Sediments excavated from dredging operations are known as dredged materials. Beneficial reuse of dredged materials in confined utilization facilities (CUFs) is a new approach that has the potential to productively utilize large quantities of dredged materials. However, several factors can inhibit the use of dredged materials in CUFs. In this study, high levels of salts and polycyclic aromatic hydrocarbons (PAHs) were investigated. In the first part of this study, 176,000 m3 of saline dredged materials was placed into a CUF. In less than 4 years, most of the dredged materials had developed horizonation and converted to Inceptisols. The formation of pedogenic Bg horizons in these soils occurred after a polygonal prism network had developed which partially disintegrated into a blocky structured, oxidized horizon with an abundance of redoximorphic features. During the study period, the soil chemistry of the weathering dredged materials shifted from Na-dominated to Ca and Mg-dominated system, allowing plant invasion. In the second part of the study, a bench-scale greenhouse bioremediation experiment was conducted to test the effectiveness of biosolids, compost, and straw at enhancing PAH degradation. Initial concentrations of PAHs decreased significantly after 150 days using standard methods of extraction. However, at 327 days the concentrations of many PAHs, especially those with higher molecular weights, had rebounded close to initial levels. This indicates that PAH bioremediation studies using organic matter additions and conducted using standard methods of extraction need to be carried out longer periods of time or that extraction methods need to be improved. / Master of Science

I denna studie har förekomst av Polycykliska aromatiska kolväten (PAHer) i musslor undersökts. Syftet var att undersöka vilka PAHer som förekom, i vilka halter och ifall dessa nivåer överskred gränsvärdena för humankonsumtion. Vissa PAHer är skadliga för människan då de kan ge upphov till cancer. Vilda och odlade musslor jämfördes för att se om innehållet av PAHer skiljde sig åt. Musslor från sex olika provplatser undersöktes. Två prov handplockades vilda utanför Stenungssund, Sverige. Danska vildfångade musslor undersöktes, likaså vildfångade svenska musslor. Även odlade musslor från Irland och odlade musslor från Sverige undersöktes. Resultaten visar att fluoranten, fenantren, pyren, krysen, benzo(e)pyren och benzo(b)fluoranten var de ämnen som förekom i högst halter. Av de alkylerade PAHerna var 2-metylantracen-9,10-dion, 2-metylfenantren, 2-metylkrysen och 1-metylfluoranten vanligast. Halterna av oxy-PAHer var låga, förutom för antracen-9,10-dion, benzo(h)quinolin samt 2-metylantracen-9,10-dion. Utifrån de riktvärden som finns för humankonsumtion överskred inga musslor gränsvärdena. Inga skillnader kunde ses mellan odlade och vilda musslor. Sammanfattningsvis förekommer PAHer i musslor, men inte i sådan halt att musslorna inte är godkända som livsmedel. / In this study, the presence of PAHs in mussels were investigated. The aim was to examine the occurrence of PAHs, at which levels and if these levels exceeded the limits for human consumption. Some PAHs are toxic to humans as they can give rise to cancer. Wild and cultivated mussels were compared to see if the content of PAHs was different. Mussels from six different test sites were examined. Two wild samples were hand-picked outside Stenungsund, Sweden. Furthermore, wild clams from both Sweden and Denmark were sampled. Also cultured mussels from Ireland and cultured mussels from Sweden were investigated. The results show that fluoranthene, phenanthrene, pyrene, chrysene, benzo(e)pyrene and benzo(b)fluoranthene were the compounds that occurred at the highest levels. The most common alkylated PAHs were 2-methylanthracene-9,10-dione, 2-methylphenanthrene, 2-methylchrysene and 1-methylfluoranthene. The concentrations of oxy-PAHs were low except for anthracene-9,10-dione, benzo(h)quinoline and 2-methylanthracene-9,10-dione. Based on the guideline values available for human consumption, no mussels exceeded the limits. No differences could be seen between wild and cultivated mussels. To sum up, PAHs were found in mussels, but not at such concentration that the mussels would not be approved for human consumption.

