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Atributos do solo, qualidade do lixiviado e crescimento de plantas de milho sob aplicação de água residuária da mandiocaMARQUES , Marise Conceição 26 February 2009 (has links)
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Previous issue date: 2009-02-26 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Cassava wastewater, wastewater from cassava (Manihot esculenta Crantz) processing industrial, is produced in volume large. When low-cost solutions are not viable, usually dumped in rivers or in the soil, provide environmental impact. The cassava wastewater fertilizer has potential because great its nutrients composition of especially potassium, but when used indiscriminately provokes of basic cations imbalance in soil. To evaluate the potential of cassava wastewater, two study were developed. The study first aimed to evaluate soil characteristics and leachate quality as function of cassava wastewater rates applied to columns containig soils of different textures. PVC columns (15 x 80 cm) were used to simulate a 60 cm soil profile. The soils studied were: Cohesive Yellow latosol, Carbonatic Haplic Vertisol and Orthic Quartzarenic Neosol. Aiming to supply the K requirement to maize, 4.7 m³ ha-1 of cassava wastewater was applied to the Vertisol and Latosol white the Neosolreceived 9.6 m3 -1ha. The Wastewater promoted increase on the K contents for the 0-20 cm layer of soil. The results showed that the cassava wastewater dose applied is safe regarding salinization and changes in floculation. In the second aimed to evaluate the potential of cassava wastewater as a potassium fertilizer to maize and the alteraions it provokes in soil chemical characteristic. Two soils (Carbonatic Haplic Vertisol and Orthic Quartzarenic Neosol) were put in 3 kg pots. These soils received wastewater doses equivalent to 0, 1, 2, 3, 4 and 5 times the amount of K recommended to maize. This was equivalent to 0, 4.7, 9.4, 14.1, 18.8, 23.6 m3-1 ha for the Vertisol and 0, 9.6, 19.2, 28.8, 38.5, 48.1 m3-1 ha the Neosol. The results showed that the application of cassava wastewater improved soil chemical characteristics, but it did not change soil pH. Cassava wastewater along with mineral mineral fertilizers poses potencial. On the other hand, wastewater alone was not able to provide the K requeriment to plant. / A água residuária da mandioca (manipueira), efluente oriundo da industrialização do processamento da mandioca (Manihot esculenta Crantz), é produzida em grande volume. Quando soluções de baixo custo não são viáveis, os efluentes são usualmente despejados em rios ou no solo, causando impacto ambiental. A manipueira apresenta grande potencial fertilizante devido à sua composição em nutrientes principalmente o potássio, mas quando utilizado de forma indiscriminada constitui implicação no desequilíbrio dos cátions básicos no solo. Com objetivo de avaliar o potencial do reaproveitamento da manipueira, foram desenvolvidos dois ensaios. No primeiro foram acondicionados, em colunas de PVC com 15 x 80 cm (diâmetro x altura), amostras de solos com diferentes texturas (Vertissolo Háplico Carbonático (VXk), Latossolo Amarelo Distrocoeso (LAdx) e Neossolo Quartizarênico Órtico (RQo)) coletadas até 60 cm. E com base no teor de potássio da manipueira, foram estabelecidas lâminas baseadas na recomendação potássica para milho, no VXk e LAdx foram aplicadas 4,7 m³ ha-1 e o RQo 9,6 m³ ha-1 ,este estudo objetivo-se avaliar os atributos do solo e da qualidade do lixiviado em resposta a aplicação da manipueira. A manipueira promoveu elevação nos teores de potássio trocável na camada de 0-20 cm. A dose aplicada não apresentou risco a salinização e alteração no grau de floculação. No segundo ensaio, objetivou-se avaliar o potencial da manipueira na adubação potássica na cultura do milho e alterações nos atributos químicos do solo. Foram acondicionados, em vasos com capacidade para 3 kg de solo, amostras de solos com diferentes texturas (Vertissolo Háplico Carbonático (VXk) e Neossolo Quartizarênico (RQo)) coletadas na profundidade de 0-20 cm, aplicou-se doses de manipueira correspondente a 0, 1, 2,3, 4 e 5 vezes a dose de adubação potássica recomendada para cultura do milho, que corresponderam a e 0, 9,6, 19,2, 28,8, 38,4, 48,1 m3-1 ha para o RQo e 0, 4,7, 9,4, 14,1, 18,8, 23,6 m3 ha -1 para o VXk, que foram complementadas com N, P e micronutrientes. Para cada solo foram acrescentados dois tratamentos adicionais: apenas adubação com manipueira na dose recomendada para K e adubação mineral (NPK). A manipueira aplicada após correção da acidez não promoveu efeito no pH do solo. O reaproveitamento da manipueira como fonte potássica apresentou potencial fertilizante quando complementada com adubação mineral.
