Glen Daigger | University of Michigan (original) (raw)

Papers by Glen Daigger

Research paper thumbnail of Performance of four full-scale nitrifying wastewater treatment plants incorporating selectors

Journal of Water Pollution Control Federation, 1990

ABSTRACT

Research paper thumbnail of Start-up and Initial Operation of Singapore's 800,000 m3/day Changi Water Reclamation Plant

Water Practice & Technology, Dec 1, 2008

Research paper thumbnail of Evaluation of Autotrophic Denitrification and Heterotrophic Nitrification in Simultaneous Biological Nutrient Removal Systems

Proceedings of the Water Environment Federation, 2000

Simultaneous biological nutrient removal (SBNR) is the occurrence of significant biological nutri... more Simultaneous biological nutrient removal (SBNR) is the occurrence of significant biological nutrient removal in biological wastewater treatment systems where defined anaerobic and anoxic zones do not exist. There is growing evidence that significant SBNR can occur in many systems, ...

Research paper thumbnail of Biofilm carrier migration model describes reactor performance

Water Science and Technology, Mar 17, 2017

Research paper thumbnail of New Concepts in Wastewater Treatment Biofilm System Modeling

Proceedings of the Water Environment Federation, 2015

Research paper thumbnail of Factors Affecting Biological Phosphorus Removal for the Vip Process, a High-Rate University of Capetown Type Process

Elsevier eBooks, 1987

ABSTRACT The phosphorus removal capabilities of the Virginia Initiative Plant (VIP) process, a hi... more ABSTRACT The phosphorus removal capabilities of the Virginia Initiative Plant (VIP) process, a high-rate biological nutrient removal (BNR) process, are presented and compared to the high-rate A2/0 and the low-rate University of Capetown (UCT) processes. The results indicate superior phosphorus removal capability for the VIP process compared to the A2/0 and UCT processes. In general, VIP process phosphorus removal was maximized by operation at the lowest possible total process mean cell residence time (MCRT) and with an aerobic hydraulic residence time (HRT) not exceeding 4 hours. A total process MCRT of 5 days provided acceptable nitrogen removal and excellent phosphorus removal for wastewater temperatures of 20°C or above, while a total process MCRT of 20 days would be required at a temperature of 12°C. Operation of the VIP process at an aerobic HRT greater than 4 hours apparently resulted in oxidation of stored organic matter that adversely affected phosphorus uptake kinetics. Data analysis suggested that the VIP process could have been operated at an anaerobic HRT as short as 20 minutes. Superior phosphorus removal performance was observed for the VIP process compared to the A2/0 process when the BOD5/TPO4 ratio of the wastewater was significantly less than 20.

Research paper thumbnail of Simultaneous Biological Nutrient Removal: Evaluation of Autotrophic Denitrification, Heterotrophic Nitrification, and Biological Phosphorus Removal in Full-Scale Systems

Water Environment Research, Mar 1, 2003

Simultaneous biological nutrient removal (SBNR) is the biological removal of nitrogen and phospho... more Simultaneous biological nutrient removal (SBNR) is the biological removal of nitrogen and phosphorus in excess of that required for biomass synthesis in a biological wastewater treatment system without defined anaerobic or anoxic zones. Evidence is growing that significant SBNR can occur in many systems, including the aerobic zone of systems already configured for biological nutrient removal. Although SBNR systems offer several potential advantages, they cannot be fully realized until the mechanisms responsible for SBNR are better understood. Consequently, a research program was initiated with the basic hypothesis that three mechanisms might be responsible for SBNR: the reactor macroenvironment, the floc microenvironment, and novel microorganisms. Previously, the nutrient removal capabilities of seven full‐scale, staged, closed‐loop bioreactors known as Orbal oxidation ditches were evaluated. Chemical analysis and microbiological observations suggested that SBNR occurred in these systems. Three of these plants were further examined in this research to evaluate the importance of novel microorganisms, especially for nitrogen removal. A screening tool was developed to determine the relative significance of the activities of microorganisms capable of autotrophic denitrification and heterotrophic nitrification‐aerobic denitrification in biological nutrient removal systems. The results indicated that novel microorganisms were not substantial contributors to SBNR in the plants studied. Phosphorus metabolism (anaerobic release, aerobic uptake) was also tested in one of the plants. Activity within the mixed liquor that was consistent with current theories for phosphorus‐accumulating organisms (PAOs) was observed. Along with other observations, this suggests the presence of PAOs in the facilities studied.

