Studies on the removal of Cryptosporidium oocysts by direct filtration suggested that high removal efficiencies (>3.0 log) can be achieved, but the vast majority of the studies focused on the assessment of downflow direct filtration. However, in comparison with downflow direct filtration, filters in upflow direct filtration systems use lower filtration rates, deeper stratified bed, and water flows from coarse to fine sand grain, which may improve the removal of oocysts. In this context, we evaluated the removal of Cryptosporidium oocysts using upflow direct filtration, on a pilot scale, to treat Paranoá Lake water (Brazil) seeded with Cryptosporidium oocysts. The experiments were conducted with raw water with low turbidity (3.2–5.7 NTU) and induced higher turbidity (28–30 NTU). Non-parametric statistical analysis was used to verify correlations between the filtered water values and removal of oocysts, particles, and turbidity. In general, no correlation was observed between the parameters analyzed, nor between their removals. The exception was the correlation between residual values of Cryptosporidium oocysts and particles of 2 to 7 µm during ripening, an aspect that needs further evaluation. Under stable operation, average removal of Cryptosporidium oocysts by upflow direct filtration was >3.87 log. During ripening, removal of oocysts was around 1 log lower.
RESUMO: Dentre as soluções existentes para efetuar o tratamento de esgoto, o reator anaeróbio do tipo UASB é largamente utilizado no Brasil, porém esta tecnologia apresenta problemas em atender aos limites estabelecidos pela legislação brasileira para lançamento de efluente em termos de nitrogênio amoniacal, fósforo e matéria orgânica, necessitando de pós-tratamento. Diante do potencial para remoção de matéria orgânica e sólidos suspensos pela flotação e da eficiência que a zeólita apresenta na remoção de amônia, a floto-filtração-adsortiva em zeólita pode ser uma promissora alternativa para tratamento deste efluente. Sendo assim, o presente trabalho visou avaliar a eficiência de um sistema de flotação associado à filtração-adsortiva, utilizando zeólita como meio filtrante, para pós-tratamento de efluente de reator UASB. Para tal, foram realizados ensaios de coagulação/floculação, flotação e filtração-adsortiva com um floteste adaptado com filtros adsorventes, utilizando efluente de reator anaeróbio do tipo UASB. Os resultados obtidos neste estudo atenderam aos padrões estabelecidos pela legislação brasileira para lançamento de efluentes em corpos d’água, alcançando 100 % de remoção de nitrogênio amoniacal, permitindo que esse efluente possa ser aproveitado para reuso. Desse modo, o sistema de flotação com a filtração-adsortiva utilizando zeólita como meio filtrante mostrou-se eficiente na remoção de todos os poluentes avaliados. Esta pesquisa teve como principal contribuição a avaliação de alternativa promissora para pós-tratamento de efluente de reator UASB buscando atender as exigências da legislação brasileira e melhorar da qualidade dos efluentes sanitários. ABSTRACT: Among the existing solutions to sewage treatment, the UASB reactor is widely used in Brazil, but this technology has problem to attend the limits established by Brazilian law for discharging of effluent, especially to ammonia nitrogen, phosphorus and organic matter, requiring post-treatment. The flotation has good performance in the removal of organic matter and solids presents in anaerobic effluent, as well as the zeolite in the removal of ammonia nitrogen, the flotation followed by filtration-adsorption in bed composed by zeolite may be a promising alternative for post-treatment of this effluent. Therefore, the objective of the present study was to investigate the efficiency of a dissolved air flotation system associated with filtration-adsorption using zeolite as filter media for post-treatment of UASB reactor effluent. Coagulation/flocculation tests were performed, flotation and filtration-adsorption with an adsorbent filters fitted with Floteste (Bench equipment for flotation) using anaerobic effluent from the UASB reactor. The results obtained in this study met the standards established by the Brazilian legislation for discharging of effluents into water bodies, reaching 100% of ammonia nitrogen removal, allowing this wastewater can be reused. Thus, the flotation-filtration-adsorption system using zeolite as filter media proved to be effective as post-treatment of anaerobic effluent. The main contribution of this study was the assessment of a promising alternative for post-treatment of UASB effluent to meet the criteria of Brazilian legislation and to improve the quality of sewage treatment.
