Jimenez, Jose

Jose Jimenez is a Vice President and Senior Process and Technical Specialist at Brown and Caldwell. Jose currently serves as Brown and Caldwell's...

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About Jimenez, Jose

Jose Jimenez is a Vice President and Senior Process and Technical Specialist at Brown and Caldwell. Jose currently serves as Brown and Caldwell's Director of Technology Innovation.

Jimenez, Jose

Jose Jimenez is a Vice President and Senior Process and Technical Specialist at Brown and Caldwell. Jose currently serves as Brown and Caldwell's Director of Technology Innovation.

Titles from this speaker

A Journey of Upgrades and Innovations to Achieve Capacity Improvements at Metro Water Services' Central WRF

Abstract

Introduction The Central WRF has undergone significant upgrades to improve its treatment efficiency and capacity. With a rated capacity of 125 MGD and peak secondary flow of 350 MGD, the facility's treatment process includes preliminary treatment, PCs, aeration tanks (ATs), SCs, and UV disinfection. A key upgrade was the conversion of the aeration tanks from draft tube aerators to fine bubble diffused aeration and from two-pass, complete-mix reactors, to a plug-flow A/O process. This upgrade came with several unique challenges due to the sidewater depth of the tanks exceeding 30 ft. The draft tube aerators were inefficient at mixing resulting in pockets of low DO or anoxic conditions and thus reduced nitrification efficiency and promoted low DO filamentous bulking and foaming. The deep tanks were also followed by SCs with a sidewater depth of 16-ft. These conditions would result in nitrogen gas dissolving into the process water in the deep ATs that would evolve in the SCs causing poor settling and floating sludge blankets. The design criteria for diffused aeration at such depths were also not available from manufacturers or in the limited literature. The deepest diffuser submergence that manufactures could factory test their diffusers at was 23 ft. Therefore, assumptions of SOTE had to be made during design that accounted for potentially lower SOTE values than expected due to the air-side oxygen depletion during bubble transit. The assumed values were validated after startup and commissioning by performing off-gas testing. Methods Relevant tank improvements in each of the 8 ATs included anaerobic selector zones, baffle walls, a new aeration system, surface wasting stations, and degassing zones. The new aeration system included blowers, control valves and airflow meters, instrumentation, and fine bubble diffusers. The efficiency of fine-pore diffusers was calculated in clean water according to the ASCE (2006) standard and in wastewater via off-gas testing (ASCE, 2018). Plug-flow was achieved by installing RFP baffle walls in a serpentine manner and divided into 5 aeration zones as shown in Fig. 1. Since the PC effluent and RAS are added separately to the anaerobic zones, an influent chimney was used to direct the influent to the bottom of the anaerobic zone where it would come into close contact with the incoming RAS flow as shown in Fig. 2. To degas the mixed liquor before the SCs, a novel solution was implemented that included mid-depth coarse bubble aeration at the end of the aerobic zones as shown in Fig. 2. This system is critical at peak flows because the degassing that occurs in the aerated effluent channels between the ATs and SCs is significantly reduced at such short retention times. To help control and reduce nuisance foaming, surface wasting stations were installed in each AT as shown in Fig. 3. As the mixed liquor flows past the wasting station, a surface baffle directs any foam to the wasting station and is wasted from the system. Results and Conclusions The anaerobic selector zone has been instrumental in improving sludge settleability. Selector zones create an environment with a high F/M to out-select filamentous organisms, favoring floc-formers with high substrate uptake rates. The first two upgraded ATs were put in service in Jun 2022, resulting in an immediate drop in SVI as demonstrated in Fig. 4. The SVI continued to stabilize as additional pairs of upgraded ATs were put in service in Sep and Nov 2022. SVI averaged 235 +/- 92 mL/g for Oct 2021 — May 2022, and subsequently averaged 91 +/- 41 mL/g for June 2022 — Dec 2022. The SVI has also started to track with changes in F/M: when F/M is greater than 1, SVI averages 69 +/- 18 mL/g. This suggests that selector zone operation is critical for SVI stability. The new surface wasting stations also contributed to improved settleability by removing nuisance organisms accumulated in surface scum that cause foaming and bulking. Rapid reductions in the scum layer were observed after the first upgraded ATs were put in service. A comparison of the surface scum of the SCs before and after upgrades are provided in Fig. 5. As shown in Fig. 6, the average effluent ammonia concentration was approximately 2.5 mg /L (Jan 2021 — May 2022) and after the initiation of the upgrades fell to consistently below the detection limit of 0.4 mg/L (>95% of samples). As shown in the plot, the effluent ammonia has not peaked above 2 mg/L even though the plant operates at an aggressive SRT of 6-8 days year-round. Off gas testing of three ATs was carried out to assess the change in performance with different diffuser age (2, 6, and 10 months of operation). The off-gas testing results are compared to the design assumptions and clean water testing in Table 1. The assumed alpha and fouling factors used to correct the clean water performance for field conditions aligned well with the values measured in the AT with 2-month-old diffusers. The fouling factors decreased significantly for the 6- and 10-month-old diffusers. This information supported the recommendation that the diffusers should be inspected and cleaned at least annually to maintain adequate efficiency. In conclusion, the upgrades at the Central WRF, including the replacement of the draft tube aerators with a fine bubble aeration system, have significantly improved plant performance. The full paper and presentation will contain expanded discussions and all technical detail

