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V.k. William Grips - One of the best experts on this subject based on the ideXlab platform.
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Cost-effective wear and oxidation resistant electrodeposited Ni–Pumice coating
Surface & Coatings Technology, 2014Co-Authors: S.t. Aruna, Shibayan Roy, Amit Sharma, G. Savitha, V.k. William GripsAbstract:In the search for newer distributed phases that can be used in Ni-composite coatings, inexpensive and naturally available Pumice has been identified as a potential candidate material. The composition of the Pumice mineral as determined by Rietveld analysis shows the presence of corundum, quartz, mulllite, moganite and coesite phases. Pumice Stone is crushed, ball-milled, dried and dispersed in a nickel sulfamate bath and Ni-Pumice coatings are electrodeposited at different current densities and magnetic agitation speeds. Pumice particles are uniformly incorporated in the nickel matrix and Ni-Pumice composite coatings with microhardness as high as 540 HK are obtained at the lowest applied current density. In the electrodeposited Ni-Pumice coatings, the grain size of Ni increases with the applied current density. The overall intensity of texture development is slightly stronger for the Ni-Pumice composite coating compared to plain Ni coating and the texture evolution is possibly not the strongest deciding factor for the enhanced properties of Ni-Pumice coatings. The wear and oxidation resistances of Ni-Pumice coating are commensurate with that of Ni-SiC coating electrodeposited under similar conditions. (C) 2014 Elsevier B.V. All rights reserved.
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Cost-effective wear and oxidation resistant electrodeposited\ud Ni–Pumice coating
Elsevier Publisher, 2014Co-Authors: S.t. Aruna, Roy Shibayan, Sharma A, Savitha G, V.k. William GripsAbstract:In the search for newer distributed phases that can be used in Ni-composite coatings, inexpensive and naturally\ud available Pumice has been identified as a potential candidate material. The composition of the Pumice mineral as\ud determined by Rietveld analysis shows the presence of corundum, quartz, mulllite, moganite and coesite phases.\ud Pumice Stone is crushed, ball-milled, dried and dispersed in a nickel sulfamate bath and Ni–Pumice coatings are\ud electrodeposited at different current densities and magnetic agitation speeds. Pumice particles are uniformly\ud incorporated in the nickel matrix and Ni–Pumice composite coatings with microhardness as high as 540 HK are obtained at the lowest applied current density. In the electrodeposited Ni–Pumice coatings, the grain size of Ni increaseswith the applied current density. The overall intensity of texture development is slightly stronger\ud for the Ni–Pumice composite coating compared to plain Ni coating and the texture evolution is possibly not the\ud strongest deciding factor for the enhanced properties of Ni–Pumice coatings. The wear and oxidation resistances\ud of Ni-Pumice coating are commensurate with that of Ni-SiC coating electrodeposited under similar conditions
S.t. Aruna - One of the best experts on this subject based on the ideXlab platform.
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Cost-effective wear and oxidation resistant electrodeposited Ni–Pumice coating
Surface & Coatings Technology, 2014Co-Authors: S.t. Aruna, Shibayan Roy, Amit Sharma, G. Savitha, V.k. William GripsAbstract:In the search for newer distributed phases that can be used in Ni-composite coatings, inexpensive and naturally available Pumice has been identified as a potential candidate material. The composition of the Pumice mineral as determined by Rietveld analysis shows the presence of corundum, quartz, mulllite, moganite and coesite phases. Pumice Stone is crushed, ball-milled, dried and dispersed in a nickel sulfamate bath and Ni-Pumice coatings are electrodeposited at different current densities and magnetic agitation speeds. Pumice particles are uniformly incorporated in the nickel matrix and Ni-Pumice composite coatings with microhardness as high as 540 HK are obtained at the lowest applied current density. In the electrodeposited Ni-Pumice coatings, the grain size of Ni increases with the applied current density. The overall intensity of texture development is slightly stronger for the Ni-Pumice composite coating compared to plain Ni coating and the texture evolution is possibly not the strongest deciding factor for the enhanced properties of Ni-Pumice coatings. The wear and oxidation resistances of Ni-Pumice coating are commensurate with that of Ni-SiC coating electrodeposited under similar conditions. (C) 2014 Elsevier B.V. All rights reserved.
