Avaliação da turbidez e do tamanho de partículas como parâmetros indicadores da remoção de oocistos de Cryptosporidium spp. nas etapas de clarificação no tratamento da água em ciclo completo

• Autor(a) principal: Lopes, Gustavo José Rodrigues
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3711
• topic: Água para consumo humano; Eficiência de remoção; Potabilidade; Water for human consumption; Efficiency of removal; CNPQ::ENGENHARIAS::ENGENHARIA SANITARIA

The monitoring of the occurrence of Cryptosporidium oocysts in the water treatment station at the Federal University of Viçosa (ETA UFV), plus the implementation of inoculation experiments of this microorganism in the water that would feed an ETA conventional (full cycle) in pilot- scale indicate that although there will be an effective removal, some oocysts can go through the treatment process. According to the results of tests on 15 inoculations, it was the conclusion that the reckoning for the removal of Cryptosporidium oocysts from the pilot installation reached, approximately, 0.5 log10 in decanting and 1.5 log10 in the complete cycle of clarification. The first result is consistent with that recorded in the literature and made standard in the U.S., but the second fell short of expectations, in which several researchers reported a range of 3.0 log10 removal. In this work indications are congregated that the removal of turbidity is more appropriate than the particle counting as an indicator of the removal of Cryptosporidium oocysts and the removal of turbidity is directly related to the particle removal with size ranging form 2 - 7 μm. In results we can t get conclusive suggestions on the association of numerical limits of turbidity with the removal of oocysts, however it has indications of that production of filtered water with low turbidity is a preventative measure. In comparison of values gotten in different equipment for measuring turbidity, for periods of drought and rain, we conclude that these measures of low values of turbidity must keep the best possible precision and the gotten results had detached the great variation obtained with different equipments. These observations keep great relevance, because it gives importance to the first decimal place differences in the values of turbidity of water filtered, as indicators of removal of protozoa. It is called, therefore attention to the necessity to have modern equipment, suitable for readings of low turbidity and to implement, routinely, procedures, best practices and standard operating procedures in a laboratory.