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Nouveaux procédés de bioremédiation pour le traitement des sols et des sédiments sélénifères / Novel bioremediation processes for treatment of seleniferous soils and sedimentWadgaonkar, Shrutika 18 December 2017 (has links)
L'objectif de cette thèse a été de développer une technologie pour l'assainissement des sols / sédiments sélénifères et d’étudier la réduction microbienne des oxy-anions de sélénium dans différentes conditions de respiration et de configurations du bioréacteur.Le sol sélénifère prélevé, dans les terres agricoles cultivées de blé au Pendjab (Inde), a été caractérisé et son lavage a été optimisé en faisant varier les paramètres tels que le temps de réaction, la température, le pH et le rapport liquide / solide. Afin de maximiser l'élimination et la récupération du sélénium à partir de ce sol, l'effet des ions compétiteurs et les composés oxydants comme les agents d'extraction pour le lavage du sol, ont également été étudiés. Bien que les agents oxydants aient montré une efficacité maximale d'élimination du sélénium (39%), la présence d'agents oxydants dans le lixiviat et le sol agricole peut augmenter le coût de leur post-traitement. Les plantes aquatiques, Lemma minor et Egeria densa ont été utilisées pour étudier la phyto-remédiation du lixiviat du sol contenant des agents oxydants. Cependant, l'efficacité d'élimination du sélénium par les plantes aquatiques a été significativement affectée par les fortes concentrations de ces agents oxydants dans le lixiviat du sol.Le rinçage du sol sélénifère a révélé un motif de migration du sélénium à travers la colonne du sol. La migration de la fraction de sélénium soluble de la couche supérieure vers la couche inférieure et sa réduction et son accumulation subséquentes dans les couches inférieures de la colonne de sol, ont été observées pendant le rinçage du sol. L'efficacité d'élimination du sélénium par la méthode de rinçage du sol a diminué avec une augmentation de la hauteur de la colonne. De plus, le lixiviat contenant des oxy-anions de sélénium obtenus à partir du lavage du sol, a été traité dans un réacteur UASB en faisant varier l'alimentation organique. Des effluents contenant moins de 5 μg de sélénium L-1 ont été obtenus, ce qui est conforme aux normes de l'USEPA pour la limite de rejet de sélénium dans les eaux usées.De plus, la bio-remédiation ex situ des oxy-anions de sélénium a été étudiée dans des conditions variables. Une bactérie aérobie (Delftia lacustris) capable de transformer le sélénate et le sélénite en sélénium élémentaire, mais aussi en composés d'ester de sélénium solubles jusque-là inconnus, a été isolée et caractérisée de manière fortuite. Alternativement, la bio-réduction anaérobie du sélénate couplé au méthane en tant que donneur d'électrons, a été étudiée dans des bouteilles de sérum et un filtre percolateur en utilisant des sédiments marins comme inoculum. Enfin, l'effet de la contamination d'autres oxy-anions chalcogènes, en plus du sélénium, a été étudié. La réduction simultanée de la sélénite et de la tellurite par un consortium microbien mixte ainsi que la rétention des nanostructures de Se et de Te biogènes dans l'EPS, ont été réalisées durant une opération de 120 jours dans un bioréacteur UASB / The aim of this Ph.D. was to develop a technology for the remediation of seleniferous soils/sediments and to explore microbial reduction of selenium oxyanions under different respiration conditions and bioreactor configurations.Seleniferous soil collected from the wheat-grown agricultural land in Punjab (India) was characterized and its soil washing was optimized by varying parameters such as reaction time, temperature, pH and liquid to solid ratio. In order to maximize selenium removal and recovery from this soil, effect of competing ions and oxidizing agents as chemical extractants for soil washing were also studied. Although oxidizing agents showed a maximum selenium removal efficiency (39%), the presence of oxidizing agents in the leachate and the agricultural soil may increase the cost of their post-treatment. Aquatic plants, Lemma minor and Egeria densa were used to study phytoremediation of the soil leachate containing oxidizing agents. However, the selenium removal efficiency by aquatic weeds was significantly affected by the high concentrations of these oxidizing agents in the soil leachate.Seleniferous soil flushing revealed the selenium migration pattern across the soil column. Migration of soluble selenium fraction from the upper to the lower layers and its subsequent reduction and accumulation in the lower layers of the soil column was observed during soil flushing. The selenium removal efficiency by the soil flushing method decreased with an increase in the column height. Furthermore, the soil leachate containing selenium oxyanions obtained from soil washing was treated in a UASB reactor by varying the organic feed. Effluent containing less than 5 μg L-1 selenium was achieved, which is in accordance with the USEPA guidelines for selenium wastewater discharge limit.Moreover, ex situ bioremediation of selenium oxyanions was studied under variable conditions. An aerobic bacterium (Delftia lacustris) capable of transforming selenate and selenite to elemental selenium, but also to hitherto unknown soluble selenium ester compounds was serendipitously isolated and characterized. Alternatively, anaerobic bioreduction of selenate coupled to methane as electron donor was investigated in serum bottles and a biotrickling filter using marine sediment as inoculum. Finally, the effect of contamination of other chalcogen oxyanions in addition to selenium was studied. Simultaneous reduction of selenite and tellurite by a mixed microbial consortium along with the retention of biogenic Se and Te nanostructures in the EPS was achieved during a 120-day UASB bioreactor operation
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