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Cost-effective wear and oxidation resistant electrodeposited\ud Ni–Pumice coating
Elsevier Publisher, 2014Co-Authors: S.t. Aruna, Roy Shibayan, Sharma A, Savitha G, V.k. William GripsAbstract:In the search for newer distributed phases that can be used in Ni-composite coatings, inexpensive and naturally\ud available Pumice has been identified as a potential candidate material. The composition of the Pumice mineral as\ud determined by Rietveld analysis shows the presence of corundum, quartz, mulllite, moganite and coesite phases.\ud Pumice Stone is crushed, ball-milled, dried and dispersed in a nickel sulfamate bath and Ni–Pumice coatings are\ud electrodeposited at different current densities and magnetic agitation speeds. Pumice particles are uniformly\ud incorporated in the nickel matrix and Ni–Pumice composite coatings with microhardness as high as 540 HK are obtained at the lowest applied current density. In the electrodeposited Ni–Pumice coatings, the grain size of Ni increaseswith the applied current density. The overall intensity of texture development is slightly stronger\ud for the Ni–Pumice composite coating compared to plain Ni coating and the texture evolution is possibly not the\ud strongest deciding factor for the enhanced properties of Ni–Pumice coatings. The wear and oxidation resistances\ud of Ni-Pumice coating are commensurate with that of Ni-SiC coating electrodeposited under similar conditions
Altamirano Pacheco, Juan Sebastián - One of the best experts on this subject based on the ideXlab platform.
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Compilación fotográfica del Centro Histórico de Latacunga
Ecuador: Latacunga: Universidad Técnica de Cotopaxi; Unidad Académica de Cienias Adminstrativas y Humanisticas; Licenciatura en Comunicación Social, 2016Co-Authors: Altamirano Pacheco, Juan SebastiánAbstract:The principle purpose which leads me to propose this topic, and addressed the Historic Center of Latacunga, is that through photography allows us to know the beauty of our city and this compilation and simple description of monuments, houses and parks are known and admired by the people who visit this latacungeño place, and tourists who come to Latacunga has a wonderful impression for the places that they visited. The historic center is considered Cultural Heritage of the State from May 25, 1982, where he was recognized for the wealth it has, however we should take advantage of the tourist and historic resource as the House of the Marquises, the church of the Merced, church and Plaza de Santo Domingo, Vicente Leon school, the Civil Hospital Hermanas Paez and Filantropia Park , church and square of San Agustin, the University of the Armed Forces, Isidro Ayora Museum, San Francisco, City Hall, the Cathedral Church and Vicente Leon Park. Latacunga, located in the center of the country, possessed of a colonial and republican architecture of special features, rich in history, tradition and culture that attract the attention of all its inhabitants, it has a full historical center of attractions that gladness who visits this city. Small streets and houses built with Pumice Stone and roof tile make this place a privileged site worthy of admiration for locals and foreigners.El principio fundamental que me lleva a proponer este tema direccionado al Centro Histórico de Latacunga, es que a través de la fotografía nos permita conocer la belleza de nuestra ciudad y que esta recopilación y descripción sencilla de sus monumentos, casas y parques sean conocidas y admiradas por la gente que visita este sector latacungueño, y que los turistas que vengan a Latacunga se lleven una grata impresión de los lugares que han visitado. El Centro Histórico está considerado como Patrimonio Cultural del Estado desde el 25 de mayo de 1982, donde fue reconocido por la riqueza que posee, sin embargo se debe aprovechar el recurso turístico e histórico que tienen estos lugares como es la Casa de los Marqueses, la iglesia de la Merced, la iglesia y Plaza de Santo Domingo, el Colegio Vicente León, el Hospital Civil de las hermanas Páez y el Parque de Filantropía, la iglesia y plaza de San Agustín, la Universidad de las Fuerzas Armadas, Museo Isidro Ayora, San Francisco, Palacio Municipal, Iglesia la Catedral y el Parque Vicente León. Latacunga, ciudad enclavada en el Centro del país, poseedora de una arquitectura colonial y republicana de características especiales, rica en historia, tradición y cultura que atrae la atención de todos sus habitantes, cuenta con un Centro Histórico lleno de atractivos que deleitan a quien visita esta ciudad. Calles estrechas y casas construidas con piedra pómez y teja, hacen de este lugar un sitio privilegiado y digno de admiración para propios y extraños.Universidad Técnica de Cotopax
