• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 3
  • 1
  • 1
  • Tagged with
  • 10
  • 6
  • 5
  • 4
  • 4
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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

Modelling landfill as a complex biophysical technology

Lowe, Martin January 1998 (has links)
Concerns regarding climate change are becoming a driver behind legislation at both UK and EU levels, and also on the wider, planetary scale. This is the case with emissions from landfills where the release of methane is being targeted for reduction. This thesis uses an integrative approach, incorporating concepts of hierarchy from systems theory, to model landfill as a complex biophysical technology. It assesses the contribution to carbon deposition and global warming of landfill through changes to that technology itself and through changes in the waste stream caused by potential waste policies. The thesis develops an holistic, conceptual model of the landfill system, mapping flows and transformations of carbon within that system. It further develops this conceptual model into a calculating model of landfill as a waste management technology incorporating measurements taken to provide new data and validate published data to calibrate the model. It thus applies modelling techniques to a biophysical technology, producing an integrated model of the landfill that allows the knowledge gained from other research to be used to explore engineering and operational decisions on landfills. The thesis includes results from measurements of the composition of household waste, and of the biochemical methane potential (BMP) of fractions of that waste. It includes measurements of the residual BMP in samples of excavated waste and measurements of gas flows. The main results suggest the following: • Early capping of landfilled waste is important in reducing the global warming impact; • If the rate of degradation of the waste is accelerated in the drive towards sustainability, capping should be carried out even earlier if the global impact is not to be increased; • Although recycling parts of the degradable elements of the waste stream has the effect of reducing the global impact, extensive recycling has implications for landfill engineering.
2

Restoration of Polluted Lake by Ecotechnology ¡Ð A Case Study in Mei-Nong Jung Jeng Lake of Taiwan

Li, Ming-Ta 25 July 2002 (has links)
Jung Jeng Lake located in Mei Nong in south of Taiwan, is the origin of Mei Nong Hakka culture. Owing to stockbreeding hogs, cultivation and domestic wastewater in the upstream of Jiang Tz Liau River that finally flows into Jung Jeng Lake for years, the lake thus suffered extremely serious problem of eutrophication. In addition, the water hyacinth remain seeds in the lake and reproduce resulting in speeding up the lacustrine silt that would greatly shorten the life of Jung Jeng Lake. Using artificial lagoon and artificial floating island were found able to improve the water quality of lake. Therefore, we could sightseeing resource, historic site, and ecological resources of Mei Nong. This research applied the advantages of ecological engineering methods to restore the Jung Jeng Lake, and thus the southern Taiwan unique Hakka tourism can be presented.
3

Avaliação da eficiência de sistemas alagados construídos em operação por bateladas no tratamento de efluentes da indústria de laticínios / Evaluating the effectiveness of wetland systems built in operation for batch in the treatment of the wastewater in the dairy industry

