03.1 - Graduação (UAST)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/2926
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Resultados da Pesquisa
Item Análise microbiológica de água de torneiras residenciais no município de Serra Talhada-PE(2019) Gomes, Maryelle Adja de Freitas; Siqueira, Virgínia Medeiros de; http://lattes.cnpq.br/5524459744893735; http://lattes.cnpq.br/0954723255699530Water can undergo chemical and biological variations along distribution systems, changing their quality when it reaches the consumer. This causes concern throughout, since inappropriate drinking water directly affects public health once water may act as a vehicle for pathogenic microorganisms of enteric origin. The objective of this study was to evaluate the microbiological quality of tap water in residences in five districts Serra Talhada-PE's municipality, as well as to analyze the effectiveness of alternative treatments such as filtration and chlorination. The samples were collected in pre-sterilized and aseptically flashed glass vials and were fractionated in three sub-samples: without treatment (ST), treated with sodium hypochlorite (T-NaCl) and filtration with microporous porcelain filters (T-Filt). All subsamples were submit to the research and quantification of total coliforms, thermotolerant coliforms and total bacteria, using methodology described by the American Public Health Association (APHA). For this, the technique of multi-tubes for 3 tubes and quantification by the Most Probable Number (NMP) and Colony Forming Units (CFU) were used. As results, two of the five subsamples (ST) presented quantification of 43 NMP and 23 NMP/mL for total coliforms, and of 7.4 NMP/mL and 3.6 NMP / mL for thermotolerant coliforms, thus being considered inappropriate human consumption according to Portaria 518/2004 of the Ministry of Health of Brazil. Regarding the analysis of total bacteria, no sample had CFU higher than 500 CFU / mL, being therefore within the required standard. The treatment with hypochlorite showed efficiency in the reduction of total bacteria, total coliforms and thermotolerant coliforms. Regarding filtration, there was an increase in microbial density in relation to the ST samples, indicating a possible contamination in the ceramic filters. However, for this same treatment (T-Filt), the results were negative for total and thermotolerant coliforms, indicating that this method was effective in the elimination of these microorganisms. It is assumed that the two samples that presented thermotolerant coliforms were contaminated by the reservoir of the residences, or the contamination comes from the pipelines of the supply network. In addition, alternative treatment using hypochlorite has proved effective and may be indicated for households that use tap water for human consumption.Item Estudo dos coagulantes naturais Cereus jamacaru, Opuntia ficus-indica e Pilosocereus gounellei como pré-tratamento para desinfecção solar(2019) Sousa, Karina Michely Leite de; Lima, Marcelo Batista de; http://lattes.cnpq.br/2424699316257149; http://lattes.cnpq.br/0109616249430654Natural coagulants are used as an alternative to a viable water treatment, targeting populations that do not have access to treated water. The objective of this work was to evaluate the coagulant capacity of Cereus jamacaru (mandacaru), Opuntia ficus-indica (palm) and Pilosocereus gounellei (xiquexique) cacti as a pretreatment for disinfection by solar radiation. Acid extracts were prepared with 0.10 mol L-1 HCl of each cactus, using the viscous (pulp) and others with the dry matter coming from the bark, all in the proportion of 2.00 g of cactus to 3.00 mL of extraction solution. Ca (OH) 2 0.10 mol L-1 was used as the alkalizing agent. Nine tests of coagulation and flocculation were performed in Jar Test with the operating conditions as fast mixing speed of 150 rpm and fast mixing time of 60 s, slow mixing speed of 45 rpm, slow mixing time of 900 if sedimentation time 15 min along with the turbidity, color and pH parameters. The raw water samples used in the coagulation and flocculation tests presented high turbidity and color parameters. The tests performed with the extracts prepared with the dry matter did not show coagulant efficiency, on the other hand those that were used the extracts prepared with the pulp of the three cacti demonstrated good coagulant action obtaining, in the best test, the turbidity and color removals with the 98% and 92% mandacaru extract, 98% and 96% palm and 98% and 96% xiquexique. After the pre-treatment, disinfection by solar radiation was carried out, where the filtered and unfiltered samples were added in PET bottles with a capacity of 2.0 L and subjected to sun exposure for a period of 6 hours. The results obtained for the coagulation and flocculation pretreatment samples were negative for the presence of total coliforms, and no samples were positive for Escherichia coli. In this way, it can be affirmed that the cacti present themselves as great potential natural coagulants to be used as occasional pretreatment of real turbid waters for subsequent solar disinfection, since after the treatment all the evaluated parameters have met the established by the Brazilian legislation for drinking water.