  hydrocarbons  on microplastics.The  adsorption  equilibrium  between  the  concentration  of  chlorinated phenols,  benzene derivatives and polycyclic aromatic hydrocarbons in water and selected types of microplastics (PEp, PE_PCPs_1, PE_PCPs_2, PEg, PET, PP, and  PLA) was established after 24 and 48 h of contact time, depending on the selected  group  of  organic  pollutants.  The  adsorption  affinity  of  chlorinated phenols,  benzene  derivatives,  and  polycyclic  aromatic  hydrocarbons  towards microplastics  was  influenced  by  both  the  physicochemical  properties  of  the compounds  and  the  characteristics  of  the  microplastics.  Based  on  the  kinetic experiments,  the  highest  adsorption  affinity  for  microplastics  was  shown  by benzene derivatives (qt=103-350 µg/g), while the lowest was  observed during the adsorption of chlorinated phenols (qt=25-225 µg/g). Benzene derivatives showed higher  adsorption  affinities  for  the  selected  microplastic  particles  than  the polycyclic  aromatic  hydrocarbons  and    chlorinated  phenols  which  had  similar logKow  values. The influence of the water matrix on adsorption of chlorinated phenols,  benzene  derivatives,  and  polycyclic  aromatic  hydrocarbons  on microplastics  depended  on  the  specific  functional  groups  of  the  investigated compounds as well as on the type of microplastics. Water matrix had little impact on  the  adsorption  of  polycyclic  aromatic  hydrocarbons  on  microplastics  but greatly impacted the adsorption of chlorinated phenols. Fitting the pseudo-second order kinetic  model to the  adsorption data of chlorinated phenols, benzene derivatives, and polycyclic aromatic hydrocarbons on microplastic particles resulted in high correlation coefficients, indicating that chemisorption  is  the  likely  adsorption  mechanism.  In  addition  to  the  high correlation coefficients obtained for all the organic pollutants investigated, the pseudo-second order rate constants obtained were lower than the initiaadsorption rate, indicating significantly faster adsorption at shorter contact times (12-24 h), with adsorption slowing down as equilibrium was reached.The adsorption mechanism of chlorinated phenols, benzene derivatives,and  polycyclic  aromatic  hydrocarbons  was  investigated  using Freundlich,Langmuir,  Redlich-Peterson,  Dubinine-Radusckevich,  and  Temkin  adsorption models.  The  Freundlich  exponent  values  for  the  adsorption  of  chlorinated phenols, benzene  derivatives, and polycyclic  aromatic  hydrocarbons were  less than 1 which indicates that the free energy of adsorption of these compounds on microplastics  decreases  as  the  initial  concentration  increases.  The  maximum adsorption capacities of PAHs on microplastic particles were in the range of 29.7-2596.5  µg/g.  High  maximum  adsorption  capacities  were  also obtained  for the adsorption  of  benzene  derivatives  on  the  tested  types  of  microplastics:  39.3-2010.1  µg/g.  The  chlorinated  phenols  behaved  differently,  and  were  more effected by the water matrix, with qmax values in  the range 20.00-205.6 µg/g. The pH of the water matrix was found to have a significant effect on the adsorption  of  chlorinated  phenols  on  microplastics,  whereas  in  the  case  of benzene  derivatives  and  polycyclic  aromatic  hydrocarbons,  the  degree  ofadsorption  was  largely  independent  of  the  water  pH.  For  the  adsorption  of chlorinated  phenols  on  microplastics,  neutral  pH  conditions  resulted  in  the greatest degrees of adsorption (55-65% at pH 7), while adsorption was inhibited under acidic (8-35% at pH 4) and basic (15-35% at pH 10) conditions. The microplastic type with the lowest observed adsorption affinities was PLA. It can be thus be assumed that in the event that this type of microplastic enters water systems, organic pollutants will only adsorb weakly to this material, such  that  it  will  have  significantly  less  impact  on  the  transport  of  the se compounds through the environment, than the other tested  types of microplastics. The results obtained in this research demonstrate that the adsorption of the selected  groups  of  organic  pollutants  on  the  microplastics  investigated  is significantly  controlled  by  the  physicochemical  properties  of  the  tested compounds, such as the dissociation constant, molecule  size, hydrophobicity,structural properties, etc. In addition, the characteristics of the water matrix play an important role in controlling adsorption of organic pollutants on microplastic, especially the water pH. In addition, the structure and aging of the polymers had a major influence  on their interactions with the selected organic pollutants. The obtained  results  also  demonstrate  the  difficulty  in  determining  a  uniform mechanism  of  adsorption  between  the  various  organic  compounds  and microplastic particles in water.
Стилі APA, Harvard, Vancouver, ISO та ін.
21

Finnilä, M. A. (Mikko A. J. ). "Bone toxicity of persistent organic pollutants." Doctoral thesis, Oulun yliopisto, 2014. http://urn.fi/urn:isbn:9789526205090.

