ABSTRACT: This study was conducted to evaluate the nutritional status of table beet plants cultivated in a greenhouse irrigated with treated dairy effluent at different irrigation depths. The experimental design used was a randomized block in a 3 x 3 + 1 factorial arrangement with four replications and conducted in a greenhouse. The treatments consisted of three types of water sources and three irrigation depths applied by drip irrigation: anaerobic effluent; anaerobic/aerobic effluent; tap water, and irrigation for replenishment 50; 100 and 150% of the crop evapotranspiration (ETc). All these treatments were applied in combination with 50% of the recommended nitrogen fertilization for the table beet cultivation. A control treatment was irrigated with tap water with irrigation depth equal to 100% ETc and received the complete dose (100%) of mineral nitrogen fertilizer. Table beet seedlings were arranged in 40 fiberglass boxes with a base area of 1 m2. Table beets were harvested 72 days after transplanting (DAT) when the leaves and roots were analyzed. Irrigation with wastewater promoted appropriate levels of macronutrients, distributed between the leaves and roots. The sodium was increased significantly in the leaves and roots of table beets in effluent treatments at increasing irrigation depths, which was antagonistic to the absorption of potassium.

Reator anaeróbio horizontal de leito fixo (RAHLF), preenchido com espumas de poliuretano, foi usado para tratar benzeno em solução etanólica, sob condições sulfetogênicas. Benzeno foi adicionado em concentração inicial de 2,0 mg.l-1, seguido de aumentos que variaram até 10 mg.l-1. O etanol foi adicionado em concentrações de 170 mg.l-1 a 980 mg.l-1. Soluções de sulfato ferroso e sulfato de sódio foram usadas, nas concentrações de 91 e 550 mg.l-1, respectivamente. O reator foi operado a 30 (± 2) ºC com tempo de detenção hidráulica de 12 h. A remoção da matéria orgânica foi próxima a 90% com taxa máxima de degradação de benzeno de 0,07 mg benzeno.mg-1SSV.d-1. O presente trabalho corrobora os dados obtidos por Cattony et al (2005), na medida em que torna mais consistente a proposta do uso de unidades compactas de RAHLF, para a biorremediação in situ de compostos aromáticos.

In this study it is reported the operation of a horizontal-flow anaerobic immobilized biomass (HAIB) reactor under sulfate-reducing condition which was also exposed to different amounts of ethanol and benzene. The HAIB reactor comprised of an immobilized biomass on polyurethane foam and ferrous and sodium sulfate solutions were used (91 and 550 mg.l-1, respectively), to promote a sulfate-reducing environment. Benzene was added at an initial concentration of 2.0 mg.l-1 followed by an increased to 9 e 10 mg.l-1, respectively. Ethanol was added at an initial concentration of 170 mg.l-1 followed by an increased range of 960 mg.l-1. The reactor was operated at 30 (± 2) ºC with hydraulic detention time of 12 h. Organic matter removal efficiency of 90% with a maximum benzene degradation rate of 0.07 mg benzene.mg-1VSS.d-1. Thus, this work corroborate the data obtained for Cattony et al (2005) and also demonstrate that compact units of HAIB reactors, under sulfate reducing conditions, are a potential alternative for in situ aromatic compounds bioremediation.

Este trabalho apresenta um estudo morfológico de microrganismos aderidos à espuma de poliuretano em reator anaeróbio horizontal de leito fixo (RAHLF), aplicado ao tratamento de esgoto sanitário. O processo de colonização do suporte pela biomassa anaeróbia e as características morfológicas das células aderidas foram monitorados durante o período de partida do reator. Bacilos e cocos não fluorescentes foram predominantes no processo de aderência direta à espuma de poliuretano. Aumento na diversidade biológica foi observado a partir da 10ª semana de operação do reator, com predominância de bacilos, cocos e arqueas metanogênicas semelhantes a Methanosaeta. Problemas hidrodinâmicos, tais como formação de canais preferenciais e colmatação do leito, foram observados no reator, principalmente devido ao acúmulo de polímeros extracelulares nos interstícios do leito. Este material acumulou principalmente nos estágios iniciais do reator, causando a diminuição gradativa do desempenho do processo anaeróbio de conversão da matéria orgânica. Os resultados demonstraram a importância e utilidade do monitoramento da dinâmica de formação do biofilme durante o período de partida de reatores, com resultados positivos para identificação de problemas operacionais.

This work focused on a morphological study of the microorganisms attached to polyurethane foam matrices in a horizontal-flow anaerobic immobilized biomass (HAIB) reactor treating domestic sewage. The experiments consisted of monitoring the biomass colonization process of foam matrices in terms of the amount of retained biomass and the morphological characteristics of the cells attached to the support during the start-up period. Non-fluorescent rods and cocci were found to predominate in the process of attachment to the polyurethane foam surface. From the 10th week of operation onwards, an increase was observed in the morphological diversity, mainly due to rods, cocci, and Methanosaeta-like archaeal cells. Hydrodynamic problems, such as bed clogging and channeling occurred in the fixed-bed reactor, mainly due to the production of extracellular polymeric substances and their accumulation in the interstices of the bed causing a gradual deterioration of its performance, which eventually led to the system's collapse. These results demonstrated the importance and usefulness of monitoring the dynamics of the formation of biofilm during the start-up period of HAIB reactors, since it allowed the identification of operational problems.