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With the water crisis affecting several countries, the use of innovative technologies and methods in irrigated agriculture is essential to increase water use efficiency. The use of magnetised water has been considered a possibility both for saving water resources and in increasing crop productivity and quality. Following this, the objective of the present study was to evaluate the growth and longevity of flower stems of ornamental sunflower (Helianthus annuus L.; Vincent's Choice) irrigated with different irrigation depths and water subjected to magnetic field treatment. The treatments consisted of five percentage of crop evapotranspiration (ETc) (20, 70, 100, 130, and 160% of ETc) and two types of irrigation water (magnetised water; and ordinary water). The following characteristics were evaluated: plant height, stem diameter, inflorescence diameter, fresh and dry masses of the leaves and stems, fresh and dry masses of the inflorescence, and post-harvest longevity of the flower stems. The growth and post-harvest longevity characteristics were not influenced by the water type. An increase in irrigation depth promoted an increase in all analysed parameters. Regarding the commercialisation patterns of cut flowers, depth equal to or greater than 0.7 ETc yielded the best classification of ornamental sunflower. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the filtration process of a commercial sand filter operating at different filtration rates and different sand particle sizes. The second objective is to carry out sand filter efficiency evaluations and compare the standard sand filter method and the proposed method. Removal efficiency was analyzed in three filtration cycles, and determined by two methodologies: counting of particles in water at the inlet and outlet of the filtration system (standard method) and in sand bed layers (proposed method). An experimental module composed of three identical commercial sand filters was used with different sand particle sizes (G1 - 0.55 mm of sand effective diameter, G2 - 0.77 mm and G3 - 1.04 mm) and filtration rate combinations (20, 40, 60, and 75 m3 m-2 h-1), repeated for three filtration cycles (C1, C2 and C3), 4 h per cycle. The removal efficiency of sand filters increases as the filtration rate increases for the water quality used, and sand particle size decreases. Between the methodologies applied to evaluate filtration systems, the method using total suspended solids retained in sand (proposed method) has shown a greater potential when compared with the standard method. The evaluation methodology proposed provides a global and accurate evaluation of the process. This form of estimation does not have the representability problem punctual water samples collected during filtration have. In addition, it is a promising methodology for farmers and technicians to carry out equipment evaluations in the field. [ABSTRACT FROM AUTHOR]

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Backwash process of sand filters requests specific surface velocity to reach the recommended filter bed height expansion, however the expansion of the filter bed height is very influenced by their characteristics. This work had as aim to evaluate the effect of different sand particle size, static filter bed layer and expansion of the filter bed height on a prototype of sand filter during backwash process. The tests were accomplished using a sand filter prototype that had structural similarity and shape as commercial equipments (24 cm of height and 12.7 cm of diameter). The treatments consisted from combinations of five separate sand particle sizes (0.15; 0.34; 0.51; 0.72 and 0.92 mm of medium diameter), five static filter bed layer (5; 7; 9; 11 and 13 cm) and different expansion of the filter bed height, with three replications. In general, the sand filter prototype was effective in characterizing with accuracy the backwash process, being possible using to obtain superficial velocity to reach specific filter bed height expansion using different sand particle sizes and static filter bed layer. [ABSTRACT FROM AUTHOR]