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G K Anderson - One of the best experts on this subject based on the ideXlab platform.
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the effect of polymer addition on granulation in an anaerobic baffled reactor abr part i Process Performance
Water Research, 2002Co-Authors: S Uyanik, Paul J Sallis, G K AndersonAbstract:Abstract The stability and Performance of an anaerobic baffled reactor (ABR) treating an ice-cream wastewater at several organic loading rates have been investigated. Specifically, it was determined whether an ABR would promote phase separation and if a polymer additive was capable of enhancing granule formation in an ABR. In order to achieve these goals, two ABRs, having identical dimensions and configurations, were used to study the above objectives using a synthetic ice-cream wastewater. The ABR proved to be an efficient reactor configuration for the treatment of a high-strength synthetic ice-cream wastewater. An organic loading rate of around 15 kg COD m−3 d−1 was treated with a 99% COD removal efficiency. From the jar test and inhibition assay, it was concluded that Kymene SLX-2 was the most effective and least inhibitory polymer tested. The methane yield was higher in the polymer-amended reactor compared to the control reactor. In addition, polymer addition resulted in a considerably higher degree of biomass retention and lower solids washout from the ABR. Consequently, it demonstrated that there was a considerable potential for sludge conditioning in ABRs by facilitating better biomass retention within the reactor which in turn led to better Process Performance. Granulation was achieved in both ABRs within 3 months. However, the granules from the polymer-amended reactor appeared earlier and were generally larger and more compact, although this was not quantified in detail during the present study. The main advantage of using an ABR comes from its compartmentalised structure. The first compartment of an ABR may act as a buffer zone to all toxic and inhibitory material in the feed thus allowing the later compartments to be loaded with a relatively harmless, balanced and mostly acidified influent. In this respect, the latter compartments would be more likely to support active populations of the relatively sensitive methanogenic bacteria and partly explains why the best granules and the highest methane yield were obtained in Compartment 2. It is unlikely that a complete separation of phases (acidogenic and methanogenic) occurred within the ABRs since methane production was observed in all compartments, although this was low (∼40% of all gas composition) in Compartment 1, becoming higher (∼70%) in the following compartments.
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the effect of polymer addition on granulation in an anaerobic baffled reactor abr part i Process Performance
Water Research, 2002Co-Authors: S Uyanik, Paul J Sallis, G K AndersonAbstract:The stability and Performance of an anaerobic baffled reactor (ABR) treating an ice-cream wastewater at several organic loading rates have been investigated. Specifically, it was determined whether an ABR would promote phase separation and if a polymer additive was capable of enhancing granule formation in an ABR. In order to achieve these goals, two ABRs, having identical dimensions and configurations, were used to study the above objectives using a synthetic ice-cream wastewater. The ABR proved to be an efficient reactor configuration for the treatment of a high-strength synthetic ice-cream wastewater. An organic loading rate of around 15 kg CODm(-3) d(-1) was treated with a 99% COD removal efficiency. From the jar test and inhibition assay, it was concluded that Kymene SLX-2 was the most effective and least inhibitory polymer tested. The methane yield was higher in the polymer-amended reactor compared to the control reactor. In addition, polymer addition resulted in a considerably higher degree of biomass retention and lower solids washout from the ABR. Consequently, it demonstrated that there was a considerable potential for sludge conditioning in ABRs by facilitating better biomass retention within the reactor which in turn led to better Process Performance. Granulation was achieved in both ABRs within 3 months. However, the granules from the polymer-amended reactor appeared earlier and were generally larger and more compact, although this was not quantified in detail during the present study. The main advantage of using an ABR comes from its compartmentalised structure. The first compartment of an ABR may act as a buffer zone to all toxic and inhibitory material in the feed thus allowing the later compartments to be loaded with a relatively harmless, balanced and mostly acidified influent. In this respect, the latter compartments would be more likely to support active populations of the relatively sensitive methanogenic bacteria and partly explains why the best granules and the highest methane yield were obtained in Compartment 2. It is unlikely that a complete separation of phases (acidogenic and methanogenic) occurred within the ABRs since methane production was observed in all compartments, although this was low (approximately 40% of all gas composition) in Compartment 1, becoming higher (approximately 70%) in the following compartments.
