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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

Integrace materiálového a energetického využití kalů z ČOV / Integration of material and energy utilization of sewage sludge

Zakov, Tomáš January 2020 (has links)
This master thesis deals in first part with options and trends on field of municipal sewage sludge management. Further thesis describes legislation in relation with sewage sludge and its incineration in European union and also in Czech republic. Second part of thesis deals with design of mechanism for material and energetic use of sludge. In design is progressively processed chioce of aparates and material and energetic balance. This data are further used for mechine technical solution of the unit. Disposition of the unit is done acording to chosen and calculated parameter of chosen aparates. Economical evaluate of project if based on investment and operation costs and capacity design of unit in the end of thesis.
2

Estimation of Nutrient Exports Resulting from Thinning and Intensive Biomass Extraction in Medium-Aged Spruce and Pine Stands in Saxony, Northeast Germany.

Knust, Christine, Feger, Karl-Heinz 27 March 2017 (has links) (PDF)
A growing interest in using forest biomass for bioenergy generation may stimulate intensive harvesting scenarios in Germany. We calculated and compared nutrient exports of conventional stem only (SO), whole tree without needles (WT excl. needles), and whole tree (WT) harvesting in two medium aged Norway spruce (Picea abies L. Karst.) and Scots pine (Pinus sylvestris L.) stands differing in productivity, and related them to soil nutrient pools and fluxes at the study sites. We established allometric biomass functions for each aboveground tree compartment and analyzed their nutrient contents. We analyzed soil nutrient stocks, estimated weathering rates, and obtained deposition and seepage data from nearby Level II stations. WT (excl. needles) and WT treatments cause nutrient losses 1.5 to 3.6 times higher than SO, while the biomass gain is only 1.18 to 1.25 in case of WT (excl. needles) and 1.28 to 1.30 in case of WT in the pine and spruce stand, respectively. Within the investigated 25-year period, WT harvesting would cause exports of N, K+, Ca2+, and Mg2+ of 6.6, 8.8, 5.4, and 0.8 kg·ha−1 in the pine stand and 13.9, 7.0, 10.6, and 1.8 kg·ha−1 in the spruce stand annually. The relative impact of WT and WT (excl. needles) on the nutrient balance is similar in the pine and spruce stands, despite differences in stand productivities, and thus the absolute amount of nutrients removed. In addition to the impact of intensive harvesting, both sites are characterized by high seepage losses of base cations, further impairing the nutrient budget. While intensive biomass extraction causes detrimental effects on many key soil ecological properties, our calculations may serve to implement measures to improve the nutrient balance in forested ecosystems.
3

[en] BIOGAS IN WASTEWATER TREATMENT PLANTS: THE MAIN LEGACIES OF THE BRAZIL-GERMANY TECHNICAL COOPERATION / [pt] BIOGÁS EM ESTAÇÕES DE TRATAMENTO DE ESGOTOS: OS PRINCIPAIS LEGADOS DA COOPERAÇÃO TÉCNICA BRASIL-ALEMANHA