Studies were undertaken to determine ecotoxicological effects of model manufactured or engineered nanoparticles (ENPs), either alone or in combination with a representative polycyclic aromatic hydrocarbon (i.e. PAHs: fluoranthene) at different levels of biological organisation (viz. biochemical, histological and behavioural levels) in a sentinel, widely distributed marine invertebrate species, Mytilus edulis. With the current and predicted levels of pollution in the marine and coastal environment, there is an urgent need to establish the potential effects of persistent and emerging contaminants which includes ENPs and PAHs, to protect human and environmental health. In this study, initially, it was aimed to optimise the induction of biotransformation enzyme P-450 as a robust biochemical tool and good progress (chapter 3) was made to standardise P-450 in mussel. Due to certain technical and logistic limitations however we could not apply measurement of P-450 as potential biochemical biomarkers in this species. The possibility of using glutathione levels instead in the cell-free component of haemolymph samples as an indicator of oxidative stress, in an analogous way to that used in mammals was evaluated (chapter 4). The evidence suggested that cell-free haemolymph samples collected from adductor muscle of Mytilus edulis may be significantly contaminated with intracellular contents of myocytes of this organ (i.e. adductor muscle) and adductor muscle tissue is more generally useful to determine glutathione system responses. The validation study of different assays using copper as a relevant environmental contaminant (chapter 5) suggested the existence of clear relationships between genotoxic (as determined by induction of DNA strand breaks using the Comet assay) and higher level effects. The results further suggested the feasibility of adoption of an integrated approach and robustness of selected biomarkers to evaluate short and long-term toxic effects of pollutants. A multiple biomarker approach was then used to determine the potential interactive effect of C60 fullerenes in combination with fluoranthene. Where appropriate analytical tools (i.e. ICP-MS, GC-MS) were used to determine the levels of contaminant exposure and characterise the properties of the ENPs. The combined exposure of fluoranthene and C60 fullerenes produced enhanced biological damage at approximately at an- “additive” rather than synergistic level, which appeared to be as a result of oxidative stress (chapter 6). The final experiments were carried out in both the early and adult life stages to test the potential toxicity resulting from photochemical transformation of C60 fullerenes in Mytilus edulis (chapter 7). In general, the results showed, for the first time, genotoxic and developmental impact of the photochemically transformed C60 fullerenes at different life stages of marine mussel. Further research is required to identify the degraded products of C60 fullerenes and to understand the mechanism by which fresh and aged C60 fullerenes induces biological responses including oxidative stress and affect ecologically relevant aquatic organisms at different life stages. The thesis has taken the opportunity to discuss (chapter 8) the importance of applications of biological responses in hazard and risk assessment posed by anthropogenic chemicals in a broader context.

No description available.