Recent upgrades to the deep aeration tanks at the MWS Central WRF have improved sludge settleability, nitrification reliability, and reduced nuisance foam. Key improvements included anaerobic selector zones, baffle walls to reduce short-circuiting, a new aeration system, surface wasting stations, and degassing zones. To degas the mixed liquor before the clarifiers, an innovate solution was implemented that included mid-depth coarse bubble aeration at the end of the aerobic zones.

SpeakerMiller, Mark

Presentation time

16:30:00

17:00:00

Session time

15:30:00

17:00:00

SessionOptimizing Design for Increased Capacity

Session number228

Session locationRoom 349

TopicFacility Operations and Maintenance, Intermediate Level, Municipal Wastewater Treatment Design

Author(s)

Miller, Mark, Jimenez, Jose, Bauhs, Kayla, Yarosz, Douglas, Rosso, Diego

Author(s)M. Miller1, J.A. Jimenez2, K. Bauhs3, D. Yarosz3, D. Rosso4

Author affiliation(s)1Brown and Caldwell, NC, 2Brown and Caldwell, FL, 3Brown and Caldwell, TN, 4University of California, Irvine, CA

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2024

DOI10.2175/193864718825159630

Volume / Issue

Content sourceWEFTEC

Word count17

Advancing Low-Energy Biological Nutrient Removal through Low Dissolved Oxygen Operation: Is Biological Selection the Key?

