Jimenez, Jose

Jose Jimenez is a Vice President and Senior Process and Technical Specialist at Brown and Caldwell who has been involved with the functional design of numerous wastewater treatment plants across the U.S. Jose currently serves as Brown and Caldwell’s Director of Technology Innovation.

Titles from this speaker

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