Um dos principais problemas ambientais que encaramos hoje é a contaminação do solo por vazamento de tanques de armazenagem de combustíveis. Os combustíveis armazenados se compõem de vários hidrocarbonetos de petróleo, entre eles os hidrocarbonetos policíclicos aromáticos. Eles são selecionados pela US EPA e pelo NIOSH como prioritários, devido à carcinogenicidade, mutagenicidade e sua persistência no ambiente. Este trabalho propõe meios de recuperação de solos contaminados utilizando a vermicompostagem. Investigou-se o papel da matéria orgânica durante o processo para melhorar a atividade de degradação no sistema solo, bem como o papel da minhoca. Em diferentes caixas foi adicionado solo dopado a 2% de diesel e quantidades estabelecidas de esterco bovino. A inoculação foi realizada com minhoca Eisenia fetida. Foram realizadas 7 coletas durante 3 meses e feitas as determinações dos HPAs por cromatografia líquida de alta eficiência (marca shimadzu, com detector UV-Vis e de fluorescência, utilizando uma coluna C-18), além de análises que indicam a humificação. Verificou-se, pela concentração dos contaminantes durante o processo, que a técnica de vermicompostagem pode ser aplicada para remediar solos contaminados por HPAs. As vantagens da vermicompostagem são: pode ser realizada no próprio local contaminado, é um processo natural, deixa o solo mais rico em nutrientes, além de ser um processo economicamente viável. Durante o processo, percebem-se diferenças nas características físico-químicas do solo devido ao processo de mineralização e um aumento do teor de ácido húmico. / One of the main environmental problems that we face today is the soil contamination due to storage fuel tanks leakages. Fuels are comprised of a variety of hydrocarbons, among them are the polycyclic aromatic hydrocarbons (PAHs). Those are classified by US-EPA and NIOSH as prioritary contaminants, due to their carcinogenic and mutagenic characteristics and their persistence in the environment. This work proposes ways of recovering contaminated soil with such hydrocarbons using vermicomposting. It was investigated the role of organic matter during the process to improve the PAHs degradation in the soil system, as well as the influence of the earthworms. In different boxes it was added soil doped with 2% of diesel and established amounts of manure cast. The inoculation was carried out with Eisenia foetida earthworm. Seven samplings were performed during three months and the PAHs determined by HPLC, as well as analyses that indicated the humification. By following the contaminants concentration during the process, it was observed that vermicomposting can be applied to clean up contaminated soils by degrading the contaminants, proving the vermicomposting is an useful tool for soil remediation. The advantages of the vermicomposting are: it can be carried out in situ; it is a natural process that leaves the soil enriched with nutrients; and it is economically viable. During the process, differences in the physico-chemical characteristics of the soil were observed due to the mineralization process and an increase in the humic acid content. The sorption of naphthalene, antracene and benzo(a)pirene in soil and in vermicompost was also studied, in order to verify the ability and availability of those compounds for the degradation process. The increase of the number of aromatic rings takes to a greater sorption in the environmental matrices soil and vermicompost.

Um dos principais problemas ambientais que encaramos hoje é a contaminação do solo por vazamento de tanques de armazenagem de combustíveis. Os combustíveis armazenados se compõem de vários hidrocarbonetos de petróleo, entre eles os hidrocarbonetos policíclicos aromáticos. Eles são selecionados pela US EPA e pelo NIOSH como prioritários, devido à carcinogenicidade, mutagenicidade e sua persistência no ambiente. Este trabalho propõe meios de recuperação de solos contaminados utilizando a vermicompostagem. Investigou-se o papel da matéria orgânica durante o processo para melhorar a atividade de degradação no sistema solo, bem como o papel da minhoca. Em diferentes caixas foi adicionado solo dopado a 2% de diesel e quantidades estabelecidas de esterco bovino. A inoculação foi realizada com minhoca Eisenia fetida. Foram realizadas 7 coletas durante 3 meses e feitas as determinações dos HPAs por cromatografia líquida de alta eficiência (marca shimadzu, com detector UV-Vis e de fluorescência, utilizando uma coluna C-18), além de análises que indicam a humificação. Verificou-se, pela concentração dos contaminantes durante o processo, que a técnica de vermicompostagem pode ser aplicada para remediar solos contaminados por HPAs. As vantagens da vermicompostagem são: pode ser realizada no próprio local contaminado, é um processo natural, deixa o solo mais rico em nutrientes, além de ser um processo economicamente viável. Durante o processo, percebem-se diferenças nas características físico-químicas do solo devido ao processo de mineralização e um aumento do teor de ácido húmico. / One of the main environmental problems that we face today is the soil contamination due to storage fuel tanks leakages. Fuels are comprised of a variety of hydrocarbons, among them are the polycyclic aromatic hydrocarbons (PAHs). Those are classified by US-EPA and NIOSH as prioritary contaminants, due to their carcinogenic and mutagenic characteristics and their persistence in the environment. This work proposes ways of recovering contaminated soil with such hydrocarbons using vermicomposting. It was investigated the role of organic matter during the process to improve the PAHs degradation in the soil system, as well as the influence of the earthworms. In different boxes it was added soil doped with 2% of diesel and established amounts of manure cast. The inoculation was carried out with Eisenia foetida earthworm. Seven samplings were performed during three months and the PAHs determined by HPLC, as well as analyses that indicated the humification. By following the contaminants concentration during the process, it was observed that vermicomposting can be applied to clean up contaminated soils by degrading the contaminants, proving the vermicomposting is an useful tool for soil remediation. The advantages of the vermicomposting are: it can be carried out in situ; it is a natural process that leaves the soil enriched with nutrients; and it is economically viable. During the process, differences in the physico-chemical characteristics of the soil were observed due to the mineralization process and an increase in the humic acid content. The sorption of naphthalene, antracene and benzo(a)pirene in soil and in vermicompost was also studied, in order to verify the ability and availability of those compounds for the degradation process. The increase of the number of aromatic rings takes to a greater sorption in the environmental matrices soil and vermicompost.

