Engenharia Agrícola
URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11733
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Resultados da Pesquisa
Item Performance of constructed wetlands in the treatment of aerated coffee processing wastewater: Removal of nutrients and phenolic compounds(Ecological Engineering, 2012-12) Rossmann, Maike; Matos, Antonio Teixeira de; Abreu, Edgar Carneiro; Silva, Fabyano Fonseca e; Borges, Alisson CarraroGiven the scarcity of studies on the behavior of constructed wetlands (CWs) when operating with previously aerated wastewater, the objective of the present study was to evaluate the influence of artificial aeration and vegetation on removal of nutrients and phenolic compounds from coffee processing wastewater (CPW) treated in CWs cultivated with ryegrass (Lolium multiflorum Lam.) For this reason, CWs were constructed measuring 0.6 m × 0.5 m × 2.0 m (H × L × W) and filled with pea gravel to a height of 0.55 m. The experiment was carried out considering a completely randomized design (CRD). Each variant of the experiment was replicated 10 times for each one of two replicates, implying in a total of 20 replicates, and 4 CWs characterized as follows: (i) ryegrass cultivated systems operating with an aerated influent (aiCWc), (ii) non-cultivated systems operating with an aerated influent (aiCW*), (iii) ryegrass cultivated system operating with a non-aerated influent (CWc), and (iv) non-cultivated systems operating with a non-aerated influent (CW*). For oxygenation of the CPW which would be supplied as aerated CPW in two treatments, an aeration system was implanted in the storage tank, consisting of a submerged Sarlobetter S520 pump with a flow of 0.52 m^3 h^−1, a gravel filter and tulle. The CPW was applied at an average flow rate of 0.020 m^3 d^−1, corresponding to a hydraulic retention time of 12 days. Efficiencies of 69, 72, 30 and 72% were obtained for the removal of total nitrogen (NT), total phosphorus (PT), total potassium (KT) and total phenolic compounds (FT), respectively, in the aiCWc. Aeration resulted in improved efficiency of pollutant removal such as N, P and phenolic compounds. The cultivated plant species (L. multiflorum) influenced the removal efficiencies of total-N, total-P and total-K in the systems, however, the best results were obtained by means of combination of vegetation with artificial aeration. Artificial aeration does not totally compensate the absence of plants, suggesting that the role of plants goes beyond the addition of oxygen to the medium, permitting the development of a more active and diverse microbial community near the root zone.Item Biological systems combined for the treatment of coffee processing wastewater: II - Removal of nutrients and phenolic compounds(Acta Scientiarum. Technology, 2012-08-09) Matos, Antonio Teixeira de; Fia, Ronaldo; Fia, Fátima Resende LuizThree treatment systems consisting of anaerobic filters with upward flow followed by constructed wetland systems (CW) were evaluated for the removal of nutrients and phenolic compounds, in the treatment of coffee processing wastewater (WCP) in Viçosa, Minas Gerais State. Filters were made of PVC (1.5 m high and 0.35 m diameter) filled with gravel # 2 and CW were made of wooden boxes (1.5 m long, 0.4 m high and 0.5 m wide) sealed by HDPE geomembrane and filled with gravel ‘zero’. The WCP had the pH adjusted with lime to values close to 7.0 and the nutrient concentration changed to obtain a BOD/N/P ratio of 100/5/1. As a result, hydraulic retention times longer than 160 h in all treatment systems during phase III had not promoted greater efficiencies for removal compared with the phase I, because the recovery time of the systems was inadequate. The F1+CW1 system that received the lowest organic load, showed a satisfactory performance with regard to the removal of nutrients (above 50%).Item Biological systems coupled for treating wastewater from processing coffee cherries: I – Removal of organic matter(Acta Scientiarum. Technology, 2012-06-26) Matos, Antonio Teixeira de; Fia, Ronaldo; Fia, Fátima Resende LuizThree treatment systems consisting of upflow anaerobic filters followed by constructed wetlands (CW) were evaluated in the treatment of wastewater from processing coffee cherries (WCP). The filters (F) were made up of PVC (1.5 m high and 0.35 m diameter) filled with gravel # 2 and SACs were made of wood boxes (1.5 m long, 0.4 m high and 0.5 m wide) sealed with HDPE geomembranes and filled with gravel ‘zero’. WCP had the pH adjusted with lime to values close to 7.0 and the nutrient concentration changed to obtain a BOD/N/P ratio equal to 100/5/1. As a result, the values of influent and effluent pH remained within the range appropriate to the biological degradation of organic material. The system could not bear the shock of the organic load, which reduced the organic matter removal efficiency. Based on the analysis of performance and operating conditions employed, only the system that received the lowest organic load (F1+CW1) on the third phase, was effective in removing organic matter.