Abstract

Introduction In the activated sludge process (ASP), dissolved oxygen (DO) is an important factor for aeration cost, nitrification efficiency, nutrient removal, and N2O emission. Even though, the term 'low DO' has been used in a somewhat subjective manner and can vary depending on the context and specific requirements, the overall objective of this study is to pave the way for full-scale implementation of low DO BNR through scientific investigation to systematically answer questions on the impact of DO concentrations on nitrification, denitrification, BPR, microbial ecology, and greenhouse gas emissions. This abstract presents results developed as part of the WRF No. 5083 titled 'Advancing Low-Energy Biological Nitrogen and Phosphorus Removal.' Methodology To quantify the impact and benefits of low DO operation in the capacity and performance of existing ASP, several participating facilities that were operating at low DO and high DO conditions were studied as part of this project. Long-term operational data from the facilities was assessed and compared with the baseline information collected during the literature review. Mixed liquor samples from the participating utilities were collected and assessed through lab-scale studies. Low dissolved oxygen control and batch test procedures were developed as part of the project and used to investigate the impact of low DO on biokinetic rates. This information provided a unique comparison and tabulation of important biokinetic parameters to better understand the implications of low DO BNR on plant capacity and performance. In addition, this provides guidelines for the selection of proper important biokinetic coefficients for process modeling. Results and Discussion Bench-scale, and full-scale experiments were conducted to investigate the impact of DO concentrations on nitrification, denitrification, BPR, microbial ecology, and N2O emissions with the goal to advance low DO BNR. The following biokinetic insights were collected as part of this study. Nitrification: Specific nitrification rates for ASP operating with long-term exposure to low DO conditions were approximately 60-80% of the nitrification rates at high DO as presented in Figure 1. This study concluded that long-term low DO operation results in a shift in the nitrifier community structure, with comammox, and in some case ammonia oxidizing archaea, being selected over ammonia oxidizing bacteria. Experimental results confirm that these communities selected under stable low DO operation have a higher oxygen affinity than AOB and Nitrobacter-related NOB. TIN Removal: The maximum TIN removal rates were found at DO concentrations ranging from 0.2 to 0.5 mg/L. At this DO range, the nitrification rate equals the denitrification rate, which would therefore lead to complete SND in non-carbon limiting conditions as depicted in Figure 2. At DO concentrations of less than 0.2 mg/L, the TINRR is inhibited by nitrification and at DO concentrations higher than 0.5 mg/L, TINRR is limited by denitrification. This observation may change from plant to plant since there are multiple parameters that could affect the results including floc size and porosity, mixing intensity, and microbial population. Biological Phosphorus Removal: Biological phosphorus removal is not impacted by low DO operation. Based on the experimental results from 12 full-scale plants, the low DO phosphorus uptake rates measured in this study were higher compared to the P uptake rates for high DO/ conventional systems. Phosphorus uptake rates slows down significantly when the DO is 0.1 mg/L suggesting that the KDO for PAO is lower around 0.1 mg/L. N2O Emissions: In this work, pilot and bench-scale testing demonstrated that long-term exposure of biomass to low DO does not result in an increase in total N2O emissions (Fig. 3a). Even though this study did not investigate the specific N2O production mechanisms and pathways associated with low DO BNR, the work suggests that the N2O emissions are lower than conventional high DO systems since the relative abundance of AOB and Nitrobacter-related NOB are relatively low (Fig. 3b) limiting the N2O produced via NH2OH oxidation pathway and nitrifier denitrification by AOB. In the low DO BNR systems, Nitrospira-related NOB and comammox were dominant nitrifiers suggesting they do not have the same reduction pathways of NO2 and NO to N2O and therefore produce less N2O comparable to AOB. Conclusion DO is an important parameter influencing aeration cost, nitrification efficiency, nitrogen and phosphorus removal efficiency, treatment plant capacity and N2O emission. As presented in this study, there are several WRRF that utilize low DO operation in the ASP achieving effluent water quality with respect to N and P and require less energy than conventional ASP. The DO setpoints in such plants vary depending on loading conditions, aeration controls, and operator's preferences. Therefore, selecting a single DO setpoint to represent low DO BNR is difficult. Based on the experimental results obtained during this study, low DO can be defined as the bulk liquid DO concentration or range in the aerobic zones where simultaneous N and P removal reactions occur, often ranging from 0.2 mg/L to 0.5 mg/L. Results from this study demonstrate that long-term exposure to biomass at these DO concentrations allow for biological selection of microorganisms with very high oxygen affinities.

In the ASP, DO is an important factor for cost, nitrification efficiency, and N2O emission. The objective of this study was to investigate the impact of DO concentrations on nitrification, denitrification, BPR, microbial ecology, and N2O emissions. Based on the experimental, low DO can be defined as the DO concentration or range in the aerobic zones where SND reactions occur, often ranging from 0.2 to 0.5 mg/L allowing for biological selection of microorganisms with very high oxygen affinities.