Polycyclic aromatic hydrocarbons (PAHs) are environmentally significant compounds due to the toxicity of some members. They are ubiquitous and are persistent bioaccumulative toxins(PBTs). The toxicity of PAHs represents a risk to human health, and there are varied risk assessment approaches to quantifying the risk posed by PAHs based on exposure routes and scenarios. PAHs are not carcinogenic until they are metabolically activated as the body attempts to break them down and forms reactive metabolites that bind to the DNA causing subsequent replication in the cells. Fundamental to assessing the risk posed by PAHs is understanding the metabolism of PAHs. Since exposure to PAHs is never to single PAHs, understanding what differences may occur in mixtures of PAHs gives accurate assessment of the dangers of PAHs. Understanding the dynamics of complex metabolism vis-a-vis single metabolism of PAHs and possible effects on the toxicity expression of PAHs is a necessary advancement to accurately impact and guide remediation strategies. Studies were carried out comparing the metabolism of the PAHs Phenanthrene (PHE), Flouranthene (FLA) and Benzo[a]pyrene (BAP) in single, binary and ternary mixtures by monitoring the disappearance of the parent compound. It was observed that PAH metabolism in the single PAH experiment differed from metabolism in both binary and ternary mixtures. Enzyme competition was evident in the metabolism of mixtures, changing significantly the metabolism patterns of individual PAHs. PAH structure was also seen to affect metabolism in mixtures and the possible creation of toxicity effects during mixture metabolism. PAH concentration changed over time with faster change during single PAH metabolism followed by ternary mixture metabolism and finally binary metabolism. These results affirm that substrate interactions must be considered in the risk assessment approaches to the dangers posed by exposure to PAHs.

Heterogeneous freezing processes in which atmospheric aerosols act as ice nuclei (IN) cause nucleation of ice crystals in the atmosphere. Heterogeneous nucleation can occur through several freezing mechanisms, including contact and immersion freezing. The mechanism by which this freezing occurs depends on the ambient conditions and composition of the IN. Aerosol properties change through chemical aging and reactions with atmospheric oxidants such as ozone. We have conducted a series of laboratory experiments using an optical microscope apparatus equipped with a cooling stage to determine how chemical oxidation changes the ability of atmospheric aerosols to act as IN. Freezing temperatures are reported for aerosols composed of fresh and oxidized soot and polyaromatic hydrocarbons (PAHs) including anthracene, phenanthrene, and pyrene. Our results show that oxidized soot particles initiate ice freezing events at significantly warmer temperatures than fresh soot, 3 °C on average. All oxidized PAHs studied had significantly warmer freezing temperatures than fresh samples. The chemical changes presumably causing the improved ice nucleation efficiency were observed using Fourier Transform Infrared Spectroscopy with Horizontal Attenuated Total Reflectance (FTIR-HATR). The addition of C=O bonds at the surface of the soot and PAHs led to changes in freezing temperatures. Finally, we have used classical nucleation theory to derive heterogeneous nucleation rates for the IN compositions in this research. The overall efficiency of the IN can be compared in order of least efficient to most efficient: fresh phenanthrene, fresh anthracene, fresh soot, oxidized phenanthrene, fresh pyrene, oxidized anthracene, oxidized soot, and oxidized pyrene. Overall oxidation of aerosols increases their ability to act as IN. Our results suggest that oxidation processes facilitate freezing at warmer temperatures at a broader range of conditions on the atmosphere.