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Compilación fotográfica del centro histórico de Latacunga
LATACUNGA UTC 2016, 2016Co-Authors: Altamirano Pacheco, Juan SebastiánAbstract:principle purpose which leads me to propose this topic, and addressed the Historic Center of Latacunga, is that through photography allows us to know the beauty of our city and this compilation and simple description of monuments, houses and parks are known and admired by the people who visit this latacungeño place, and tourists who come to Latacunga has a wonderful impression for the places that they visited. The historic center is considered Cultural Heritage of the State from May 25, 1982, where he was recognized for the wealth it has, however we should take advantage of the tourist and historic resource as the House of the Marquises, the church of the Merced, church and Plaza de Santo Domingo, Vicente Leon school, the Civil Hospital Hermanas Paez and Filantropia Park , church and square of San Agustin, the University of the Armed Forces, Isidro Ayora Museum, San Francisco, City Hall, the Cathedral Church and Vicente Leon Park. Latacunga, located in the center of the country, possessed of a colonial and republican architecture of special features, rich in history, tradition and culture that attract the attention of all its inhabitants, it has a full historical center of attractions that gladness who visits this city. Small streets and houses built with Pumice Stone and roof tile make this place a privileged site worthy of admiration for locals and foreigners.El principio fundamental que me lleva a proponer este tema direccionado al Centro Histórico de Latacunga, es que a través de la fotografía nos permita conocer la belleza de nuestra ciudad y que esta recopilación y descripción sencilla de sus monumentos, casas y parques sean conocidas y admiradas por la gente que visita este sector latacungueño, y que los turistas que vengan a Latacunga se lleven una grata impresión de los lugares que han visitado. El Centro Histórico está considerado como Patrimonio Cultural del Estado desde el 25 de mayo de 1982, donde fue reconocido por la riqueza que posee, sin embargo se debe aprovechar el recurso turístico e histórico que tienen estos lugares como es la Casa de los Marqueses, la iglesia de la Merced, la iglesia y Plaza de Santo Domingo, el Colegio Vicente León, el Hospital Civil de las hermanas Páez y el Parque de Filantropía, la iglesia y plaza de San Agustín, la Universidad de las Fuerzas Armadas, Museo Isidro Ayora, San Francisco, Palacio Municipal, Iglesia la Catedral y el Parque Vicente León. Latacunga, ciudad enclavada en el Centro del país, poseedora de una arquitectura colonial y republicana de características especiales, rica en historia, tradición y cultura que atrae la atención de todos sus habitantes, cuenta con un Centro Histórico lleno de atractivos que deleitan a quien visita esta ciudad. Calles estrechas y casas construidas con piedra pómez y teja, hacen de este lugar un sitio privilegiado y digno de admiración para propios y extraños
Matthew J. Andrews - One of the best experts on this subject based on the ideXlab platform.
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Gas-Phase Conversion of 1,3-Dithiolane-2-Thione Into 1,3-Dithiolan-2-One Over Molybdenum Trioxide
Frontiers Media S.A., 2019Co-Authors: Alan R. Aitken, Thomasine E. Curzon, Matthew J. AndrewsAbstract:Gas-phase reaction of 1,3-dithiolane-2-thione over molybdenum trioxide supported on Pumice Stone results in efficient conversion into 1,3-dithiolan-2-one. The solid reagent is regenerated on exposure to air and thus acts as a catalyst for the overall conversion of the thione and oxygen from the air into the ketone and sulfur dioxide. The process can be carried out under either dynamic vacuum or atmospheric pressure flow conditions and using a solid reagent prepared either by physical mixing of MoO3 with the support or by solution impregnation, with an isolated yield of up to 67% obtained
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Presentation_1_Gas-Phase Conversion of 1,3-Dithiolane-2-Thione Into 1,3-Dithiolan-2-One Over Molybdenum Trioxide.pdf
2019Co-Authors: Alan R. Aitken, Thomasine E. Curzon, Matthew J. AndrewsAbstract:Gas-phase reaction of 1,3-dithiolane-2-thione over molybdenum trioxide supported on Pumice Stone results in efficient conversion into 1,3-dithiolan-2-one. The solid reagent is regenerated on exposure to air and thus acts as a catalyst for the overall conversion of the thione and oxygen from the air into the ketone and sulfur dioxide. The process can be carried out under either dynamic vacuum or atmospheric pressure flow conditions and using a solid reagent prepared either by physical mixing of MoO3 with the support or by solution impregnation, with an isolated yield of up to 67% obtained.
