Feasibility of Anaerobic Digestion for the Direct Treatment of, and the Energy Recovery from Urban Wastes

Lettinga, G.; Velsen, A.F.M. van; Hobma, S.W.; Zeeuw, W. De

doi:10.1016/s0166-1116(08)71356-6

Cited by 8 publications

(6 citation statements)

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“…Although it has been documented that pelletization occurs in UASB reactors ( , ), the mechanisms of pellet formation under anaerobic conditions have not been adequately investigated (). Research on the bioflocculation mechanisms in aerobic systems has supported the idea that high molecular weight extracellular polymers play a crucial role in the process by promoting the electrostatic or physical bonding among the cells and other particulate material to form a three-dimensional matrix or floc ().…”

Section: Resultsmentioning

confidence: 99%

“…The UASB process is a modification of the biolytic tank that relies on the superior settling characteristics of an upflow anaerobic sludge blanket ( , ). The sludge blanket (bed) can be considered as a separate fluid phase (with its own specific properties) that remains fairly stable while simultaneously withstanding relatively high mixing forces ().…”

Section: Introductionmentioning

confidence: 99%

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Particulate Organic Carbon Solubilization in an Acid-Phase Upflow Anaerobic Sludge Blanket System

Elefsiniotis

Wareham

Oldham

1996

Environ. Sci. Technol.

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The effects of operational and environmental parameters on particulate organic carbon solubilization during the acid-phase digestion of primary municipal sludge were studied using a bench-scale, upflow anaerobic sludge blanket (UASB), continuous-flow reactor. Short-chain volatile fatty acids (VFAs), the main products of the process, are preferred substrates for the bacteria involved in the biological removal of phosphorus. Both particulate organic matter solubilization [measured by filtered total organic carbon (TOC) increase or volatile suspended solids (VSS) reduction] and product formation (mainly VFAs) were affected by the changes in hydraulic retention time (HRT) from 6 to 15 h. Variation in solids retention time (SRT) from 5 to 20 days (at a constant HRT of 12 h) had a small effect on specific TOC solubilization rate and percent VSS reduction. In contrast, VFA production decreased sharply at the shortest SRT investigated. At an HRT of 12 h and a SRT of 20 days, a decrease in pH from 5.1 to 4.5 did not significantly influence system behavior. However, an increase in pH from 5.1 to 6.1 produced a higher specific TOC solubilization rate and a lower net VFA production. The settling properties of the UASB sludge blanket were excellent. Gas generation from the system was small. The amount of VFAs generated, in most runs, was large enough to support subsequent biological phosphorus removal processes.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Particulate Organic Carbon Solubilization in an Acid-Phase Upflow Anaerobic Sludge Blanket System

Elefsiniotis

Wareham

Oldham

1996

Environ. Sci. Technol.

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“…Inicialmente empregados para efluentes industriais de elevada carga orgânica (processamento de batata e beterraba), os reatores UASB foram aos poucos sendo utilizados no tratamento de esgotos sanitários (LETTINGA et al, 1981;LETTINGA;ROERSMA;GRIN, 1983). Com base nos resultados obtidos, foi possível constatar como principais vantagens da tecnologia UASB a sua simplicidade construtiva e operacional (não havendo necessidade do emprego de equipamentos eletrointensivos), o desenvolvimento do lodo de alta sedimentabilidade por causa da sua formação granular e, por fim, a produção de biogás, que pode ser empregado para fins energéticos.…”

Section: Processos Anaeróbios Antecedentes à Tecnologia Uasbunclassified

Consolidação da tecnologia de reatores UASB no estado do Paraná para o tratamento de esgotos sanitários

Rietow

Aisse

Baréa³

et al. 2023

Eng. Sanit. Ambient.

