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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Reduction of Pathogens in Biosolids in Mexico Using Solar Drying Beds

Dominguez Sanchez, Teodulo January 2005 (has links)
In this study, die-off patterns of helminth ova, fecal coliforms, and Salmonella spp. in biosolids were documented using three small-scale sand drying beds located in a greenhouse. Treatments involved tilling the biosolids with differing frequencies. The results indicate that the inactivation rate for helminth ova was 0.88, 0.55, and 0.22 eggs/4 g TS day-1 for the intensively-tilled, moderately-tilled, and control beds, respectively. Achievement of Class A criteria was only possible in the intensively-tilled bed by Day 70 of the experiment. Salmonella spp. were inactivated to Class A levels in 9 days for the intensively and moderately-tilled beds. Regrowth of Salmonella spp. occurred thereafter in all beds, but high levels were seen only in the control bed. Fecal coliforms reached Class A criteria late in the experiment. Tilling treatments enhanced the inactivation rate of helminth ova and offer a potentially cost-effective method of pathogen reduction.
2

Amenizantes em solo contaminado com bário

Lima, Ana Lúcia de [UNESP] 12 January 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-01-12Bitstream added on 2014-06-13T20:41:10Z : No. of bitstreams: 1 lima_al_dr_jabo.pdf: 429258 bytes, checksum: 393f433735bd537f36ca781d73acea45 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A contaminação do solo é um problema ambiental que pode causar perda da produtividade agrícola, alteração na diversidade microbiana e nos processos biológicos do solo e acumulo de elementos traço em alimentos. O Ba é um elemento traço pouco estudado e que pode trazer problemas ambientais quando em excesso no ambiente. Medidas diversas têm sido utilizadas para minimizar a contaminação do solo por ETs, dentre elas está o uso de remediadores para imobilizar esses ETs no solo, impedindo ou diminuindo a absorção pelas plantas e a entrada dos contaminantes na cadeia alimentar e parâmetros microbianos são empregados como indicadores da qualidade do solo pela sua sensibilidade a fatores abióticos e bióticos. Os objetivos do trabalho foram avaliar se os remediadores e a contaminação do solo com sais de Ba influenciaram a comunidade microbiana e avaliar se os remediadores, diminuem a disponibilidade do Ba no solo e absorção pela planta. O delineamento experimental foi de blocos casualizados com esquema fatorial 4x5 mais um controle. Foram usados 4 remediadores: lodo de esgoto (LE), lama vermelha (LV), esterco bovino (EB) e calcário (CA), além de uma testemunha sem adição de remediador, e 4 fontes de contaminação com sais de Ba [Ba(NO3)2, BaCl2.2H2O, BaSO4 e BaCO3] com quatro repetições. A aplicação de Ba reduziu a respiração basal (RB) e o coeficiente metabólico (qCO2) em relação ao controle e estimulou a hidrólise do FDA. O uso de remediadores aumentou a RB e o qCO2 e o uso de LE e EB estimularam a atividade do FDA no solo contaminado em relação ao solo sem remediação. A contaminação do solo com os sais mais solúveis de Ba causou redução na massa seca de raiz de da parte aérea, aumentou a concentração e o acúmulo de Ba nas plantas e diminuiu a absorção de Ca. O uso dos remediadores... / Soil contamination is an environmental problem that can lead to agricultural productivity loss, alterations on microbial diversity and on the soil's biological processes and also accumulation of trace-elements in foods. Barium is a trace-element barely studied and can bring environmental problems when present in excess on the environment. Several measures have been taken to minimize soil contamination by trace-elements. Among them is the use of amendments to immobilize these elements in soils, avoiding or reducing plant absorption as long as the entrance of contaminants in the food chain, and the employment of microbial parameters as indicators of soil quality for its sensitivity to biotic and abiotic factors. The experiment's objectives were to evaluate if amendments and soil contamination with barium salts influence microbial community and also to evaluate if amendments reduce barium availability on soils and plant absorption of this element. The experimental design used was random blocks with factorial scheme of 4x5 plus one control. Four amendments were used: sewer sludge (SS), red mud (RM), cattle manure (CM) and limestone (LS), along with another control with no amendment addition, and four contamination sources with barium salts [Ba(NO3)2, BaCl2.2H2O, BaSO4 e BaCO3] with four repetitions. Barium application reduced basal respiration (BR) and metabolic quotient (qCO2) in relation with control, and stimulated FDA hydrolysis. Amendments use increased BR and qCO2 and the use of SS and CM stimulated FDA activity in contaminated soil in relation to soil without amendment use. Soil contamination with more soluble barium salts caused reduction on aerial and roots' dry mass, increased barium concentration and accumulation on plants and reduced calcium absorption. Amendments use, with the exception... (Complete abstract click electronic access below)
3

