Sun, Yewei

Sun, Yewei

Yewei Sun was a speaker at the WEFTEC 2024 conference in New Orleans, LA October 5-9, 2024.

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About Sun, Yewei

Yewei Sun was a speaker at the WEFTEC 2024 conference in New Orleans, LA October 5-9, 2024.

Sun, Yewei

Yewei Sun was a speaker at the WEFTEC 2024 conference in New Orleans, LA October 5-9, 2024.

Titles from this speaker

Description: Combination of EBPR, Endogenous Denitrification, Partial...

Combination of EBPR, Endogenous Denitrification, Partial Nitrification/Denitrification and Anammox to Achieve Cost-effective Nutrient Removal

Abstract

To address the problem of eutrophication in the marine environment caused by excessive nutrient release and meet stringent nutrient discharge limits (e.g., TIN < 3 mg/L), a costeffective BNR (biological nutrient removal) technology is needed for equipping coastal wastewater treatment plants (WWTPs) with nutrient removal capacity. This pilot work was aimed to demonstrate how a conventional “A2O + tertiary MBBR” process can be easily modified to collectively achieve EBPR, endogenous denitrification, and Partial nitrification/ denitrification and anammox (PANDA) in one combination under novel system automation control. Nutrient discharge limits (average TIN < 3 mg/L) were met. Large amount of carbon and oxygen can be saved throughout the secondary and tertiary treatment innovation. The volume of aeration tank can be reduced.

Enhanced biological phosphorus removal (EBPR), endogenous denitrification, and Partial nitrification/ denitrification and anammox (PANDA) can be incorporated in an 'A2O + tertiary MBBR' process to achieve cost-effective nutrient removal under system automation control. Nutrient discharge limits (average TIN < 3 mg/L) were met. Large amount of carbon and oxygen can be saved throughout the secondary and tertiary treatment innovation. The volume of aeration tank can be reduced.

SpeakerWANG, JIEFU

Presentation time

09:30:00

10:00:00

Session time

08:30:00

10:00:00

SessionPdNA Whole Plant Considerations

Session locationRoom S504a - Level 5

TopicIntermediate Level, Nutrients

Author(s)

Wang, Jiefu

Author(s)J. Wang 1; Y. Sun 2 ; W. Khunjar 3; Z Wang 1; M. Winkler 4; R.K. Goel 5;

Author affiliation(s)Department of Biological Systems Engineering, Virginia Tech 1; Hazen and Sawyer 2 ; Hazen and Sawyer 3; Department of Biological Systems Engineering, Virginia Tech, Blacksburg, VA, USA 1; Department of Civil and Environmental Engineering, University of Washington 4; Department of Civil and Environmental Engineering, University of Utah 5;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159157

Volume / Issue

Content sourceWEFTEC

Word count15

Combining Metabolic, Kinetic and Physical Selection to Achieve Full-Scale Continuous Flow Densified Activated Sludge and Nutrient Removal at Robert W. Hite Treatment Facility