Research paper thumbnail of Is it PAO-GAO competition or metabolic shift in EBPR system? Evidence from an experimental study

Water Science and Technology, Oct 1, 2008

Research paper thumbnail of A Dynamic Model for Physico-chemical Phosphorus Removal: Validation and Integration in ASM2d Introduction

ABSTRACT Modelling concepts: HFO precipitation, aging, P adsorption Validation with experiments i... more ABSTRACT Modelling concepts: HFO precipitation, aging, P adsorption Validation with experiments in tap water (Szabo et al., 2008) Influence of mixing Influence of HFO aging and time Low P effluent requirement  chemical dosing Objective: Ensuring compliant effluent phosphorus concentrations, saving chemicals and limiting chemical sludge production Method: development of a model able to  optimize multi-point dosage  optimize temporal dosage  predict interaction of bio-P and chemP  predict alkalinity loss Background: Iron dosage leads to rapid hydrous ferric oxide (HFO, close to 2-line ferrihydrite) precipitation. Phosphorus is removed mainly by:  adsorption of phosphate onto HFO  co-precipitation of phosphate into HFO flocs (Smith et al., 2008)

Research paper thumbnail of Applications of Mobile Carrier Biofilm Modelling for Wastewater Treatment Processes

Lecture notes in civil engineering, 2017

One-dimensional (1-D) biofilm models have been demonstrated reliable for specific types of biofil... more One-dimensional (1-D) biofilm models have been demonstrated reliable for specific types of biofilm reactor design. Limitations using mechanistic biofilm models for engineering design do not rely on improved biofilm models, but rely on improved biofilm reactor models. This is important when considering that biofilm reactors containing submerged, free-moving biofilm carriers are the most widely applied biofilm system(s) for municipal wastewater treatment. This paper presents a new biofilm reactor model that considers the impact of submerged free-moving biofilm carrier (Xcarrier) movement on system performance. The model accounts for a hydrodynamic condition characterized as plug flow with back mixing (to model axial dispersion). The relevance of this new biofilm reactor model to engineering situations is evaluated by applying it to relevant scenarios and comparing model results.

Research paper thumbnail of Application of Computational Fluid Dynamics to Closed-Loop Bioreactors: II. Simulation of Biological Phosphorus Removal Using Computational Fluid Dynamics

Water Environment Research, Jun 1, 2007

Based on the International Water Association's (London) Activated Sludge Model No. 2 (ASM2), ... more Based on the International Water Association's (London) Activated Sludge Model No. 2 (ASM2), biochemistry rate expressions for general heterotrophs and phosphorus‐accumulating organisms (PAOs) were introduced to a previously developed, three‐dimensional computational fluid dynamics (CFD) activated sludge model that characterized the mixing pattern within the outer channel of a full‐scale, closed‐loop bioreactor. Using acetate as the sole carbon and energy source, CFD simulations for general heterotrophs or PAOs individually agreed well with those of ASM2 for a chemostat with the same operating conditions. Competition between and selection of heterotrophs and PAOs was verified using conventional completely mixed and tanks‐in‐series models. Then, competition was studied in the CFD model. These results demonstrated that PAOs and heterotrophs can theoretically coexist in a single bioreactor when the oxygen input is appropriate to allow sufficient low‐dissolved‐oxygen zones to develop.

Research paper thumbnail of Critical Review on the Degradability of Endogenous Decay Products

Proceedings of the Water Environment Federation, 2012

Research paper thumbnail of Chemically Mediated Phosphorus Removal to Low Levels: Analysis and Interpretation of Data

Proceedings of the Water Environment Federation, 2008

1 Department of Chemistry, Wilfrid Laurier University, Waterloo, Ontario, Canada, N2L 3C5 2 Depar... more 1 Department of Chemistry, Wilfrid Laurier University, Waterloo, Ontario, Canada, N2L 3C5 2 Department of Geography and Environmental Studies, Wilfrid Laurier University, Waterloo, Ontario, Canada, N2L 3C5 3 University of Technology and Economics, 1111 Budapest, ...