Повний текст джерела
Анотація:
Abstract Persistent organic pollutants (POPs), especially dioxin-like chemicals, have been shown to have adverse effects on skeleton and these effects are likely to be mediated via the aryl hydrocarbon receptor (AHR). In spite of the extensive research, the characteristics of developmental effects of POPs are poorly known and the role of AHR in POP bone toxicity and skeletal development in general. In this project changes in bone morphology and strength as well as tissue matrix mechanics are studied by applying state of the art biomedical engineering methods. This allows understanding of the effects of dioxins exposure and AHR activity on the development and maturation of extracellular matrix in musculoskeletal tissues from a completely new perspective, and thereby improving the health risk assessment of POPs. In the present study skeletal properties of rats exposed maternally to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), Northern Contaminant Mixture (NCM) and Aroclor1254 (A1254) were studied for cross-sectional morphometric and biomechanical properties, and data were analysed with benchmark dose modelling. In addition, extracellular matrix properties were analysed using nanoindentation. Similar measurements were performed for adult wild-type and AHR-null mice after TCDD exposure. The same animals were also analysed for microstructural changes using micro-computed tomography and their bone cell activity was estimated from serum markers and gene expression. Analyses show decreased bone length and cross-sectional properties with consequently decreased bone strength. On the other hand, an increased trabecular BMD in response to NCM and A1254 was observed. In addition, bone matrix properties indicated delayed maturation or early senescence after maternal or adult exposure, respectively. The AHR is mainly responsible for bone toxicity of dioxin-like compounds and plays a role in bone development. This is likely due to disturbed bone remodeling as indicated by altered serum markers and gene expression. Overall these results indicate that POPs decrease bone strength, but the interpretation is difficult as there is more trabecular bone within cortical bone with compromised quality and increased porosity
Tiivistelmä Altistumisen pysyville orgaanisille ympäristökemikaaleille on todettu heikentävän luustoa. Dioksiinien ja dioksiininkaltaisten yhdisteiden vaikutusten on havaittu välittyvän aryylihiilivetyreseptorin (AHR) välityksellä. Huolimatta pitkään kestäneestä tutkimuksesta POP-yhdisteiden sikiönkehityksen aikaisen altistuksen vaikutukset ja etenkin niiden mekanismit ovat edelleen huonosti tunnettuja, samoin kuin AHR:n osuus POP-yhdisteiden luutoksisuudessa ja luuston kehityksessä ylipäätään. Tässä työssä tutkittiin luuston rakenteellisia ja mekaanisia ominaisuuksia niin perinteisillä kuin uusimmilla biolääketieteen tekniikan menetelmillä. Tutkimuksen tavoitteena on saada uutta tietoa POP-altistuksen ja AHR-aktiivisuuden vaikutuksista luuston kehitykseen ja luukudoksen ikääntymisprosesseihin, mikä edesauttaa kyseisten yhdisteiden riskinarviointia. Tutkimuksissa altistettiin kantavia rottaemoja 2,3,7,8-tetraklooridibenzo-p-dioksiinille (TCDD), pohjoiselle saasteseokselle ja kaupalliselle Arokloori 1254 PCB-seokselle. Sikiönkehityksen aikana altistuneiden jälkeläisten luuston poikkileikkausen morfologia ja biomekaaniset ominaisuudet mitattiin ja tulokset mallinnettiin vertailuannoksen määrittämiseksi. Lisäksi TCDD-altistettujen rottien luustomatriisin ominaisuuksia selvitettiin nanoindentaatiomenetelmällä. Samaa menetelmää käytettiin myös aikuisiässä TCDD:lle altistettujen villityypin hiirten ja AHR-poistogeenisiten hiirten tutkimiseen. Näiden hiirten luuston hienorakennetta mitattiin myös korkean resoluution mikro-tietokonetomografialla ja niiden luusolujen aktiivisuutta tutkittiin seerumin biomarkkerien ja luun muodostumiseen osallistuvien geenien ekspressiotasojen avulla. Sikiönkehityksen aikainen altistuminen pohjoiselle saasteseokselle ja Arokloori 1254:lle hidasti luiden pituuskasvua. Lisäksi luiden poikkileikkauspinta-alat olivat pienentyneet ja mekaaniset ominaisuudet heikentyneet. Toisaalta hohkaluun määrä oli lisääntynyt altistumisen seurauksena. Myös sikiönkehityksen aikainen altistuminen TCDD:lle hidasti luukudoksen kypsymistä ja johti aikuisiällä luukudoksen ennenaikaiseen vanhenemiseen. AHR:llä oli päärooli ainakin aikuisiän vaikutusten ilmenemiselle ja reseptorilla vaikutti olevan rooli luuston kehityksessä ylipäätään. Seerumin biomarkkereiden ja geeniekspression muutosten perusteella nämä vaikutukset johtuvat todennäköisesti luuston uusiutumisen häiriöistä. Yhteenvetona voidaan todeta, että POP-yhdisteet heikentävät luustoa, mutta tämän ilmiön diagnosoiminen on hankalaa, koska huonolaatuisen kuoriluun sisällä hohkaluun määrä on lisääntynyt
Стилі APA, Harvard, Vancouver, ISO та ін.
22

Yang, Congqiao. "Persistent organic pollutants in lacustrine environments." Thesis, University of Birmingham, 2014. http://etheses.bham.ac.uk//id/eprint/5030/.

Повний текст джерела
Анотація:
Water samples taken from nine English freshwater lakes from a mix of urban, rural, and remote locations on 13 occasions between April 2008 and February 2012 were analysed for selected non-dioxin like-PCBs, tri- through hexa-PBDEs, and the three main HBCD diastereomers (\(\alpha\)-, \(\beta\)-, and \(\gamma\)-HBCD). Concentrations of PCBs and HBCDs declined over the sampling period with half-lives of 3.8 and 5.1 years, respectively. In addition, concentrations of PCBs, HBCDs, tri- through deca-BDEs, and 32 selected NBFRs were measured in radiometrically-dated sediment core slices taken in summer 2011/2 from seven of the same English lakes. Temporal trends in contamination with “legacy” POPs generally accord with historical trends in UK manufacture and use, with PCB contamination at all lakes increasing from ~1950, peaking generally between the late-1960s and mid-1980s, before declining steadily thereafter. In contrast, at most sites, BDE-209 displayed generally smooth increases following its initial emergence, and showed no obvious levelling off trend. Contamination with some NBFRs displayed significantly increasing trends. Spatial variation in POPs contamination of the lakes studied was evident; with regression analysis suggesting concentrations are higher in lakes with surface areas that are small relative to their catchment area, and that are closer to areas of high population density. The estimated PCB burden in the British environment is 521 tons, with TBPH (281 tons) and BDE-209 (147 tons) following not far behind. Estimated UK burdens of the remaining target compounds were significantly lower.
Стилі APA, Harvard, Vancouver, ISO та ін.
23

