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Entre le milieu du XIXème et du XXème siècle, le secteur sidérurgique a été l’une des principales sources de richesse en France. Toutefois, la production de ferromanganèse a généré une quantité considérable de déchets, notamment lors du lavage des fumées des hauts fourneaux. Ces boues d’épuration, riches en zinc (Zn), manganèse (Mn) et plomb (Pb) (5 à 40% en masse), ont été déposées dans des bassins de décantation en périphérie des sites sidérurgiques. Depuis la fermeture des usines, ces terrains sont restés en l’état et certains, comme à Pompey (Lorraine), ont été progressivement colonisés par la végétation. Compte tenu des risques sanitaires liés aux concentrations en métaux, une décontamination semble inévitable. Néanmoins, on prend conscience aujourd’hui de l’épuisement des ressources, et ces bassins apparaissent comme un gisement de ressources secondaires. Ce travail vise à développer un procédé hydrométallurgique pour extraire Zn, Mn et Pb de ces résidus, dans l’optique de récupérer ces métaux sous forme pure et revalorisable, tout en décontaminant ces sites. Tout d’abord, les expériences ont permis déterminer les conditions optimales (quantité d’acide, temps, température, ajout de réactifs, densité de pulpe) pour parvenir à extraire sélectivement Zn et Mn contenus dans les boues et former un résidu riche en Pb. Le Zn a été ensuite récupéré sous forme de ZnO ou ZnS par précipitation ou sous forme métallique par électrodéposition. Enfin, le Mn a été précipité sous forme de MnCO3 avec une concentration acceptable en impuretés. Une étude technico-économique a été réalisée pour évaluer l’intérêt de l’industrialisation du procédé / During the XIXth and XXth centuries, steel industry has been one of the main sources of wealth in France. However, ferromanganese manufacturing has produced huge quantities of wastes, for instance after blast-furnace gas washing. The residual sludge, containing high concentrations of zinc (Zn), manganese (Mn) and lead (Pb) (5 to 40 wt %), has been deposited in ponds, in the vicinity of steel-making plants. Since plant closure, these fields have been left untouched; some of them, like in Pompey (Lorraine) have been colonized by vegetation. These sites may be considered as a threat to health and environment and should be cleaned up. Nevertheless, with awareness of metal shortage, these ponds may be considered as deposits of secondary resources. This works aims at designing a hydrometallurgical process to extract Zn, Mn and Pb from these residues and recover them in a valuable form, while decontaminating the sites. At first, experiments have enabled us to determine the optimal conditions (acid concentration, duration, temperature, reactant addition, pulp density) to extract selectively Zn and Mn from the sludge and leave a Pb-rich residue. Then, Zn was recovered as ZnO or ZnS after precipitation or as Zn after electrowinning. Mn was recovered as MnCO3 at an acceptable purity. A technico-economic study has been done to assess the industrial interest of the process

Este trabalho experimental apresenta os resultados da avaliação do desempenho de uma instalação piloto, composta por reator UASB seguido de lagoa aerada aeróbia e lagoa de decantação, no tratamento dos esgotos afluente a ETE - Jundiaí, que contém elevada contribuição de despejos industriais. O reator UASB e a lagoa de decantação tem volume útil de 3,0 m3 e 2,0 m3, respectivamente. O volume da lagoa aerada aeróbia é variável entre 7,2 m3 e 21,6 m3 de modo a permitir variar o tempo de detenção hidráulica. O sistema foi avaliado em termos da eficiência de remoção de DQO, DBO5, sólidos suspensos, nitrogênio total, fósforo total e cor verdadeira para tempos de detenção hidráulica na lagoa aerada aeróbia variando entre 1,0 e 3,5 dias mantendo, tanto no reator UASB quanto, na lagoa de decantação o tempo de detenção constante em 8,0 horas e 1,8 dia, respectivamente. O sistema completo apresentou uma eficiência de remoção de DQO total entre 85% e 87%, de DBO5 total entre 92% e 96%, de SST entre 81% e 87%, de SSV entre 80 e 88%, de nitrogênio total entre 55 e 57%, de fósforo total entre 60 e 70% e de cor verdadeira entre 50 e 60%, para tempos de detenção hidráulica na lagoa aerada aeróbia variando entre 1,5 e 3,5 dias. O reator UASB foi responsável pela remoção de cerca de 50% da DQO total, 60% da DBO5 total e 40% dos SST do afluente, operando em média com um tempo de detenção hidráulica de 8,0 horas. As eficiências alcançadas no sistema completo produziram um efluente final com uma concentração de DQO total entre 170 e 230 mg/L, de DBO5 total entre 30 e 60 mg/L, de SST entre 30 e 45 mg/L, de SSV entre 24 e 40 mg/L, de nitrogênio total entre 24 e 28 mg NH3/L, de fósforo total entre 3,5 e 5,5 mg P/L e de cor verdadeira entre 375 e 600 mg Pt/L. O sistema pesquisado mostrou-se uma alternativa viável para o tratamento do esgoto afluente à ETE - Jundiaí e poderá resultar em redução da área e em menor consumo de energia que os hoje necessários na ETE - Jundiaí, que emprega um sistema composto por lagoas aeradas aeróbias seguidas de lagoas de decantação. / This experimental investigation was carried out in order to evaluate the performance of a pilot plant, composed of an UASB reactor followed by an aerated lagoon and a settling pond, treating the Wastewater Treatment Plant of Jundiaí city (WWTPJ) influent sewage, which contains in its composition an expressive amount of industrial effluents. The UASB