Research paper thumbnail of A Dynamic Physicochemical Model for Chemical Phosphorus Removal

Proceedings of the Water Environment Federation, 2013

A dynamic physico-chemical model for chemical phosphorus removal in wastewater is presented as a ... more A dynamic physico-chemical model for chemical phosphorus removal in wastewater is presented as a tool to optimize chemical dosing simultaneously while ensuring compliant effluent phosphorus concentration. This new model predicts the kinetic and stoichiometric variable processes of precipitation of hydrous ferric oxides (HFO), phosphates adsorption and co-precipitation. It is combined with chemical equilibrium and physical precipitation reactions in order to model observed bulk dynamics in terms of pH. The model is calibrated and validated based on previous studies and experimental data from Smith et al. (2008) and Szabo et al. (2008) as a first step for full-plant implementation. The simulation results show that the structure of the model describes adequately the mechanisms of adsorption and co-precipitation of phosphate species onto HFO and that the model is robust under various experimental conditions.

Research paper thumbnail of Biodegradability Enhancement of EO/PO Block Copolymers and Alkylphenol Ethoxylates using the H202/Ozone Advanced Oxidation Process: Laboratory Studies and Economic Analysis

Research paper thumbnail of Start-Up and Initial Operation Of Singapore's 800,000 M<SUP>3</SUP>/Day (211 MGD) Changi Water Reclamation Plant

Proceedings of the Water Environment Federation, 2008

Research paper thumbnail of Operating Experience of the First and Largest Low Level Nitrogen Removal Facility in Long Island Sound

Proceedings of the Water Environment Federation, 2007

Research paper thumbnail of Impact of Global Warming Concerns on Wastewater Treatment Plant Design and Operation

American Society of Civil Engineers eBooks, Jun 30, 2004

This paper provides an overview of the impact of global wanning concerns on wastewater treatment ... more This paper provides an overview of the impact of global wanning concerns on wastewater treatment plant design and operation. The issues surrounding global wanning concerns are discussed, along with the linkage between global warming and greenhouse gas emissions. US greenhouse gas emission inventories are reviewed, along with the role of wastewater treatment plants in reducing such emissions. It is found that process related emissions from wastewater treatment plants are less than 1% of total greenhouse gas emissions. Limited flexibility exists to reduce process-related emissions. One of the principal options is to minimize CH 4 emissions at the expense of CO 2 emissions by stabilizing biodegradable organic matter aerobically rather than anaerobically, or by capturing and combusting any CH 4 produced. The global warming potential of CH 4 is 21 times higher than that of CO 2 . Principal options for reducing greenhouse gas emissions involve selection of biosolids reuse options and energy consumption measures. Landfilling of waste biosolids should be avoided as this leads to CH 4 emissions. Agricultural reuse can reduce greenhouse gas emissions if land management practices increase soil organic carbon content and/or if crops are grown that can be used to produce renewable fuels (such as ethanol). Greenhouse gas emissions can also be reduced by energy conservation measures that reduce the use of fossil fuels, or the consumption of energy produced from them. Greenhouse gas emissions may be considered during the evaluation of alternatives for upgrading wastewater treatment plants, or as part of an overall emissions inventory.

Research paper thumbnail of Characterization of the Floc Micro-Environment in Dispersed Growth Systems

Proceedings of the Water Environment Federation, 2000

Abstract: The phenomenon of nitrogen and phosphorus removal in aerated biological reactors where ... more Abstract: The phenomenon of nitrogen and phosphorus removal in aerated biological reactors where no formal anoxic or anaerobic zones are present is referred to as simultaneous biological nutrient removal (SBNR). One possible mechanism for SBNR is ...