Zhao, Xuebo. "Adsorption of pollutants and hydrogen storage on nanoporous materials." Thesis, University of Newcastle Upon Tyne, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427411.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
24

Paul, Jessica Marie. "Behavior of organic pollutants in Arctic sediments /." Click here for download, 2008. http://proquest.umi.com/pqdweb?did=1436385051&sid=1&Fmt=2&clientId=3260&RQT=309&VName=PQD.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
25

清家, 伸康, and 新太 片山. "Monitoring and Remediation of Persistent Organic Pollutants." 日本農薬学会, 2007. http://hdl.handle.net/2237/10923.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
26

Lee, Song-Yng. "Adsorption of moisture and indoor pollutants on a mixed-adsorbent /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9841165.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
27

Kolář, Michal. "Degradation of organic pollutants employing various photocatalytic systems." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2008. http://tel.archives-ouvertes.fr/tel-00731166.

Повний текст джерела
Анотація:
La dégradation photoinduite du Monuron (herbicide) a été étudiée dans trois systèmes différents produisant des radicaux hydroxyle : en présence du complexe Fe(III)Cit, dans une suspension de TiO2 et dans un système combiné Fe(III)Cit / TiO2. Le but principal était d'améliorer l'efficacité photocatalytique. La spéciation et la photoactivité du complexe ont été déterminées en fonction du pH. La cinétique de dégradation du Monuron photoinduite par le complexe se fait en deux étapes avec deux sources successives de radicaux °OH : 1) photolyse du complexe ; 2) cycle photoredox du fer. La présence de TiO2 améliore l'efficacité du système Fe(III)Cit à pH acide alors qu'à pH neutre l'efficacité du système est complètement inhibée. La concentration en oxygène et le pH sont les facteurs clés en présence du complexe Fe(III)Cit. De plus, dans un système pilote utilisant du TiO2, l'influence d'un solvant organique lors de la dégradation du 4-chlorophénol en milieu aquatique a été examinée.
Стилі APA, Harvard, Vancouver, ISO та ін.
28

Akinyeye, Richard Odunayo. "Nanostructured polypyrrole impedimetric sensors for anthropogenic organic pollutants." Thesis, University of the Western Cape, 2007. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_5301_1248150815.

Повний текст джерела
Анотація:

The main aim of this study was to develop a novel strategy for harnessing the properties of electroconductive polymers in sensor technology by using polymeric nanostructured blends in the preparation of high performance sensor devices.

Стилі APA, Harvard, Vancouver, ISO та ін.
29

Koskela, A. (Antti). "Bone as a target for persistent organic pollutants." Doctoral thesis, Oulun yliopisto, 2016. http://urn.fi/urn:isbn:9789526214306.