Abstract

Introduction: Metro Water Recovery's (Metro) Robert W. Hite Treatment Facility (Hite) in Denver, CO is permitted for a maximum month (MM) flow of 220 mgd and has two parallel liquids treatment trains including the North Secondary (NSEC). The NSEC utilizes a modified Ludzack Ettinger (MLE) process with a sidestream anaerobic reactor (SAR) to achieve nutrient removal. In 2018, Metro's facility plan identified a need for increased aerobic solids retention time (aSRT) to meet future potential total nitrogen (TN) and total phosphorus (TP) regulations (Colorado Regulation 31). To avoid costly expansion, Metro commissioned a full-scale demonstration train (NAB2) to trial densified activated sludge (DAS). This work documents findings from the full-scale demonstration facility and discusses how Metro is translating DAS into a full-scale solution at the RWHTF. Specifically, this paper will discuss factors that have led to the development and long-term operation of DAS with biological and physical selection, as well as provide insights into how particle size distribution (PSD) may be impacted by operational parameters and influence nutrient removal. Materials and Methods: DAS facility: The DAS demonstration facility (denoted as NAB2) consisted of an isolated, paired aeration basin and secondary clarifier from NSEC. Description of the facility is provided elsewhere (Avila et al., 2021). Metro operated NAB2 to test multiple distinct metabolic and kinetic selector configurations, with two primary configurations, Fig 1. A 'control' train was also operated without physical and biological selection. Routine influent/eff concentrations of organics, solids and nutrient content were determined using Standard Methods for the Examination of Water and Wastewater. PSD of the MLSS, hydrocyclone UF, and hydrocyclone OF were routinely characterized. Settling Column Testing: Settling column testing of bulk DAS ML was conducted on multiple occasions to determine the Vesilind equation settling coefficients (V0 & k) as well as the PSD. Additionally, settling properties for particle size fractions: <200µm, 200-600µm, and >600µm were characterized across a concentration range of approximately 1,500 mg/L to 6,000 mg/L. Activity Testing: Batch scale activity testing of bulk mixed liquor and three particle size fractions was used to evaluate nutrient removal rates of activated sludge in 5-gallon reactors. Analytes (NH4, NO3, NO2, and PO4) were measured with HACH TNT kits. Hydrocyclone Nozzle Testing: Hydrocyclone UF nozzle sizes ranging from 15 to 25 mm were individually tested at a target pressure of 30 psi. Flow measurements from the hydrocyclone feed and OF were recorded via flow meter. Total suspended solids (TSS) and PSD samples were collected from the RAS, OF, and UF. Process and Capacity Modeling - Data from NAB2 testing were used to develop, calibrate, and validate AB2 specific and a whole plant process model in BioWinTM and computational fluid dynamics (CFD) models of the NSEC secondary clarifiers. These models establish system capacity of existing infrastructure and design criteria for full-scale implementation. Results and Discussion: Impact of biological selection on densification: PSD of NAB2 biomass during configuration 1 (SAR-MLE) mode) stabilized into a uni-modal distribution, with median size increasing from 100 to 200 um respectively (Fig 2A). The average SVI30 for the NAB2 versus control basins were 102 mL/g and 153 mL/g respectively. PSD of NAB2 biomass during configuration 2 (SAR-A2O) mode reflected a bi-model distribution (Fig 2B). The average SVI30 for the test versus control basins were 81 mL/g and 173 mL/g respectively. Cumulatively, results suggest that improved settleability is observed when the mass fraction of granules (particles >212 um) in the sludge exceeds 15%. This was observed on multiple occasions when NAB2 operated in SAR-A2O mode with anaerobic food to microorganism ratio (F/M) being sustained between 1.0 and 3.0 lb sCOD/lb MLVSS-day. Impacts on PSD on Settling Performance and Biomass Activity: Settling velocity and compressibility were observed to increase as the particle size fraction increased (Table 1). Biomass activity results indicated that larger particle size fractions had lower denitrification and nitrification rates versus smaller particle size fractions while Bio-P activity was highest in particles greater than 200 um. These results indicate that minimizing particles sizes greater than 600 um may allow Metro to exploit high nitrification/denitrification/Bio-P rates and with superior settling and compressibility (Quoc et al., 2021). Influence of Physical Selective Pressures on PSD in NAB2 (Fig 3): Results indicated that mass flow through the UF could be reduced when the nozzle size decreases (Fig 2). This phenomenon can potentially be exploited to craft a wasting strategy focused on developing and keeping a target PSD. DAS impacts on Capacity: Stress testing indicated that NAB2 could be loaded at surface overflow rates (SORs) >700 gpd/sf and solids loading rates (SLRs) >60 pounds per day per square foot (ppd/sf) while still maintaining reliable blanket control and stable effluent TSS (Fig 4). Whole plant process and CFD modeling indicated that the densified scenario could allow Metro to successfully treat 2040 flows without needing to invest in additional aeration basins or secondary clarifiers, allowing for savings of $50 million dollars.

To meet future nitrogen and phosphorus regulations without constructing new infrastructure, Metro Water Recovery conducted a full-scale demonstration of densified activated sludge (DAS) at its Robert W. Hite Treatment Facility. This study evaluated the DAS system, focusing on metabolic and kinetic selector configurations, particle size distribution, and nutrient removal efficiency. Results include impacts of configurations, particle size, and nozzle size and projected capital cost savings.

SpeakerMaltos, Rudy

Presentation time

09:00:00

09:30:00

Session time

08:30:00

10:00:00

SessionFull-scale Intensification Experience

Session number510

Session locationRoom 343

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

Author(s)

Maltos, Rudy, Rauch-Williams, Tanja, Freedman, Daniel, Cavanaugh, Liam, Scopp, Anna, Priest, Ryan, Griborio, Alonso, Mayer, Alyssa, Noteboom, Haley, Latimer, Ron, Sun, Yewei, Khunjar, Wendell

Author(s)R. Maltos1, T. Rauch-Williams1, D. Freedman1, L.M. Cavanaugh1, A. Scopp2, R. Priest2, A. Griborio3, A.J. Mayer4, H. Noteboom5, R.J. Latimer6, Y. Sun7, W. Khunjar8

Author affiliation(s)1Metro Water Recovery, CO, 2Hazen and Sawyer, CO, 3Hazen & Sawyer, FL, 4Hazen & Sawyer, OH, 5Hazen & Sawyer, NY, 6Hazen and Sawyer, GA, 7Hazen and Sawyer, VA, 8Hazen & Sawyer PC, VA