Hughes Dermot - One of the best experts on this subject based on the ideXlab platform.
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Biological phosphorus removal during high-rate, low-temperature, anaerobic digestion of wastewater
'Frontiers Media SA', 2019Co-Authors: Keating Ciara, Chin, Jason P., Hughes Dermot, Manesiotis Panagiotis, Cysneiros Denise, Mahony Therese, Smith, Cindy J., Mcgrath, John W., O'flaherty VincentAbstract:We report, for the first time, extensive biologically mediated phosphate removal from wastewater during high-rate anaerobic digestion (AD). A hybrid sludge bed/fixed-film (packed Pumice Stone) reactor was employed for low-temperature (12°C) anaerobic treatment of synthetic sewage wastewater. Successful phosphate removal from the wastewater (up to 78% of influent phosphate) was observed, mediated by biofilms in the reactor. Scanning electron microscopy and energy dispersive X-ray analysis revealed the accumulation of elemental phosphorus (~2%) within the sludge bed and fixed-film biofilms. 4', 6-diamidino-2-phenylindole (DAPI) staining indicated phosphorus accumulation was biological in nature and mediated through the formation of intracellular inorganic polyphosphate (polyP) granules within these biofilms. DAPI staining further indicated that polyP accumulation was rarely associated with free cells. Efficient and consistent chemical oxygen demand (COD) removal was recorded, throughout the 732-day trial, at applied organic loading rates between 0.4 and 1.5 kg COD m(-3) d(-1) and hydraulic retention times of 8-24 h, while phosphate removal efficiency ranged from 28 to 78% on average per phase. Analysis of protein hydrolysis kinetics and the methanogenic activity profiles of the biomass revealed the development, at 12°C, of active hydrolytic and methanogenic populations. Temporal microbial changes were monitored using Illumina MiSeq analysis of bacterial and archaeal 16S rRNA gene sequences. The dominant bacterial phyla present in the biomass at the conclusion of the trial were the Proteobacteria and Firmicutes and the dominant archaeal genus was Methanosaeta. Trichococcus and Flavobacterium populations, previously associated with low temperature protein degradation, developed in the reactor biomass. The presence of previously characterized polyphosphate accumulating organisms (PAOs) such as Rhodocyclus, Chromatiales, Actinobacter, and Acinetobacter was recorded at low numbers. However, it is unknown as yet if these were responsible for the luxury polyP uptake observed in this system. The possibility of efficient phosphate removal and recovery from wastewater during AD would represent a major advance in the scope for widespread application of anaerobic wastewater treatment technologies.This work was supported by the Science Foundation Ireland Charles Parsons Award (06_CP_E006), Investigator Programme Grant (14/IA/2371), Science Foundation Ireland (14/IA/2371), and the Irish Environmental Protection Agency (2014-W-LS-7). CJS is supported by Science Foundation Ireland Starting Investigator-COFUND fellowship (11/SIRG/B2159).peer-reviewe
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Biological phosphorus removal during high-rate, low-temperature, anaerobic digestion of wastewater
Frontiers Media, 2019Co-Authors: Keating Ciara, Chin, Jason P., Hughes Dermot, Manesiotis Panagiotis, Cysneiros Denise, Mahony Therese, Smith, Cindy J., Mcgrath, John W., O\u27flaherty VincentAbstract:We report, for the first time, extensive biologically mediated phosphate removal from wastewater during high-rate anaerobic digestion (AD). A hybrid sludge bed/fixed-film (packed Pumice Stone) reactor was employed for low-temperature (12°C) anaerobic treatment of synthetic sewage wastewater. Successful phosphate removal from the wastewater (up to 78% of influent phosphate) was observed, mediated by biofilms in the reactor. Scanning electron microscopy and energy dispersive X-ray analysis revealed the accumulation of elemental phosphorus (~2%) within the sludge bed and fixed-film biofilms. 