Cette étude vise à explorer les mécanismes de tolérance des plantes aux xénobiotiques organiques de la famille des HAPs (phénanthrène), à travers l’analyse de l’impact des évènements de spéciation par hybridation et duplication génomique (allopolyploïdie). Nous avons pour cela mené une approche comparative sur un modèle de spéciation allopolyploïde récente, constitué des espèces parentales hexaploïdes S. alterniflora et S. maritima, et de l’allopolyploïde S. anglica qui résulte de la duplication du génome de leur hybride F1 S. x townsendii. Une approche intégrative basée sur des analyses physiologiques et moléculaires nous a permis de montrer que chez Spartina l’hybridation et le doublement du génome augmentent la tolérance aux xénobiotiques. Le parent paternel S. maritima se montre particulièrement sensible au phénanthrène par rapport au parent maternel S. alterniflora. Différentes analyses transcriptomiques ont permis l’identification de novo de transcrits spécifiquement exprimés en condition de stress, et l’annotation des petits ARNs (miARNs, leurs gènes cibles, et siARNs) agissant en tant que régulateurs de l’expression des gènes et la régulation des éléments transposables. Les analyses d’expression différentielle en réponse au stress ont permis de générer un modèle de régulation (miARN/gènes cibles) en réponse aux HAPs, testé par validation fonctionnelle en système hétérologue chez Arabidopsis. Un travail exploratoire de profilage du microbiome de la rhizosphère des spartines exposées au phénanthrène a été réalisé pour préciser les mécanismes de dégradation des xénobiotiques dans l’environnement en vue d’une application dans les stratégies de remédiation verte. / We explored mechanisms involved in tolerance to organic xenobiotics belonging to PAHs (phenanthrene), in the context of allopolyploid speciation (hybrid genome duplication). We developed a comparative approach, using a recent allopolyploidization model including the hexaploid parental species S. alterniflora and S. maritima, and the allopolyploid S. anglica, which resulted from genome doubling of the F1 hybrid S. x townsendii. Integrative approach based on physiological and molecular analyses highlights that hybridization and genome doubling enhance tolerance to xenobiotics in Spartina. The paternal parent S. maritima exhibits higher sensitivity compared to the maternal parent S. alterniflora. Various transcriptomic analyses were performed, to identify de novo stress responsive transcripts, and to annotate small RNAs (miRNAs, their target genes, and siRNAs) involved in gene expression and transposable element regulations. Differential expression analyses in response to stress allowed us to develop a putative miRNA regulatory network (miRNA/target genes) in response to PAH, functionally validated in Arabidopsis as heterologous system. An exploratory profiling of Spartina rhizosphere microbiome exposed to phenanthrene was also performed to characterize environmental degradation abilities, in the perspective of optimizing green remediation strategies.

The need of understanding transport processes of contaminants in groundwater has grownalong with the discovering of contamination of soil and groundwater due to industrialization.Mobility of an organic contaminant in the soil is affected by its partitioning to dissolvedorganic carbon, DOC. Partitioning of hydrophobic organic contaminants, HOCs, to DOC isdescribed by the contaminant’s KDOC value. The effects of DOC on transport processes oforganic contaminants with groundwater are still relatively unexplored even though somereviews have been carried out in this particular field of research. The aim of this thesis workwas to investigate transport processes for the PAH phenanthrene and the phthalate Di(2-ethylhexyl) phthalate, DEHP, with DOC by constructing a transport model with the computerprogram FEFLOW 6.1. The thesis work was performed as part of an ongoing Research &Development project investigating alternative remediation techniques at Domsjö industrialsite, located 2 km south of Örnsköldsvik. Generally, the groundwater at the site was characterized by low phenanthrene and DEHPcontent together with high DOC content. In the sampling points with highest reportedcontaminant concentration also DOC was present in highest concentrations. During theperformed literature study it was found that tabulated KDOC values for phenanthrene wasavailable but not for DEHP, which had to be calculated based on available KOC and KOWvalues. Five different modeling scenarios were developed: 1. Transport of phenanthrene with KDOC minimum value. 2. Transport of phenanthrene with KDOC maximum value. 3. Transport of phenanthrene with KDOC median value. 