Engenharia Agrícola

URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11733

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2012 - 20183

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Autor: search.filters.author.Teixeira, Denis LeocádioData inicial: 2010Assunto: search.filters.subject.Wastewater treatment

Resultados da Pesquisa

Agora exibindo 1 - 3 de 3
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    The influence of plant roots on the clogging process and the extractive capacity of nutrients/pollutants in horizontal subsurface flow constructed wetlands
    (Ecological Engineering, 2018-09) Teixeira, Denis Leocádio; Matos, Antonio Teixeira de; Matos, Mateus Pimentel de; Vieira, Delilah Pires; Araújo, Edcássio Dias; Ferraz, Liliane Aparecida
    The root system of plants grown in horizontal subsurface flow constructed wetlands (HSSF CWs), although it favors the removal of nutrients/pollutants from the wastewater under treatment, can contribute to the clogging of these systems. The objective of this work was therefore to evaluate the influence of Vetiver and Tifton 85 grass roots on the process of clogging and extraction of nutrients/pollutants in HSSF CWs. The drainable porosity in the medium was quantified before planting and after 250 days of cultivating the above-mentioned grass, having obtained the volume, productivity and nutrient extraction of the roots and shoots of these plants. There was a reduction in the porosity of the medium in the HSSF CWs due to the development of roots of the Vetiver and Tifton 85 grasses in the medium, however these roots occupied only 3.07 and 4.11% of the total pore space, respectively, and therefore are not factors of great influence in clogging process. HSSF CWs cultivated with Vetiver grass presented higher extractions of K and P by the roots, especially when the medium saturating solution presented greater availability of nutrients. On the other hand, higher extraction capacity of nutrients/pollutants was presented by the Tifton 85 shoots.
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    Evaluation of the effects of drainage and different rest periods as techniques for unclogging the porous medium in horizontal subsurface flow constructed wetlands
    (Ecological Engineering, 2018-09) Teixeira, Denis Leocádio; Leocádio, Denis; Matos, Mateus Pimentel de; Miranda, Suymara Toledo; Vieira, Delilah Pires
    The development of easy-to-perform techniques for unclogging of horizontal subsurface flow constructed wetlands (HSSF-CW) is essential to make them operationally simpler and increase their useful life. The objective of this work was to evaluate the drainable porosity, the extension of the bed presenting surface runoff and the characterization and quantification of the constituent solids clogging the porous medium of the HSSF-CW, after they were drained and submitted to different rest periods. Three systems were evaluated measuring 1.0 m wide and 4.0 m long, with 0.25 m working depth; one was cultivated with Vetiver grass (Chrysopogon zizanioides), the other with Tifton 85 (Cynodon spp.) and a control, in which no plant species were cultivated, where all were used for the treatment of municipal wastewater and presented conditions of partially clogged porous medium. After drainage of the system, the drainable porosity of the porous medium increased exponentially with the rest time during which they remained unsaturated, where the control and the HSSF-CW cultivated with Tifton 85 grass tended to stabilize. There was an increase in porosity of 18, 19 and 39% in relative to the initial porosity for the control HSSF-CW and those cultivated with the Tifton 85 and Vetiver grasses, respectively. Surface runoff in the HSSF-CW bed stopped completely between the 7th and 13th days after draining. However, no change was observed in the volatile solids content in the clogging material of the porous medium due to drainage of the HSSF-CWs.
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    Filtration rates in inorganic filters submitted to different repose periods
    (Acta Scientiarum. Agronomy, 2012-01-23) Teixeira, Denis Leocádio; Matos, Antonio Teixeira De; Monaco, Paola Alfonsa Vieira Lo; Eustáquio Júnior, Valdeir; Baker, Sandy Athaíde Archer
    This work aimed to evaluate the filtration rate in organic filters after being subjected to different repose periods in the primary treatment of swine wastewater (SWW). Filtration columns were mounted in PVC pipes measuring 100 mm in diameter and 600 mm in length and filled with 2-5 mm sawdust particles. Five different repose periods were evaluated: 1, 2, 4, 8 and 16 days after the first filtration, carrying out three batches. The SWW filtration rate decreased with the operating time of the filters, which can be attributed to clogging of pores resulting from high concentrations of suspended solids (SS) present in this type of wastewater. In the three batches, it was observed that the repose periods of 1, 2 and 4 days were not sufficient to unclog the pores, however, repose periods of 8 and 16 days for the filter medium resulted in increases of the filtration rate, only 59 and 72% of the initial rate, respectively.