4\u27, 6-diamidino-2-phenylindole (DAPI) staining indicated phosphorus accumulation was biological in nature and mediated through the formation of intracellular inorganic polyphosphate (polyP) granules within these biofilms. DAPI staining further indicated that polyP accumulation was rarely associated with free cells. Efficient and consistent chemical oxygen demand (COD) removal was recorded, throughout the 732-day trial, at applied organic loading rates between 0.4 and 1.5 kg COD m(-3) d(-1) and hydraulic retention times of 8-24 h, while phosphate removal efficiency ranged from 28 to 78% on average per phase. Analysis of protein hydrolysis kinetics and the methanogenic activity profiles of the biomass revealed the development, at 12°C, of active hydrolytic and methanogenic populations. Temporal microbial changes were monitored using Illumina MiSeq analysis of bacterial and archaeal 16S rRNA gene sequences. The dominant bacterial phyla present in the biomass at the conclusion of the trial were the Proteobacteria and Firmicutes and the dominant archaeal genus was Methanosaeta. Trichococcus and Flavobacterium populations, previously associated with low temperature protein degradation, developed in the reactor biomass. The presence of previously characterized polyphosphate accumulating organisms (PAOs) such as Rhodocyclus, Chromatiales, Actinobacter, and Acinetobacter was recorded at low numbers. However, it is unknown as yet if these were responsible for the luxury polyP uptake observed in this system. The possibility of efficient phosphate removal and recovery from wastewater during AD would represent a major advance in the scope for widespread application of anaerobic wastewater treatment technologies.This work was supported by the Science Foundation Ireland Charles Parsons Award (06_CP_E006), Investigator Programme Grant (14/IA/2371), Science Foundation Ireland (14/IA/2371), and the Irish Environmental Protection Agency (2014-W-LS-7). CJS is supported by Science Foundation Ireland Starting Investigator-COFUND fellowship (11/SIRG/B2159)
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Biological phosphorus removal during high-rate, low-temperature, anaerobic digestion of wastewater
'Frontiers Media SA', 2016Co-Authors: Keating Ciara, Chin, Jason P., Hughes Dermot, Manesiotis Panagiotis, Cysneiros Denise, Mahony Therese, Smith, Cindy J., Mcgrath, John W., O’flaherty VincentAbstract:We report, for the first time, extensive biologically mediated phosphate removal from wastewater during high-rate anaerobic digestion (AD). A hybrid sludge bed/fixed-film (packed Pumice Stone) reactor was employed for low-temperature (12°C) anaerobic treatment of synthetic sewage wastewater. Successful phosphate removal from the wastewater (up to 78% of influent phosphate) was observed, mediated by biofilms in the reactor. Scanning electron microscopy and energy dispersive X-ray analysis revealed the accumulation of elemental phosphorus (∼2%) within the sludge bed and fixed-film biofilms. 4′, 6-diamidino-2-phenylindole (DAPI) staining indicated phosphorus accumulation was biological in nature and mediated through the formation of intracellular inorganic polyphosphate (polyP) granules within these biofilms. DAPI staining further indicated that polyP accumulation was rarely associated with free cells. Efficient and consistent chemical oxygen demand (COD) removal was recorded, throughout the 732-day trial, at applied organic loading rates between 0.4 and 1.5 kg COD m-3 d-1 and hydraulic retention times of 8–24 h, while phosphate removal efficiency ranged from 28 to 78% on average per phase. Analysis of protein hydrolysis kinetics and the methanogenic activity profiles of the biomass revealed the development, at 12°C, of active hydrolytic and methanogenic populations. Temporal microbial changes were monitored using Illumina MiSeq analysis of bacterial and archaeal 16S rRNA gene sequences. The dominant bacterial phyla present in the biomass at the conclusion of the trial were the Proteobacteria and Firmicutes and the dominant archaeal genus was Methanosaeta. Trichococcus and Flavobacterium populations, previously associated with low temperature protein degradation, developed in the reactor biomass. The presence of previously characterized polyphosphate accumulating organisms (PAOs) such as Rhodocyclus, Chromatiales, Actinobacter, and Acinetobacter was recorded at low numbers. However, it is unknown as yet if these were responsible for the luxury polyP uptake observed in this system. The possibility of efficient phosphate removal and recovery from wastewater during AD would represent a major advance in the scope for widespread application of anaerobic wastewater treatment technologies
