Polymers are subjected to physical and chemical changes during their processing, service life, and further recovery, and they may also interact with impurities that can alter their composition. These changes substantially modify the stabilisation mechanisms and mechanical properties of recycled polymers. The assessment of the quality properties of recycled polymers is therefore crucial to guarantee the performance of recyclates in further applications. Three key quality properties have been defined for this quality analysis: degree of mixing (composition), degree of degradation, and presence of low molecular weight compounds (degradation products, contaminants, additives). Furthermore, detailed knowledge about how the different stages of their life cycle affect the degree of degradation of polymeric materials is important when discussing their further waste recovery possibilities and the performance of recycled plastics. A dual-pronged experimental approach employing multiple processing and thermo-oxidation has been proposed to model the life cycle of recycled high-impact polystyrene (HIPS used in packaging applications, and electrical and electronic equipment (E&E). Both reprocessing and thermo-oxidative degradation are responsible for coexistent physical and chemical effects (chain scission, crosslinking, apparition of oxidative moieties, polymeric chain rearrangements, and physical ageing) on the microstructure and morphology of polybutadiene (PB) and polystyrene (PS) phases; these effects ultimately influence the long-term stability, and the rheological and mechanical behaviour of HIPS. The PB phase has proved to be the initiation point of HIPS degradation throughout the life cycle. Thermo-oxidation seems to have more severe effects on HIPS properties; therefore, it can be concluded that previous service life may be the part of the life cycle with the greatest influence on the recycling possibilities and performance of HIPS recyclates in second-market applicat / Vilaplana Domingo, FJ. (2008). Analytical strategies for the quality assessment of recycled high-impact polystyrene (HIPS) [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/2186

The first of a series of mass mortalities of Nile crocodiles in the Olifants and Letaba rivers in the Kruger National Park (KNP) was reported in the winter of 2008. The present study investigated the levels and possible effects on eggshell thickness of inorganic elements and organic pollutants in Nile crocodile eggs from these rivers, and comparing them with eggs from a reference crocodile farm and a reference dam inside the KNP. The egg contents were analyzed for chlorinated organic compounds and brominated flame retardants. Eggshells and egg contents were analyzed for inorganic elements. The elemental concentrations in the eggshells and contents were low when compared with previous studies. The highest concentrations were found in the eggs from the reference crocodile farm. The eggs from the reference dam and the crocodile farm had thicker shells, and the eggs from the Olifants and Letaba rivers had thinner shells. Not all eggs in a female develop at the same rate, while eggshell formation presumably occurs at the same time for all eggs. As a result, the elemental profile of egg contents may differ between eggs of the same clutch, but less so for the shells. Weak or no associations were found between the elemental concentrations of the content and eggshells and eggshell thinning. A possible organic pollutant–induced eggshell thinning effect was found. The compounds found were not at levels that could have caused the mortalities, but may affect the sex ratios through endocrine disruption. Further studies are therefore required. / Thesis (M.Sc (Environmental Science))--North-West University, Potchefstroom Campus, 2011.

The first of a series of mass mortalities of Nile crocodiles in the Olifants and Letaba rivers in the Kruger National Park (KNP) was reported in the winter of 2008. The present study investigated the levels and possible effects on eggshell thickness of inorganic elements and organic pollutants in Nile crocodile eggs from these rivers, and comparing them with eggs from a reference crocodile farm and a reference dam inside the KNP. The egg contents were analyzed for chlorinated organic compounds and brominated flame retardants. Eggshells and egg contents were analyzed for inorganic elements. The elemental concentrations in the eggshells and contents were low when compared with previous studies. The highest concentrations were found in the eggs from the reference crocodile farm. The eggs from the reference dam and the crocodile farm had thicker shells, and the eggs from the Olifants and Letaba rivers had thinner shells. Not all eggs in a female develop at the same rate, while eggshell formation presumably occurs at the same time for all eggs. As a result, the elemental profile of egg contents may differ between eggs of the same clutch, but less so for the shells. Weak or no associations were found between the elemental concentrations of the content and eggshells and eggshell thinning. A possible organic pollutant–induced eggshell thinning effect was found. The compounds found were not at levels that could have caused the mortalities, but may affect the sex ratios through endocrine disruption. Further studies are therefore required. / Thesis (M.Sc (Environmental Science))--North-West University, Potchefstroom Campus, 2011.