reactor and settling pond have an useful volume of 3.0 m3 and 2.0 m3, respectively. The aerated lagoon volume is variable from 7.2 m3 to 21.6 m3 to make possible the hydraulic retention time variation. The COD, BOD5, suspended solids, total nitrogen, total phosphorus and true colour removal efficiencies of the system were evaluated when the aerated lagoon hydraulic retention time varied from 1.0 to 3.5 days and in the UASB reactor and settling pond was mainteined constant at 8.0 hours and 1.8 day, respectively. The range of removal efficiencies obtained in the system are: 85 - 87% for total COD, 92 - 96% for total BOD5, 81 - 87% for TSS, 80 - 88% for VSS, 55 - 57% for total nitrogen, 60 - 70% for total phosphorus, and 50 - 60% for true color, when the aerated lagoon hydraulic retention time varied from 1.5 to 3.5 days. The UASB reactor operating at 8.0 hours hydraulic retention time removes almost 50% of total COD, 60% of total BOD5 and 40% of TSS from the influent contents. The system performance lead to a final effluent with a total COD, total BOD5, TSS, VSS, total nitrogen, total phosphorus, and true color concentrations in the range of: 170 - 230 mg/L, 30 - 60 mg/L and 30 - 45 mg/L, 24 - 40 mg/L, 24 - 28 mg N/L, 3,5 - 5,5 mg P/L and 375 - 600 mg Pt/L, respectively. The system studied is a practicable alternative for the treatment of the WWTPJ influent sewage, probably with less area and energy saving whem compared to the WWTPJ current needs, which uses a system composed by an aerated lagoon followed by a settling pond

Este trabalho experimental apresenta os resultados da avaliação do desempenho de uma instalação piloto, composta por reator UASB seguido de lagoa aerada aeróbia e lagoa de decantação, no tratamento dos esgotos afluente a ETE - Jundiaí, que contém elevada contribuição de despejos industriais. O reator UASB e a lagoa de decantação tem volume útil de 3,0 m3 e 2,0 m3, respectivamente. O volume da lagoa aerada aeróbia é variável entre 7,2 m3 e 21,6 m3 de modo a permitir variar o tempo de detenção hidráulica. O sistema foi avaliado em termos da eficiência de remoção de DQO, DBO5, sólidos suspensos, nitrogênio total, fósforo total e cor verdadeira para tempos de detenção hidráulica na lagoa aerada aeróbia variando entre 1,0 e 3,5 dias mantendo, tanto no reator UASB quanto, na lagoa de decantação o tempo de detenção constante em 8,0 horas e 1,8 dia, respectivamente. O sistema completo apresentou uma eficiência de remoção de DQO total entre 85% e 87%, de DBO5 total entre 92% e 96%, de SST entre 81% e 87%, de SSV entre 80 e 88%, de nitrogênio total entre 55 e 57%, de fósforo total entre 60 e 70% e de cor verdadeira entre 50 e 60%, para tempos de detenção hidráulica na lagoa aerada aeróbia variando entre 1,5 e 3,5 dias. O reator UASB foi responsável pela remoção de cerca de 50% da DQO total, 60% da DBO5 total e 40% dos SST do afluente, operando em média com um tempo de detenção hidráulica de 8,0 horas. As eficiências alcançadas no sistema completo produziram um efluente final com uma concentração de DQO total entre 170 e 230 mg/L, de DBO5 total entre 30 e 60 mg/L, de SST entre 30 e 45 mg/L, de SSV entre 24 e 40 mg/L, de nitrogênio total entre 24 e 28 mg NH3/L, de fósforo total entre 3,5 e 5,5 mg P/L e de cor verdadeira entre 375 e 600 mg Pt/L. O sistema pesquisado mostrou-se uma alternativa viável para o tratamento do esgoto afluente à ETE - Jundiaí e poderá resultar em redução da área e em menor consumo de energia que os hoje necessários na ETE - Jundiaí, que emprega um sistema composto por lagoas aeradas aeróbias seguidas de lagoas de decantação. / This experimental investigation was carried out in order to evaluate the performance of a pilot plant, composed of an UASB reactor followed by an aerated lagoon and a settling pond, treating the Wastewater Treatment Plant of Jundiaí city (WWTPJ) influent sewage, which contains in its composition an expressive amount of industrial effluents. The UASB reactor and settling pond have an useful volume of 3.0 m3 and 2.0 m3, respectively. The aerated lagoon volume is variable from 7.2 m3 to 21.6 m3 to make possible the hydraulic retention time variation. The COD, BOD5, suspended solids, total nitrogen, total phosphorus and true colour removal efficiencies of the system were evaluated when the aerated lagoon hydraulic retention time varied from 1.0 to 3.5 days and in the UASB reactor and settling pond was mainteined constant at 8.0 hours and 1.8 day, respectively. The range of removal efficiencies obtained in the system are: 85 - 87% for total COD, 92 - 96% for total BOD5, 81 - 87% for TSS, 80 - 88% for VSS, 55 - 57% for total nitrogen, 60 - 70% for total phosphorus, and 50 - 60% for true color, when the aerated lagoon hydraulic retention time varied from 1.5 to 3.5 days. The UASB reactor operating at 8.0 hours hydraulic retention time removes almost 50% of total COD, 60% of total BOD5 and 40% of TSS from the influent contents. The system performance lead to a final effluent with a total COD, total BOD5, TSS, VSS, total nitrogen, total phosphorus, and true color concentrations in the range of: 170 - 230 mg/L, 30 - 60 mg/L and 30 - 45 mg/L, 24 - 40 mg/L, 24 - 28 mg N/L, 3,5 - 5,5 mg P/L and 375 - 600 mg Pt/L, respectively. The system studied is a practicable alternative for the treatment of the WWTPJ influent sewage, probably with less area and energy saving whem compared to the WWTPJ current needs, which uses a system composed by an aerated lagoon followed by a settling pond