Mendonça, Henrique Vieira de 25 February 2011 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-07-19T13:23:26Z No. of bitstreams: 1 henriquevieirademendonca.pdf: 11929351 bytes, checksum: 9efab95f034b43d60bf37ea6393484be (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-22T15:14:40Z (GMT) No. of bitstreams: 1 henriquevieirademendonca.pdf: 11929351 bytes, checksum: 9efab95f034b43d60bf37ea6393484be (MD5) / Made available in DSpace on 2016-07-22T15:14:40Z (GMT). No. of bitstreams: 1 henriquevieirademendonca.pdf: 11929351 bytes, checksum: 9efab95f034b43d60bf37ea6393484be (MD5) Previous issue date: 2011-02-25 / Os sistemas alagados construídos (SACs) aplicados na depuração de águas residuárias de laticínios são muito pouco estudados no que diz respeito ao dimensionamento, métodos operacionais e eficiência destes sistemas. Sendo assim, neste trabalho procurou-se estudar a influência de substratos e espécies vegetais cultivadas, sobre a eficiência na remoção de DBO e nutrientes de seis unidades experimentais operando em bateladas em escala piloto. Os seis SACs foram construídos em tanques de PEAD com volume de 115 litros, com relação comprimento/largura na proporção de 2:1, obedecendo a dinâmica de escoamento em pistão. Os substratos utilizados foram a brita 0 em três dos SACs e brita 0 e areia em outros três, na proporção de 80% brita e 20% areia. Quatro das unidades experimentais foram cultivadas e duas mantidas como testemunhas. As espécies selecionadas foram as macrófitas Typha dominguensis (taboa) e o Hedychium coronarium (lírio-do-brejo). O sistema apresenta a vantagem de utilizar o sistema solo-planta-microrganismos e a radiação solar como reatores para depuração dos resíduos a um baixo custo. Trata-se de um sistema de fácil instalação, operação e manutenção e que, além de apresentar desempenho favorável nas condições climáticas do Brasil, ainda é esteticamente adequado ao ambiente. A eficiência média mínima encontrada no tratamento foi de 77,8 % e máxima de 95,2 % em termos de DBO5, 29,4 a 53,5% e 16,8 a 48.2% na remoção de Nitrogênio e Fósforo respectivamente. Os seis tratamentos apresentaram remoção de compostos carbonáceos biodegradáveis semelhantes. O mesmo não ocorreu com a eficiência de remoção de nutrientes, sendo que as unidades experimentais vegetadas superaram significativamente as não vegetadas. O tratamento mostrou-se eficiente, havendo a remoção prévia do alto índice de compostos orgânicos e redução considerável de nutrientes eutrofizantes, principalmente compostos nitrogenados. Embora preliminar, o estudo mostrou que os sistemas alagados construídos operando em bateladas podem ser utilizados no tratamento de águas brutas de laticínios. / The present study concerns the influence of substrates and cultivated plant species on the removal efficacy of BOD of six pilot-scale batch-working experimental units. The six SACs was mounted in 115 litters in volume HDPE tanks, in the length/width ratio of 2:1, in order to obey the dynamics of plug flow. In three of the SACs, gravel 0 was used as substrate, while gravel # 0 and sand was used in the others, in the percentage of 80% and 20%, respectively. Four of the experimental units were cultivated, and two sustained as witness. Selected species was the macrophytes, Typha domingensis (southern cattail) and Hedychium coronarium (ginger lily). The system offers the advantage of using the soil-plant-microorganisms and solar radiation as reactors for purification of waste at low cost. It is a system for easy installation, operation and maintenance, which, besides showing favorable performance in the climatic conditions of Brazil, yet is aesthetically suitable for the environment. According to the results, the maximum efficiency rate was 77.8% and the minimum efficiency rate was 95.2% in terms of DBO5. Besides a rate between 29.4 and 53.5% and a rate between 16.8 and 48.2% in removal of Nitrogen and Phosphorus respectively. The six treatments showed the removal of similar biodegradable carbonaceous compounds. Nevertheless, the same do not occurs with the removal efficacy of nutrients, since the vegetated experimental units considerably overcome the not-vegetated experimental units. The treatment has been shown efficient, having the earlier removal of the high index of organic compounds, and a considerable reduction of nutrients which are euthrophics, mainly the nitrogenated compounds. Although preliminary, this study showed that the batch-working constructed wetlands systems can be used in treatment of dairy crude water.
4

"Ecofiction: Realizing the Full Potential of the Genre Through Speculative and Ecofeminist Theory" and "Tricolored Waters: A Novel -- Part I"

McGinnis, Kayla 11 May 2021 (has links)
No description available.
5

Appropriate Technologies for Soil Remediation in Low Prioritized Region : Developing Countries and Sparsely Populated Regions

Haller, Henrik January 2015 (has links)
Contaminated sites in low prioritized regions demand remediation technologies that are cost- and energy-effective and locally adapted. Parameters such as the time frame during which bioremediation degradation needs to occur may not be as restraining as in urban environments. This licentiate project aims to explore opportunities and constraints for appropriate soil remediation based on organic by-products in tropical developing countries and sparsely populated areas in industrial countries. Ecological Engineering and the Framework for Strategic Sustainable Development were explored as planning tools to steer bioremediation methods towards sustainability. The use of the five concepts of Ecological Engineering within the Framework for Strategic Sustainable Development can steer bioremediation in low prioritized regions towards sustainability. Pilot-scale and laboratory experiments were undertaken to evaluate the feasibility of such bioremediation methods. Experiments carried out at the experiment station in Chontales, Nicaragua showed some promising results, but also revealed problems associated with the clay rich soils, which are typical for tropical regions. Treatment of diesel contaminated ultisol with 6 mL whey kg-1 dw in a pilot-scale experiment considerably increased the degradation rate of diesel constituents, but no effects on the degradation rates were observed after treatment with compost tea or pyroligneous acid.The soil columns study suggests that despite a favorable particle size distribution for microbial transport, the sandy loam retained a greater fraction of the microorganisms present in the ACT in the top 10 cm than the clay loam, presumably because the lower bulk density and higher SOM in the clay loam aided transport and growth of microorganisms.
6

