Dados da dissertação de mestrado

Author: Wallace Alberto da Silva de Andrade
 
Title: Alternative water treatment using seeds of Moringa oleifera for remotion of cyanobacteria bloom
 
Year: 2019                                         Full text (in Portuguese)
 
Abstract:
Moringa oleifera is a plant species native from India that has been well studied and recognized for its high nutritional value. The ability of its seeds also is known to act as a coagulant of water impurities. Currently, several studies prove the capacity of Moringa oleifera seeds to remove cyanobacteria blooms. The objective of this study was to verify the efficiency of M. oleifera seeds as an alternative water treatment for removal of cyanobacteria blooms and other microbiological contaminants. The final aim was to propose a simple and efficient methodology for the treatment of water in situations of inadequate conventional basic sanitation. Initially, an experiment was performed with jar-test equipment, using cells from the Microcystis aeruginosa species (NPLJ-4 strain). To verify the efficiency of the process, three concentrations of ground and sieved seeds of M. oleifera (10, 25 and 100 mg/L) were tested using water with different pH values (5 to 9). Water samples were harvested at various intervals (1, 6, 24 and 48 hours) to determiny turbidity (uT), concentration of chlorophyll-a and microcystins. Two other experiments were performed using raw water containing a natural cyanobacterial bloom from Funil reservoir (RJ). In both experiments, the concentration of the ground and sieved moringa seeds were 25, 50, or 100 mg/L. In the first experimente, the efficiency of the seeds was measured by the turbidity values (uT), chlorophyll-a and microcystins concentration at two intervals (6 and 24h). For the second experiment, variations of turbidity (uT), total coliforms, and Escherichia coli were analyzed. The removal of total coliforms and E. coli was not efficient. But the results showed that seeds of M. oleifera can be used as an alternative treatment to improve the quality of raw water containing natural cyanobacteria blooms. However, after the treatment with the seeds, the water needs to filter and chlorinated before consumption.