SpeakerJimenez, Jose

Presentation time

13:40:00

13:50:00

Session time

13:30:00

15:00:00

SessionMicrobial Ecology Selection Under Low DO Concentration

Session number409

Session locationRoom 253

TopicAdvanced Level, Energy Production, Conservation, and Management, Municipal Wastewater Treatment Design, Nutrients, Research and Innovation

Author(s)

Jimenez, Jose, Miller, Mark, Bauhs, Kayla, Sturm, Belinda, Wittman, Megan, Dold, Peter, Fevig, Stephanie

Author(s)J.A. Jimenez1, M. Miller2, K. Bauhs3, B. Sturm4, M. Wittman4, P. Dold5, S.M. Fevig6

Author affiliation(s)1Brown and Caldwell, FL, 2Brown and Caldwell, NC, 3Brown and Caldwell, TN, 4University of Kansas, KS, 4, 5Envirosim Associates Ltd., ON, 6South Platte Renew, CO

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2024

DOI10.2175/193864718825159576

Volume / Issue

Content sourceWEFTEC

Word count16

Biological and Physical Selection for Continuous-flow Sludge Densification

Abstract

Abstract
Biological and physical selectors used together for the accumulation and use of aerobic granules, and densified biological flocs (collectively referred to as AGS, herein) in continuously flowing WRRF (referred to as CF, herein) processes is a topic of leading-edge research and practice. This study focuses on the application and design guidelines of biological selectors to promote the growth of densified biological flocs and its interaction with physical selectors to provide selective pressure for the formation and retention of aerobic granular sludge in CF systems.
Introduction
Biological treatment for carbon and nutrient control is key for the sustainability and future of WRRF. Advancing biological technologies that allow for unlocking treatment capacity, while minimizing capital and operating costs and improving effluent quality is therefore critical. Processes that intensify CF WRRF through the controlled accumulations of AGS are a focus of research and practice. These processes intensify CF WRRF through biological and physical selection to promote the growth and retention of a biological-aggregate that seek to achieve process intensification via improvements to sludge settling velocity and SRT de-coupling. The key for the design and implementation of sludge densification can be based on the biological architecture concept, defined as form and function (or morphology and physiology). For this study the authors present three function levels of physiology/function desired for CF-AGS as presented in Figure 1. Methods Experimental and performance data presented in this study was collected from several full-scale WRRF for over two years to study biological and physical selection for CF-AGS.
Results and Discussion
Biological Selection Biological selection is defined as the accumulation of specific bacteria in aerobic granules, and biological flocs through bacteria feast and famine. Selector design and applications for bulking control in full-scale activated sludge plants have become common practice in recent years and are still worldwide the most applied engineering tool for prevention of bulking sludge in biological processes. The term biological selection is employed to describe processes where natural selection governs or limits the growth of undesirable bacterial species. The specific objective of biological selectors for process intensification is to provide the adequate feast and famine conditions to maximize the production of EPS for biological aggregation while preventing the excessive growth of filamentous organisms. Figure 2 (left) shows the impact of biological selector's F/M, as a condition to express feast, on densified biological flocs. The high F/M in the biological selector reduces diffusion-limited growth by promoting substrate penetration into the biological aggregate core, supporting the uptake of readily biodegradable substrate and creating desired microenvironments within the floc structure, which is critical to form densified biological flocs. The high feast conditions in the selector causes elevated production of EPS resulting in an increase floc diameter and density which are key to sludge densification and AGS formation.