Análise da eficiência de um sistema combinado de alagados construídos na melhoria da qualidade das águas / Assessment of efficiency of combined constructed wetlands system for water quality improvement

Cunha, Caroline de Andrade Gomes da 14 September 2006 (has links)
Este trabalho teve como objetivo avaliar a eficiência de um sistema combinado de alagados construídos, localizado no Parque Ecológico do Tietê em São Paulo, na melhoria da qualidade das águas. A estação de estudo é composta por um canal de decantação, um canal de macrófitas flutuantes (Eicchornia crassipes, Pistia stratioides, Salvinia auriculata) e emergentes (Typha angustifolia) de fluxo superficial, e duas células paralelas de solos filtrantes de fluxo vertical descendente cultivados com arroz (Oryza sativa). As coletas de água foram realizadas mensalmente, na entrada e saída de cada etapa do sistema, no período de fevereiro, março, junho e julho de 2004 e de março a setembro de 2005. As variáveis físicas, químicas e biológicas da água foram medidas e taxas de eficiência de remoção parcial e total do sistema foram calculadas. A estação construída de alagados mostrou-se eficiente principalmente na remoção de sulfato (52%), turbidez (86%), 'DBO IND.5' (41 - 64%), fósforo total (51 – 68%), nitrogênio albuminóide (51,7%), nitrito (77,8%) e nitrogênio amoniacal (57 – 84%). Os canais de macrófitas apresentaram um alto desempenho de remoção média para maioria das variáveis analisadas no trabalho, contribuindo com a maior porção na taxa de remoção total do sistema. Durante o período de estudo, provavelmente devido à falta de manejo do sistema, observou-se a volta dos nutrientes assimilados pelas macrófitas para a coluna d`água (N, P, Fe) com a decomposição das plantas e condições de anaerobiose nos solos filtrantes. Esses fatores, juntamente com a presença dos animais do parque atraídos pelo arroz, contribuíram com o baixo desempenho do canal de macrófitas e dos solos filtrantes na remoção de cor, turbidez, ferro total e coliformes em alguns meses de coleta. Para a maioria das variáveis analisadas, a água tratada pelo sistema de alagados construídos alcançou os limites e padrões estabelecidos pela Resolução CONAMA 357/2005 para águas doces de classe 2 (BRASIL, 2005). Contudo, em função dos dados obtidos, não se pode enquadrar totalmente o efluente, embora seja esperado que com a estabilização do sistema e um manejo adequado, a água tratada consiga atingir as características exigidas e possa ser enquadrada em águas doces de classe 2. / The aim of this work was evaluate the efficiency of combined constructed wetlands, located in the Tiete Ecological Park in São Paulo, in water quality improvement. The station consists of a settling channel, one free-floating (Eichhornia crassipes, Salvinia auriculata, Pistia stratiotes) and rooted emergent macrophyte-based system (Typha angustifolia) with surface flow and two cells of vertical flow filter soils in parallel, planted with rice (Oryza sativa). The water samples were collected monthly at the inlet and outlet of each step of the system, in the period of February, March, June and July of 2004 and of March to September of 2005. The physical, chemical and biological variables of the water were measured and efficiency rates of the system were made. The constructed wetlands system mainly showed efficient removal rates in sulphate (52%), turbidity (86%), BDO (41 - 64%), total phosphorus (51 - 68%), organic nitrogen (51,7%), nitrite (77,8%) and ammonia nitrogen (57 - 84%). The settling channel and macrophyte-based system presented a high removal performance for most of the variables analyzed in the work, contributing with the largest portion in the total removal rate of the system. During the study period, probably due to the lack of system management, the return of nutrients previously uptaken (N, P, Fe) by macrophytes for the water column was observed with the decay of aging plants and anaerobic conditions in the HDS system. Those factors, added with the presence of the park´s animals attracted for the rice, contributed with the low performance of macrophyte-based and HDS system in the removal of color, turbidity, total iron and coliforms in some months of collection. For most of the analyzed variables, the water treated by the constructed wetlands system reached the limits and patterns established by the Resolution CONAMA 357/2005 for fresh water of class 2 (BRAZIL, 2005). However, due to the obtained data, the treated water cannot be totally classified as class 2, although it is expected that with the stabilization of the system and appropriate handling, the treated water reach the demanded characteristics and can be classified in fresh water of class 2.
7

Social Experiments in Innovative Environmental Management: The emergence of ecotechnology

