SOUZA, J.; http://lattes.cnpq.br/3941210590487917; SOUZA, Joseneto de.
Résumé:
This study aimed to verify compliances and non-compliances of the water indicators,
aluminum, chloride, hardness, iron, manganese and turbidity with the standard of
acceptance for human consumption, according Brazilian Ministry of Health Ordinance
518/2004, of water distributed at pressure zones A and B of water network of
Campina Grande (7°13'50" S and 35°52'52"W), Paraiba state, northeast Brazil.
Samples from six monitoring points were collected at three distinct times within the
daily cycle from March to December 2009. These points were chosen according the
criteria established in the National Guidance for the Sampling Plan on Health
Surveillance related with water quality for human consumption. The application of
one-factor analysis of variance (ANOVA) to the various data sets from monitoring of a
same variable demonstrated that variations in the behavior of indicators were
dependent on the position of sampling point rather than on time collection. From all
indicators analyzed only aluminium (62.12%) and turbidity (3.42%) presented noncompliances
with the already mentioned standard for human consumption
acceptance, being these non-compliances related with both changes in raw water
stored at the reservoir in rainy season and a water treatment plant operation
schedule without flexibility to work with those changes. Ordinarily, none coagulation
chemical agent is used during dry season, but from the beginning of rainy season
aluminium sulphate is dosed in order to face up the significant increase on turbidity in
raw water. But, without a rigorous control of factors which promote an optimal
clarification, coagulant dosage tend to overlap its real demand and leave a residue of
aluminium in the water which is more than the standardized maximum permissible
concentration of 0.2mgAI/L.