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RESUMO O clima favorável e os menores custos de construção e operação, se comparados com sistemas aeróbios de tratamento, fizeram dos reatores anaeróbios de fluxo ascendente de manto de lodo (UASB) uma das tecnologias de tratamento de esgoto sanitário mais empregadas nos países da América Latina e Caribe, sobretudo no Brasil. Este último é caracterizado por deter o maior parque de reatores anaeróbios do mundo. A consolidação dos reatores UASB no país se deu principalmente pelo pioneirismo do estado do Paraná no desenvolvimento de pesquisas e na adoção dessa tecnologia como ferramenta capaz de impulsionar os índices de coleta de tratamento de esgotos sanitários ainda no início da década de 1980. Presente em mais de 230 estações de tratamento de esgoto espalhadas pelo Paraná, os reatores UASB, também conhecidos no estado por reatores anaeróbios de leito fluidizado, sofreram ao longo dos últimos 40 anos uma série de adaptações de modo a propiciar a melhora dos sistemas de retirada de lodo, escuma e biogás. Desse modo, o presente artigo de revisão teve como objetivo contextualizar o histórico e a importância dos reatores UASB no estado do Paraná para o setor de saneamento brasileiro, trazendo os principais aspectos ocorridos nas últimas quatro décadas de emprego dessa tecnologia.

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“…This study consisted of three phases. During the first phase the reactor was fed with the combined substrate namely, glucose and molasses solution (50% each) so as to get the starting organic loading rate (OLR) of 1.5 g COD/l.day as suggested by Lettinga et al, 1978. Thereafter, the OLR was increased in steps.…”

Section: Reactor Loadingmentioning

confidence: 99%

Start Up And Operation Of A UASB Rector With Molasses As A Preferred Substrate – A Case Study

Suneeth Kumar Saragur, Indra Mani Mishra

2023

tjjpt

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Anaerobic digestion followed by aerobic treatment has gained wide acceptability for many of the wastewater treatment. Several novel bio-reactors have been developed. All these reactors pose a problem of shock loading, when the high COD organic industrial waste is fed in to the reactor. Further, the normal substrates like glucose, sewage, citric acid may result in addition of a large volume of the substrate solution for a given organic loading. Both these problems are solved by adopting molasses, a typical by-product from the sugar industry. Among the bio-reactors to treat high strength waste waters, the Up-flow Anaerobic Sludge Blanket Reactor (UASBR), has received wide popularity for the treatment of domestic waste waters as well as for a variety of industrial wastewaters. This paper is to present a cogent and a clear picture of the startup and steady state operation of an UASB Reactor with molasses as the initial startup substrate for the development of well settleable sludge granules, the major feature of an UASB Reactor. The UASB reactor was fabricated in transparent Plexiglas. The reactor had a working volume of 9.75 liters with provision of ports for input, output, collection of samples, and collection of gas. Inside the settler, a gas-liquid-solid separation system using a glass funnel and a gas pressurizing plexiglass tube was provided. The aim was to granulate the sludge and acclimatizing it completely to take high organic loading. The feed was supplemented with a fixed COD: N: P ratio by adding urea for nitrogen and KH2PO4 for phosphorous. The HRT was fixed to be 8 hours. The reactor temperature was maintained at 35 ± 20oC. In about 55 days, the buttery seed sludge got granulated at an OLR of 8 g COD/l.day. The SEM of the granules exhibited a mixed morphology on the surface of the granules while filamentous Methanothrix proliferation could be clearly seen in the interior of the granule. Methanoceata and Methanothrix are the two dominant species found in the granules.

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Feasibility of Anaerobic Digestion for the Direct Treatment of, and the Energy Recovery from Urban Wastes

Cited by 8 publications

References 1 publication

Particulate Organic Carbon Solubilization in an Acid-Phase Upflow Anaerobic Sludge Blanket System

Particulate Organic Carbon Solubilization in an Acid-Phase Upflow Anaerobic Sludge Blanket System

Consolidação da tecnologia de reatores UASB no estado do Paraná para o tratamento de esgotos sanitários

Start Up And Operation Of A UASB Rector With Molasses As A Preferred Substrate – A Case Study

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