Análise Comparativa entre Água Sintética à Base de Caulim e Substâncias Húmicas e Água Natural Superficial em Ensaios de Coagulação-Floculação

Resumo

Treatability tests are part of the continuous improvement routine in a water treatment process for supply
purposes. The use of synthetic waters is widely observed, promoting the standardization and versatility
of raw water samples. Among the most commonly used reagents, kaolin and humic and fulvic acids stand
out. This study examined the behavior of parameters frequently monitored in natural raw waters in relation
to kaolin and humic and fulvic acid concentrations, assessing the relationship between their values and
the coagulant demand required to reach the isoelectric point. Once the conditions of a synthetic water
similar to natural water in terms of turbidity and coagulant demand were established, comparative jar
tests with natural water were conducted. The results showed no significant difference at the 5% level for
the charge neutralization mechanism and low-turbidity waters. However, the synthetic water exhibited
greater turbidity reduction in medium-turbidity water samples, where the sweep coagulation mechanism
was predominant. This divergent result may be explained by the presence of small particles naturally
occurring in raw water, such as non-humic organic matter, which can hinder the coagulation process, in
contrast to the more uniform and larger-diameter particles in the prepared synthetic water.