Rose, Gregory January 2003 (has links)
Human production needs are met through the use of modern technology that is increasingly recognised as a threat to the planetary ecosystem and social sub-system. In light of this recognition, there is evidence that a planned transition towards more sustainable technological infrastructure is occurring across various production sectors. This change is often associated with re-orientating technology based on the concept of sustainable development and national-level strategies such as <i>ecological modernisation</i>, which prescribes phasing-out environmentally malignant conventional technology for cleaner post-industrial solutions. There is evidence, however, that a transition towards cleaner technological options is occurring at the local level. In southern Ontario, Canada ecological technology (<i>ecotechnology</i>) has been adopted in small-scale agricultural and educational facilities for the management of manure and domestic sewage. Ecotechnology is designed to meet human production requirements and to restore the environment through combining natural systems and engineered components to achieve cleaner production. Two types of ecotechnologies were investigated during this research: <i>constructed treatment wetlands</i> for the management of manure and <i>greenhouse-based biological technologies</i> for the management of domestic sewage. These options are novel and can be expected to encounter barriers resulting from a <i>selection environment</i> favouring pre-existing technological options that have previously become established. The overall objective of the research was <i>to identify key factors both driving and constraining the adoption and implementation of the ecotechnology</i> across four case studies. This objective was accomplished through employing a qualitative, collective case study approach. The case studies revealed the motivation behind the adoption of the ecotechnology arose from the environmental values of users and formed the basis for rejecting the conventional options because they were not viewed as capable of improving the environment. However, the ecotechnology also exceeded user's aesthetic and operational level expectations. Barriers to the implementation of ecotechnology were also identified. The investigation revealed the existence of a <i>perspective-gap</i> between the ecological engineering science and traditional engineering science, which constrained implementation of the ecotechnology. Skepticism was found to arise due to the unique performance parameters and <i>soft</i> operational characteristics of ecotechnology, which contrast the <i>hard</i> technological fixes that are familiar to traditional engineering science. This perspective-gap may account for the institutional inertia, which became clear after the 1996 provincial budget reductions decreased the level of support for research and environmental technology development programs in Ontario. These reductions also devolved authority for small-scale wastewater treatment to the municipal level where lack of technical expertise and reliance on standardised regulations has constrained the development of alternatives. Constructive technology assessment suggests that the development of technology must be guided in cooperative <i>social learning</i> processes capable of reflecting the needs and values of stakeholders in order to achieve beneficial social and technological change. Evidence from the case studies revealed that a significant amount of capacity was developed when stakeholders collaborated and legitimated the <i>social experiments</i> where the ecotechnology was applied. These experiments demonstrate the significance of creating settings where users, technology proponents and provincial and local approval agents can collaborate. Through collaboration, social learning can be facilitated during the development of alternative technological solutions that may be congruent with ecological modernisation and the re-orientation of technology towards options that are ecologically-oriented.
8

Social Experiments in Innovative Environmental Management: The emergence of ecotechnology

Rose, Gregory January 2003 (has links)
Human production needs are met through the use of modern technology that is increasingly recognised as a threat to the planetary ecosystem and social sub-system. In light of this recognition, there is evidence that a planned transition towards more sustainable technological infrastructure is occurring across various production sectors. This change is often associated with re-orientating technology based on the concept of sustainable development and national-level strategies such as <i>ecological modernisation</i>, which prescribes phasing-out environmentally malignant conventional technology for cleaner post-industrial solutions. There is evidence, however, that a transition towards cleaner technological options is occurring at the local level. In southern Ontario, Canada ecological technology (<i>ecotechnology</i>) has been adopted in small-scale agricultural and educational facilities for the management of manure and domestic sewage. Ecotechnology is designed to meet human production requirements and to restore the environment through combining natural systems and engineered components to achieve cleaner production. Two types of ecotechnologies were investigated during this research: <i>constructed treatment wetlands</i> for the management of manure and <i>greenhouse-based biological technologies</i> for the management of domestic sewage. These options are novel and can be expected to encounter barriers resulting from a <i>selection environment</i> favouring pre-existing technological options that have previously become established. The overall objective of the research was <i>to identify key factors both driving and constraining the adoption and implementation of the ecotechnology</i> across four case studies. This objective was accomplished through employing a qualitative, collective case study approach. The case studies revealed the motivation behind the adoption of the ecotechnology arose from the environmental values of users and formed the basis for rejecting the conventional options because they were not viewed as capable of improving the environment. However, the ecotechnology also exceeded user's aesthetic and operational level expectations. Barriers to the implementation of ecotechnology were also identified. The investigation revealed the existence of a <i>perspective-gap</i> between the ecological engineering science and traditional engineering science, which constrained implementation of the ecotechnology. Skepticism was found to arise due to the unique performance parameters and <i>soft</i> operational characteristics of ecotechnology, which contrast the <i>hard</i> technological fixes that are familiar to traditional engineering science. This perspective-gap may account for the institutional inertia, which became clear after the 1996 provincial budget reductions decreased the level of support for research and environmental technology development programs in Ontario. These reductions also devolved authority for small-scale wastewater treatment to the municipal level where lack of technical expertise and reliance on standardised regulations has constrained the development of alternatives. Constructive technology assessment suggests that the development of technology must be guided in cooperative <i>social learning</i> processes capable of reflecting the needs and values of stakeholders in order to achieve beneficial social and technological change. Evidence from the case studies revealed that a significant amount of capacity was developed when stakeholders collaborated and legitimated the <i>social experiments</i> where the ecotechnology was applied. These experiments demonstrate the significance of creating settings where users, technology proponents and provincial and local approval agents can collaborate. Through collaboration, social learning can be facilitated during the development of alternative technological solutions that may be congruent with ecological modernisation and the re-orientation of technology towards options that are ecologically-oriented.
9

