• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 25
  • 10
  • 8
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • Tagged with
  • 50
  • 50
  • 23
  • 14
  • 12
  • 11
  • 9
  • 8
  • 8
  • 7
  • 7
  • 6
  • 6
  • 6
  • 6
  • 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.
21

Groundwater contamination from septic systems receiving detergents of two types of formulation

Alhajjar, Bashar Jamil. January 1900 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1985. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 264-281).
22

La perméabilité des réservoirs à lisier en béton /

Denis, Jacques January 1989 (has links)
No description available.
23

The effect of distance between artificial drainage facilities and disposal trenches on the movement of biological and chemical pollutants from septic tank effluent

Stewart, Larry Wayne January 1982 (has links)
A field study was conducted at a residence in Chesapeake, Virginia to determine the effect of setback distances from a drainage ditch on the disposal of septic tank effluent. The study was done from September 1979 to August 1981. The soil used is the Tomotley series belonging to the fine-loamy, mixed, thermic family of Typic Ochraquults. Four prototype trenches were installed at 1.5, 3, 6 and 21 m from the edge of a drainage ditch which was 1.5 m deep. The trenches were pressure dosed equally with 2.4 to 4 cm per day. Replicated nests of sampling wells at depths 90, 150 and 300 cm were placed with distance from the trenches. Continuous stage recorders were positioned 4.5, 29.1 and 60 m from the ditch to monitor water table behavior. Groundwater analysis included fecal coliforms, the NH₄, NO₃, NO₂, Na, Ca, Mg, Cl and PO₄ ions, pH and EC. Ammonium concentrations in the soil beneath the trenches indicated nonuniform effluent infiltration yet more uniform than with conventional gravity flow distribution. High sodium absorption ratios of the septic tank effluent ranging from 18 to 45 did not significantly reduce infiltration rates as no ponding of effluent in the trenches was observed. The existing land surface was sloped greater than the water table gradient resulting in decreasing unsaturated depths with closeness to the ditch. The mean distances between the trench bottom and the water table were 64 cm at 3 m, 80.1 at 6 m and 90.4 cm at 21 m. The accumulation of fecal coliforms, NH₄, P, Cl and total salts (EC) in the groundwaters at 120 to 150 cm depth was inversely proportional to the mean distances from the trench bottoms to the water table. The lack of denitrification occurring underneath the trench with the most extensive unsaturated zone suggests NO₃ may accumulate under disposal systems that have mean unsaturated depths of ≥ 90 cm. Effluent movement was mainly lateral and in the upper zone of the water table with limited vertical movement below the water table surface. An equation applying D-F theory to infinitely deep soil was developed to describe flow for the given drainage system and for the inclusion of standard size drain fields. The current practical setback distance of 21 m is considered counterproductive for effluent treatment for some situations. / Ph. D.
24

Avaliação da co-disposição do lodo de tanques sépticos e fração orgânica de resíduos sólidos domiciliares em reatores anaeróbios / Evaluation of co-disposal of sludge from septic tanks and organic fraction of domestic solid waste in anaerobic reactors