Une étude approfondie a été menée dans deux zones distinctes (Estarreja au Portugal, noté EST, et Casier Peyraud 6 en France, noté PEY) pour évaluer les niveaux de contamination, ainsi que leurs comportements dans des anthroposols et les risques potentiels de ces contaminants pour des organismes vivants du sol. L’objectif principal étant d’évaluer la mobilité environnementale des retardateurs de flamme bromés (RFBs) dans un écosystème terrestre, notamment vers les vers de terre (Eisenia fetida) et les plants (luzerne (Medicago sativa), cresson (Nasturtium officinale), moutarde blanche (Sinapsis alba), dans une prospective d’évaluation du risque de transferts de ces molécules.Le facteur de bioaccumulation (BAF) ainsi que les indices SET et ERITME ont été calculés. Le BAF permet de déterminer si une substance est accumulée dans un organisme donné et s’il existe un risque d’entrée et de diffusion tout au long de la chaine alimentaire. Les indices SET et ERITME permettent de classer les sites testés en fonction du transfert efficace des COs par les anthroposols aux organismes testés, et d’avoir une idée du risque potentiel pour l’écosystème. L’indice SET donne une idée globale de l’excès de transfert pour tous les contaminants dans les matrices étudiées. L’indice ERITME permet d’évaluer le risque environnemental global inhérent associé à l’excès de transfert des contaminants considérés. Compte tenu des valeurs ERITME, les matrices étudiées peuvent être classées dans un ordre de toxicité qui est aussi conforme pour l’ensemble des organismes testés (E. fetida, luzerne, cresson et moutarde). / A comprehensive study was conducted in two distinct areas (Estarreja in Portugal, noted EST, and Casier Peyraud 6 in France, noted PEY) to assess the contamination levels as well as their behavior in soils and the potential risks posed by these contaminants to soil organisms. The principal aim was to evaluate the environmental mobility of brominated flame retardants (BFRs) in a terrestrial ecosystem, namely to earthworms (Eisenia fetida) and plants (alfalfa (Medicago sativa), watercress (Nasturtium officinale) and white mustard (Sinapis alba)), concerning the BFRs transfer risk evaluation. The Bioaccumulation factor (BAF) as well as the SET and ERITME indexes were calculated. The BAF allow to determine if a substance is accumulated in a certain organism and if there exists the risk of entry and diffusion along the food chain. SET and ERITME indexes allow to rank the tested sites according to the effective OCs transfer from anthroposoils to the tested organisms and have an idea of the potential risk to the ec system. The SET index gives a global idea of the excess of transfer for all the contaminants in the studied matrices. The ERITME index allows to evaluate the possible inherent global environmental risk associated with the excess of transfer on the considered contaminants. Considering the ERITME values, the studied matrices can be classified in an apparent increasing order of toxicity that it is also in accordance with the levels of OCs found in the all the tested organisms (E. fetida, alfalfa, cress and mustard).

This diploma thesis was focused on the analysis of four compounds from brominated flame retardants group, namely pentabromoethylbenzene, hexabromocyclododecane, hexabromobenzene and tetrabromobisphenol A. Matrices were represented by four soil samples and four seat of fire samples. In addition, bisphenol A was also determined. First of all, process of extraction of analytes from matrices was optimized. Three different extraction techniques were tested (pressurized solvent extraction, microwave-assisted extraction and ultrasound-assisted extraction). Next step was to verify stability of target compounds in strongly acidic conditions and to optimize clean-up of extract by column chromatography. Gas chromatography with electron capture detection (GC-ECD) was chosen as an appropriate analytical method for the determination of brominated flame retardants. Bisphenol A was determined by gas chromatography with mass spectrometric detection (GC-MS). The derivatization of phenolic analytes before their final analytical determination was also essential.