A incompatibilidade entre desenvolvimento sustentável e os padrões de produção e consumo, sugere que as organizações incorporem práticas de gestão sustentável nos seus negócios, de forma a conciliar o crescimento econômico com as questões ambientais e sociais. As exigências de diferentes perfis de clientes a todo o momento, força o setor hoteleiro a se transformar para implementar no cerne das operações hoteleiras, os três principais pilares da sustentabilidade: o econômico, o social e o ambiental, visando a redução de riscos, redução de custos, aumento das receitas e fortalecimento da marca. O presente artigo tem como proposta ampliar os conhecimentos acerca da gestão de marcas verdes no setor hoteleiro. O estudo aborda aspectos teóricos sobretudo acerca do turismo sustentável e da gestão de marcas verdes, além de um estudo de campo da gestão de marcas verdes no setor hoteleiro de Brasília.
Pig breeding generates waste that, if not handled correctly, can cause serious environmental problems. The application of these residues in the soil appears as a sustainable alternative, since the manure, being rich in organic matter and mineral nutrients, promotes the improvement of the physical, chemical and biological quality of the soil avoiding the contamination of natural resources if it is released in the water or directly on the ground without proper treatment. The objective of this study was to evaluate the development of banana seedlings fertigated with pig slurry (PS) analyzing its efficiency compared to conventional treatment (chemical). The experiment was carried out in a completely randomized design with six treatments and six replications (3 seedlings per repetition), the doses being defined based on the fertilizer recommendation for the production of banana seedlings and the nutrient in greater concentration in the manure, which, in this case, was nitrogen, considered as the dose limiter. The results showed that PS was efficient in supplying nutrients to the banana seedlings and it can be used as a substitute for chemical fertilizer. The treatment with manure corresponding to 25.0% of the nitrogen recommended to produce banana seedlings provided the greatest development.
<p><em>En la presente investigación fueron realizados experimentos de filtración de flujo ascendente en línea, a escala piloto, para evaluar el desempeño del coagulante natural quitosano en la extracción de microesferas de poliestireno con dimensiones similares a Cryptosporidium oocysts, en el tratamiento de aguas con turbidez natural aproximada de 30 uT, inducida con caolinita. Los parámetros evaluados fueron turbidez, materia orgánica (absorbancia a 254 nm) y concentración de microesferas. Inicialmente, se realizaron pruebas de jarras para la construcción del diagrama de coagulación y la definición de las condiciones para ser adoptadas en experimentos de filtración.</em> Los experimentos de filtración de flujo ascendente en línea se efectuaron en condiciones de coagulación de dosis óptimas, super-óptimas y sub-óptimas. El diagrama de coagulación mostró una región de un rendimiento óptimo de quitosano, correspondiente a los valores de turbidez del efluente de 0,5 uT a 0.25 uT en dosis entre 0,9 e 1,5 mg/L y pH valores entre 5 y 6. En los experimentos de filtración en condiciones de coagulación óptima la turbiedez promedio del efluente fue 0.29 uT durante el funcionamiento normal del sistema. En la coagulación de esta condición la extracción de microesferas osciló entre 4,3 log e log 4.9. En condiciones de coagulación super-óptima y subóptima, se afectó el rendimiento del filtro con incrementos en la turbidez del efluente y fue acompañado por la reducción en la extracción de microesferas con respecto a la condición de coagulación óptima del orden de 0,65 a 0,98 log, respectivamente, durante el funcionamiento normal del sistema, lo que indica que estas condiciones de coagulación conducen a aumentar el número de partículas con dimensiones similares a <em>Cryptosporidium oocysts</em> en el efluente del filtro, lo cual puede comprometer la calidad microbiológica del agua producida<em>. Finalmente, en todas las condiciones de coagulación investigadas con absorbancia (UV254 nm) la extracción media fue de 50%.</em></p>
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