4. Transport of DEHP with KDOC calculated with KOC. 5. Transport of DEHP with KDOC calculated with KOW. Calculations of contaminant concentration in groundwater were made with an equation thatrequires both site and contaminant specific constants. These constants had to be estimatedduring this thesis work, which resulted in insecurities possibly affecting the model results.However, the minimum and the median value of KDOC showed best modeled phenanthreneconcentration after six years compared to measured values. Best result of modeledconcentrations of DEHP was obtained with KDOC calculated with KOC. Correlation analysis ofDOC and contaminants showed a significant correlation between DOC and phenanthrene at99% confidence level, and between DOC and DEHP at 90% confidence level. / I takt med ökad kännedom om industriellt förorenade områden har det också blivitbetydelsefullt att känna till de processer som påverkar transport av föroreningar medgrundvattnet. Rörligheten av en hydrofobisk organisk förorening, HOC, påverkas av dessfördelning till löst organiskt kol, DOC, och beskrivs med fördelningskoefficienten KDOC.Effekterna av DOC på föroreningstransporten är relativt okända trots att forskning harbedrivits inom området. Syftet med examensarbetet var att undersöka spridning av fenantren(ämnesklass PAH) och Di(2-etylhexyl)ftalat med DOC genom att konstruera enföroreningsspridningsmodell i datorprogrammet FEFLOW 6.1. Examensarbetet utfördes somdel i ett pågående Forsknings & Utvecklingsprojekt med syfte att utreda en alternativsaneringsteknik för Domsjö industriområde, 2 km söder om Örnsköldsvik. Generellt sett karaktäriserades grundvattnet på platsen av låg fenantren- och DEHP-halttillsammans med hög DOC-halt. På samma ställen där föroreningarna förekom i högstakoncentration var också DOC-koncentrationen som högst. Vid genomförd litteraturstudieåterfanns tabellerade KDOC-värden endast för fenantren. KDOC för DEHP saknades och fickberäknas med ekvationer baserat på förhållandet mellan KDOC och KOC respektive KOW. Femolika modelleringsscenarier utvecklades: 1. Spridning av fenantren med minsta tillgängliga KDOC-värde. 2. Spridning av fenantren med högsta tillgängliga KDOC-värde. 3. Spridning av fenantren med median KDOC-värde. 4. Spridning av DEHP med KDOC beräknat med KOC. 5. Spridning av DEHP med KDOC beräknat med KOW. Beräkning av föroreningarnas koncentration i grundvattnet gjordes med en ekvation somegentligen kräver både plats- och föroreningsspecifika konstanter. Då detta inte fanns att tillgågjordes uppskattning av värdena vilket resulterar i osäkerheter som kan ha påverkan påmodellerade resultat. De bästa modellerade koncentrationerna av fenantren efter sex årssimulering jämfört med uppmätta koncentrationer uppnåddes med minsta och median-värdeav KDOC. Bästa modellerade koncentrationerna av DEHP gavs av KDOC beräknat med KOC.Korrelationstest med DOC och respektive förorening visade en signifikant korrelation mellanDOC och fenantren vid 99% konfidensnivå, och mellan DOC och DEHP vid 90% konfidensnivå.

In this thesis work the hydrogenation kinetics of phenanthrene inhibited by the basic nitrogen compound acridine and the non-basic carbazole was investigated. Based on a transient reactor model a steady state plug flow model was developed and kinetic parameters were estimated through nonlinear regression to experimental data. The experimental data was previously collected from hydrotreating of phenanthrene in a bench-scale reactor packed with a commercial NiMo catalyst mixed with SiC. As a first two-step solution, the yields of the hydrogenation products of phenanthrene were predicted as a function of conversion, which subsequently was used to calculate concentration profiles as a function of position in reactor. As a second improved solution, the concentration profiles were calculated directly as a function of residence time, and these results were then used for further analysis. Reaction network 2 in figure 7 was considered sufficient to describe the product distribution of phenanthrene, with a pseudo-first-order rate law for the nitrogen compounds. Both solution methods provided similar results which gave good predictions of the experimental data, with a few exceptions. These cases could be improved by gathering more experimental data or by investigating the effect of some model assumptions. The two-step method thus proved useful in evaluating the phenanthrene reaction network and providing an initial estimate of the parameters, while the onestep method then could give a more precise solution by calculating all parameters simultaneously. As expected, acridine was shown to be more inhibiting than carbazole, both in the produced concentration profiles and estimated parameters. A possible saturation effect was also seen in the inhibition behavior, where adding more nitrogen compounds only had a small additional effect on the phenanthrene conversion. The Mears and Weisz-Prater criteria were found to be inversely proportional to the concentrations of the nitrogen compounds and otherwise only depend on rate constants, with values well below limits for diffusion controlled processes. Sensitivity analyses also supported that the global minimum had been found in the nonlinear regression solution.

