poster - International Conference of Agricultural Engineering

al. (2010) studied either the conventional method of dosing the coagulant solution and muslin
pouches with powdered seeds of Moringa oleifera by the immersion of the pouch in the turbid
water. The authors evidenced the necessity of optimization of pouches.
Considering the recommendations of Arantes (2010) and Pritchard et al. (2010), the
objective of this study was to develop a new method for applying the coagulant from the
hypothesis that the powdered seeds in pouches provide the protein and retain part of the
organic matter that remains in the water.
2. METHODS
2.1. Protein dissolution
The dissolution behavior of the protein present in the powdered seeds of Moringa
oleifera in pouches was evaluated to determine the pouch to be used for the clarification of
synthetic turbid water.
Five types of materials for the manufacture of pouches were tested: stitched nonwoven
fabric; Mellita ® filter paper and 3 types of synthetic non-woven fabrics (white, gray and
black).
After addition of 2 g of not sieved powdered seeds of Moringa oleifera in each pouch,
they were closed and locked in an acrylic strip as shown in Figure 1. The area for the
Moringa oleifera powder in pouches was approximately 31 cm -2 .
(a) (b) (c) (d) (e)
FIGURE 1: Pouch used: (a) black fabric, (b) gray fabric, (c) white fabric, (d) non-woven
fabric, (e) commercial filter paper for coffee.
Two liters of deionized distilled water were added to each jar of the Jar-Test
equipment. Two grams of prepared powder were directly added in a jar and each one of the
5 pouches containing the powdered seeds were placed in each jar on the Jar-Test
equipment. The assays were carried out during 24 h. Samples were collected at 0, 1, 5, 30,
60, 120, 240, 1200 and 1440 min. The Jar-Test was kept with slow stirring, with a velocity
gradient of approximately 10 s -1 . The turbidity was determined according to Standard
Methods (APHA, 2005) and the protein content was quantified by spectrophotometer with the
modified method of Lowry (1951) as described by Madrona (2010). Each experiment was
carried out in triplicate.
2.2. Clarification of synthetic turbid water
After determining the appropriate pouch, it was assessed its efficiency in water
clarification, as well as comparison with the coagulant solution.
2.2.1 Preparation of synthetic turbid water
The preparation of the raw water follows the method proposed by Mendes (1989) and
adapted by Paterniani et al. (2010). The synthetic turbid water was prepared by adding 0.2 g
L -1 of bentonite in deionized distilled water. This mixture was taken to the Jar-Test equipment
under agitation with a gradient of 400 s -1 for 30 min. The suspension was left for
sedimentation for 24 h. The supernatant was collected after this period, which presented a
turbidity of 65 NTU and was used as raw water.
2.2.2. Preparation of the coagulant solution and determination of the dose of
powdered seed in pouches
The preparation of the coagulant solution was based on Ramos (2005), with
adjustments of Arantes (2010). Non-shelled Moringa oleifera seeds were ground to powder