Повний текст джерела
Анотація:
Abstract Persistent organic pollutants (POPs) are ubiquitous and bioaccumulative man-made chemicals, resistant to chemical, biological and photolytic degradation and widely distributed to sediments, wildlife, and human. Many of these chemicals have adverse effects on a variety of targets, including the endocrine system, organogenesis and reproduction. Due to these effects and wide distribution, many of them are either banned or strictly controlled. However, because of persistency, they continue to interact with organisms globally. Despite the existing knowledge of the adverse effects of POPs, the effects of many chemicals on bone tissue are still poorly known. In the present study, we investigated the adverse effects of three common POPs, including tributyltin (TBT), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and perfluorooctanoic acid (PFOA) on the skeletal system. In vitro models were used to study the effects of PFOA in mouse and in human, and the co-effects of TBT and TCDD on differentiating osteoblasts and osteoclasts of mice. An in vivo model for mice was used to study the developmental effects of maternal PFOA-exposure on pups among with morphometrical and biomechanical property analyses. Mass-spectrometry was used to study the presence of PFOA in bones both in mice and in human, the latter acquired from the bone bank held in the Oulu University Hospital, Finland. The bones were also analyzed with cone beam computer tomography and microcomputer tomography. The results show that PFOA exposure in utero and during lactation leads to the accumulation of PFOA in bone, traceable even 17 months after exposure. PFOA exposure decreased the mineral density of the tibias and increased the medullary area. Nearly all of the human samples contained PFAS, including PFOA. PFOA also disturbed the differentiation of osteoblasts and with lower doses, increased bone resorption of osteoclasts both in mouse and human, the phenomenon being slightly stronger in mice. Co-exposure to TBT and TCDD led to decreased differentiation of osteoblasts and osteoclast, and the co-effect was partially synergistic in osteoblasts. These results show disruption of bone development, bone cell differentiation, and PFAS accumulation in bone. Further studies are recommended to evaluate the co-effects of different POPs and the possible effects of long-term accumulation of POPs in bone and other tissues
Tiivistelmä Pysyvät orgaaniset ympäristömyrkyt (POP-yhdisteet) ovat kemikaaleja, jotka ovat levinneet ihmisen toiminnan seurauksena laajalle ympäristöön, sen eliöihin ja ihmisiin. Monilla POP-yhdisteillä on haitallisia vaikutuksia esimerkiksi hormonaaliseen toimintaan, elinten muodostukseen ja hedelmällisyyteen. Toksisten vaikutusten ja niiden yleisyyden vuoksi monien POP-yhdisteiden käyttö on joko rajattua tai kielletty kokonaan. Laajan levinneisyytensä ja hitaan puoliintumisaikansa takia POP-yhdisteet ovat kuitenkin edelleen vuorovaikutuksessa ympäristön ja sen eliöiden kanssa. POP-yhdisteiden luustovaikutuksista tiedetään edelleen vähän. Tässä väitöskirjassa tutkittiin kolmen yleisen POP-yhdisteen, tributyylitinan (TBT), 2,3,7,8-tetraklooridibentso-p-dioksiinin (TCDD) ja perfluoro-oktaanihapon (PFOA), vaikutuksia luustoon. PFOA:n vaikutuksia hiiren ja ihmisen luustoon sekä TBT:n ja TCDD:n yhteisvaikutuksia hiiren erilaistuvien osteoblastien ja osteoklastien suhteen selvitettiin in vitro -malleilla. In vivo -mallilla tutkittiin hiiriemon PFOA-altistuksen vaikutusta syntyvien poikasten luuston kehitykseen ja remodelaatioon analysoimalla poikkileikekuvia sekä luiden biomekaanisia ominaisuuksia. Lisäksi luiden PFOA-pitoisuudet mitattiin massaspektrometrilla. Tutkimusta laajennettiin ihmiseen analysoimalla Oulun yliopistollisen sairaalan luupankkinäytteitä. Ihmisnäytteet analysoitiin myös kartiokeila-TT:n ja mikro-TT:n avulla. Tulosten mukaan PFOA kertyy luuhun; hiiriltä voitiin mitata PFOA-pitoisuuksia jopa 17 kuukautta altistumisen jälkeen. Lisäksi PFOA-altistus pienensi luun mineraalitiheyttä ja kasvatti luuydinontelon tilavuutta. Lähes kaikki ihmisluunäytteet sisälsivät PFOA:ta ja muita PFAS-yhdisteitä. Solukokeiden perusteella PFOA-altistus häiritsee osteoblastien erilaistumista ja pienillä pitoisuuksilla lisää osteoklastien luunhajotusta sekä hiirellä että ihmisellä. TBT:n ja TCDD:n yhteisaltistus vaikuttaa puolestaan vähentävän sekä osteoblastien että osteoklastien erilaistumista ja toimintaa; osteoblastien osalta yhteisvaikutus oli osaksi synergistinen. Väitöskirja antaa lisätietoa POP-yhdisteiden vaikutuksista luun kehitykseen ja luusolujen erilaistumiseen sekä PFAS-yhdisteiden kertymisestä luuhun. Väitöksessä myös suositellaan lisätutkimuksia yhdisteiden yhteisvaikutuksista sekä pitkän aikavälin ympäristökemikaalikertymän vaikutuksista luussa ja muissa kudoksissa
Стилі APA, Harvard, Vancouver, ISO та ін.
30

Raff, Jonathan Daniel. "Transport of organic pollutants and their atmospheric fates." [Bloomington, Ind.] : Indiana University, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3292440.

Повний текст джерела
Анотація:
Thesis (Ph. D.)--Indiana University, School of Public and Environmental Affairs, 2007.
Title from dissertation home page (viewed May 28, 2008). Source: Dissertation Abstracts International, Volume: 68-11, Section: B, page: 7189. Adviser: Ronald A. Hites.
Стилі APA, Harvard, Vancouver, ISO та ін.
31

Cousins, Ian T. "Air-soil exchange of persistent organic pollutants (POPs)." Thesis, Lancaster University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310506.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
32

Zaballa, Vicente. "Photoelectrocatalytic degradation of organic pollutants with TiOâ‚‚ electrodes." Thesis, University of Strathclyde, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248657.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
33

Leat, Eliza Helen Kelsey. "Persistent organic pollutants in great skuas Stercorarius skua." Thesis, University of Glasgow, 2013. http://theses.gla.ac.uk/4192/.

Повний текст джерела
Анотація:
The bioaccumulation of persistent organic pollutants (POPs) is of particular environmental concern in top predators, which accumulate high concentrations of POPs that can cause adverse effects. Previous small scale studies found high concentrations of POPs in adult great skuas, Stercorarius skua, a top predator in the marine environment. This thesis investigates the factors affecting concentrations and patterns of POPs (contribution of individual POPs to the ΣPOPs) in the great skua across its breeding range in the north-east Atlantic. Clear differences between colonies in both concentration and pattern of POPs in adult plasma were not indicative of being caused by long range transport of POPs in the atmosphere. Variation in diet between colonies is the mostly likely explanation for these colony differences, with great skuas from some colonies having a greater proportion of fish in their diet whilst others eat more seabird prey. Although seabirds are often used in studies of POPs in the environment, the effect of migratory behaviour has not previously been studied in detail. By using a combination of global location sensor (GLS) loggers and feather stable isotopes from winter grown feathers, the wintering areas of individuals from three breeding populations of great skuas were identified. Great skuas spend the winter in three distinct areas across the North Atlantic, with birds from the same breeding colonies wintering in different areas. In two of the three breeding populations, wintering area explained a significant proportion of variation in organochlorines (OCs) concentrations and pattern. However in the colony with the highest concentrations of OCs, no effect of wintering area was found, possibly as a result of these great skuas feeding at a higher trophic level during the breeding season than other populations. Temporally, concentrations of OCs were higher in 1980 than 2008 in eggs, whilst newer contaminants polybrominated diphenyl ethers (PBDEs) and perfluorinated chemicals (PFASs) show the opposite trend. In conclusion, concentrations of POPs in the great skua were influenced primarily by breeding season diet with wintering area and sex also having small but significant effects on POPs. Wintering area explained the most variation in the pattern of POPs in great skuas. The POP concentrations found in this study exceeded those which have been found to cause adverse effects on the immune system and reproduction in other species of seabird.
Стилі APA, Harvard, Vancouver, ISO та ін.
34

Kolar, Michal. "Degradation of organic pollutants employing various photocatalytic systems." Clermont-Ferrand 2, 2008. http://www.theses.fr/2008CLF21885.