Persistent organic pollutants (POPs), which include polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), are widely distributed in the environment. Some investigations have demonstrated that these pollutants will cause potential impacts such as carcinogenic and mutagenic for human health. In this study, we analyzed the concentrations and distributions of PAHs and PCBs in sediments of the Er-ren River, as well as the relations with total organic carbon (TOC) and particle sizes. Several molecular ratios were utilized to distinguish the major sources in this study. Results showed that PAH and PCB concentrations in Er-ren River ranged from 12.1 to 1460 and 0.45-591 (ng/g dw), respectively. The maximum concentrations of PAHs and PCBs were mostly found in sediments from Sanyegong River. In comparison with other studies all over the world, the concentrations of PAHs in this study were between low and mid-low levels. PCB concentrations in sediments of the Er-ren River were lower than those reported from previous studies. PAH and PCB concentrations showed no significant correlation between TOC and particle size. Petrogenic and petroleum combustion origin were the main sources of PAHs in sediments of Er-ren River In addition, perylene was the most dominant compound in Er-ren River, suggesting that it could be a useful indicator to differentiate various PAH sources in sediments. The results of hierarchical cluster analysis (HCA) and principal components analysis (PCA) indicated that PAH groups were clustered based on the loading of perylene, while PCB groups were clustered by the compositional homologues of PCBs. Comparing with sediments quality guidelines (SQGs), the PAH concentrations in all the sampling sites were below ERL value, suggesting that few adverse ecological effects would arise from the PAHs. However, the PCB concentrations in 14 sampling sites ranged between TEL and PEL values, indicating that adverse effects could arise for benthic organisms. The £UESBTUFCV of PAHs and the toxic equivalents (TEQ) of PCBs were both lower than quality values reported, suggesting that adverse ecological effects might be not expected.

PAHs are hydrophobic organic compounds, which have received considerable attention because of their high bioaccumulation, toxicity, carcinogenicity, and mutagenicity. Because of their hydrophobic characteristics, PAHs intent to adsorb on particles, most of PAHs contained in wastewaters are treated biologically, especially in activated sludge systems. But due to the low construction cost and high efficiency, macrophyte-based treatment systems received increasing attention lately. In this work, batch experiments were conducted to study the adsorption behaviors between the aquatic plant (Najas graminea Del.) and PAHs aqueous solutions, including acenaphthene (Acp), fluorene (Flu), phenanthrene (Phe) and pyrene (Pyr). The interactions between different PAHs and if the plant conditions affected the adsorption were also discussed. The kinetic studies showed that the more hydrophobic the PAHs are, the faster the equilibriums achieve, The kinetic constants were found to correlate with Kow. Linear adsorption isotherms were observed in all the adsorption experiments. The adsorption equilibrium constants (K) increase with the Kow indicates that the hydrophobicity of the PAHs dominates the adsorption behaviors. The existence of small mount of Pyr could lower the adsorption of Phe on the plant, while Flu couldn¡¦t. Because the hydrophobicity of Flu is too weak to compete with Phe, so the competition was not observed. The plant after dry process had even better performances in both kinetic and adsorption experiments, which provide more flexibility when put this technology into practice.