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2024

DOI10.2175/193864718825159645

Volume / Issue

Content sourceWEFTEC

Word count24

Effect of Feast/Famine Conditions on Continuous Flow Aerobic Granulation

Abstract

In this study, continuous flow aerobic granulation was successfully achieved in plug flow reactors (PFRs) when the number of completely stirred tank reactors (CSTRs) in series decreased from 10 to 8. It was found that the feast/famine conditions of COD and NH3 always presented in the PFR despite the great influent composition fluctuation, and the morphology of the sludge will transform from fluffy flocs to granules along with the transition from feast to famine which also leads to the sludge settleability improvement. The transformation from granules to loose and fluffy flocs during feast period may attribute to the fact that those fluffy flocs possess better organic absorption capacity thus can absorb more organic during feast period to support the bacterial growth during the famine period. Besides, it was proved in this study that flocs and granules are two phenotypes of the activated sludge, and it was the feast to famine operation that caused the transformation between these two phenotypes. Nevertheless, although phenotype of the sludge could transform from flocs to granules during the transition from feast to famine conditions, it was found that an excessive famine period may lead to granules disintegration

SpeakerSun, Yewei

Presentation time

13:50:00

14:10:00

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)

R. AngelottiY. Sun,M. BrooksZ. Wang

Author(s)R. Angelotti2; Y. Sun1; ,3; M. Brooks2; Z. Wang1;

Author affiliation(s)Occoquan Laboratory, Department of Civil and Environmental Engineering, Virginia Tech1; Upper Occoquan Service Authority, VA2; Hazen and Sawyer3

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2020

DOI10.2175/193864718825157396

Volume / Issue

Content sourceWEFTEC

Word count10

Description: Full-scale Mainstream Deammonification via Partial...

Full-scale Mainstream Deammonification via Partial Nitrification-Denitrification-Anammox

Abstract

Introduction Partial nitrification/denitrification coupled with anaerobic ammonia oxidation (PdNA, PANDA) process has the potential to result in capacity, chemical and energy savings at water resource recovery facilities (WRRFs). In this process, ammonia oxidation is controlled to achieve a specific NO3/NH3 ratio. Partial denitrification driven by supplemental carbon addition (e.g., methanol) is then used to stably generate NO2--N accumulation. Anaerobic ammonia oxidizers can then remove both nitrite and ammonia to achieve effluent NH3 and TN limits. Successful PdNA/PANDA has been documented in pilot and full-scale. This work documents advancement and implementation of PANDA at the Fairfax County Noman M. Cole Pollution Control Plant (NCPCP) to achieve TN limits less than 3 mg/L. Specifically, the work will discuss full-scale results demonstrating effective anoxic ammonia removal via the PANDA mode of operation Materials and methods Full-scale reactor setup. The full-scale MBBR system was commissioned in 2013 and is comprised of six trains, five of which are currently equipped with fixed-film media and ancillary equipment. Each train includes two anoxic denitrification cells (approximately 2.4 MG in total volume) in series followed by a single re-aeration cell (approximately 0.6 MG in volume). The anoxic denitrification cells are equipped with mixers and flat screens for media retention. The re-aeration cells are equipped with medium bubble aeration diffusers and cylindrical screens. All cells are equipped with K1 media, which provide the surface area necessary for attached growth of nitrifying and denitrifying bacteria. Methanol dosing was controlled via feed-back nitrate paced addition. Ammonia and nitrate for the tertiary MBBR PANDA demonstration was provided via process control adjustments to the secondary process, including changes to step-feed configuration, DO and airflow setpoints, load paced equalization and methanol feeding. Results and discussion Full-scale results — Full-scale demonstration testing of PANDA mode commenced in Q3 of 2022 and is ongoing. Results indicated:

*Anoxic ammonia removal between 1 and 2.0 mg/L has been observed since startup and the full-scale facility has been able to maintain weekly effluent ammonia concentration below 0.5 mg/L, monthly effluent TN concentrations of between 2 and 4 mg/L and an average annual effluent TN of 2.9 during the past 12 months of operation (2023).

*Unit methanol use at the facility has decreased by approximately 20% and unit energy demand at the facility has decreased by approximately 5% relative to 2021-2022 plant operations since operating in PANDA mode.

*Full-scale demonstration has confirmed that partial denitrification/anammox is sensitive to the NO3/NH3 ratio in the MBBR influent. Optimal performance (greater than 90% anoxic ammonia removal, COD to Nitrate removed less than 4.0 and influent ammonia above 1.1 mg/L) has been observed at NO3/NH3 ratio of 3.1 to 5.1.

*The FFX NCPCP has historically observed intermittent spikes in secondary effluent ammonia concentration. Potential causes of these spikes may be attributed to load peaking and/or suppressive compounds in the wastewater. A recent ammonia spike resulted in secondary effluent ammonia of 3.6 mgNH3-N/L to the MBBR. The PANDA mode of operation reduced 2.7 mgNH3-N/L to achieve a MBBR effluent ammonia of 0.9 mgNH3-N/L and MBBR effluent TIN of 2.5 mgTIN/L at a NO3/NH3 ratio of 1.5.

