poster - International Conference of Agricultural Engineering

Therefore, there is great importance on studying this parasite and understand its dispersal
ability, strength and resistance to the stages of water treatment (XIAO et al., 2004). Thus, it
is necessary to improve the systems of coagulation / flocculation or create filtration barriers
for retention of oocysts in water. In locations with no conventional treatment, it is necessary
to find alternative methods to improve the water treatment conditions.
Many studies aimed to verify the removal of Cryptosporidium using oocysts as a means of
checking the efficiency of the water treatment. However, the great problems are the high
costs of reagents, the methodological difficulties of detection and the risk of contamination of
handlers with inactive oocysts. Therefore, many studies have addressed the use of
indicators, or even synthetic substitutes with similar characteristics to the oocysts.
The polystyrene microspheres are an alternative substitute of Cryptosporidium oocysts
widely used by many researchers in the evaluation of water treatments (BROWN &
EMELKO, 2009).
Natural coagulants are used as an alternative treatment to improve the quality of water in
regions where there are no conventional water treatments. Moringa oleifera Lam is a tropical
tree from Northwestern Indian cultivated because of nutritional, medicinal and industrial value
and in the water treatment for human consumption. It belongs to the plant family
Moringaceae, whose seeds present coagulation properties for treating water in regions
without conventional treatments.
So far, other types of natural coagulants such as based on the Moringa oleifera seeds were
not tested for the removal of polystyrene microspheres, simulating the removal of
Cryptosporidium spp.
Due to the importance of testing the coagulation with Moringa oleifera seeds for the removal
of polystyrene microspheres simulating Cryptosporidium spp., this study aimed to evaluate a
system of coagulation / flocculation using a coagulant solution based on seeds of Moringa
oleifera, followed by slow filtration in non-woven synthetic fabrics for the reduction of
fluorescent polystyrene microspheres.
2. Methodology
The experiment was conducted in a bench scale, with the intent of employing water with both
low turbidity and concentration of fluorescent polystyrene microspheres. To obtain water with
low turbidity, on range of 18 NTU, the optimum dosage of coagulant solution of Moringa
oleifera to the treatment was 25 mg L -1 (FRANCISCO et al. 2011). Tests of coagulation and
flocculation in static reactors (Jar Test) were performed followed by filtration with non-woven
synthetic fabrics.
The system received water synthetically prepared with bentonite, which generated an 18
NTU turbidity value, and the jars from the equipment Jar Test were filled with 2 liters of this
sample. In sequence, it was inoculated approximately 2 x 10 6 polystyrene microspheres
previously counted in hemacytometer. The microspheres had a size of 3 m and were stored
in a vial with 2.5% aqueous suspension (1.69 x 10 9 particles / ml), as informed by the
manufacturer (Polysciences). The microspheres viewed under a microscope exhibited
excitation maximum at 441 nm and emission maximum at 486 nm (Cerqueira, 2008).