Tosetto, Vitor 31 August 2009 (has links)
Apesar de surgir como um país emergente, infelizmente a situação do saneamento básico no Brasil é bastante precária. Dos 5.507 municípios brasileiros apenas 52,2% possuem algum tipo de serviço de esgotamento sanitário (IBGE, 2000). Diante deste cenário alarmante, soluções individuais passam a ganhar mais importância. A adoção de tanques sépticos como uma alternativa para a solução do esgoto sanitário, em regiões carentes de rede de esgoto, passa a ser viável devido ao seu baixo custo e eficiência satisfatória. No entanto, a operação inadequada dessas pequenas unidades podem se tornar um passivo ambiental, em virtude do lodo produzido, subproduto da degradação anaeróbia. A solução mais fácil e prática seria a sua disposição em Estações de Tratamento de Efluente, no entanto é uma minoria dos municípios brasileiros, 20,2% (IBGE, 2000), que contam com estas unidades. A proposta do presente trabalho foi simular a comportamento da disposição do Lodo de Tanques Sépticos (LTS) em aterros sanitários, juntamente com resíduos sólidos domiciliares (RSD). Por meio de quatro reatores anaeróbios, com 50 litros cada, avaliaram-se os efeitos da degradação anaeróbia da Fração Orgânica do RSD (FORSD) na presença de LTS. Todos os reatores possuíam a mesma quantidade de FORSD, 28 kg. Cada unidade experimental recebeu quantidades diferentes de LTS: reator 1 = 0 L; reator 2 = 4,9 L; reator 3 = 9,8 L e reator 4 = 14,7 L. O monitoramento acompanhou as características químicas e a quantidade do lixiviado, a composição do biogás e as mudanças físico-químicas na mistura de FORSD e LTS no início e no final do experimento. Entre os resultados obtidos, destaca-se a eficiência de remoção de DQO da FORSD, 21%, 51%, 68% e 73% para os reatores 1, 2, 3 e 4 respectivamente. E a aceleração na degradação anaeróbia nos reatores que receberam LTS, devido a produção precoce de metano, aparecimento no 40º dia nos reatores tratados com LTS e pela disponibilidade imediata de nutrientes, observada pelas análises de nitrogênio amoniacal. / Despite being an emerging country, unfortunately the sanitary situation of Brazil is quite precarious. Only 52.2% of the 5,507 brazilian municipalities have some type of sanitary service (IBGE, 2000). In this alarming scenario, individual solutions are gaining more importance. The adoption of septic tanks as an alternative to the solution of the sewage becomes viable due to its low cost and satisfactory performance. However, the inappropriate operation of these small units can become an environmental problem because of the produced sludge, sub product of anaerobic degradation. This material must be managed adequately and securely to prevent possible contamination of soil and water. The easiest and practice solution would be its disposal in sewage treatment stations, however there are only 20.2% (IBGE, 2000) of all the brazilian cities which rely on these units. The purpose of this study was to evaluate the performance of the disposal of sludge from septic tanks (LTS) in landfills, along with domestic solid waste (RSD). Using four anaerobic reactors, with 50 liters each, the effects of anaerobic degradation of organic fraction of the RSD (FORSD) in the presence of LTS were evaluated. All reactors had the same amount of FORSD, 28 kg. Each experimental unit received different amounts of LTS: Reactor 1 = 0 L; Reactor 2 = 4.9 L, Reactor 3 = 9.8 L and Reactor 4 = 14.7 L. The monitoring followed the characteristics and quantity of leachate, the composition of biogas and changes in physical-chemical mixture of FORSD and LTS at the beginning and the end of the experiment. The results highlight the efficiency of removal of the DQO of FORSD, 21%, 51%, 68% and 73% for reactors 1, 2, 3 and 4, respectively, and the acceleration in the degradation in anaerobic reactors that received LTS, due to early production of methane, appearing in 40º day in reactors treated with LTS and the ready availability of nutrients, observed by the analysis of ammonia nitrogen.
25

Avaliação da co-disposição do lodo de tanques sépticos e fração orgânica de resíduos sólidos domiciliares em reatores anaeróbios / Evaluation of co-disposal of sludge from septic tanks and organic fraction of domestic solid waste in anaerobic reactors