*NCPCP operators have easily shifted from PANDA to conventional mode of treatment when necessary to manage outside factors that might interfere with normal operations. Cumulatively, this work is the first to effectively demonstrate full-scale deammonification via PANDA while meeting stringent nutrient limits. Ongoing efforts are focused on optimizing the NO3/NH3 ratio, stabilize phosphorus removal while continuing to reduce energy and methanol associated with nutrient removal at the NCPCP.

This paper was presented at the WEFTEC 2024 conference in New Orleans, LA October 5-9.

SpeakerPace, Gregory

Presentation time

09:30:00

10:00:00

Session time

08:30:00

10:00:00

SessionProgression of PdNA: Development to Full-Scale

Session number504

Session locationRoom 240

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

Author(s)

Pace, Gregory, Khunjar, Wendell, Sun, Yewei, Wang, Jiefu, Wang, Zhiwu, Chitrakar, Sajana, Rasel, Munshi Md

Author(s)G.J. Pace1, W. Khunjar2, Y. Sun3, J. Wang4, Z. Wang4, S. Chitrakar5, M. Rasel5

Author affiliation(s)1Hazen and Sawyer, 2Hazen & Sawyer, 3Hazen and Sawyer, 4Virginia Tech, 5Noman M Cole Jr Pollution Control Center, 5City of Springfield

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2024

DOI10.2175/193864718825159719

Volume / Issue

Content sourceWEFTEC

Word count7

Description: Leveraging Densified Activated Sludge and Partial...

Leveraging Densified Activated Sludge and Partial Nitrification/Denitrification/Anammox within an Integrated Advanced Water Treatment Facility for Large-Scale Potable Reuse

Abstract

The Los Angeles County Sanitation Districts (Districts) have been exploring options for implementing nitrogen removal at the Joint Water Pollution Control Plant (JWPCP), a 400-MGD capacity high purity oxygen activated sludge (HPOAS) facility, due to potential reuse and regulatory drivers. This paper summarizes pilot-scale demonstrations of a secondary BNR (Densified Activated Sludge, DAS) and a tertiary BNR (tertiary moving bed biofilm reactor, TMBBR). These approaches has proven successful at meeting the nitrogen removal targets and provide program enhancements, including densification and PANDA/PdNA.

The Los Angeles County Sanitation Districts are exploring nitrogen removal options at the Joint Water Pollution Control Plant (JWPCP), a 400-MGD capacity high purity oxygen activated sludge (HPOAS) facility, to address potential reuse and regulatory drivers. Two potential approaches developed were a three stage A2O configuration and a tertiary moving bed biofilm reactor. Both approaches were successfully pilot tested and demonstrated the ability to meeting nitrogen removal targets.

SpeakerSun, Yewei

Presentation time

13:30:00

14:00:00

Session time

13:30:00

15:00:00

SessionReconsidering Biological Treatment for Water Purification: Reuse-nutrient Removal-nexus I

Session locationRoom S404c - Level 4

TopicIntermediate Level, Municipal Wastewater Treatment Design, Nutrients, Potable Reuse, Water Reuse and Reclamation

Author(s)

Sun, Yewei

Author(s)Y. Sun 1; B. Danker 2 ; R. Deco 3; H. Long 3; M. Liu 4; A. Laleian 5; N. Melitas 4; B. Mansell 5; P. Ackman 6; P. Pitt 7; W. Khunjar 8; R. Latimer 9; H. Noteboom 10; R.M. Deco 3; H.C. Long

Author affiliation(s)Hazen & Sawyer 1; Hazen & Sawyer 2 ; Los Angeles County Sanitation Districts 3; Los Angeles County Sanitation Districts 3; Los Angeles County Sanitation Districts 4; Los Angeles County Sanitation Districts, 24501 Figueroa Street, Carson, CA, 90745 5; Los Angeles County Sanitation Districts 4; Los Angeles County Sanitation Districts 5; Los Angeles County Sanitation Districts 6; Hazen & Sawyer 7; Hazen & Sawyer 8; Hazen & Sawyer 9; 10; Los Angeles County Sanitation Districts 3; Los Angeles County Sanitation Districts 3;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159099

Volume / Issue

Content sourceWEFTEC

Word count19

Leveraging Glycerol-Driven and Primary-Effluent-Driven PdNA within Advanced Wastewater Treatment Facility