Повний текст джерела
Анотація:
La dégradation photoinduite du Monuron (herbicide) a été étudiée dans trois systèmes différents produisant des radicaux hydroxyle : en présence du complexe Fe(III)Cit, dans une suspension de TiO2 et dans un système combiné Fe(III)Cit / TiO2. Le but principal était d'améliorer l'efficacité photocatalytique. La spéciation et la photoactivité du complexe ont été déterminées en fonction du pH. La cinétique de dégradation du Monuron photoinduite par le complexe se fait en deux étapes avec deux sources successives de radicaux °OH : 1) photolyse du complexe ; 2) cycle photoredox du fer. La présence de TiO2 améliore l'efficacité du système Fe(III)Cit à pH acide alors qu'à pH neutre l'efficacité du système est complètement inhibée. La concentration en oxygène et le pH sont les facteurs clés en présence du complexe Fe(III)Cit. De plus, dans un système pilote utilisant du TiO2, l'influence d'un solvant organique lors de la dégradation du 4-chlorophénol en milieu aquatique a été examinée
Стилі APA, Harvard, Vancouver, ISO та ін.
35

Zhou, Li. "Surface modified nanocarbons for photodegradation of organic pollutants." Thesis, Curtin University, 2016. http://hdl.handle.net/20.500.11937/342.

Повний текст джерела
Анотація:
Photocatalysis is a green and powerful technology and the key factor is the efficiency of photocatalysts. This study aims to develop metal-free, visible-light-responsive photocatalysts for water remediation and solar energy conversion based on graphitic carbon nitride. Surface modification and hybridization with metal-free nanocarbons (nanodiamonds and single-walled carbon nanotubes) were employed to extend the absorbance threshold and enhance the photocatalytic efficiency of the prepared photocatalysts. The mechanism was also discussed.
Стилі APA, Harvard, Vancouver, ISO та ін.
36

Boissel, Viviane. "Heterogeneous catalysis and selective adsorption for the control of atmospheric pollutants." Thesis, King's College London (University of London), 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404809.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
37

Quirino, Torres Leopoldo Leonardo. "Radon adsorption on activated charcoal in the presence of indoor pollutants /." free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9901272.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
38

Sowerby, Beverley. "Drying of organic vapours by adsorption." Thesis, University of Bath, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284567.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
39

Diboune, Mathieu. "Elaboration de peintures zéolithiques pour la décontamination moléculaire en orbite." Thesis, Mulhouse, 2021. https://www.learning-center.uha.fr/.