Vitor Tosetto 31 August 2009 (has links)
Apesar de surgir como um país emergente, infelizmente a situação do saneamento básico no Brasil é bastante precária. Dos 5.507 municípios brasileiros apenas 52,2% possuem algum tipo de serviço de esgotamento sanitário (IBGE, 2000). Diante deste cenário alarmante, soluções individuais passam a ganhar mais importância. A adoção de tanques sépticos como uma alternativa para a solução do esgoto sanitário, em regiões carentes de rede de esgoto, passa a ser viável devido ao seu baixo custo e eficiência satisfatória. No entanto, a operação inadequada dessas pequenas unidades podem se tornar um passivo ambiental, em virtude do lodo produzido, subproduto da degradação anaeróbia. A solução mais fácil e prática seria a sua disposição em Estações de Tratamento de Efluente, no entanto é uma minoria dos municípios brasileiros, 20,2% (IBGE, 2000), que contam com estas unidades. A proposta do presente trabalho foi simular a comportamento da disposição do Lodo de Tanques Sépticos (LTS) em aterros sanitários, juntamente com resíduos sólidos domiciliares (RSD). Por meio de quatro reatores anaeróbios, com 50 litros cada, avaliaram-se os efeitos da degradação anaeróbia da Fração Orgânica do RSD (FORSD) na presença de LTS. Todos os reatores possuíam a mesma quantidade de FORSD, 28 kg. Cada unidade experimental recebeu quantidades diferentes de LTS: reator 1 = 0 L; reator 2 = 4,9 L; reator 3 = 9,8 L e reator 4 = 14,7 L. O monitoramento acompanhou as características químicas e a quantidade do lixiviado, a composição do biogás e as mudanças físico-químicas na mistura de FORSD e LTS no início e no final do experimento. Entre os resultados obtidos, destaca-se a eficiência de remoção de DQO da FORSD, 21%, 51%, 68% e 73% para os reatores 1, 2, 3 e 4 respectivamente. E a aceleração na degradação anaeróbia nos reatores que receberam LTS, devido a produção precoce de metano, aparecimento no 40º dia nos reatores tratados com LTS e pela disponibilidade imediata de nutrientes, observada pelas análises de nitrogênio amoniacal. / Despite being an emerging country, unfortunately the sanitary situation of Brazil is quite precarious. Only 52.2% of the 5,507 brazilian municipalities have some type of sanitary service (IBGE, 2000). In this alarming scenario, individual solutions are gaining more importance. The adoption of septic tanks as an alternative to the solution of the sewage becomes viable due to its low cost and satisfactory performance. However, the inappropriate operation of these small units can become an environmental problem because of the produced sludge, sub product of anaerobic degradation. This material must be managed adequately and securely to prevent possible contamination of soil and water. The easiest and practice solution would be its disposal in sewage treatment stations, however there are only 20.2% (IBGE, 2000) of all the brazilian cities which rely on these units. The purpose of this study was to evaluate the performance of the disposal of sludge from septic tanks (LTS) in landfills, along with domestic solid waste (RSD). Using four anaerobic reactors, with 50 liters each, the effects of anaerobic degradation of organic fraction of the RSD (FORSD) in the presence of LTS were evaluated. All reactors had the same amount of FORSD, 28 kg. Each experimental unit received different amounts of LTS: Reactor 1 = 0 L; Reactor 2 = 4.9 L, Reactor 3 = 9.8 L and Reactor 4 = 14.7 L. The monitoring followed the characteristics and quantity of leachate, the composition of biogas and changes in physical-chemical mixture of FORSD and LTS at the beginning and the end of the experiment. The results highlight the efficiency of removal of the DQO of FORSD, 21%, 51%, 68% and 73% for reactors 1, 2, 3 and 4, respectively, and the acceleration in the degradation in anaerobic reactors that received LTS, due to early production of methane, appearing in 40º day in reactors treated with LTS and the ready availability of nutrients, observed by the analysis of ammonia nitrogen.
26

Estudo da codisposição de resíduos de fossas e tanques sépticos, com e sem a remoção prévia de gordura, no desempenho de tratamento de esgoto com reatores UASB / Codisposição study of waste and seotic tanks e repair, with and without prior removal of fat in the performance of sewage treatment with UASB reactors