Protein-based EPS predominantly comprise aerobic granules and are considered to be more adhesive than carbohydrate-based EPS. Therefore, selecting environmental conditions to promote the production of protein-rich EPS is expected to enhance biological-floc densification. As depicted in Figure 2 (right), the high F/M conditions resulted in higher concentration of protein-rich EPS compared to the concentration of carbohydrates in the EPS matrix resulting in lower SVI and larger floc diameter for densified biological flocs. A goal of biological selection is to promote storage-product accumulating heterotrophic bacteria growth, which seems to be the key to sludge densification and ultimately, AGS formation. These bacteria condense excess organic substrate as internal storage products and produces EPS. Storage-product accumulating heterotrophic bacteria have a competitive advantage over ordinary heterotrophic bacteria in WRRF processes that promote bacteria feast and famine. During feast conditions, storage-product accumulating heterotrophic bacteria consumes an organic substrate at a rate that is greater than that of their growth; hence, bacteria can condense excess organic substrate as internal storage products that can be hydrolyzed during famine conditions. Therefore, it can be argued that storage-product heterotrophic bacteria can used their stored carbon as electron donor for denitrification during low carbon conditions, which is a topic of interest for researchers and practitioners. Figure 3 presents specific denitrification rate results, with no external carbon addition, from mixed liquor samples at different biological selector F/M conditions expressing higher denitrification rates for the samples exposed to higher feast conditions indicating higher storage-product. PHA data at different biological selector F/M conditions will be provided with the full manuscript.
Physical Selection Physical selection occurs through devices such as rotary-drum screens, hydrocyclones and surface wasting devices that are, typically, incorporated with waste solids strategies. It is well understood that washing out smaller and lighter flocculent particles can aid to AGS formation. However, physical selectors to proper function as such, need the aid of biological selection for optimum process intensification results. Figure 4 (left) presents the impact of F/M on the particle size distribution for biological selection only and biological and physical selections. Two main points can be concluded from these figures: 1. F/M impacts the particles size distribution in systems with biological selection only and biological and physical selection. 2. Despite of the F/M, biological selection seems to be the key for densified biological floc formation; more so than physical selectors. Sieve analysis from a hydrocyclone, presented in Figure 4 (right), show the particle sizes selection in the underflow and overflow with greater the fraction of 200 Î¼m particles being retained in the system via the underflow; resulting in lower SVI and better settleability. Figure 5 shows the hydrocyclones can allow for SRT de-coupling providing an ecological niche for slow-growing bacteria (e.g., storage-product accumulating heterotrophic bacteria and autotrophic nitrifying bacteria) where, as presented in Figure 4, a higher nitrifier (SNR) and phosphorus release and uptake rates (PRR and PUR) activity in the underflow (containing 70% granules) of the hydrocyclone compared to the waste activated sludge overflow (containing 35% granules) allowing clear opportunities to de-couple SRT for densified biological flocs and AGS.
Conclusions
Keys for biological architecture for CF-AGS can be summarized as:
- Granule Generation. Biological selection strategies including selector design, feast-famine conditions and SRT control.
- Granule Retention. Physical selectors, such as hydrocyclones and screens, for the controlled retentions of densified biological flocs and AGS in BNR systems.
- Granule Management. Management of densified sludge to increase biologically active fraction and reaction rates of BNR organisms.
The key to engineering CF-AGS is the control of the biological architecture and thereby build engineering approaches based on functional levels.