Research paper thumbnail of Oxygen Transfer in Moving Bed Biofilm Reactor and Integrated Fixed Film Activated Sludge Processes

Water Environment Research, Jul 1, 2018

Research paper thumbnail of Performance of four full-scale nitrifying wastewater treatment plants incorporating selectors

Journal of Water Pollution Control Federation, 1990

ABSTRACT

Research paper thumbnail of Start-up and Initial Operation of Singapore's 800,000 m3/day Changi Water Reclamation Plant

Water Practice & Technology, Dec 1, 2008

Research paper thumbnail of Evaluation of Autotrophic Denitrification and Heterotrophic Nitrification in Simultaneous Biological Nutrient Removal Systems

Proceedings of the Water Environment Federation, 2000

Simultaneous biological nutrient removal (SBNR) is the occurrence of significant biological nutri... more Simultaneous biological nutrient removal (SBNR) is the occurrence of significant biological nutrient removal in biological wastewater treatment systems where defined anaerobic and anoxic zones do not exist. There is growing evidence that significant SBNR can occur in many systems, ...

Research paper thumbnail of Biofilm carrier migration model describes reactor performance

Water Science and Technology, Mar 17, 2017

Research paper thumbnail of New Concepts in Wastewater Treatment Biofilm System Modeling

Proceedings of the Water Environment Federation, 2015

Research paper thumbnail of Factors Affecting Biological Phosphorus Removal for the Vip Process, a High-Rate University of Capetown Type Process

Elsevier eBooks, 1987

ABSTRACT The phosphorus removal capabilities of the Virginia Initiative Plant (VIP) process, a hi... more ABSTRACT The phosphorus removal capabilities of the Virginia Initiative Plant (VIP) process, a high-rate biological nutrient removal (BNR) process, are presented and compared to the high-rate A2/0 and the low-rate University of Capetown (UCT) processes. The results indicate superior phosphorus removal capability for the VIP process compared to the A2/0 and UCT processes. In general, VIP process phosphorus removal was maximized by operation at the lowest possible total process mean cell residence time (MCRT) and with an aerobic hydraulic residence time (HRT) not exceeding 4 hours. A total process MCRT of 5 days provided acceptable nitrogen removal and excellent phosphorus removal for wastewater temperatures of 20°C or above, while a total process MCRT of 20 days would be required at a temperature of 12°C. Operation of the VIP process at an aerobic HRT greater than 4 hours apparently resulted in oxidation of stored organic matter that adversely affected phosphorus uptake kinetics. Data analysis suggested that the VIP process could have been operated at an anaerobic HRT as short as 20 minutes. Superior phosphorus removal performance was observed for the VIP process compared to the A2/0 process when the BOD5/TPO4 ratio of the wastewater was significantly less than 20.

Research paper thumbnail of Simultaneous Biological Nutrient Removal: Evaluation of Autotrophic Denitrification, Heterotrophic Nitrification, and Biological Phosphorus Removal in Full-Scale Systems

Water Environment Research, Mar 1, 2003

Simultaneous biological nutrient removal (SBNR) is the biological removal of nitrogen and phospho... more Simultaneous biological nutrient removal (SBNR) is the biological removal of nitrogen and phosphorus in excess of that required for biomass synthesis in a biological wastewater treatment system without defined anaerobic or anoxic zones. Evidence is growing that significant SBNR can occur in many systems, including the aerobic zone of systems already configured for biological nutrient removal. Although SBNR systems offer several potential advantages, they cannot be fully realized until the mechanisms responsible for SBNR are better understood. Consequently, a research program was initiated with the basic hypothesis that three mechanisms might be responsible for SBNR: the reactor macroenvironment, the floc microenvironment, and novel microorganisms. Previously, the nutrient removal capabilities of seven full‐scale, staged, closed‐loop bioreactors known as Orbal oxidation ditches were evaluated. Chemical analysis and microbiological observations suggested that SBNR occurred in these systems. Three of these plants were further examined in this research to evaluate the importance of novel microorganisms, especially for nitrogen removal. A screening tool was developed to determine the relative significance of the activities of microorganisms capable of autotrophic denitrification and heterotrophic nitrification‐aerobic denitrification in biological nutrient removal systems. The results indicated that novel microorganisms were not substantial contributors to SBNR in the plants studied. Phosphorus metabolism (anaerobic release, aerobic uptake) was also tested in one of the plants. Activity within the mixed liquor that was consistent with current theories for phosphorus‐accumulating organisms (PAOs) was observed. Along with other observations, this suggests the presence of PAOs in the facilities studied.