Повний текст джерела
Анотація:
La contamination moléculaire en orbite est l’une des problématiques majeures de l’industrie spatiale. En effet, lorsque les satellites sont en orbite, les molécules organiques contenues dans les peintures, adhésifs ou encore les colles utilisés dans la conception des satellites peuvent dégazer et ainsi former des films ou des gouttelettes en se déposant sur les surfaces sensibles comme les instruments optiques et électroniques ou encore les surfaces de contrôle thermique ce qui a pour conséquence d’endommager ces équipements. Les hydrocarbures ainsi que les plastifiants émis ont été identifiés comme étant les contaminants majeurs. Parmi les matériaux poreux testés pour l’adsorption de ces polluants organiques, les zéolithes se sont avérées être les plus efficaces de par leur capacité à piéger ces molécules présentes à de très faibles concentrations dans les conditions spatiales. La synthèse des zéolithes conduisant généralement à des poudres qui seraient elles-mêmes source de contamination particulaire, une mise en forme de ces zéolithes est donc nécessaire. Des pastilles, billes et films zéolithiques ont été élaborées lors de précédents projets mais ces mises en forme comportent leur lot de désavantages comme l’ajout d’équipements additionnels pour insérer les pastilles à la structure des satellites, les mauvaises propriétés mécaniques des billes ou encore la faible quantité de zéolithe mise en jeu dans le cas des films ainsi que de la difficulté d’application de ces derniers sur de grandes surfaces. C’est pourquoi, le développement de peintures zéolithiques a été envisagé étant donné que ces dernières présentent notamment l’avantage de pouvoir être directement appliquées sur la surface interne des satellites. L’objectif de cette thèse est donc d’élaborer des peintures zéolithiques qui adhèrent sur les éléments de surface des satellites, qui soient stables mécaniquement (chocs et vibrations subis par les satellites, gradients de température) et qui puissent piéger les polluants organiques. Des zéolithes de type structural FAU (hydrophile) et MFI (hydrophobe) ont été utilisées en combinaison avec des résines silicones comme liants dans le but d’élaborer des peintures zéolithiques pouvant répondre aux contraintes spatiales. Ces peintures zéolithiques ont montré de bonnes propriétés d’adhésion (notes de 0 au test d’adhésion selon la norme ISO 2409) ainsi qu’une bonne stabilité mécanique et thermique dans des conditions pouvant être rencontrées en orbite. Les liants utilisés n’obstruent que très peu voire pas du tout l’accessibilité à la porosité des peintures zéolithiques et de bonnes capacités d’adsorption du n-hexane ont été obtenues. Différentes quantités de pigment noir (charbon animal ou noir de carbone) ont également été ajoutées à certaines peintures zéolithiques pour développer des peintures zéolithiques carbonées dans le but d’absorber la lumière afin de répondre à un autre phénomène responsable de la contamination d’équipements optiques : la lumière parasite
The phenomenon of on-orbit molecular contamination is one of the major issues encountered by the space industry. Indeed, when satellites are placed in orbit, organic molecules contained in coatings, adhesives or glues used in the conception of satellites can degas and thus form films or droplets by depositing themselves on sensitive surfaces such as optical and electronic instruments or thermal control surfaces. This contamination leads to a drastic decrease of on-board equipment performance. Hydrocarbons as well as plasticizers have been identified as major contaminants. Among several porous materials tested for the adsorption of these organic pollutants, zeolites were found to be the most efficient due to their ability to trap organic molecules at a very low concentration in space conditions. The synthesis of zeolites generally leads to powders that would themselves be a source of particulate contamination, therefore a shaping of these zeolites appears to be necessary. Pellets, beads and zeolite films were developed in previous projects, but these processes have some disadvantages such as the addition of additional equipment to insert pellets into the structure of satellites, poor mechanical properties of beads or the small quantity of zeolite involved in the case of films and the difficulty of applying them to large surfaces. That is why, zeolite coatings were selected because they can be applied directly to the internal surface of satellites. The main goal of this project is to develop zeolite coatings that adhere to the surface elements of satellites, that are mechanically stable (shocks and vibrations undergone by satellites, temperature gradients) and that can trap organic pollutants. FAU-type (hydrophilic) and MFI-type (hydrophobic)zeolites were used in combination with silicone resins as binders in order to develop zeolite coatings that can that can fulfill spatial requirements. These zeolite coatings showed good adhesion properties (adhesion note of 0 according the ISO 2409 standard) as well as good mechanical and thermal stability under conditions encountered in orbit. Zeolite coatings porosity remain mostly accessible despite the use of a binder and good n-hexane adsorption capacities were obtained. Different quantities of black pigment (bone char or carbon black) were also added to some zeolite coatings to develop black zeolite coatings with the aim of absorbing light in order to respond to another phenomenon responsible of optial equipment contamination: stray light
Стилі APA, Harvard, Vancouver, ISO та ін.
40

Kwon, Beatsam. "Catalytic reduction of organic pollutants using supported metal nanoparticles." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/23190/.

Повний текст джерела
Анотація:
Metal nanoparticle catalysts have in the last decades been extensively researched for their enhanced performance compared to their bulk counterpart. Properties of nanoparticles can be controlled by modifying their size and shape as well as adding a support and stabilizing agent. In this study, preformed colloidal gold nanoparticles supported on activated carbon were tested on the reduction of 4-nitrophenol by NaBH4, a model reaction for evaluating catalytic activity of metal nanoparticles and one with high significance in the remediation of industrial wastewaters. Methods of wastewater remediation are reviewed, with case studies from literature on two major reactions, ozonation and reduction, displaying the synergistic effects observed with bimetallic and trimetallic catalysts, as well as the effects of differences in metal and support. Several methods of preparation of nanoparticles are discussed, in particular, the sol immobilization technique, which was used to prepare the supported nanoparticles in this study. Different characterization techniques used in this study to evaluate the materials and spectroscopic techniques to analyze catalytic activities of the catalyst are reviewed: ultraviolet-visible (UV-Vis) spectroscopy, dynamic light scattering (DLS) analysis, X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) imaging. Optimization of catalytic parameters was carried out through modifications in the reaction setup. The effects of the molar ratio of reactants, stirring, type and amount of stabilizing agent are explored. Another important factor of an effective catalyst is its reusability and long-term stability, which was examined with suggestions for further studies. Lastly, a biochar support was newly tested for its potential as a replacement for activated carbon.
Стилі APA, Harvard, Vancouver, ISO та ін.
41

Krop, Hildo Boudewijn. "Thermodynamic approaches for the environmental chemistry of organic pollutants." [Amsterdam] : Amsterdam : Universiteit van Amsterdam ; Universiteit van Amsterdam [Host], 2003. http://dare.uva.nl/document/87599.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
42

Hancock, Andrew Paul. "Determination and fate of organic pollutants in the environment." Thesis, Northumbria University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367413.

Повний текст джерела
Анотація:
Different sample preparation methodologies were evaluated for the determination of pollutants in different matrices. The methods investigated were chosen on the merits of decreased sample preparation time and low toxic solvent consumption with the aim to provide viable alternatives to more laborious methods, such as, Soxhlet extraction. Techniques were developed to extract and quantify organic pollutants from contaminated soils and water. The results from shake flask extraction of aged phenolic contaminated soils were used in attempt to relate sorption to both the soil, and pollutant properties. This was to help gain an understanding of the transport and fate of phenols in different environmental situations. The partitioning (sorption/desorption) of radiolabelled phenols between aqueous solution and soil was investigated using a modified shake flask technique. This provides additional information which can be related to soil characteristics, hence pertaining to the fate mechanisms involved for phenols in the environment. The results from these investigations suggest that more than one factor contributes to the sorption of phenols in soils.
Стилі APA, Harvard, Vancouver, ISO та ін.
43

D'Silva, Kyle David. "Brominated organic micro-pollutants in food and environmental biota." Thesis, University of Leeds, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423582.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
44

Yun, Ji Sub. "Purification of Indoor Air Pollutants Utilizing Hydrophobic Adsorbents." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/41613.