This study focuses on the application of biological selectors to promote the growth of densified biological flocs and its interaction with physical selectors to provide selective pressure for the formation and retention of AGS in CF systems.

SpeakerJimenez, Jose

Presentation time

16:30:00

16:55:00

Session time

15:30:00

17:00:00

TopicMunicipal Wastewater Treatment Design, Nutrients

Author(s)

Jimenez, Jose

Author(s)Jose Jimenez1; Pusker Regmi1; Mark Miller1; Sudhir Murthy2; Belinda Sturm3

Author affiliation(s)Brown and Caldwell, Maitland, FL1;NewHub Corp., Herndon, VA 2; University of Kansas, Lawrence, KS3

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2022

DOI10.2175/193864718825158734

Volume / Issue

Content sourceWEFTEC

Word count9

Evaluating Nitrogen Oxides Transformations at Low Dissolved Oxygen Concentrations

Abstract

This paper was presented at WEFTEC 2023 in Chicago, IL.

This study evaluates nitrogen oxides transformations at low-DO concentrations. Microbial community data coupled with biokinetics, and detailed process modeling facilitated an analysis of the fundamental mechanisms associated with SND and its interaction between biomass and intermediate nitrogen oxide species and readily biodegradable COD.

SpeakerJimenez, Jose

Presentation time

08:30:00

08:50:00

Session time

08:30:00

10:00:00

SessionLow Carbon BNR Fundamentals and Controls

Session locationRoom S502 - Level 5

TopicAdvanced Level, Facility Operations and Maintenance, Municipal Wastewater Treatment Design, Nutrients

Author(s)

Jimenez, Jose

Author(s)J. Jimenez 1; J. Boltz 2 ; M. Miller 3; K. Bauhs 5; B. Sturm 6; B. Rittmann 7; J. Jimenez 1;

Author affiliation(s)Brown and Caldwell 1; Woodard and Curran 2 ; Brown and Caldwell 3; Brown and Caldwell 5; University of Kansas 6; Arizona State University 7; Brown and Caldwell 1;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159062

Volume / Issue

Content sourceWEFTEC

Word count10

Improving Clarifier Models by Describing Extracellular Polymeric Substances

Abstract

Improved settleability in activated sludge processes is an essential feature of new innovations. To accelerate the adoption of such technologies, the ability to link operational conditions with settling characteristics is needed to support process design and prediction of improvements in settleability. The previous works indicated that the threshold of flocculation (TOF) (Mancell-Egala et al., 2017a), which describes the collision efficiency of particles, was successfully introduced as a simple experimental method to calculate the flocculent settling coefficient (rp) in 1-D clarifier models and to enhance the ability to predict clarifier effluent solids. TOF also showed to have a clear relationship with effluent quality making it a useful operational parameter to detect flocculation limitations. In addition, extracellular polymeric substances (EPS) quality, most often expressed as a protein over polysaccharides ratio has been linked to flocculation behavior, densification and granulation (McSwain et al., 2005). This knowledge was used to develop an empirical function between the composition of (EPS) expressed as EPS-TKN/COD and TOF. This relationship between EPS composition and TOF was introduced as a means of linking biological process models (i.e. Sumo2C model) and 1-D clarifier models (Ngo et al., 2021b). Essential for this approach is the prediction of EPS amounts and quality from process models as a function of feast-famine, and other operational conditions as this defines settling behavior. This paper discusses three approaches for EPS prediction from process models and will provide insights on 2 which type of EPS modeling might be needed for different purposes. While this abstract describes different datasets tested for the different models, the full paper will provide a full comparison of the three models on the full-scale dataset collected at Blue Plains

This paper discusses three approaches for EPS prediction from process models and will provide insights on which type of EPS modeling might be needed for different purposes. With optimized EPS quality prediction, it is possible to simulate settling improvements based on changes in operational conditions both based on a wide range of SRT as well as based on feast-famine driver. The latter will help to accelerate the adoption of intensification technologies.

SpeakerNgo, Nam

Presentation time

10:35:00

10:50:00

Session time

10:30:00

12:00:00

SessionPushing the Boundaries of Our Biological Models

Session locationRoom S404a - Level 4

TopicFacility Operations and Maintenance, Intermediate Level, Municipal Wastewater Treatment Design, Research and Innovation

Author(s)

Ngo, Khoa Nam

Author(s)N. Khoa Nam 1; T. Wadhawan 2 ; B. Sturm 3; J.P. Boltz 4; J. Hinojosa 5; A.N. Massoudieh 6; I. Takacs 7; J. Jimenez 8; H. De Clippeleir 9;

Author affiliation(s)District of Columbia Water and Sewer Authority 1; Dynamita SARL, France 2 ; University of Kansas 3; Woodard & Curran Arizona State University, USA 4; District of Columbia Water and Sewer Authority 5; Catholic University of America 6; Dynamita SARL, France 7; Brown and Caldwell, USA 8; District of Columbia Water and Sewer Authority, USA 9;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159190

Volume / Issue

Content sourceWEFTEC

Word count9

Kinetic Considerations for Metabolic Selectors Design for Process Intensification

Abstract

WEFTEC, the largest water event of its kind in North America, offers water quality professionals the best in water quality education and training. With almost 200 technical sessions, workshops, mobile sessions, local facility tours and 1,000+ exhibitors, it is the premier water conference! The WEFTEC technical program is selected through a rigorous, peer-review process, ensuring that attendees experience the highest-quality education. WEFTEC speakers are experts and innovators, leading the way in water quality. The following paper was presented at WEFTEC 2020.