Abstract

Introduction The Los Angeles County Sanitation Districts (LACSD) and Metropolitan Water District of Southern California (MWD) have collaborated to evaluate the development of the Pure Water Southern California (PWSC) Program. The PWSC Program would implement a full-scale advanced water treatment facility (AWTF) to produce up to 150 million gallons per day (mgd) for indirect and potentially direct potable reuse. One of the AWTF options considered would include a new biological nutrient removal (BNR) facility followed by RO/UV/AOP. The new BNR facility would be constructed at the existing A.K. Warren Water Resource Facility (Warren Facility), which is a 400 mgd capacity high purity oxygen activated sludge facility. The AWTF and BNR upgrades are intended to achieve a nitrate <19 mg/L, prior to the RO/UV/AOP facility. Partial nitrification/denitrification/anammox (PANDA/PdNA) was identified by the PWSC team as a promising approach to intensify BNR, by facilitating reduction of supplemental carbon needs and potentially increasing TIN removal capacity, without increasing tank volume. This work summarizes findings from an ongoing multi-year pilot effort focused on validating the PANDA/PdNA concept within a large-scale reuse program. Specifically, the objectives were to: i) demonstrate the ability to achieve nutrient targets reliably by intensifying a tertiary MBBR and IFAS configuration with PANDA/PdNA; ii) validate carbon savings that can be achieved by implementing PANDA/PdNA; and iii) investigate the feasibility of incorporating primary effluent driven partial denitrification to further reduce projected operating costs associated with the PWSC Program. Methods Tertiary MBBR: A tertiary MBBR was configured as a step-feed BNR process, consisting of alternated aerobic and anoxic cells, with zone configuration and influent feed split (Figure 1). Both primary effluent (PE) and a glycerol-based supplemental carbon source (MicroC 2000) were used for supporting denitrification in anoxic zones. This flexible configuration allowed for performing both conventional BNR and PANDA/PdNA. Tertiary IFAS: The MBBR system was modified to include clarifiers to retain flocculant biomass. Additionally, a Solitax probe (Hach) was added in the last cell of the system to monitor the mixed liquor suspended solid concentration in the system. The first aerobic zone of Tertiary MBBR was converted to anoxic because the RAS feed was able to recycle sufficient NOx load into the that zone, negating the need for nitrification in that zone. Monitoring: Composite samples (24-hr) were used to monitor influent and effluent solids, organics and nutrients. Profile samples were grabbed from different cells across the system periodically to analyze for nitrogen species and organics (Hach TNT). Operational Modes: Three different operational modes were tested: 1) Hybrid conventional BNR mode in MBBR, during which both PE and glycerol were supplied to the system to perform full denitrification; 2) PANDA/PdNA mode in MBBR, during which both PE and glycerol were supplied to the system to perform partial denitrification and anoxic ammonia removal via anammox; and 3) PANDA/PdNA mode in IFAS (on-going), during which suspended biomass is retained in the system by using a clarifier. Results and Discussion Hybrid BNR Mode: The system operated in this mode from July 2022 to April 2023. Findings were reported in Sun et al., 2023. Briefly, both the ammonia target of 1 mg/L and the NOx target of 16 mg/L were achieved during hybrid BNR mode operation, confirming that a conventional BNR option could reliably achieve nutrient targets. MBBR PANDA Mode: The MBBR system was transitioned to PANDA/PdNA mode in May 2023 and operated until October 2023. Key findings are as follows:

*The system was able to reliably achieve the effluent ammonia and NOx targets of 1 mg/L and 16 mg/L, respectively (Figure 2). It was also possible to further decrease effluent TIN as low as ~ 9 mg/L, without increasing total system volume (Figure 2).

*Carbon usage was tracked during different phases of operation (Table 1). During the hybrid BNR and PANDA phases, approximately 7 to 9% of the total flow was comprised of PE. The COD addition/N removal ratio reduced from ~3.9 lb sCOD/lb NOx during hybrid BNR phase to ~1.2 lb sCOD/lb NOx during the PANDA/PdNA phase. This reduction was due to enhanced anammox activity and represents greater than 70% savings in supplemental carbon needs.

*Investigation into PdNA activity within the system revealed that partial denitrification was likely driven by both PE (first anoxic) and glycerol (second anoxic), with PE driven PdNA accounting for 3 to 7 mgN/L anoxic ammonia removal (Figure 3) and glycerol driven PdNA accounting for up to 9.4 mgN/L anoxic ammonia removal (Table 1). Batch tests confirmed that PE and internally stored carbon could be used to successfully drive partial denitrification if sufficient control of carbon, nitrate and ammonia is provided (Figure 4). PANDA/PdNA in IFAS Mode: In November 2023, the system was transitioned to operate in IFAS PANDA/PdNA mode. The IFAS phase of operation will be completed in mid-2024, the results of which and lessons learned will be presented during the conference.

The Los Angeles County Sanitation Districts are exploring nitrogen removal options to address potential reuse and regulatory drivers. A tertiary step-feed moving bed biofilm reactor (tMBBR) configuration was evaluated as an approach. The tMBBR configuration was successfully pilot tested and demonstrated the ability to meet nitrogen removal targets. It was also found that by leveraging glycerol-driven and PE-driven PdNA, aeration energy and carbon savings can be ~28% and up to 70%, respectively.