HÉLINAH CARDOSO MOREIRA 26 December 2017 (has links)
[pt] Apesar dos avanços verificados nos últimos anos, o aproveitamento energético do biogás no Brasil ainda não é uma prática consolidada no tratamento de esgotos. Em estações de tratamento de esgotos (ETEs) com processos anaeróbios, o biogás se mostra como um produto estratégico econômico, social e ambientalmente, em muitos países do mundo, em especial na Alemanha. O projeto de cooperação técnica Brasil-Alemanha – PROBIOGÁS – foi o propulsor da discussão do biogás no saneamento no país. O presente trabalho retrata as principais ações e impactos do PROBIOGÁS no setor de tratamento de esgotos brasileiro e propõe uma continuidade às ações desenvolvidas por meio de instituições chave. Além disso, são levantados os desafios e perspectivas do biogás no setor, usando como base o histórico na Alemanha. No âmbito do PROBIOGÁS, os resultados foram bastante exitosos e consolidam as bases para o avanço do tema no Brasil. Como legados do projeto, desenvolveram-se diversas referências técnicas nacionais, promoveu-se a integração de diversos atores chave, fomentou-se a pesquisa aplicada e foram desenvolvidas capacidades de mil e oitocentas pessoas. Apesar disso, ainda se faz necessário que todo o conhecimento produzido seja replicado para as diversas realidades no país. Além disso, os principais desafios passam pela fragilidade da estratégia de gestão, pouca integração entre o desenvolvimento científico e sua aplicação, e necessidade de desenvolvimento de capacidades. Por fim, fica claro que, para o desenvolvimento de projetos de biogás de ETEs bem-sucedidos torna-se indispensável a incorporação do conceito de ETE Indústria. / [en] The current context of sewage treatment in Brazil is critical: only 40 percent of all generated wastewater is treated (ANA, 2015). Therefore, the expansion of the provision of sewage treatment services must take place within a scenario of investment difficulties, more stringent quality standards, higher energy and sludge operation costs and sewer rates that do not reflect real costs. Given that the provision of this service is not compromised and to move forward effectively on this issue, a change in management and paradigm breakdown must be done by establishing the concept of Industrial waste water treatment plant (WWTP). This concept envisions the WWTP as a closed loop, which receives an effluent for treatment and that through the efficiency of its processes delivers a treated effluent, seeking to optimize costs, recover and value the by-products and promote public health, based on a sustainable servicing of the institutional, social, environmental and economic dimensions. One of the potential by-products of sewage treatment is the biogas. This is because the UASB reactors for the treatment of domestic sewage is consolidated in the country (VAN HAANDEL et al., 2006; CHERNICHARO et al., 2015), considering the WWTP in operation, in different sizes and in the projects contemplated by the Growth Acceleration Program (PAC, in Portuguese). Chernicharo (2017) counted 908 anaerobic reactors that serve about 23 million inhabitants and routinely produce biogas. Considering the diagnosis of WWTPs carried out by the Agência Nacional de Águas - (2016), a Brazilian water agency, it shows that more than a third of the plants use anaerobic reactors. By transforming biogas from a by-product of the treatment process into a renewable energy source, WWTP also promotes a new level of service delivery, generating distributed energy that provides an improvement in the management of its energy and in the treatment processes. From the point of view of service provision, biogas plays a strategic role because it acts as a fuel to promote a sustainable service from a social, environmental and economic perspectives.
4

Estimation of Nutrient Exports Resulting from Thinning and Intensive Biomass Extraction in Medium-Aged Spruce and Pine Stands in Saxony, Northeast Germany.

Knust, Christine, Feger, Karl-Heinz 27 March 2017 (has links)
A growing interest in using forest biomass for bioenergy generation may stimulate intensive harvesting scenarios in Germany. We calculated and compared nutrient exports of conventional stem only (SO), whole tree without needles (WT excl. needles), and whole tree (WT) harvesting in two medium aged Norway spruce (Picea abies L. Karst.) and Scots pine (Pinus sylvestris L.) stands differing in productivity, and related them to soil nutrient pools and fluxes at the study sites. We established allometric biomass functions for each aboveground tree compartment and analyzed their nutrient contents. We analyzed soil nutrient stocks, estimated weathering rates, and obtained deposition and seepage data from nearby Level II stations. WT (excl. needles) and WT treatments cause nutrient losses 1.5 to 3.6 times higher than SO, while the biomass gain is only 1.18 to 1.25 in case of WT (excl. needles) and 1.28 to 1.30 in case of WT in the pine and spruce stand, respectively. Within the investigated 25-year period, WT harvesting would cause exports of N, K+, Ca2+, and Mg2+ of 6.6, 8.8, 5.4, and 0.8 kg·ha−1 in the pine stand and 13.9, 7.0, 10.6, and 1.8 kg·ha−1 in the spruce stand annually. The relative impact of WT and WT (excl. needles) on the nutrient balance is similar in the pine and spruce stands, despite differences in stand productivities, and thus the absolute amount of nutrients removed. In addition to the impact of intensive harvesting, both sites are characterized by high seepage losses of base cations, further impairing the nutrient budget. While intensive biomass extraction causes detrimental effects on many key soil ecological properties, our calculations may serve to implement measures to improve the nutrient balance in forested ecosystems.

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