Concetta M Tomei - One of the best experts on this subject based on the ideXlab platform.
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two stage anaerobic and post aerobic mesophilic digestion of sewage sludge analysis of Process Performance and hygienization potential
Science of The Total Environment, 2016Co-Authors: Concetta M Tomei, Domenica Mosca Angelucci, Caterina LevantesiAbstract:Sequential anaerobic-aerobic digestion has been demonstrated to be effective for enhanced sludge stabilization, in terms of increased solid reduction and improvement of sludge dewaterability. In this study, we propose a modified version of the sequential anaerobic-aerobic digestion Process by operating the aerobic step under mesophilic conditions (T=37 °C), in order to improve the aerobic degradation kinetics of soluble and particulate chemical oxygen demand (COD). Process Performance has been assessed in terms of "classical parameters" such as volatile solids (VS) removal, biogas production, COD removal, nitrogen species, and polysaccharide and protein fate. The aerobic step was operated under intermittent aeration to achieve nitrogen removal. Aerobic mesophilic conditions consistently increased VS removal, providing 32% additional removal vs. 20% at 20 °C. Similar results were obtained for nitrogen removal, increasing from 64% up to 99% at the higher temperature. Improved sludge dewaterability was also observed with a capillary suction time decrease of ~50% during the mesophilic aerobic step. This finding may be attributable to the decreased protein content in the aerobic digested sludge. The post-aerobic digestion exerted a positive effect on the reduction of microbial indicators while no consistent improvement of hygienization related to the increased temperature was observed. The techno-economic analysis of the proposed digestion layout showed a net cost saving for sludge disposal estimated in the range of 28-35% in comparison to the single-phase anaerobic digestion.
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erratum to sequential anaerobic aerobic digestion for enhanced sludge stabilization comparison of the Process Performance for mixed and waste sludge
Environmental Science and Pollution Research, 2015Co-Authors: Concetta M Tomei, Nicola Antonello CarozzaAbstract:Sequential anaerobic-aerobic digestion has been demonstrated as a promising alternative for enhanced sludge stabilization. In this paper, a feasibility study of the sequential digestion applied to real waste activated sludge (WAS) and mixed sludge is presented. Process Performance is evaluated in terms of total solid (TS) and volatile solid (VS) removal, biogas production, and dewaterability trend in the anaerobic and double-stage digested sludge. In the proposed digestion lay out, the aerobic stage was operated with intermittent aeration to reduce the nitrogen load recycled to the wastewater treatment plant (WWTP). Experimental results showed a very good Performance of the sequential digestion Process for both waste and mixed sludge, even if, given its better digestibility, higher efficiencies are observed for mixed sludge. VS removal efficiencies in the anaerobic stage were 48 and 50 % for waste and mixed sludge, respectively, while a significant additional improvement of the VS removal of 25 % for WAS and 45 % for mixed sludge has been obtained in the aerobic stage. The post-aerobic stage, operated with intermittent aeration, was also efficient in nitrogen removal, providing a significant decrease of the nitrogen content in the supernatant: nitrification efficiencies of 90 and 97 % and denitrification efficiencies of 62 and 70 % have been obtained for secondary and mixed sludges, respectively. A positive effect due to the aerobic stage was also observed on the sludge dewaterability in both cases. Biogas production, expressed as Nm3/(kgVSdestroyed), was 0.54 for waste and 0.82 for mixed sludge and is in the range of values reported in the literature in spite of the low anaerobic sludge retention time of 15 days.
