Ce travail de thèse a porté sur l’étude des méthodes de traitement des sédiments de dragage en vue de leur remédiation et leur valorisation : la méthode électrocinétique et la méthode solidification/stabilisation. Deux dispositifs expérimentaux (à deux échelles différentes) ont été développés et une série d’essais électrocinétiques ont été effectués sous différentes conditions (valeurs du potentiel électrique, système ouvert/fermé, solutions d’électrolyte : EDTA, EDDS, NTA et Acide citrique). Chaque chélatant fournit une efficacité d’extraction sur un métal donné. Les résultats obtenus montrent que le contrôle de pH à la cathode par l’acide citrique et l’ajout d’un tensio-actif (Tween 20) peuvent augmenter l’effet de remédiation des métaux. Par ailleurs, lorsque le système est fermé, l’efficacité d’électroremédiation est plus élevée. Les abattements obtenus pour les métaux dans la matrice des sédiments sous des conditions optimales peuvent atteindre 60 %. Pour ce qui est de la solidification/stabilisation, plusieurs formulations (de chaux, de ciment et de fumée de silice) associées au sédiment ont été testées dans le but de reconstituer un matériau résistant et durable dans l’objectif de son utilisation dans les remblais routiers. Les éprouvettes de sédiment traitées ont été soumises à des conditions sévères de température et d’humidité. Des essais de lixiviation ont été effectués sur le matériau obtenu afin de déterminer la capacité des formulations à stabiliser les éléments polluants contenus dans le sédiment. Les résultats obtenus avec 12 différentes formulations ont montré que la résistance requise est obtenue avec des proportions raisonnables d’ajouts, tandis que l’exigence de durabilité nécessite une plus grande proportion de chaux. / This thesis research is devoted to investigate the treatment methods of dredged sediments in order their restoration and valorisation: electroremediation and solidification/stabilization. Two experimental set-up (at two different scales) have been designed and a series of tests were performed under different conditions (electric potential values, opened/closed system, electrolyte solutions: EDTA, EDDS, NTA and Citric Acid). Each chelating agent provides an extraction efficiency for a given metal. The obtained results show that the pH control at the cathode by citric acid and its combinations with a surfactant (Tween 20) can increase the metal removal effect. Moreover, under closed system condition, metal removal efficiency became stronger. The obtained metal removals values within the matrix of sediment under optimal conditions can reach 60%. As regard to the solidification/stabilization, serval formulations (of lime, cement and silica fume) associated to the sediment were tested in order to create a resistant and sustainable material forwarding to be used as a road embankments. The specimens of treated sediment were submitted to severe conditions of temperature and wettability. Leaching tests were carried out on the obtained material in order to assess a capability of used formulations to stabilize pollutant elements contained in the sediment. The obtained results from 12 different formulations showed that the required resistance is obtained with the reasonable proportions of binders, while the sustainability requirement need higher lime content in the formulation.

The production of oil in Brazil is increasing to each year. As result a increasing volume of production water is generated as part of the process itself of formation of the deposits, many times in bigger ratios that the oil itself. The produced water owns a great diversity of contaminants, what ally to its high volume, brings serious problems at the moment of giving a final disposal to it. Some solutions had been attempted; on account of the more restrictive laws each day of the ambient agencies, but still in palliative way. The present work considers evaluating eletrodics materials and experimental conditions adjusted to be used in reactors, propitiating the electrochemical treatment of this residue. As anodes Ânodos Dimensionalmente Estáveis (ADE) commercial had been used, with nominal composition of Ti/Ru0,34Ti0,66O2. As cathodes the ADE, 316 steel and graphite had been evaluated. Amongst the cathodic materials studied the steel it presented performance better, as much with regard to efficiency of the process how much in the reduction of the cathodic incrustation. In the studies in batelada, was verified that the dilution of the solution and the current density influence significantly in the efficiency of the oxidation process. The increase of the dilution increases greatly the efficiency of the process. Already the speed of reduction of the DQO increases with the current density, however, the increase is not linear indicating that the process is controlled for diffusion. The efficiency of the electrochemical process in the reduction of the DQO of the sample was associated the three factors:a) the direct oxidation of the organic residue on the electrode; b) removal of the powdered material for the eletrogenerated gases (eletroflotation); c) indirect oxidation through reactive intermediate species. In the case of the reactor, it could be noticed that, the control of the outflow and the current density, as well as of the height of the flotant column influence in the efficiency of the treatment of the effluent, one beyond minimizing the incrustation on the cathodes. In the optimized conditions: outflow 800mLh-1, current density of 50mAcm-2 and flotant column of 10cm got it considerable reduction of the DQO and the TOG, proving the possibility of the application of the electrochemical technology in the treatment of the produced water of oil. / Conselho Nacional de Desenvolvimento Científico e Tecnológico / A produção de petróleo no Brasil vem aumentando a cada ano. Em conseqüência, um volume crescente de água de produção é gerado como parte do próprio processo de formação das jazidas, muitas vezes em proporções maiores que o próprio óleo. A água produzida possui uma grande diversidade de contaminantes, o que aliado ao seu alto volume, traz sérios problemas no momento de lhe dar uma disposição final. Várias soluções foram tentadas, por conta das leis cada dia mais restritivo dos órgãos ambientais, mas ainda de maneira paliativa. O presente trabalho propõe avaliar materiais eletródicos e condições experimentais adequadas para serem utilizadas em reatores, propiciando o tratamento eletroquímico desse resíduo. Como ânodo foram utilizados ânodos dimensionalmente estáveis (ADE) comerciais, com composição Ti/Ru0, 34Ti0,66O 2. Como cátodos foram avaliados os ADE, aço 316 e grafite. Dentre os materiais catódicos estudados o aço apresentou melhor desempenho, tanto com relação à eficiência do processo, quanto na redução da incrustação catódica. Nos estudos em batelada, verificou-se que a diluição da solução e a densidade de corrente influenciam significativamente na eficiência do processo de oxidação. O aumento da diluição aumenta acentuadamente a eficiência do processo. Já a velocidade de redução da DQO aumenta com a densidade de corrente, no entanto o aumento não é linear indicando que o processo é controlado por difusão. A eficiência do processo eletroquímico na redução da DQO da amostra foi associada a três fatores: a) ((oxidação direta do resíduo orgânico sobre o eletrodo; b) remoção do material particulado pelos gases eletrogerados (eletroflotação); c) oxidação indireta através de espécies intermediárias reativas. No caso do reator, pôde ser notado que, o controle da vazão e da densidade de corrente, bem como da altura da coluna flotante influenciam na eficiência do tratamento do efluente, além de minimizar a incrustação sobre os cátodos. Nas condições otimizadas: vazão de 800 cm3. h-1, densidade de 50mAcm-2 e coluna flotante de 10 cm obteve-se a redução considerável da DQO e do TOG, comprovando a possibilidade da aplicação da tecnologia eletroquímica no tratamento da água produzida de petróleo.