Orientadores: Antonio Roberto Siviero, Jose Roberto Guimarães / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-08T16:52:01Z (GMT). No. of bitstreams: 1 Wutke_MariaCristinaBahia_M.pdf: 1667345 bytes, checksum: f2c17ac6d032f4d086c45f59a4125faf (MD5) Previous issue date: 2006 / Resumo: O crescimento populacional e o desenvolvimento de novas tecnologias e equipamentos com os quais se procura viabilizar mais qualidade de vida, podem muitas vezes contribuir para o aumento da produção de agentes poluentes e da proliferação de agentes patogênicos. As doenças respiratórias no Brasil têm sido importante causa de preocupação e de internações hospitalares. Diversos processos bioquímicos têm sido pesquisados e aplicados no tratamento e desinfecção do ar. A fotocatálise heterogênea com dióxido de titânio (TiO2/UV) é um dos processos oxidativos avançados, utilizados devido às suas inúmeras vantagens em sua aplicação: mais eficiência a longo prazo, produção de resíduos com menor toxidade e alta potencialidade de aplicação com baixo custo. No presente trabalho confeccionou-se um reator fotocatalítico para coletas e tratamento de amostras do ar ambiente de laboratório de Saneamento da UNICAMP, em Campinas, SP, de 19 de junho a 28 de julho de 2006. Trabalhou-se com um total de 540 placas de Petri, em dois experimentos, com tratamentos distintos entre si, em períodos matutinos, vespertinos e noturnos, sendo utilizadas 135 placas com o meio de cultivo Ágar Infusão Cérebro Coração - BHI para bactérias e outras 135 com o meio de cultivo Saboraud Dextrose para fungos, por experimento. Em cada experimento as amostras foram submetidas a quatro sistemas de desinfecção - S1: coleta de ar do interior do reator sem TiO2/UV, S2: coleta de ar do interior do reator com uma luz UV e sem TiO2 e S3: coleta de ar do ), interior do reator com duas luzes UV e sem TiO2, no experimento 1 e S5: coleta de ar do interior do reator com TiO2 e sem luz UV, S6: coleta de ar do interior do reator com TiO2 e uma luz UV e S7: coleta de ar do interior do reator com TiO2 e duas luzes UV no experimento 2, submetidos a três tempos de coleta de ar ? 1, 2 e 3 minutos (t1, t2 e t3) com 15 repetições (R) por sistema. Para os dados referentes às colônias de bactérias foram utilizados testes de qui-quadrado, para freqüências, e o teste não paramétrico ?de Friedman?, nos níveis de 1% e 5% de significância. Aqueles relativos às colônias de fungos foram analisados por teste paramétrico, com análise de variância e testes de diferenças entre médias, com transformação prévia dos dados em ?N, e comparação de médias pelos testes de t e Tukey, ao nível de 5% de significância. O processo de desinfecção de bactérias do ar ambiente é mais eficiente com a utilização de uma ou duas lâmpadas UV-C no interior do reator, sendo necessários, entretanto, 1 e 3 minutos de exposição quando utilizados no sistema, os processos de fotocatálise heterogênea (com TiO2) e de fotólise (sem TiO2), respectivamente. Em relação à desinfecção de fungos, o tempo de 1 minuto é eficiente tanto sem quanto com a utilização de TiO2 no interior do reator, constatando-se ação germicida com uma ou duas lâmpadas UV-C. O processo de fotocatálise heterogênea (TiO2/UV) é um método efetivo na desinfecção adequada de microrganismos - fungos e bactérias, presentes no ar de ambiente confinado laboratorial, por tempo de exposição de 1 minuto com uma ou duas lâmpadas UV-C / Abstract: The populational growth and development of new technologies and equipments to improve quality of life can many times contribute to an increase of polluent agents and the proliferation of pathogenic ones. Respiratory-tract diseases in Brazil have been an important cause of concern and hospitable internations. Several biochemical processes are under research and applied for air treatment and disinfection. Heterogeneous photocatalysis with titanium dioxide (TiO2/UV) is one of the advanced oxidatives process utilized due to several advantages of application: more efficiency on long term basis, production of lower tocity residues and high potencial at low cost of application. In this study a photocatalytic reactor was elaborated for collecting and treating environmental air samples from the Sanitization Laboratory located at UNICAMP, in Campinas, SP, from June 19th to July 28th of 2006. A total of 540 Petri dishes were analyzed in two different experiments, during morning, afternoon and night periods. At each experiment were utilized 135 dishes with culture media of Brain Heart Infusion Agar - BHI for bacteria and 135 other ones with Saboraud Dextrosis culture media for fungus. At each experiment the samples were submitted to four disinfection systems. In the Experiment 1 they were - S1: air collected from inside the reactor without TiO2/UV, S2: air collected from inside the reactor with one UV light and without TiO2 and S3: air collected from inside the reactor with two UV lights and without TiO2. In the Experiment 2 they were - S5: air collected from inside the reactor with TiO2 and without UV light, S6: air collected from inside the reactor with TiO2 and one UV light and S7: air collected from inside the reactor with TiO2 and two UV lights. Air samples were collected at ? 1, 2 and 3 minutes (t1, t2 and t3) time intervals for each experiment, with 15 replications (R) for each system. Bacteria colonies data were analyzed using qui-square tests for frequencies and non-parametric test of ?Friedman? at the levels of 1% and 5% of significance. Results from fungus colonies were analyzed by parametric test, with analysis of variance and tests of differences between average values, with previous transformation of data into ?N. Average data were compared by tests t and Tukey at the level of 5% of significance. Bacteria disinfection process of surrounding air is more efficient by using one or two UV-C lights inside the reactor with 1 and 3 minutes of exposition when are used heterogeneous photocatalysis (with TiO2) and photolysis (without TiO2) processes respectively. One minute time of exposition, with or without TiO2 inside the reactor is efficient for fungus removal, and germicide action was observed using one or two UV-C lights. The heterogeneous photocatalysis process (TiO2/UV) is an effective method for appropriate disinfection of microrganisms - fungus and bacteria, detected in the air of a restricted environmental from a laboratory, during one minute of exposition, with one or two UV-C lights / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil

Thesis (M. Tech. (Environmental health: Food safety )) - Central university of Technology, Free State, 2013 / Food processing plants and agricultural environments have a long-standing history of being known to provide a conducive environment for the prevalence and distribution of microorganisms which emanate as a consequence of activities undertaken in such premises. Microorganisms in the aforementioned environments may be found in the atmosphere (airborne), and/or on food contact surfaces. Airborne microorganisms from food handlers and in food products and raw materials (as part of bioaerosols) have in the past been implicated as having a potential to cause adverse health effects (especially in indoor environments) and therefore also to have economic implications. Recently their effect on food safety has received increased interest. The recent international interest in bioaerosols in the food industry has played a role in rapidly providing increased understanding of bioaerosols and their effects in different food processing environments. However, there is still a lack of research on the actual impact of bioaerosols over time in most of the food premises especially in Southern Africa and other developing countries. The overall purpose of this dissertation was to assess possible microbial contaminants and the role of selected environmental parameters on these microbes at a dairy farm plant in central South Africa. In relation to the purpose of the study, the objectives of this dissertation were to investigate and establish the food handler’s food safety knowledge, attitude, behaviour and practices. The sub-objective was to investigate the prevalence and distribution of microbial contaminants (both airborne and food contact surface populations), and concomitant environmental parameters. The microbe isolates from both investigations (i.e. air samples and food contact surfaces) were identified to strain level using matrix-assisted laser desorption ionization – time of flight mass spectrometry (MALDI-TOF MS). The findings of this study in relation to food handlers’ food safety knowledge, attitude, behaviour and practices indicated a dire need for training of employees as well as improved health and hygiene measures as emphasised by some of the identified strains. The environmental parameters (both indoor and outdoor) were similar, with no relationship established between airborne microbes’ prevalence and environmental parameters. The samples of the airborne microbial populations in both indoor and outdoor environments were similar. Airborne microbial counts at the dairy farm plant over the entire duration of the study ranged between 1.50 x 101cfu.m-3and 1.62 x 102cfu.m-3. Microbial counts on food contact surfaces ranged between 2.50 x 102 cfu.cm-2 and 1.10 x 105 cfu.cm-2 over the entire duration of the study. A wide variety of microorganisms (from air and food contact surfaces) such as the Gram-positive bacteria, Gram-negative bacteria, as well as fungi were present at the dairy farm plant. A number of the isolated genera have previously been associated with agricultural environments whilst others are associated with hospital environments. The positively identified strains were from genera such as Aeromonas, Arthrobacter, Candida, Pseudomonas, Pantoea, Citrobacter, Staphylococcus, Bacillus, Escherichia, Rhodococcus and Rhodotorula, amongst others. The isolation of microorganisms associated with food spoilage and foodborne disease outbreaks, which are known as indicator organisms such as Escherichia coli, Staphylococcus and Bacillus from both air and surface samples, signified possible faecal contamination and could be attributed to poor health and hygiene practices at the dairy farm plant. Despite the isolation of microorganisms associated with food spoilage and foodborne disease outbreaks, the isolation of microorganisms not usually associated with the food processing industry (usually associated with hospital environments) was an enormous and serious concern which suggested a need for further investigations at dairy farm plants as the implications of these pathogenic microorganisms in food is not known. The isolation of similar microorganisms from both the air samples and surface swabs suggests that airborne microbes have a potential of settling on food contact surfaces, therefore having a potential to contaminate dairy products which are known to be more prone to contamination and which, because of their nutritional status, serve as a good substrate for the growth of microorganisms.

Thesis (Ph. D.)--University of Oklahoma. / Bibliography: leaves 247-258.

Thesis (M.S.)--Medical College of Ohio, 1996. / Major advisor: William J. Davis. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis--University of Oklahoma. / Bibliography: leaves 50-53.

Thesis (M.S.)--Medical College of Ohio, 1996. / Major advisor: William J. Davis. Includes bibliographical references.