SpeakerSun, Yewei

Presentation time

11:00:00

11:30:00

Session time

10:30:00

12:00:00

SessionAnoxic Reactor Design for Low Energy BNR

Session number520

Session locationRoom 335

TopicEnergy Production, Conservation, and Management, Facility Operations and Maintenance, Intermediate Level, Municipal Wastewater Treatment Design, Nutrients

Author(s)

Sun, Yewei, Mansell, Bruce, Coracero, Ariana, Farrokh Shad, Mojtaba, Tsai, Raymond, Pitt, Paul, Khunjar, Wendell, Latimer, Ron, Danker, Bryce, Sun, Yian

Author(s)Y. Sun1, B.O. Mansell2, A.K. Coracero3, M. Farrokh Shad2, R. Tsai4, P.A. Pitt5, W. Khunjar6, R.J. Latimer7, B. Danker8, Y. Sun5, M. Farrokh Shad2

Author affiliation(s)1Hazen and Sawyer, VA, 2LA County Sanitation District, CA, 3Los Angeles County Sanitation Districts, CA, 4LACSD, CA, 5Hazen and Sawyer, CA, 6Hazen & Sawyer PC, VA, 7Hazen and Sawyer, GA, 8Hazen, CA

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2024

DOI10.2175/193864718825159618

Volume / Issue

Content sourceWEFTEC

Word count11

Description: Mechanistic Understanding of the Kinetic Difference Between the Methanol and...

Mechanistic Understanding of the Kinetic Difference Between the Methanol and Glycerol-driven Partial Denitrification Anammox in Low Nitrogen Polishing Moving Bed Biofilm Reactors

Abstract

Introduction Partial denitrification coupled with anaerobic ammonia oxidation (PdNA) process has been identified as a promising approach to intensify biological nutrient removal systems to increase total nitrogen removal capacity while reducing chemical and energy demand (Campolong, 2019; Le et al., 2019; Zhang et al., 2020). Understanding how operational factors impact PdNA is necessary to extract optimal performance at water resource recovery facilities (WRRFs) regardless of the configuration employed. For example, work performed previously (Campolong, 2019; Le et al., 2019) has shown that PdNA is impacted by multiple factors including the type of carbon utilized e.g., methanol, glycerol, acetate, etc.). This prior work hypothesized that partial denitrification results due to two main mechanisms, i) rate differential between heterotrophic nitrate and nitrite reduction due to different substrate availability and carbon sources, ii) nitrite sink due to anammox activity (Al-Omari et al., 2021). This current study provides insights into understanding how these different mechanisms may dictate partial denitrification in a low nitrogen polishing environment. Data from long term operation (417 days) of two pilot-scale MBBR treatment trains treating secondary effluent from the Noman M. Cole Jr. Pollution Control Plant (NCPCP) was used to develop a mechanistic understanding of methanol versus glycerol driven PdNA performance with a view to informing how to scale PdNA into other WRRFs. This work also provides a framework for informing design practices as related to stimulating stable PdNA. Materials and methods Reactor setup and operation: Two parallel MBBR treatment trains dosed with methanol and glycerol, respectively, were operated on site at NCPCP. In each treatment train, two 14 L working volume anoxic MBBRs filled with K1 media at a volumetric fraction of 45% were connected in series, followed by an 8 L working volume reaeration reactor filled with K1 media at a volumetric fraction of 32% (configuration simulated full-scale MBBR trains at NCPCP). K1 media with established biofilms of heterotrophs and nitrifiers from the full-scale MBBR train were used to seed the pilots. The pilots were operated for 417 days with a focus on demonstrating the ability to achieve effluent nutrient limits while reducing supplemental carbon needs. A description of performance is provided in (Sun, 2022; WANG, 2022). Model development: Kinetic analysis of PdNA was investigated by developing expressions describe denitratation (NO3--N â†’ NO2--N) and denitritation (NO2--N â†’ N2) (Glass and Silverstein, 1998). The specific nitrate uptake rate of denitratation culture (qDenitra.) can be expressed as Equation 1 according to Activated Sludge Model NO. 1 (Henze et al., 2000). Similarly, the specific nitrite uptake rate of denitritation culture (qDenitri.) can also be expressed as Equation 2. Equation 3 shows the specific nitrite uptake rate of anammox (AMX) bacteria (Bi et al., 2015). qAMX/qDenitri., qAMX/qDenitra. and qDenitra/qDenitri. as shown in Equations 4, 5 and 6 were used to compare effects of conditions on specific substrate uptake rates with a view to identifying which process might govern performance. All the kinetic parameters used in the investigation are listed in Table 1. Results and discussion Pilot results: Methanol-driven PdNA achieved an effluent TIN concentration of 2.6 +/- 0.6 mg/L and observed an average of 1.3 mg/L anoxic NH4+-N removal. Glycerol-driven PdNA achieved an effluent TIN concentration of 2.7 +/- 1.0 mg/L and observed an average of 1.3 mg/L anoxic NH4+-N removal. Results confirmed it was possible to achieve nutrient targets while also reducing supplemental carbon by 20 to 30% relative to conventional BNR. Nitrite sink by AMX governed PdNA performance in methanol fed train: Data from pilot operation were overlaid on heat maps plotting specific utilization rate ratios of denitratation, denitritation and AMX (Figures 1, 2 and 3). Results indicated that the in situ anammox substrate utilization rate (qAMX) was likely greater than the denitritation utilization rate (qDenitri) for the entire 372 days of operation period. Additionally, it was observed that anammox substrate utilization and denitratation utilization rates were similar i.e., qAMX/qDenitra ~ 1. Collectively, these results suggest that heterotrophic denitritation was outcompeted by anammox for nitrite in the methanol system. This implies that nitrite sink from anammox governed PdNA performance. Rate differential for heterotrophic denitratation versus denitritation governed PdNA performance in glycerol fed train: In contrast to the methanol train, pilot data from the glyercol train suggested that qAMX was less than qDenitri for the majority of pilot operation. Further, it was observed that qAMX was less than qDenitra while qDenitra. was greater than qDenitri. This data implies that the rate differential for heterotrophic nitrate and nitrite reduction dictated PdN performance in the glycerol train. Significance of Results The approach described in this paper can be used to help improve our understanding of existing PdNA systems to help clarify how different conditions may impact which mechanisms dictate performance.