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sequential anaerobic aerobic digestion of waste activated sludge analysis of the Process Performance and kinetic study
New Biotechnology, 2011Co-Authors: Concetta M Tomei, Sara Rita, G MininniAbstract:Sequential anaerobic–aerobic digestion was applied to waste activated sludge (WAS) of a full scale wastewater treatment plant. The study was performed with the objective of testing the sequential digestion Process on WAS, which is characterized by worse digestibility in comparison with the mixed sludge. Process Performance was evaluated in terms of biogas production, volatile solids (VS) and COD reduction, and patterns of biopolymers (proteins and polysaccharides) in the subsequent digestion stages. VS removal efficiency of 40%, in the anaerobic phase, and an additional removal of 26%, in the aerobic one, were observed. For total COD removal efficiencies of 35% and 25% for anaerobic and aerobic stage respectively, were obtained. Kinetics of VS degradation Process was analyzed by assuming a first order equation with respect to VS concentration. Evaluated kinetic parameters were 0.44 ± 0.20 d−1 and 0.25 ± 0.15 d−1 for the anaerobic stage and aerobic stage, respectively. With regard to biopolymers, in the anaerobic phase the content of proteins and polysaccharides increased to 50% and 69%, respectively, whereas in the subsequent aerobic phase, a decrease of 71% for proteins and 67% for polysaccharides was observed. The average specific biogas production 0.74 m3/(kgVS destroyed), was in the range of values reported in the specialized literature for conventional anaerobic mesophilic WAS digestion.
S Uyanik - One of the best experts on this subject based on the ideXlab platform.
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the effect of polymer addition on granulation in an anaerobic baffled reactor abr part i Process Performance
Water Research, 2002Co-Authors: S Uyanik, Paul J Sallis, G K AndersonAbstract:Abstract The stability and Performance of an anaerobic baffled reactor (ABR) treating an ice-cream wastewater at several organic loading rates have been investigated. Specifically, it was determined whether an ABR would promote phase separation and if a polymer additive was capable of enhancing granule formation in an ABR. In order to achieve these goals, two ABRs, having identical dimensions and configurations, were used to study the above objectives using a synthetic ice-cream wastewater. The ABR proved to be an efficient reactor configuration for the treatment of a high-strength synthetic ice-cream wastewater. An organic loading rate of around 15 kg COD m−3 d−1 was treated with a 99% COD removal efficiency. From the jar test and inhibition assay, it was concluded that Kymene SLX-2 was the most effective and least inhibitory polymer tested. The methane yield was higher in the polymer-amended reactor compared to the control reactor. In addition, polymer addition resulted in a considerably higher degree of biomass retention and lower solids washout from the ABR. Consequently, it demonstrated that there was a considerable potential for sludge conditioning in ABRs by facilitating better biomass retention within the reactor which in turn led to better Process Performance. Granulation was achieved in both ABRs within 3 months. However, the granules from the polymer-amended reactor appeared earlier and were generally larger and more compact, although this was not quantified in detail during the present study. The main advantage of using an ABR comes from its compartmentalised structure. The first compartment of an ABR may act as a buffer zone to all toxic and inhibitory material in the feed thus allowing the later compartments to be loaded with a relatively harmless, balanced and mostly acidified influent. In this respect, the latter compartments would be more likely to support active populations of the relatively sensitive methanogenic bacteria and partly explains why the best granules and the highest methane yield were obtained in Compartment 2. It is unlikely that a complete separation of phases (acidogenic and methanogenic) occurred within the ABRs since methane production was observed in all compartments, although this was low (∼40% of all gas composition) in Compartment 1, becoming higher (∼70%) in the following compartments.