Повний текст джерела
Анотація:
Sick building syndrome (SBS) is a particular concern in places with inadequate ventilation and frequently attributed to chemical contaminants such as volatile organic compounds (VOCs)released from indoor sources that are frequently encountered in everyday life such as adhesives, carpeting, upholstery, manufactured wood products, copy machines, pesticides, cleaning agents inside buildings, plumbing vents, and painting. Furthermore, it is a major issue for modern human beings who spend most of their time indoors or must stay indoors for self-isolation due to special circumstances such as the coronavirus disease-19 (COVID-19) pandemic that occurred in 2019 and 2020. Main indoor VOCs are trichloroethylene (TCE), benzene, toluene, and para-xylene (p-xylene). In general, these compounds are not present in indoor spaces at acute concentrations, but prolonged exposure to these compounds can have chronic health effects such as allergic sensitization, increased cancer risks, and respiratory diseases. In this study, the adsorption process with various advantages has been applied to remove VOC’s using commercially available hydrophobic adsorbents. The hydrophobic adsorbents can contribute to reducing the possibility of chemical adsorption (chemisorption) of moisture from the air, which can decrease the capacity of adsorbent by clogging the pores. The adsorption of these major VOCs was investigated in this work for three major types of industrial hydrophobic adsorbents: activated carbons, zeolites, and polymer. This study will show the investigation into finding the most promising hydrophobic adsorbent for removal of TCE, benzene, toluene, and p-xylene, which are the main VOCs found indoors. The promising hydrophobic adsorbent has been determined by comparing Henry’s law constants and heat of adsorption values for the different adsorbents, which were estimated by using a concentration pulse chromatographic technique by utilizing a gas chromatograph equipped with a flame ionization detector. For all adsorbents, Henry’s law constants at room temperature of p-xylene were always the highest followed by toluene, benzene, and TCE. For all adsorbates, Henry’s law constants at room temperature of AC BPL and HiSiv 3000 were higher than the other hydrophobic adsorbents. For a developing modern society dealing with a pandemic, this study can contribute to producing the optimized gas masks and indoor filters for the removal of indoor air pollutants, which can help people who suffer from SBS. It can also help society for taking preventative actions towards dealing with SBS.
Стилі APA, Harvard, Vancouver, ISO та ін.
45

Huang, Pin-Ru. "The interaction of sedimentary organic matter with metals and organic pollutants in landfill barriers." Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/396594/.

Повний текст джерела
Анотація:
This research examines the composition, sedimentary history and chemical properties of sedimentary organic matter [SOM] and its application in determining the content and source of heavy metals and hydrophobic organic contaminants [HOCs] and their fate in waste disposal sites. Previous research has utilised Oxford Clay (OxC) from across the outcrop. In this study a continuous shallow core of OxC and adjoining Kellaways Sand (KS) from Brogborough, UK was used. This avoided the influence of different sedimentary conditions, thereby reducing the problem of sample variability. Relationships have been made between sedimentary and organic petrology and SOM abundance and metals concentration (V, Cr, Co, Ni, Cu, Zn and As). The co-association/binding of different metals to different types of SOM components from the OxC was shown to be dictated by the depositional environment. The organic rich parts (Total Organic Carbon (TOC) > 5 %) of the OxC displayed positive correlations between the elements V, Co, As and total pyrite % (p<1.1E-3, ? >0.7); however, there was an apparent negative correlation with TOC % (p<4.3E-5, ?<-0.4). This may be because of: 1) the rapid accumulation of the OM reduced the time for development of the pyrite (Ave. dia. =5.3?m, SD=2.4); and/or 2) the insufficient concentration of Fe to allow pyrite formation. This could be due to the high sedimentation rate that accelerates the accumulation of OM, which prevents its decomposition in the water column, as well as reducing the time for pyrite that is entrapped in the marine snow to capture metals from seawater during its settlement. Cu has a significant positive correlation with TOC (p=1.9E-2, ?=1.3), which could be the consequence of Cu being an essential element in OM. The OxC with a lower OM content (TOC < 5 %) showed a different distribution of metals. V, Cr and Cu found in OM was found to have a significant positive correlation with TOC (p<2.9E-2, ?>0.05). The Kellaways Sand core showed that the V, Co, Ni, Cu, Zn and As had a strong connection both with TOC (p<1.6E-3, ?=0.03~37.3) and pyrite (p<4.9E-3, ?=0.23~5.5), suggesting that both OM and pyrite were major metal sinks in Kellaways Sand. The more significant positive correlation between V, Cr and pyrite compared to V, Cr and TOC implies that pyrite contains more V and Cr than did TOC. Other studies used the OxC from Bletchley, the Kimmeridge Clay (KC) from Kimmeridge Bay, Dorset, and Tertiary mud (Wittering Formation-WF) from Whitecliff, Isle of Wight due to their distinctive OM characteristics (AOM rich and/or phytoclast rich). Organic material was isolated for identification and analysis using a novel extraction method (heavy liquid extraction) and traditional methods involving HF digestion. These organic materials were then used to determine influences of extraction on HOCs (toluene and naphthalene) sorption and desorption. Organic petrology classification was applied to identify the various types of isolated OM. AOM from KC displayed a higher sorption capacity (Kd=6,481, 59,670; for toluene and naphthalene, respectively) compared to literature values. AOM rich sorbent extracts demonstrated a higher absorption capacity than the phytoclasts rich sorbents (e.g. WF, Kd=219, 20,661; for toluene and naphthalene, respectively). However, the phytoclast rich sorbent showed a higher sorption/desorption hysteresis capacity for toluene than AOM. Implications of results in landfill design/risk assessment and modelling are discussed.
Стилі APA, Harvard, Vancouver, ISO та ін.
46

Åkesson, Patrik. "Molecular Dynamics of the Adsorption of Organic Molecules on Organic Substrates." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-103688.