This study explores using methanol and glycerol as carbon sources in partial denitrification coupled with anammox (PdNA) in tertiary moving bed biofilm reactors (MBBRs). Over 371 days, two MBBR trains were tested. Both achieved effluent total inorganic nitrogen (TIN) below 3 mg/L, with methanol being more cost-effective for nitrogen removal. Anammox (AMX) played a key role in nitrite sink, guiding future full-scale PdNA applications for improved efficiency and cost savings.

SpeakerWang, Jiefu

Presentation time

16:30:00

17:00:00

Session time

15:30:00

17:00:00

SessionEnhancing Nitrogen Removal: Insights Into Carbon Sources and Mechanisms

Session number420

Session locationRoom 340

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

Author(s)

Wang, Jiefu, Chitrakar, Sajana, McGrath, Michael, Sun, Yewei, Khunjar, Wendell, Pace, Gregory, Wang, Zhiwu

Author(s)J. Wang1, S. Chitrakar2, M.J. McGrath3, Y. Sun4, W. Khunjar5, G.J. Pace6, Z. Wang1

Author affiliation(s)1Virginia Tech, VA, 2Noman M Cole Jr Pollution Control Center, VA, 3Fairfax County Government, VA, 4Hazen and Sawyer, VA, 5Hazen & Sawyer PC, VA, 6Hazen and Sawyer, DC

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2024

DOI10.2175/193864718825159506

Volume / Issue

Content sourceWEFTEC

Word count23

Description: Polishing Tertiary Effluent Nitrogen Via The Synergy Between Methanol-Driven Partial...

Polishing Tertiary Effluent Nitrogen Via The Synergy Between Methanol-Driven Partial Denitrification and Anaerobic Ammonia Oxidation In Moving Bed Biofilm Reactors