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the effect of polymer addition on granulation in an anaerobic baffled reactor abr part i Process Performance
Water Research, 2002Co-Authors: S Uyanik, Paul J Sallis, G K AndersonAbstract:The stability and Performance of an anaerobic baffled reactor (ABR) treating an ice-cream wastewater at several organic loading rates have been investigated. Specifically, it was determined whether an ABR would promote phase separation and if a polymer additive was capable of enhancing granule formation in an ABR. In order to achieve these goals, two ABRs, having identical dimensions and configurations, were used to study the above objectives using a synthetic ice-cream wastewater. The ABR proved to be an efficient reactor configuration for the treatment of a high-strength synthetic ice-cream wastewater. An organic loading rate of around 15 kg CODm(-3) d(-1) was treated with a 99% COD removal efficiency. From the jar test and inhibition assay, it was concluded that Kymene SLX-2 was the most effective and least inhibitory polymer tested. The methane yield was higher in the polymer-amended reactor compared to the control reactor. In addition, polymer addition resulted in a considerably higher degree of biomass retention and lower solids washout from the ABR. Consequently, it demonstrated that there was a considerable potential for sludge conditioning in ABRs by facilitating better biomass retention within the reactor which in turn led to better Process Performance. Granulation was achieved in both ABRs within 3 months. However, the granules from the polymer-amended reactor appeared earlier and were generally larger and more compact, although this was not quantified in detail during the present study. The main advantage of using an ABR comes from its compartmentalised structure. The first compartment of an ABR may act as a buffer zone to all toxic and inhibitory material in the feed thus allowing the later compartments to be loaded with a relatively harmless, balanced and mostly acidified influent. In this respect, the latter compartments would be more likely to support active populations of the relatively sensitive methanogenic bacteria and partly explains why the best granules and the highest methane yield were obtained in Compartment 2. It is unlikely that a complete separation of phases (acidogenic and methanogenic) occurred within the ABRs since methane production was observed in all compartments, although this was low (approximately 40% of all gas composition) in Compartment 1, becoming higher (approximately 70%) in the following compartments.
Heracles Petropakis - One of the best experts on this subject based on the ideXlab platform.
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direct osmotic concentration of tomato juice in tubular membrane module configuration ii the effect of using clarified tomato juice on the Process Performance
Journal of Membrane Science, 1999Co-Authors: Konstantinos Petrotos, Peter Quantick, Heracles PetropakisAbstract:Abstract A study was carried out by using a new tubular direct osmosis module, constructed by PCI UK and equipped with a novel AFC99 membrane 400 μm thick, to investigate the effect of clarifying tomato juice on the rate of direct osmotic concentration. Under virtually the same operating conditions five respective clarifications of juice were tried including full, unclarified, tomato juice. The Process Performance was calculated in terms of permeation flux. In all the experimental runs the osmotic medium was sodium chloride brine (initial concentration approx. 23% NaCl). A remarkable increase of permeation flux (over 100%) was observed shifting from unclarified to the clarified tomato juice. Clarification was carried out by passing the juice through 35 μm mesh and also by using membranes of molecular weight cut-off 200 000, 100 000 and 25 000 Daltons (Da), respectively, in order to obtain the juice ultrafiltrates. It is also worth mentioning that the flux value obtained with 25 000 Daltons (Da) ultrafiltrate appeared to be considerably higher than values reported in experiments carried out by other researchers, where unclarified juice was used, despite the disadvantage of a far thicker membrane being used in the present investigation. This specific finding discloses great potential in using a combined low temperature and pressure ultrafiltration and direct osmosis Process to produce tomato concentrates.
