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Introduction: among the factors that affect the quality of water, we can mention suspended solids, which can be made up of organic and inorganic matter, hardness, pH, presence of bacteria, coliforms, etc. Objective: establish a comparison of the flocculation efficiency between two types of alum (KAl (SO4)2. 12H2O): commercial and prepared from recycling material (aluminum foil), used as a flocculating agent, in the inlet water of the Metropolitan University (Caracas). Materials and Methodology: water samples are taken, located at different points, within the University. They are characterized from the physicochemical point of view. Next, the coagulation-flocculation procedure is carried out, beginning with the determination of the isoelectric point, which will determine the appropriate pH, where the process will be carried out. The optimum concentration of the coagulant, necessary to achieve effective flocculation, is determined. The values obtained are, respectively, 47 ppm for commercial alum and 40 ppm for synthesized alum, from recycled material. Results: after applying the two types of alum, an improvement in the visual appearance of the samples (turbidity) was observed in both cases. It involved a reduction in absorbance (clarification), on average, of 73 % with commercial alum and 58 % for that obtained from recycled material. Regarding hardness, the decrease was 26 % and 27 % respectively and the decrease in conductivity, 70 % in both cases. Conclusions: from the investigation, the effectiveness of both types of alum, as a flocculating agent, emerges. In both cases the results were similar, which could lead to a lowcost method if commercial alum is substituted for alum prepared from recycled material. [ABSTRACT FROM AUTHOR]

The fig is a climacteric fruit with great perishability and short postharvest life. It has an ostiole that serves as a pollination medium and an entry site for fungal pathogens. In this work, three different protection strategies and their effect on the development of the ostiole were evaluated in addition to the presence of fungi. Fifteen white fig plants of the "Guarinta" variety were used. Images wereobtained by scanning electron microscope. The ostioli were evaluated in their structure and diameter. The presence of microorganisms was performed simultaneously. The mean diameter (mm) of pore in the control 'C' was 7.64, in protection with mesh 'M' it was 5.36 and protection with aluminum foil 'PA', 0.98; showing significant differences between the PA and C treatments. Figs wrapped with PA showed a higher incidence of pathogenic fungi. This constitutes a first approximation in the evaluation of types of protection. [ABSTRACT FROM AUTHOR]

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