Estudos de formação e remoção de subprodutos de desinfecção (SPDS) em aguas contendo acidos humicols quando sumetidas a dioxido de cloro / Studies of formation and remotion of disinfection by products (DBP), generated by the oxidation of solutions containing humic substances throught the use of chlorine dioxide

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The objective of the present research was to analyze the formation of disinfection by products (DPB), generated by the oxidation of solutions containing humic substances with the addition of bromide ions through the use of chlorine dioxide, isolated or associated with free chlorine in different concentrations and reaction times. The technique of gaseous chromatography was applied in order to detect the formed trihalomethanes (THM), aldehydes and organic acids. The results of the chromatographic analyses allowed to choose the sample that presented the higher concentration of each DBP to carry out the assays of adsorption in different concentrations of powdered activated carbon (PAC), followed by simulation, under laboratory conditions, of conventional process of water treatment. The obtained results indicated that the use of chlorine dioxide in the oxidation of solutions containing humic acids with and without the presence of bromides resulted in THM concentrations under the ones established by the resolution n. 518 of Brazilian Health Ministry, while the use of free chlorine, after the use of chlorine dioxide as a primary oxidant, combined with the presence of bromide ions, produced higher concentrations of these. The variation of chlorine dioxide dosages resulted in the formation of aldehydes in lower concentrations, and the variation of humic acids and bromide ions dosages did not result in a significant formation of these. For the dosages of humic acids, bromides and oxidants there was no significant formation of organic acids. The use of PAC, followed by the conventional process of water treatment promoted the adequacy of the water in the maximum values allowed by the national regulations for the color and e turbity parameters, maintaining the quality of the original water, not causing loss of quality to the original water. The variation of PAC dosage influenced the treatment of the water, with more effective removal of THM for the higher dosages. On the contrary, for aldehyds, lower dosages showed to be more efficient

ASSUNTO(S)

agua - estações de tratamento carvão agua - purificação - floculação carbon water water purification plants water agua - purificação - oxidação

ACESSO AO ARTIGO

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