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Understanding of the fate of oil in the environment is of utmost importance; however, accurate, predictive models are still in very early stages. To aid in the development of these models, photodegradation of selected polycyclic aromatic hydrocarbons (PAHs) in an n-alkane hydrocarbon matrix was followed for individual PAHs and mixtures of PAHs similar to that found in the Deepwater Horizon spill. Tetracene in tetradecane photodegraded quickest of all observed PAHs, with a loss of 99% after only one hour of irradiation. Binary mixtures of PAHs showed different degradation amounts, including changes in PAH kinetics. These results suggest that the formation of dimers or aggregates as well as photosensitization reaction is important in the degradation of PAHs in oil. Kinetics of PAH photodegradation and PAH sensitized photodegradation will be presented. This information will provide a better understanding of the fate of oil in environmental systems.

Les hydrocarbures aromatiques polycycliques (HAP) sont des polluants persistants très répandus dans les écosystèmes du monde entier. L’utilisation des microorganismes pour la dégradation des HAP est une méthode économique et ayant un grand potentiel. Ce travail avait pour objectif d’étudier la dissolution et la biodégradation du phénanthrène (HAP modèle) en présence de tensioactifs. Les microorganismes choisis dans ce travail sont Pseudomonas putida DSMZ 8368 et un consortium microbien Pyr01. La première partie de la thèse concerne l’étude de l’effet des tensioactifs, de la dispersion et du traitement thermique sur la solubilité et la biodégradation du phénanthrène par P. putida DSMZ 8368. Les meilleurs résultats ont été obtenus en combinant l’utilisation d’un tensioactif Brij 30 (0,5 g L-1) avec un traitement thermique préliminaire. La deuxième partie présente les résultats sur la dégradation du phénanthrène par le consortium Pyr01. La comparaison entre la biodégradation du phénanthrène par P. putida DSMZ 8368 et le consortium Pyr01 a été réalisée. Contrairement à ce qui a été observé dans le cas de la biodégradation par P. putida DSMZ 8368, la présence du Brij 30 (0,5 g L-1) a eu un effet négatif sur la biodégradation du phénanthrène par le consortium Pyr01. La troisième partie de ce travail a consisté en l’étude de la solubilisation du phénanthrène au point de trouble du Brij 30. L’effet de l’abaissement de la température jusqu’à la valeur de la température de culture de P. putida DSMZ 8368 sur la solubilisation du phénanthrène a été également étudié. / Polycyclic aromatic hydrocarbons (PAHs) are persistent pollutants widely represented in ecosystems all over the world. The utilization of microorganisms for degradation of PAHs is an economically effective method having a great potential. The aim of the present work was to study the dissolution and the biodegradation of phenanthrene (model PAH) in the presence of surfactants. The chosen microorganisms were Pseudomonas putida DSMZ 8368 and a microbial consortium Pyr01.The first part of the thesis concerns the study of the effect of surfactants, dispersion and a thermal treatment on solubility and biodegradation of phenanthrene by P. putida DSMZ 8368. The best results were obtained by combining the use of Brij 30 surfactant with a preliminary thermal treatment. The second part presents results on the degradation of phenanthrene by Pyr01 consortium. The comparison between the biodegradation of phenanthrene by P. putida DSMZ 8368 and by Pyr01 consortium was done. Contrary to what has been observed in the case of the biodegradation by P. putida DSMZ 8368, the presence of Brij 30 (0.5 g L-1) had a negative effect on the biodegradation of phenanthrene by Pyr01 consortium. The third part of this work consisted in the study of phenanthrene solubilisation at cloud point of Brij 30. The effect of lowering the temperature to that of the culture conditions for P. putida DSMZ 8368 on the solubilization of phenanthrene was also studied.