Análise da eficiência de um sistema combinado de alagados construídos na melhoria da qualidade das águas / Assessment of efficiency of combined constructed wetlands system for water quality improvement

Caroline de Andrade Gomes da Cunha 14 September 2006 (has links)
Este trabalho teve como objetivo avaliar a eficiência de um sistema combinado de alagados construídos, localizado no Parque Ecológico do Tietê em São Paulo, na melhoria da qualidade das águas. A estação de estudo é composta por um canal de decantação, um canal de macrófitas flutuantes (Eicchornia crassipes, Pistia stratioides, Salvinia auriculata) e emergentes (Typha angustifolia) de fluxo superficial, e duas células paralelas de solos filtrantes de fluxo vertical descendente cultivados com arroz (Oryza sativa). As coletas de água foram realizadas mensalmente, na entrada e saída de cada etapa do sistema, no período de fevereiro, março, junho e julho de 2004 e de março a setembro de 2005. As variáveis físicas, químicas e biológicas da água foram medidas e taxas de eficiência de remoção parcial e total do sistema foram calculadas. A estação construída de alagados mostrou-se eficiente principalmente na remoção de sulfato (52%), turbidez (86%), 'DBO IND.5' (41 - 64%), fósforo total (51 – 68%), nitrogênio albuminóide (51,7%), nitrito (77,8%) e nitrogênio amoniacal (57 – 84%). Os canais de macrófitas apresentaram um alto desempenho de remoção média para maioria das variáveis analisadas no trabalho, contribuindo com a maior porção na taxa de remoção total do sistema. Durante o período de estudo, provavelmente devido à falta de manejo do sistema, observou-se a volta dos nutrientes assimilados pelas macrófitas para a coluna d`água (N, P, Fe) com a decomposição das plantas e condições de anaerobiose nos solos filtrantes. Esses fatores, juntamente com a presença dos animais do parque atraídos pelo arroz, contribuíram com o baixo desempenho do canal de macrófitas e dos solos filtrantes na remoção de cor, turbidez, ferro total e coliformes em alguns meses de coleta. Para a maioria das variáveis analisadas, a água tratada pelo sistema de alagados construídos alcançou os limites e padrões estabelecidos pela Resolução CONAMA 357/2005 para águas doces de classe 2 (BRASIL, 2005). Contudo, em função dos dados obtidos, não se pode enquadrar totalmente o efluente, embora seja esperado que com a estabilização do sistema e um manejo adequado, a água tratada consiga atingir as características exigidas e possa ser enquadrada em águas doces de classe 2. / The aim of this work was evaluate the efficiency of combined constructed wetlands, located in the Tiete Ecological Park in São Paulo, in water quality improvement. The station consists of a settling channel, one free-floating (Eichhornia crassipes, Salvinia auriculata, Pistia stratiotes) and rooted emergent macrophyte-based system (Typha angustifolia) with surface flow and two cells of vertical flow filter soils in parallel, planted with rice (Oryza sativa). The water samples were collected monthly at the inlet and outlet of each step of the system, in the period of February, March, June and July of 2004 and of March to September of 2005. The physical, chemical and biological variables of the water were measured and efficiency rates of the system were made. The constructed wetlands system mainly showed efficient removal rates in sulphate (52%), turbidity (86%), BDO (41 - 64%), total phosphorus (51 - 68%), organic nitrogen (51,7%), nitrite (77,8%) and ammonia nitrogen (57 - 84%). The settling channel and macrophyte-based system presented a high removal performance for most of the variables analyzed in the work, contributing with the largest portion in the total removal rate of the system. During the study period, probably due to the lack of system management, the return of nutrients previously uptaken (N, P, Fe) by macrophytes for the water column was observed with the decay of aging plants and anaerobic conditions in the HDS system. Those factors, added with the presence of the park´s animals attracted for the rice, contributed with the low performance of macrophyte-based and HDS system in the removal of color, turbidity, total iron and coliforms in some months of collection. For most of the analyzed variables, the water treated by the constructed wetlands system reached the limits and patterns established by the Resolution CONAMA 357/2005 for fresh water of class 2 (BRAZIL, 2005). However, due to the obtained data, the treated water cannot be totally classified as class 2, although it is expected that with the stabilization of the system and appropriate handling, the treated water reach the demanded characteristics and can be classified in fresh water of class 2.
10