SpeakerJimenez, Jose

Presentation time

13:30:00

13:50:00

Session time

13:30:00

14:30:00

SessionKinetic Considerations for Granulation and Densification

Session number401

TopicMunicipal Wastewater Treatment Design, Nutrients, Research and Innovation, Resilience, Disaster Planning and Recovery

Author(s)

J. JimenezP. RegmiB. SturmM.W. Miller

Author(s)J. Jimenez1; P. Regmi1; B. Sturm2; M.W. Miller1;

Author affiliation(s)Brown And Caldwell, FL1; Department of Civil, Environmental and Architectural Engineering, University of Kansas2

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2020

DOI10.2175/193864718825157395

Volume / Issue

Content sourceWEFTEC

Word count10

Description: Model-based Investigation of the Fate and Transport of Internal and External Carbon...

Model-based Investigation of the Fate and Transport of Internal and External Carbon Sources to Drive Partial deNitrification (PdN)-based Nitrogen Removal Processes

Abstract

This paper was presented at WEFTEC 2023 in Chicago, IL.

SpeakerAl-Omari, Ahmed

Presentation time

11:30:00

11:45:00

Session time

10:30:00

12:00:00

SessionPushing the Boundaries of Our Biological Models

Session locationRoom S404a - Level 4

TopicFacility Operations and Maintenance, Intermediate Level, Municipal Wastewater Treatment Design, Research and Innovation

Author(s)

Al-Omari, Ahmed

Author(s)A. Al-Omari 1; P. Regmi 2 ; T. Wadhawan 3; M.L. Bachmann 4; K. Bauhs 5; J.A. Jimenez 7; I. Takacs 8; CB Bott 4; A. Al-Omari 1;

Author affiliation(s)Brown and Caldwell 1; HRSD 2 ; Dynamita 3; HRSD 4; Dynamita 5; Dynamita 7; Dynamita 8; Dynamita 4; Brown and Caldwell 1;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159193

Volume / Issue

Content sourceWEFTEC

Word count22

Sludge Densification and Low DO BNR: Anaerobic Selectors are the Key!

Abstract

Intensification of wastewater treatment aims to create higher treatment capacity while reducing energy demand. Low dissolved oxygen (DO) operation can reduce energy costs, but there are concerns about process performance, particularly sludge settleability. Three phases of experimentation were completed on two bench-scale treatment configurations to compare sludge settleability and microbial kinetic rates: 1. High DO, 2. Low DO and 3. Low DO, with an extended anaerobic HRT. Excellent sludge settleability was obtained in the A/O configuration (average SVI 83 ± 5 mL/g) at low DO concentrations of 0.3 – 0.6 mg/L. Whereas, an A2 /O configuration experienced filament growth and sludge bulking. When the HRT was increased to 1.5 hour anaerobic HRT and 0.5 hour anoxic HRT, the A2 /O train was able to achieve good sludge settleability (average SVI 101 ± 7 mL/g).

Low dissolved oxygen (DO) operation is an attractive approach compared to typical aeration levels of 1.5 - 2 mg/L. However, there are concerns for process performance, specifically sludge settleability and lower microbial kinetic rates. Two bench-scale treatment plant configurations (A2/O and A/O) were operated at high and low DO. An Excellent sludge settleability (SVI 101 ï‚± 7 mL/g) was achieved at low DO concentrations with a longer anerobic HRT of the selector zone.

SpeakerSturm, Belinda

Presentation time

14:30:00

14:45:00

Session time

13:30:00

15:00:00

SessionAdvancing Low-energy Biological Nitrogen and Phosphorus Removal Through Low DO Operation

Session locationRoom N426b - Level 4

TopicAdvanced Level, Municipal Wastewater Treatment Design, Nutrients

Author(s)

Sturm, Belinda

Author(s)B. Sturm 1; M. Wittman 1 ; Y. Hiripitiyage 2; J. Jimenez 3;

Author affiliation(s)University of Kansas 1; University of Kansas 1 ; University of Kansas 2; Brown and Caldwell 3;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159077

Volume / Issue

Content sourceWEFTEC

Word count12

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