Made available in DSpace on 2015-03-26T13:51:55Z (GMT). No. of bitstreams: 1 texto completo.pdf: 638022 bytes, checksum: 770358d90456348a933e0711ab667f05 (MD5) Previous issue date: 2011-07-26 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Polycyclic aromatic hydrocarbons (PAH) consist exclusively of carbon and hydrogen atoms arranged in a linear, angular or clustered. Several PAH suffer enzymatic activation and tend to bind to DNA, causing mutations and replication errors. Many of these molecules are known to be toxic, mutagenic and carcinogenic. The PAH are recalcitrant compounds due to its low water solubility and high sorption to soil. The use of biosurfactants has been an option usually effective for removing hydrophobic organic contaminants in complex matrices such as soil. The surfactin is a lipopeptide synthesized by Bacillus subtilis and highly effective in reduction of tension between water and hydrophobiccompounds.Unlike of an exhaustive extraction, the biosurfactants act by increasing the bioavailability of the contaminant and facilitates its degradation.In this work the experiment of phenanthrene biodegradation was conducted in clayed soils contaminated with 14C-phenanthrene and 4 12C-phenanthrene concentrations (1, 10, 40 and 100 mg g-1). Biodegradation was evaluated with the addition of supplements: surfactin (0.825 mg g-1), yeast extract (1.0 mg g-1) and an inoculum (30 mg g-1) obtained from the addition of diesel to a compost made of the municipal solid waste, for enrichment of microorganisms degraders of hydrocarbons. The flasks were kept at 35 °C for 49 days. The 14CO2 produced was captured in scintillation vials containing 2 ml of KOH (1 mol L-1). The bottles were changed on days 8, 18, 25, 32, 37, 44 and 49. After replacing the vials on the thirtieth-second day, was made a second application of surfactin (0.230 mg g-1) in all treatments. The highest degradation activity was achieved in the first 8 days of incubation, only treatments that received the inoculum. After the eighth day until the new surfactin supplementation (32 days), increased activity was not significant in any of the treatments. The activity increased again after the addition of surfactin further, but at a lower rate than achieved in the first 8 days. This result was attributed to the lower concentration of surfactin and the effects of adsorption of phenanthrene to the soil. The degradation activity in samples with the highest concentration of phenanthrene (100 mg g-1) did not differ in the treatments with and without surfactin. This result suggests that the concentration of bioavailable phenanthrene on this dose remained high enough to sustain the activity of degradation. Supplementation with yeast extract resulted in a lower degradation activity in treatments with 10, 40 and 100 mg g-1 of phenanthrene. In the treatments with the lowest dose of phenanthrene (1 mg g-1), yeast extract stimulated the degradation of the contaminant. It is concluded that supplementation with yeast extract stimulated the degradation of surfactin, which resulted in reducing the degradation of phenanthrene in higher concentrations of the contaminant. The results of the work indicate that the bioremediation of soils contaminated with PAH requires the maintenance of solubilizing agents such as surfactin. Due to the rapid degradation of biosurfactant on the ground, it is suggested that the best strategy is to inoculate microorganisms producers of this class of compounds and the maintenance of favorable conditions to ensure the production of biosurfactants in situ, during the process of bioremediation. / Os hidrocarbonetos policíclicos aromáticos (HPAS) são constituídos exclusivamente por átomos de carbono e hidrogênio e organizados sob forma linear, angular ou agrupada. Diversos HPA ao sofrerem ativação enzimática, tendem a ligar-se ao DNA, c ausando erros de replicação e mutações. Muitas dessas moléculas são reconhecidas como tóxicas, mutagênicas e carcinogênicas. Os HPA são compostos recalcitrantes, em razão de sua baixa solubilidade em água e alta sorção ao solo. O uso de biossurfactantes é uma opção geralmente eficaz na remoção de contaminantes orgânicos hidrofóbicos de matrizes complexas, como o solo. A surfactina é um lipopeptídeo sintetizado por Bacillus subtilis e possui alta atividade de redução da tensão entre compostos hidrofóbicos e a água. Diferente de uma extração exaustiva, os biossurfactantes agem aumentando a