Amenizantes em solo contaminado com bário /

Lima, Ana Lúcia de. January 2012 (has links)
Orientador: Wanderley Jose de Melo / Banca: Aline Renee Coscione Gomes / Banca: Mara Cristina Pessoa da Cruz / Banca: Marco Antonio Nogueira / Banca: João Antonio Galbiatti / Resumo: A contaminação do solo é um problema ambiental que pode causar perda da produtividade agrícola, alteração na diversidade microbiana e nos processos biológicos do solo e acumulo de elementos traço em alimentos. O Ba é um elemento traço pouco estudado e que pode trazer problemas ambientais quando em excesso no ambiente. Medidas diversas têm sido utilizadas para minimizar a contaminação do solo por ETs, dentre elas está o uso de remediadores para imobilizar esses ETs no solo, impedindo ou diminuindo a absorção pelas plantas e a entrada dos contaminantes na cadeia alimentar e parâmetros microbianos são empregados como indicadores da qualidade do solo pela sua sensibilidade a fatores abióticos e bióticos. Os objetivos do trabalho foram avaliar se os remediadores e a contaminação do solo com sais de Ba influenciaram a comunidade microbiana e avaliar se os remediadores, diminuem a disponibilidade do Ba no solo e absorção pela planta. O delineamento experimental foi de blocos casualizados com esquema fatorial 4x5 mais um controle. Foram usados 4 remediadores: lodo de esgoto (LE), lama vermelha (LV), esterco bovino (EB) e calcário (CA), além de uma testemunha sem adição de remediador, e 4 fontes de contaminação com sais de Ba [Ba(NO3)2, BaCl2.2H2O, BaSO4 e BaCO3] com quatro repetições. A aplicação de Ba reduziu a respiração basal (RB) e o coeficiente metabólico (qCO2) em relação ao controle e estimulou a hidrólise do FDA. O uso de remediadores aumentou a RB e o qCO2 e o uso de LE e EB estimularam a atividade do FDA no solo contaminado em relação ao solo sem remediação. A contaminação do solo com os sais mais solúveis de Ba causou redução na massa seca de raiz de da parte aérea, aumentou a concentração e o acúmulo de Ba nas plantas e diminuiu a absorção de Ca. O uso dos remediadores... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Soil contamination is an environmental problem that can lead to agricultural productivity loss, alterations on microbial diversity and on the soil's biological processes and also accumulation of trace-elements in foods. Barium is a trace-element barely studied and can bring environmental problems when present in excess on the environment. Several measures have been taken to minimize soil contamination by trace-elements. Among them is the use of amendments to immobilize these elements in soils, avoiding or reducing plant absorption as long as the entrance of contaminants in the food chain, and the employment of microbial parameters as indicators of soil quality for its sensitivity to biotic and abiotic factors. The experiment's objectives were to evaluate if amendments and soil contamination with barium salts influence microbial community and also to evaluate if amendments reduce barium availability on soils and plant absorption of this element. The experimental design used was random blocks with factorial scheme of 4x5 plus one control. Four amendments were used: sewer sludge (SS), red mud (RM), cattle manure (CM) and limestone (LS), along with another control with no amendment addition, and four contamination sources with barium salts [Ba(NO3)2, BaCl2.2H2O, BaSO4 e BaCO3] with four repetitions. Barium application reduced basal respiration (BR) and metabolic quotient (qCO2) in relation with control, and stimulated FDA hydrolysis. Amendments use increased BR and qCO2 and the use of SS and CM stimulated FDA activity in contaminated soil in relation to soil without amendment use. Soil contamination with more soluble barium salts caused reduction on aerial and roots' dry mass, increased barium concentration and accumulation on plants and reduced calcium absorption. Amendments use, with the exception... (Complete abstract click electronic access below) / Doutor

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