Peixoto, Aline Vieira 15 July 2013 (has links)
Submitted by Jaqueline Silva (jtas29@gmail.com) on 2014-12-08T18:01:37Z No. of bitstreams: 1 Dissertação-Aline Vieira Peixoto-2013.pdf: 3799528 bytes, checksum: 6a3b319d28bdad78b71d1bd2920717de (MD5) / Rejected by Jaqueline Silva (jtas29@gmail.com), reason: on 2014-12-08T20:24:04Z (GMT) / Submitted by Jaqueline Silva (jtas29@gmail.com) on 2014-12-12T19:33:30Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação-Aline Vieira Peixoto-2013.pdf: 3799528 bytes, checksum: 6a3b319d28bdad78b71d1bd2920717de (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2014-12-16T09:22:47Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação-Aline Vieira Peixoto-2013.pdf: 3799528 bytes, checksum: 6a3b319d28bdad78b71d1bd2920717de (MD5) / Made available in DSpace on 2014-12-16T09:22:49Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação-Aline Vieira Peixoto-2013.pdf: 3799528 bytes, checksum: 6a3b319d28bdad78b71d1bd2920717de (MD5) Previous issue date: 2013-07-15 / In Brazil, according to a national survey conducted by the Brazilian Institute of Geography and Statistics (IBGE, 2010), 44.8% of the municipalities use simplified domestic waste treatment systems such as septic tanks, rudimentary cesspools and dry pits. Such systems lead to the production of potentially polluting waste which requires suitable co-treatment. Several co-treatment alternatives have been proposed. The present study, which is part of the Program on Basic Sanitation Research (PROSAB), aimed to evaluate the interference caused by septage disposal from cesspools and septic tanks on the performance of the Upflow Anaerobic Sludge Blanket Reactor (UASB) in the city of Itumbiara- Goiás. The study took nine months and was divided into three distinct phases, in which the volumetric flow rate of wastewater from cesspools and septic tanks into the reactor ranged from 0.17% to 0.51%, displaying an intermediate phase of 0.34%.In the third phase, another fat flotation phase was added to the pre-treatment prior to discharge. During the study, we utilized all the waste volume from cesspools and septic tanks produced by the municipality and discharged into the Itumbiara Wastewater Treatment Plant (WWTP), already working at its full capacity. Statistical tests have proved that wastes from cesspool and septic tanks disposed into UASB reactors showed no significant difference in the final effluent quality. It was not evidenced also significant differences in the operation and maintenance of the reactors. The biological sludge from the UASB reactors got stable after being added the wastes (ratio VS/TS between 0.53 and 0.58 average). The receiving reactor’s begs had a worse efficiency but statistical tests showed that the difference was not significant when compared to the control reactors. It was observed in this study, there is no need for the pre-flotation of waste before being released at WWTP with UASB system. Thus the UASB is a viable alternative, but it is necessary to follow a protocol to establish criteria such as the waste application rate, the WWTP site for waste discharge, physical structure and people, as well as to choose for relevant parameters for the waste monitoring before co-treatment. / No Brasil, segundo Pesquisa Nacional de Saneamento Básico do Instituto Brasileiro de Geografia e Estatística (IBGE, 2010), 44,8% dos municípios utilizam sistemas simplificados para tratamento dos esgotos domésticos como: tanques sépticos, fossas rudimentares, fossas secas. Estes sistemas têm como consequência a produção de resíduos com potencial poluidor que necessitam de codisposição adequada. Diferentes alternativas de codisposição têm sido propostas. O presente trabalho, inserido na rede de pesquisa do Programa de Pesquisas em Saneamento Básico (PROSAB), tem como objetivos avaliar as interferências da disposição de resíduos de fossas e tanques sépticos no desempenho do Reator Anaeróbio de Manta de Lodo de fluxo ascendente ou Upflow Anaerobic Sludge Blanket (UASB), na cidade de Itumbiara-Goiás. O estudo teve duração de nove meses e foi dividido em três fases distintas, alterando a taxa de aplicações volumétrica dos resíduos de fossas e tanques sépticos no reator que variou de 0,17% a 0,51%, tendo uma fase intermediária de 0,34%, além de, na terceira fase, acrescentar mais uma etapa de flotação da gordura no tratamento preliminar, antes do lançamento dos resíduos. Durante a pesquisa, foi utilizado todo o volume de resíduos de fossas e tanques sépticos gerados pelo município e dispostos na ETE de Itumbiara que já trabalha com a carga máxima. Testes estatísticos comprovaram que a disposição de resíduos de fossas e tanques sépticos nos reatores UASB não apresentou diferença significativa na qualidade do efluente. Também não foram comprovadas alterações significativas na operação e manutenção dos reatores. O lodo biológico dos reatores UASB apresentou estabilidade após a disposição dos resíduos (relação SV/ST entre 0,53 a 0,58 em média). Os leitos do reator receptor apresentaram pior eficiência, porém testes estatísticos comprovaram que a diferença não foi significativa quando comparado com reatores testemunhos. Foi observou neste estudo, que não há necessidade da flotação prévia dos resíduos antes de serem lançados nas ETEs com sistema UASB. Portanto o UASB é uma alternativa viável, porém é necessário seguir um protocolo com critérios que estabelecerá a taxa de aplicação dos resíduos, o local na ETE onde será lançado o resíduo, estrutura física e de pessoal da ETE e determinar parâmetros de relevância para o monitoramento dos resíduos antes da codisposição.
27

Investigation to determine the effectiveness of a commercially available pit latrine additive and the development and evaluation of a testing protocol.