Research paper thumbnail of Is it PAO-GAO competition or metabolic shift in EBPR system? Evidence from an experimental study

Water Science and Technology, Oct 1, 2008

Research paper thumbnail of A Dynamic Model for Physico-chemical Phosphorus Removal: Validation and Integration in ASM2d Introduction

ABSTRACT Modelling concepts: HFO precipitation, aging, P adsorption Validation with experiments i... more ABSTRACT Modelling concepts: HFO precipitation, aging, P adsorption Validation with experiments in tap water (Szabo et al., 2008) Influence of mixing Influence of HFO aging and time Low P effluent requirement  chemical dosing Objective: Ensuring compliant effluent phosphorus concentrations, saving chemicals and limiting chemical sludge production Method: development of a model able to  optimize multi-point dosage  optimize temporal dosage  predict interaction of bio-P and chemP  predict alkalinity loss Background: Iron dosage leads to rapid hydrous ferric oxide (HFO, close to 2-line ferrihydrite) precipitation. Phosphorus is removed mainly by:  adsorption of phosphate onto HFO  co-precipitation of phosphate into HFO flocs (Smith et al., 2008)

Research paper thumbnail of Applications of Mobile Carrier Biofilm Modelling for Wastewater Treatment Processes

Lecture notes in civil engineering, 2017

One-dimensional (1-D) biofilm models have been demonstrated reliable for specific types of biofil... more One-dimensional (1-D) biofilm models have been demonstrated reliable for specific types of biofilm reactor design. Limitations using mechanistic biofilm models for engineering design do not rely on improved biofilm models, but rely on improved biofilm reactor models. This is important when considering that biofilm reactors containing submerged, free-moving biofilm carriers are the most widely applied biofilm system(s) for municipal wastewater treatment. This paper presents a new biofilm reactor model that considers the impact of submerged free-moving biofilm carrier (Xcarrier) movement on system performance. The model accounts for a hydrodynamic condition characterized as plug flow with back mixing (to model axial dispersion). The relevance of this new biofilm reactor model to engineering situations is evaluated by applying it to relevant scenarios and comparing model results.

Research paper thumbnail of Application of Computational Fluid Dynamics to Closed-Loop Bioreactors: II. Simulation of Biological Phosphorus Removal Using Computational Fluid Dynamics

Water Environment Research, Jun 1, 2007

Based on the International Water Association's (London) Activated Sludge Model No. 2 (ASM2), ... more Based on the International Water Association's (London) Activated Sludge Model No. 2 (ASM2), biochemistry rate expressions for general heterotrophs and phosphorus‐accumulating organisms (PAOs) were introduced to a previously developed, three‐dimensional computational fluid dynamics (CFD) activated sludge model that characterized the mixing pattern within the outer channel of a full‐scale, closed‐loop bioreactor. Using acetate as the sole carbon and energy source, CFD simulations for general heterotrophs or PAOs individually agreed well with those of ASM2 for a chemostat with the same operating conditions. Competition between and selection of heterotrophs and PAOs was verified using conventional completely mixed and tanks‐in‐series models. Then, competition was studied in the CFD model. These results demonstrated that PAOs and heterotrophs can theoretically coexist in a single bioreactor when the oxygen input is appropriate to allow sufficient low‐dissolved‐oxygen zones to develop.

Research paper thumbnail of Critical Review on the Degradability of Endogenous Decay Products

Proceedings of the Water Environment Federation, 2012

Research paper thumbnail of Chemically Mediated Phosphorus Removal to Low Levels: Analysis and Interpretation of Data

Proceedings of the Water Environment Federation, 2008

1 Department of Chemistry, Wilfrid Laurier University, Waterloo, Ontario, Canada, N2L 3C5 2 Depar... more 1 Department of Chemistry, Wilfrid Laurier University, Waterloo, Ontario, Canada, N2L 3C5 2 Department of Geography and Environmental Studies, Wilfrid Laurier University, Waterloo, Ontario, Canada, N2L 3C5 3 University of Technology and Economics, 1111 Budapest, ...