biodisponibilidade do contaminante e facilitam a sua biodegradação. Neste trabalho, foi conduzido um experimento de biodegradação de fenantreno em latossolo argiloso, contaminado com 14C-fenantreno e com 4 concentrações de 12C-fenantreno (1, 10, 40 e 100 μg g-1). A biodegradação foi avaliada com a adição dos suplementos surfactina (0,825 mg g-1), extrato de levedura (1,0 mg g-1) e de um inóculo (30 mg g-1), obtido a partir da adição de óleo diesel a composto de resíduo sólido urbano, para enriquecimento de micro-organismos degradadores de hidrocarbonetos. Os frascos foram mantidos a 35 °C por 49 dias. O 14CO2 produzido foi capturado em tubos de cintilação, contendo 2 mL de KOH (1 mol L-1). Os frascos foram substituídos nos dias 8, 18, 25, 32, 37, 44 e 49. Após a troca do frasco no trigésimo segundo dia, foi feita uma segunda aplicação de surfactina (0,230 mg g-1), em todos os tratamentos. A maior atividade de degradação foi alcançada nos primeiros 8 dias de incubação, somente nos tratamentos que receberam o inóculo. Após o oitavo dia, até a nova suplementação com surfactina (32° dia), o aumento da atividade não foi significativo em nenhum dos tratamentos. A atividade voltou a aumentar após a adição suplementar de surfactina, porém, em uma taxa inferior à alcançada nos primeiros 8 dias. Esse resultado foi atribuído à menor concentração da surfactina e a efeitos de adsorção do fenantreno ao solo. Nas amostras com a maior concentração de fenantreno (100 μg g-1) a atividade de degradação não diferiu em função dos tratamentos com e sem surfactina. Esse resultado sugere que a concentração do fenantreno biodisponível, nessa dose, se manteve suficientemente alta para sustentar a atividade de degradação. A suplementação com extrato de levedura resultou em menor atividade de degradação, nos tratamentos com 10, 40 e 100 μg g-1 de fenantreno. Nos tratamentos com a menor dose de fenantreno (1 μg g-1), o extrato de levedura estimulou a degradação do contaminante. Conclui-se que a suplementação com extrato de levedura estimulou a degradação da surfactina, o que resultou em redução da degradação do fenantreno nas maiores concentrações do contaminante. Os resultados do trabalho indicam que a biorremediação de solos contaminados com HPA requer a manutenção de agentes solubilizadores, como a surfactina. Em razão da rápida degradação do biossurfactante no solo, sugere-se que a melhor estratégia seja a inoculação de micro-organismos produtores dessa classe de compostos e a manutenção de condições favoráveis a produção de biossurfactantes in situ, ao longo do processo de biorremediação.

Neonatal hypoxic-ischemic encephalopathy (HIE) is a common clinical problem. Tanshinone IIA is a compound purified from the Chinese herb Danshen ( Radix Salviae Miltiorrhiza Bge). Thrombopoietin (TPO) and Erythropoietin (Epo) are hematopoietic growth factors. The effects of tanshinone IIA, EPO and TPO on hypoxia-ischemia brain injury were investigated in this study, using in vitro model of neural cell culture and an in vivo model of hypoxic-ischemic brain damage. / Our observation provided the first evidence showing the expression of functional TPO receptor c-mpl in central nervous system. It revealed that novel agents TPO, EPO and tanshinone IIA have neuroprotection effects against brain injury induced by hypoxia-ischemia in neonatal rats, and these agents could be developed for clinical applications. / To investigate the effect of TPO, EPO and tanshinone IIA on in-vivo neural protection, a neonatal rat model of hypoxic-ischemic brain damage was established. Our results demonstrated significant and sustained brain injury in the hypoxic-ischemic and vehicle-treated group, measured by the reduction in relative weights of the ipsilateral (right) to the contralateral (left) brain at 1 and 3 weeks post-surgery, compared with those of sham-operated animals. At 3 weeks post-surgery, the hypoxic-ischemic animals had decreased cortical neuron density quantified by neuron-specific enolase (NSE) staining, and compromised sensorimotor functions in response to the postural reflex test. Treatment with TPO, EPO and tanshinone IIA significantly reduced the severity of brain injury, as indicated by the significantly increased ipsilateral brain weight and neuron density. Recoveries of sensorimotor functions (p < 0.05) and histopathology were also observed in animals that received TPO, EPO and tanshinone IIA. The plasma of tanshinone IIA-treated animals exhibited