Bindoff, Anna Maria. January 2008 (has links)
The provision of sanitation services during the apartheid era in South Africa was minimal or non-existent in the previous "black" areas and for farm workers. Whatever service that was provided was often in a bad state of disrepair. One of the priorities established in the post 1994 elections was to improve the quality of lives for the previously marginalised and neglected communities. This was done through the development and implementation of a policy for reducing the sanitation backlog, and for the provision of a basic level of sanitation. The principles encompassed in the policies developed for poverty alleviation and sustainable development had many points in common with the United Nations Millennium Development Goals and targets declared in 2000. The provision of Ventilated Improved Pit (VIP) latrines by municipalities satisfies the minimum requirements for basic sanitation. This provision together with the awareness programs are seen to offer communities an improved environment and hence living conditions. Problems arise however, due to the rapid filling, blockages and even the overflow of these pits. The emptying of these pits is also hazardous due to the nature of the waste. One of the solutions proposed by entrepreneurs was to supply additives that would enhance the degradation processes in the pit thereby increasing the Iifespan of these pits as well as offering other benefits; reduced odours, and flies. The aim of this research work was to test the claim of enhanced degradation by determining the effectiveness of an additive, M, which was deemed to be representative of a group of additive; made up of aerobic microbes and enzymes. The objective was to supply information to the municipality planners and decision makers in municipalities to assist them in their planning for improved management of pits. Waste was removed from suitable VIPs and used as samples for laboratory scale experiments. Reactor vessels were designed to simulate pit conditions. The additive was tested on the waste as recommended by the supplier and compared in activity against waste tested as references. The reference tests had (i) no addition of additive or water, as well as (ii) varying the volume of water added and (iii) varying the frequency of water addition, no additive added. Measurements were made of the following variables: • Total mass • Chemical oxygen demand. • Total solids • Volatile solids. • Ash. The results of the experimental vessels were analysed and compared with the reference vessels to reveal any differences. The results obtained did not present enough precision and reliability to make any conclusive decision as to whether the additive is effective or not. Recommendations made were to improve the test methodology using the same additive, to obtain results that would make a conclusive decision possible. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2008.
28

Un système septique modifié pour gerer efficacement les eaux usées de ferme laitière /

Morin, Sophie, 1978- January 2007 (has links)
No description available.
29

Transport and transformations of nitrogen compounds in effluent from sand filter-septic system draintile fields

Bushman, Jennifer L. 12 February 1996 (has links)
A total of 44 intermittent sand filter-septic systems, in five counties of Western Oregon, were sampled over a three-month period during the summer of 1995. The sand filter systems varied in age from 36 months up to 167 months (3 to 13.9 years). Liquid samples were taken from the septic tank and distribution box. In addition, soil samples were taken adjacent to the disposal trench and away from the disposal field area (control). All samples were analyzed for Total Kjeldahl Nitrogen (TKN) and nitrate and nitrite. Nitrite was not detected in any of the samples. The average removal of total nitrogen (TKN + nitrate) through the filter was found to be 43%. Nitrate was determined to be the dominant form of nitrogen in the sand filter effluent making up 94% of the total nitrogen. The age of the system was found not to be a predictor of the system's performance. Once the effluent entered the disposal field, little if any transformation of nitrogen occurred at an average depth of 30 inches (76.2 cm). / Graduation date: 1996
30

SLUDGE ACCUMULATION AND CHARACTERIZATION IN DECENTRALIZED COMMUNITY WASTEWATER TREATMENT SYSTEMS WITH PRIMARY CLARIFIER TANKS AT EACH RESIDENCE

LOSSING, HEATHER 29 April 2009 (has links)
Sludge accumulation, treatment and disposal can represent a high percentage of the operating cost for a wastewater system. This is especially important for small-scale and onsite wastewater treatment systems, where sludge removal can be one of the few operating costs of the system. In 2000, as a result of a large number of septic system failures, the community of Wardsville installed a Clearford Industries Inc. Small Bore Sewer™ (SBS™) system which included two-chamber 3600 L tanks located on the properties of individual homes. The tanks were collectively attached to a small bore piping system to deliver the effluent from the tanks to a small community wastewater treatment system. During the summer of 2007, a field study was initiated with a community survey, followed by a review of candidate sites, leading to the selection of 29 sites for site investigation and sampling. Sampling involved the collection of samples for sludge characterization along with the measurements of the height of solids (scum and sludge) within the tank. The data were analyzed to determine the factors having a statistically significant impact on solids accumulation rates within each of the two chambers of the tank. Household water usage was found to be the variable having the strongest association with sludge and scum accumulation, and models were estimated relating solids accumulation to water usage in order predict pump out frequency. A second field sampling program was conducted in Wardsville during April 2008, involving only the first chamber of 13 primary clarifier tanks. Overall contributions have been made in understanding and quantifying solids accumulation rates and sludge characterization in onsite primary clarifier tanks. As well, the information gained from the analysis of the data collected provides a meaningful insight into the factors influencing solids accumulation within individual residential primary clarifier tanks, and points to future research directions for understanding the factors influencing solids accumulation. / Thesis (Master, Civil Engineering) -- Queen's University, 2009-04-25 15:34:46.243

Page generated in 0.0825 seconds