Influência da granulometria e taxas de filtração no tratamento de água utilizando dupla filtração

The contamination of water sources of public drinking by waste originated by anthropogenic activities has brought various risks to human health. Among the consequences of such activities can highlight the bloom of microalgae and cyanobacteria, which have the potential to produce toxins dangerous to humans, and the presence of humic substances that are generated by the decomposition of natural organic matter (NOM), such as vegetation. When found in water sources for public supply, present negative aspects conferring high color, odor and taste. The double filtration technology has good efficiency in water with the presence of cyanobacteria and different quality variations. Therefore, this study aimed to evaluate the behavior of the technique of double filtration with pre-oxidation for water purifiers the lagoon of Extremoz-RN, which currently has high concentrations of cyanobacteria. The research is summarized in four phases: the first phase turned to static tests in jarteste equipment in the laboratory and subsequent phases were tested in the Pilot Plant of Double Filtration. For the second and third stage filtration rates were tested filtration rates of 120 and 180 m3 / m2 .day for ascending boulders filters and 160 and 240 m3 / m2 .day in the filters in quick sand descendants. The last phase aimed to evaluate the double filtration with pre-oxidation. The results demonstrated that the system could produce double filtration in all trials of good quality water according to the Decree nº. 2914/11 of the Ministry of Health. The use of preoxidation favored the removal of microcystin and color at the end of the tests, reaching a percentage of color removal around 60%. The analysis of variance in the data, enabled prove that the filtration rates of 180 m3 / m2.d the gravel filter and 240 m3 /m2 .d in rapid filters, were the most significant for the removal of turbidity. The ascending filter of boulder 4 with particle size finer filter layer showed the best performance and the best means of turbidity and apparent color. The rapid filter downward 1 was more efficient in removing turbidity reaching removal about 100%