higher antioxidant activities (oxygen radical absorbance capacity assay) than those from vehicle-treated rats. / TPO and TPO receptor (c-mpl) mRNA was identified in human cerebral hemispheres, cerebellum, mouse neural progenitor cell line C17.2 and four neuroblastoma cell lines (SK-N-MC, MHH-NB-11, SK-N-AS and SH-SY-5Y) using RT-PCR methods. TPO proteins were detected in human cerebrospinal fluid (CSF) and plasma by ELISA. Furthermore, TPO receptor c-mpl was confirmed in human cerebral hemispheres, hippocampus, cerebellum, brainstem and spinal cord using immunohistostaining. TPO had a stimulating effect on the growth of neural progenitor cell C17.2 in culture via the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway as demonstrated by Western blot. The anti-apoptotic effects of TPO, EPO on C17.2 cells were demonstrated by staining with Annexin-V and PI. EPO exerted a protective effect against SHSY-5Y cell damage induced by NMDA (N-methyl-d-aspartate), as demonstrated by the MTT and LDH assay. The anti-oxidative property of tanshinone IIA was studied in the C17.2 cell line. Tanshinone IIA increased the viability of these cells subjected to 2,2'-azobis (2-amidino propane hydrochloride) (AAPH)-induced oxidative stress. / by Xia Wen-Jie. / "May 2005." / Advisers: Kwok-Pui Fung, Tai-Fai Fok. / Source: Dissertation Abstracts International, Volume: 67-01, Section: B, page: 0126. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 126-146). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Σκοπός της παρούσας μελέτης είναι η κατανόηση του μηχανισμού ρόφησης του φαινανθρενίου σε δείγματα γαιανθράκων και των αντίστοιχων χουμικών τους οξέων και η διερεύνηση της καταλληλότητας τους ως ροφητικών υλικών για την απορρύπανση ποτάμιων και λιμναίων συστημάτων, στα οποία υπάρχει πρόβλημα ρύπανσης από πολυκυκλικούς αρωματικούς υδρογονάνθρακες. Για την επίτευξη του σκοπού αυτού μελετήθηκαν τέσσερα δείγματα λιγνίτη και δύο δείγματα τύρφης και τα αντίστοιχα δείγματα των χουμικών οξέων. Η μεθοδολογία που ακολουθήθηκε για την απομόνωση των χουμικών οξέων βασίστηκε στην τροποποιημένη μεθοδολογία, που προτείνεται από την IHSS (International Humic Substances Society). Για τη μελέτη της ρόφησης φαινανθρενίου κατασκευάστηκαν οι ισόθερμες καμπύλες ρόφησης, ύστερα από την πραγματοποίηση πειραμάτων ρόφησης με συγκεντρώσεις φαινανθρενίου σε υδατικά διαλύματα 30, 50, 100, 300 και 500 μg/l. Τα αποτελέσματα δείχνουν ότι η ρόφηση στα περισσότερα δείγματα των χουμικών οξέων είναι μεγαλύτερη από ό,τι στα αντίστοιχα δείγματα των μητρικών τους γαιανθράκων. Επίσης στα δείγματα των γαιανθράκων παρατηρείται μεγαλύτερη ρόφηση στις χαμηλές συγκεντρώσεις φαινανθρενίου από ό,τι στις υψηλές, με αποτέλεσμα η ρόφηση να μην είναι γραμμική. Σχετικά με τη χρήση τους ως ροφητικά υλικά για απορρύπανση για δυο δείγματα λιγνίτη προτείνεται η χημική τους επεξεργασία, προκειμένου να χρησιμοποιηθούν ως ροφητικά υλικά, ενώ για τα υπόλοιπα δείγματα η διαφορά στη ροφητική ικανότητα μεταξύ των μητρικών γαιανθράκων και των παραγόμενων χουμικών οξέων δεν είναι τόσο σημαντική, με αποτέλεσμα να μπορεί να χρησιμοποιηθεί απευθείας το μητρικό υλικό / The scope of this study is the determination of the phenanthrene sorption mechanism for some Greek lignite and peat samples, as well as for their extracted humic acids. The scope is to assess their suitability for application in remediation of fresh water environments from polycyclic aromatic hydrocarbons (PAHs) For the extraction of the humic acids, the methodology provided by the IHHS (International Humic Substances Society) with some alterations, was applied. The sorption experiments were conducted by mixing 0,004 g of the sorbent within water solutions of phenanthrene at different concentrations of 30, 50, 100, 300 and 500 μg/l. The results show that phenanthrene sorption is higher in the humic acid samples rather than in the original lignite and peat. The original samples display higher sorption at low phenanthere concentration solutions (30 μg/l) than at the denser phenanthrene concentration solution (500 μg/l). Thus, the sorption in these samples is non-linear. In order to use these materials as sorbents, the TH4 and MT6 samples might have to be treated, because sorption is higher in the humic acid fraction than in the source material. The rest of the samples display lower variation in the sorption capacity between the humic acid samples and the original samples, thus there is no need for chemical treatment.