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a study of the direct osmotic concentration of tomato juice in tubular membrane module configuration i the effect of certain basic Process parameters on the Process Performance
Journal of Membrane Science, 1998Co-Authors: Konstantinos Petrotos, Peter Quantick, Heracles PetropakisAbstract:Abstract A novel tubular module was used to investigate the direct osmosis concentration Process in the case of tomato juice. This module, was constructed, according to given specifications, by PCI UK and consisted of an external stainless steel shroud accommodating, internally, a set of two identical RO membrane tubes having no support lengthwise and properly sealed at their ends. The Process Performance was measured in terms of water permeation flux and its response to changes of the Process parameters was experimentally assessed and established. The Process parameters which were investigated in the course of this study were: the kind of osmotic medium, the viscosity of osmotic medium, the osmotic medium concentration, the juice temperature, the juice flow rate, the juice concentration and the membrane thickness. Sodium chloride brine was found to be the best osmotic medium, among the six which were tried, and this was due to its very low viscosity. The above parameter appears to be of paramount importance regarding the effectiveness of an osmotic medium. Higher osmotic medium concentrations yielded to higher osmotic permeation rates. Increasing the juice temperature was found to markedly increase the permeation flux. However, only a slight enhancement of flux was observed by increasing the juice flow rate. Moreover, higher juice concentrations up to approximately 12° Brix led to a lowering of the osmotic flux. Finally, as far as the membrane thickness was concerned, a strong trend was revealed for exponential increase of permeation by shifting towards lower membrane thicknesses. This trend however needs to be further investigated as an inadequate number of experimental points were obtained due to lack of additional membranes.
Wil M P Van Der Aalst - One of the best experts on this subject based on the ideXlab platform.
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data based description of Process Performance in end to end order Processing
Cirp Annals-manufacturing Technology, 2020Co-Authors: Gunther Schuh, Wil M P Van Der Aalst, Andreas Gutzlaff, Seth SchmitzAbstract:Abstract To master ongoing market competitiveness, manufacturing companies try to increase Process efficiency through Process improvements. Mapping the end-to-end order Processing is particularly important, as one needs to consider all order-fulfilling core Processes to evaluate Process Performance. However, today's traditional Process mapping methods such as workshops are subjective and time-consuming. Therefore, Process improvements are based on gut feeling rather than facts, leading to high failure probabilities. This paper presents a Process mining approach that provides data-based description of Process Performance in order Processing and thus objectively and effortlessly maps as-is end-to-end Processes. The approach is validated with an industrial case study.
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lifecycle based Process Performance analysis
Cooperative Information Systems, 2018Co-Authors: Bart F A Hompes, Wil M P Van Der AalstAbstract:Many business Processes are supported by information systems that record their execution. Process mining techniques extract knowledge and insights from such Process execution data typically stored in event logs or streams. Most Process mining techniques focus on Process discovery (the automated extraction of Process models) and conformance checking (aligning observed and modeled behavior). Existing Process Performance analysis techniques typically rely on ad-hoc definitions of Performance. This paper introduces a novel comprehensive approach to Process Performance analysis from event data. Our generic technique centers around business artifacts, key conceptual entities that behave according to state-based transactional lifecycle models. We present a formalization of these concepts as well as a structural approach to calculate and monitor Process Performance from event data. The approach has been implemented in the open source Process mining tool ProM and its applicability has been evaluated using public real-life event data.
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a generic framework for context aware Process Performance analysis
International Conference on Move to Meaningful Internet Systems, 2016Co-Authors: Bart F A Hompes, Jcam Joos Buijs, Wil M P Van Der AalstAbstract:Process mining combines model-based Process analysis with data-driven analysis techniques. The role of Process mining is to extract knowledge and gain insights from event logs. Most existing techniques focus on Process discovery (the automated extraction of Process models) and conformance checking (aligning observed and modeled behavior). Relatively little research has been performed on the analysis of business Process Performance. Cooperative business Processes often exhibit a high degree of variability and depend on many factors. Finding root causes for inefficiencies such as delays and long waiting times in such flexible Processes remains an interesting challenge. This paper introduces a novel approach to analyze key Process Performance indicators by considering the Process context. A generic context-aware analysis framework is presented that analyzes Performance characteristics from multiple perspectives. A statistical approach is then utilized to evaluate and find significant differences in the results. Insights obtained can be used for finding high-impact points for optimization, prediction, and monitoring. The practical relevance of the approach is shown in a case study using real-life data.