Application of ecological technology for removal of COD, nitrogen and phosphorus from piggery wastewater after biogas production technology

Vu, Thi Nguyet, Tran, Van Tua, Dang, Dinh Kim, Bui, Thi Kim Anh, Vu, Hai Yen 07 January 2019 (has links)
Despite a positive contribution to economic – social development, the growth of piggeries has caused heavily environmental pollution. Currently, treated wastewater of pig farms unfortunately does not meet the national discharge standards yet. This paper presents some research results on the removing COD, nitrogen and phosphorus in piggery wastewater after anaerobic (biogas) process at pilot scale by the combined system using Phragmites australis, Cyperus alternifolius, Vetiveria zizanioides and Eichhornia crassipes. The experimental results showed that the wastewater loading rate of 47.35 l/m2.day with initial concentrations of 203.24 mg COD/l, 111.94 mgTN/l and 13.61 mgTP/l gave removal efficiency of 71.66 %, 79.26 % and 69.65 %, respectively. Thus, the removed quantity of total nitrogen (TN) and total phosphorus (TP) was of 4201.35 mg TN/m2.day và 448.76mg TP/m2.day. The obtained results indicated that the flow wetland system, using Phragmites australis, Cyperus alternifolius, Vetiveria zizanioides and Eichhornia crassipes has a rather high COD, TN and TP removal efficiency with simple operation so that it could be feasible if applied for treating pig wastewater. However, the system should be functioned longer for taking data and for evaluating its stability. / Mặc dù có những đóng góp tích cực cho sự phát triển kinh tế - xã hội, việc phát triển chăn nuôi lợn đã gây ô nhiễm môi trường nghiêm trọng. Hiện nay, nước thải chăn nuôi lợn từ các cơ sở chăn nuôi sau xử lý vẫn chưa đáp ứng được các tiêu chuẩn thải của quốc gia và tiêu chuẩn ngành. Bài báo này trình bày kết quả nghiên cứu về khả năng loại bỏ COD, nitơ (N) và phôtpho (P) trong nước thải chăn nuôi lợn đã qua xử lý bằng hầm biogas của hệ thống phối hợp cây Sậy, Thủy Trúc, cỏ Vetiver và Bèo Tây ở qui mô pilot. Kết quả thực nghiệm ở tải lượng 47,35 l/m2.ngày, với COD, tổng nitơ (TN) và tổng phôtpho (TP) đầu vào trung bình là 203,24 mg/l, 111,94 mg/l và 13,61 mg/l, tương ứng, thì hiệu suất xử lý lần lượt là 71,66 %; 79,26 % và 69,65 %. Như vậy lượng TN và TP loại bỏ là 4201,35 mgN/m2.ngày và 448,76 mgP/m2.ngày. Kết quả nhận được cho thấy hệ thống sử dụng cây Sậy, Thủy Trúc, cỏ Vetiver và Bèo Tây có hiệu quả loại bỏ COD, TN và TP khá cao trong khi vận hành đơn giản nên có triển vọng áp dụng trong điều kiện thực tế để xử lý nước thải chăn nuôi lợn. Tuy nhiên để đánh giá tính ổn định, hệ thống cần được hoạt động với thời gian lâu dài hơn.

Page generated in 0.0535 seconds