Повний текст джерела
Анотація:
A great interest has been shown for self-assembled organic nano-structures that can be used in a variety of optoelectronic applications, from element detection to home electronics. It is known from experimental research that sexiphenyl (6P) grown on muscovite mica substrate form uniaxially self-assembled nanofibers which together with sexithiophene (6T) deposited on top gives the possibility to tune their polarized emission. A key to continue develop and explore the full potential of this technique is to understand the mechanisms behind the growth. This thesis investigate the initial growth of 6P and 6T on a 6Pˆ nanofiber substrate through Molecular Dynamics (MD) simulations. The adsorption of the molecules has been simulated with Simulated Annealing (SA) where 6P align perfectly with the substrate for all coverage while 6T starts to align after a certain amount of coverage. Both molecules show a monotonic increase in the adsorption energy per molecule with an increasing coverage. The surface diffusion of the molecules has been studied and shows a higher movement for both in the direction of the longmolecular axis.
Project P25154-N20 "Hetero-epitaxy of organic-organic nanofibers"
Стилі APA, Harvard, Vancouver, ISO та ін.
47

Odem, Wilbert Irwin Jr. "Natural Organic Matter Interactions with CU(II) in groundwater." Diss., The University of Arizona, 1991. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1991_471_sip1_w.pdf&type=application/pdf.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
48

Newby, Ruth. "Gas adsorption studies in metal-organic frameworks." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/32287/.

Повний текст джерела
Анотація:
This thesis describes the synthesis of a novel highly stable metal-organic framework, NOTT-300(Cr), as well as the synthesis of three new mixed metal analogues of NOTT-300 using different compositions of aluminium and chromium. These new MOFs were used in gas sorption experiments to investigate potential selectivity and uses for gas stream separations with particular focus on CO2 and C2 hydrocarbons. The gas adsorption properties of NOTT-300(Al) for CO2 and C2 hydrocarbons are also investigated in detail. Chapter 1 – An introduction to MOFs, including their synthesis and various applications along with examples from the literature is discussed. The potential application of MOFs for difficult industrial separations is considered and a brief background on CO2 and climate change is discussed along with the current issues facing carbon capture technologies. The uses of C2 hydrocarbons and their difficult separation are also assessed. Chapter 2 – A novel Cr(III) containing analogue of NOTT-300 has been successfully synthesised (NOTT-300(Cr)) and the structure solved from the PXRD pattern. The gas adsorption properties, with specific focus on CO2 uptake and selectivity, are described and compared with those obtained for NOTT 300(Al). The CO2 adsorption in NOTT-300(Cr) was further probed using ¬in situ¬ gas loaded PXRD studies. Flow experiments were used along with IAST calculations to assess and compare the CO2/CH4 and CO2/N2 selectivity in NOTT-300(Cr) and compared with NOTT-300(Al). Although the CO2 adsorption capacity is higher for NOTT-300(Cr) than for NOTT 300(Al) (10.1 vs. 9.5 mmol g-1 at 273 K and 20 bar), the CO2 selectivity is lower due to an increased adsorption capacity for other gases such as CH4. Chapter 3 – A mixed metal NOTT-300 series containing varying amounts of Al and Cr, i.e. NOTT-300(AlCr2:1), NOTT-300(AlCr1:1) and NOTT 300(AlCr2:3), was synthesised in order to further probe the effect of the metal content on the CO2 adsorption and selectivity of this framework. Each of the materials show high CO2 adsorption capacity, however, there appears to be no specific trend in adsorption properties with respect to metal ratio. The CO2 adsorption and selectivity in NOTT 300(AlCr2:1) was further investigated using dual component adsorption isotherms and in situ gas loaded PXRD and IR studies. The three different OH groups present in the mixed metal materials form interactions of differing strength with the CO2 molecules, explaining the different adsorption properties across the series. The mixed metal series displays higher CO2 adsorption than NOTT-300(Al), but lower CO2 selectivity. When compared to NOTT 300(Cr) the CO2 adsorption of the heterometallic series is lower but the selectivities are comparable. Chapter 4 – The adsorption of C2 hydrocarbons and possible C2 separations and C2/C1 separations are investigated and compared in the NOTT-300 materials described in this thesis. All frameworks display considerably higher adsorption capacity for C2 hydrocarbons vs. CH4. However, the potential for C2 separations was more varied, with NOTT-300(AlCr1:1) showing moderate C2H4/C2H6 selectivity (2.7:1), while the calculated selectivity for NOTT 300(Cr) was negligible (1:1). NOTT-300(Al) was used in breakthrough experiments to assess the separation capability of two different hydrocarbon mixtures (C2H2/C2H4 and C2H4/C2H6).
Стилі APA, Harvard, Vancouver, ISO та ін.
49

Wei, Zongsu. "Trichloroethylene (TCE) Adsorption Using Sustainable Organic Mulch." University of Toledo / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1279301053.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
50

Barnabas, Ian Joseph. "Sample preparation in environmental organic analysis." Thesis, Northumbria University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245205.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Ми пропонуємо знижки на всі преміум-плани для авторів, чиї праці увійшли до тематичних добірок літератури. Зв'яжіться з нами, щоб отримати унікальний промокод!

До бібліографії