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Low-temperature anaerobic digestion as a core technology for the sustainable treatment of municipal wastewater
2014Co-Authors: Hughes DermotAbstract:The currently applied paradigm for municipal wastewater treatment in the European Union does not meet basic sustainability criteria. Indeed, it runs counter to the stated goals of recent European Council policies regarding sustainable development. This disposal based linear system uses aerobic microbiology as the core technology. This results -- in the case of activated sludge plants, for example -- in a requirement for large capital investment, heavy usage of fossil fuels, high technology operational control and the generation of large quantities of sludge requiring treatment before safe reuse/recycle. A direct anaerobic treatment approach is proposed in this study would assist in meeting sustainability criteria and offer significant advantages to the conventional treatment approach. Anaerobic digestion (AD) has long been recognised as a sustainable waste/wastewater treatment strategy. The major application of high-rate AD has been for high-strength industrial wastewaters, e.g. food processing, brewing, etc., where mesophilic high-rate AD has been tremendously successful. There is great potential for expanding the application of anaerobic wastewater treatment. One area of particular interest is AD for the treatment of low-strength, high volume wastestreams which are discharged at sub-mesophilic (1 year), low-temperature (10-15°C) anaerobic bioreactor operation, for the treatment of synthetic sewage, was investigated. The effect of temperature on the bioprocess was investigated through the use of a mesophilically (37°C) operated control bioreactor. Three hybrid bioreactors (R1-R3) were seeded with a mesophilic inoculum, and used to treat a synthetic sewage wastewater at 37, 15 and 10°C respectively. Organic loading rates (OLRs) of 0.5-6 kg chemical oxygen demand (COD) m-3 d-1 and hydraulic retention times (HRTs) of 1.5-12 h were applied during a 1.5-year trial. Despite transient disimprovements, mean total COD removal efficiency and methane biogas concentrations exceeded 70% and 50%, respectively, for all bioreactors. Specific methanogenic activity (SMA) testing indicated that a psychroactive biomass developed in the low-temperature bioreactors. The data obtained suggest that a mesophilic inoculum can physiologically adapt to sub-optimal temperature, and efficiently treat low-strength wastewater at temperatures as low as 10°C. In the second phase of this study (chapter 3) two hybrid bioreactors (R4 and R5), were each seeded with a mesophilic biomass, and employed for the treatment of synthetic sewage at 12°C and applied OLRs of 0.5-6 kg COD m-3 d-1, and HRTs of 2-24 h. Based on the results obtained in chapter 2 the use of an alternative fixed-film matrix material; granulated Pumice Stone, to enhance process efficiency and stability was evaluated. In addition the reproducibility of LtAD for municipal wastewater treatment was investigated. Stable bioprocess performance was demonstrated with COD removal efficiencies of >70% obtained by both bioreactors. SMA and biodegradability assays demonstrated the development of a psychrotolerant, sewage-degrading consortium within the biomass of both bioreactors. Bacterial communities, as deduced from clone library analysis at the conclusion of the trial, were phylogenetically diverse, consisting of important fermentative and hydrolytic populations. Archaeal methanogenic dynamics indicated that acetoclastic methanogenic activity directly correlated to bioreactor performance. In the final phase of this study (chapter 4) the feasibility of direct anaerobic treatment of raw and settled sewage under temperate climatic conditions (12°C) was investigated. Two expanded granular sludge bed (EGSB) anaerobic filter (AF) hybrid bioreactors, R6 and R7, were employed to treat raw sewage and settled sewage (primary effluent; the liquid fraction following settlement of primary sludge), respectively, sourced from the city of Galway, Ireland. The bioreactors were operated at HRTs of 3-24 h in a trial of c.140 days. Successful treatment of both influent types was achieved with consistent effluent quality of