Research paper thumbnail of A Dynamic Physicochemical Model for Chemical Phosphorus Removal

Proceedings of the Water Environment Federation, 2013

A dynamic physico-chemical model for chemical phosphorus removal in wastewater is presented as a ... more A dynamic physico-chemical model for chemical phosphorus removal in wastewater is presented as a tool to optimize chemical dosing simultaneously while ensuring compliant effluent phosphorus concentration. This new model predicts the kinetic and stoichiometric variable processes of precipitation of hydrous ferric oxides (HFO), phosphates adsorption and co-precipitation. It is combined with chemical equilibrium and physical precipitation reactions in order to model observed bulk dynamics in terms of pH. The model is calibrated and validated based on previous studies and experimental data from Smith et al. (2008) and Szabo et al. (2008) as a first step for full-plant implementation. The simulation results show that the structure of the model describes adequately the mechanisms of adsorption and co-precipitation of phosphate species onto HFO and that the model is robust under various experimental conditions.

Research paper thumbnail of Biodegradability Enhancement of EO/PO Block Copolymers and Alkylphenol Ethoxylates using the H202/Ozone Advanced Oxidation Process: Laboratory Studies and Economic Analysis

Research paper thumbnail of Start-Up and Initial Operation Of Singapore's 800,000 M<SUP>3</SUP>/Day (211 MGD) Changi Water Reclamation Plant

Proceedings of the Water Environment Federation, 2008

Research paper thumbnail of Operating Experience of the First and Largest Low Level Nitrogen Removal Facility in Long Island Sound

Proceedings of the Water Environment Federation, 2007

Research paper thumbnail of Impact of Global Warming Concerns on Wastewater Treatment Plant Design and Operation

American Society of Civil Engineers eBooks, Jun 30, 2004

This paper provides an overview of the impact of global wanning concerns on wastewater treatment ... more This paper provides an overview of the impact of global wanning concerns on wastewater treatment plant design and operation. The issues surrounding global wanning concerns are discussed, along with the linkage between global warming and greenhouse gas emissions. US greenhouse gas emission inventories are reviewed, along with the role of wastewater treatment plants in reducing such emissions. It is found that process related emissions from wastewater treatment plants are less than 1% of total greenhouse gas emissions. Limited flexibility exists to reduce process-related emissions. One of the principal options is to minimize CH 4 emissions at the expense of CO 2 emissions by stabilizing biodegradable organic matter aerobically rather than anaerobically, or by capturing and combusting any CH 4 produced. The global warming potential of CH 4 is 21 times higher than that of CO 2 . Principal options for reducing greenhouse gas emissions involve selection of biosolids reuse options and energy consumption measures. Landfilling of waste biosolids should be avoided as this leads to CH 4 emissions. Agricultural reuse can reduce greenhouse gas emissions if land management practices increase soil organic carbon content and/or if crops are grown that can be used to produce renewable fuels (such as ethanol). Greenhouse gas emissions can also be reduced by energy conservation measures that reduce the use of fossil fuels, or the consumption of energy produced from them. Greenhouse gas emissions may be considered during the evaluation of alternatives for upgrading wastewater treatment plants, or as part of an overall emissions inventory.

Research paper thumbnail of Characterization of the Floc Micro-Environment in Dispersed Growth Systems

Proceedings of the Water Environment Federation, 2000

Abstract: The phenomenon of nitrogen and phosphorus removal in aerated biological reactors where ... more Abstract: The phenomenon of nitrogen and phosphorus removal in aerated biological reactors where no formal anoxic or anaerobic zones are present is referred to as simultaneous biological nutrient removal (SBNR). One possible mechanism for SBNR is ...

Research paper thumbnail of Oxygen Transfer in Moving Bed Biofilm Reactor and Integrated Fixed Film Activated Sludge Processes

Water Environment Research, Jul 1, 2018