Abstract

Introduction
Tertiary moving bed biofilm reactors (MBBRs) have been used as a polishing process for biological nitrogen removal (BNR) to meet low effluent TN concentration, e.g.,< 3 mg TN/L. In these applications, supplemental carbon is often needed to drive nitrate removal. Partial nitrification/denitrification coupled with anaerobic ammonia oxidation (PdNA, PANDA) process can result in capacity, chemical and energy savings throughout the secondary and tertiary processes at treatment facilities if properly applied in tertiary MBBR processes. This is because anammox is an autotrophic process can convert ammonium and nitrite to dinitrogen without external carbon while aeration requirements can be reduced because only a fraction of ammonium needs to be oxidized (Xu et al. 2020). Partial denitrification has indeed emerged as a promising approach for stimulating stable NO2-N accumulation because of the challenge in suppressing nitrite oxidizing bacteria (NOB) under the low mainstream temperature and nitrogen level (Zhang et al. 2019). Briefly, the mechanisms behind PD can be attributed to: i) imbalanced activities of NO3-N and NO2-N reductases, which can be controlled by carbon source types and dosages and HRT; and ii) selection and enrichment of denitratating community. This work documents results from piloting efforts to evaluating the feasibility of using methanol driven PdNA/PANDA to reduce carbon and aeration demand at the Fairfax County Noman M. Cole Pollution Control Plant (NCPCP) and achieve TN limits less than 3 mg/L. The objectives of this study are to: i) verify the feasibility of performing nitrogen removal in the tertiary effluent via the PdNA/PANDA with methanol as external carbon source; ii) evaluate the system performance and the effluent quality under the diurnal and seasonal influent fluctuation; iii) determine the optimal operating conditions (carbon dosages and frequencies, etc.); and iv) make recommendations for full-scale operation.
Materials and methods Reactor setup:
A MBBR treatment train dosed with methanol was operated on site at Noman M. Cole Jr., Pollution Control Plant (NCPCP) (Figure 1a). Briefly, two 14 L working volume anoxic MBBRs filled with K1 media at a volumetric fraction of 45% were connected in sequence and then followed by a 8 L working volume reaeration reactor filled with K1 media at a volumetric fraction of 32% to simulate the full-scale NCPCP MBBR train used in NCPCP. K1 media with established methylotrophs were collected from the same full-scale MBBR train (Figures 1a and b). The designed HRTs of each anoxic and aeration cell in Figures 1a and b were 19.4 min and 10.3 min, respectively. Realtime feed-forward control: Real time NO3-N, NO2-N, NH4+-N, and dissolved oxygen (DO) data of tertiary effluent from Chemscan real-time analyzer and DO probe (Figure 1b) were sent to Spyder (python 3.8) in a PC. A programmable pump receiving signals from the PC can precisely dose chemicals to the systems according to the following controller formulas: NH4+-N feed = NO3-Ninf or a setpoint (1) CODfeed = (CODfeed/NO3-Ninf)setpoint Ã— (NO3-Ninf â# ’ NO3-Neff, setpoint) + (CODfeed/DOinf)setpoint Ã—DOinf (2) Activity Testing: In-situ batch tests for AMX activity were conducted by dosing ammonium chloride at 10 mg NH4+-N /L and sodium nitrite at 12 mg NO2-N /L after isolating reactors and suspending COD dosing for one hours prior to the batch testing. NO3-N, NO2-N, NH4+-N, and sCOD were measured with Hach tubes in 0.45Î¼m filtered grab samples of reactors at various intervals of time ranging from 5 to 30 minutes for a period of 2.5 hours. qPCR analysis: Quantitative polymerase chain reaction (qPCR) was performed to quantify the copy numbers of total bacterial 16S ribosomal RNA (rRNA) gene, the 16S rRNA of Candidatus Kuenenia and hzsB gene on a QuantStudio 3 thermocycler (Applied Biosystems, Waltham, MA). Each 20-Î¼L qPCR reaction mixture contained 10 Î¼L of 2Ã— SYBRâ„¢ Green PCR Master Mix with ROX (Life Technologies, Carlsbad, CA), 1 Î¼L each of forward and reverse primers (0.2 Î¼M), 7 Î¼L molecular-grade water (Sigma-Aldrich, St. Louis, MO) and 1 Î¼L DNA template. The thermal cycling conditions for qPCR amplification were as follows: 95 â„ƒ for 2 min, 40 cycles at 95 â„ƒ for 15 s, 60 â„ƒ for 15 s, 72 â„ƒ for 20 s, melt-curve for 45 s (95 â„ƒ for 15 s, 60 â„ƒ for 15 s and 95 â„ƒ for 15 s). All qPCR runs had an efficiency between 90% and 110% with an R2 > 0.95. Each gene was quantified in duplicate with a standard curve and negative control (with water as template). Results were reported as absolute abundance (copies per gram dry weight). Results and discussion PD performance: As can be seen from Figure 2a, after the adjustment of carbon dosing by decreasing NO3-N setpoint and increasing COD/N ratios, NO3-N concentration in Cell B dropped to around 1 mg/L after 180-day operation. Meanwhile, NO2-N residual (0.7 Â± 0.2 mg/L) and stable PD efficiency (43.7 Â± 4.8%) were achieved in Cell A (Figure 2b). Le et al. (2019) reported that methanol-driven PD was only observed in batch test but not in continuous flow reactors. Conversely, in our study, stable PD was achieved after 6-month operation which indicates that culture acclimation might have played an important role, and methanol-driven PD actually can be achieved in MBBRs fed with low nitrogen concentrations. This is in line with the findings reported by Campolong (2019) who also found that methanol had a lower PD efficiency than glycerol and acetate during the startup, and that the process efficiency gradually improved over time as the community acclimated (Figure 2b) AMX activity and its contribution to total inorganic nitrogen (TIN) removal: Given the stable PD performance, strong AMX activity has been observed in the in-situ batch test (Figure 3a), which is in line with the abundance of Anammox 16S rRNA and hzsB measured by qPCR in Figure 3b. As a result, between 1.5 and 2.0 mg/L anoxic NH4+-N removal was observed and low effluent TIN concentrations (< 3 mg/L) were achieved in MBBR pilot after 6-month operation. AMX were estimated to contribute 43.4 Â± 5.5% of the TIN removed (Figure 2c). This work is one of the few where PdNA/PANDA studies were performed in secondary or tertiary processes where NO3-N concentration was well below 10 mg/L (Du et al. 2019, You et al. 2020). Figure 2c shows that methanol can be used as a suitable carbon source for PdNA/PANDA in a low nitrogen environment. Carbon savings: The Î”sCOD/Î”TIN profile in Figure 4 showed that the pilot reactor consumed 41.4% less COD for the removal of a unit TIN as compared to the full-scale MBBR operated in the same plant. Hence, methanol can be used as a more cost-effective and eco-friendly carbon source for full-scale MBBRs applied for polishing the effluent TIN.

In this study, a tertiary treatment train (moving bed bioreactor) dosed with methanol was operated on site to remove nitrogen from secondary effluent. This pilot tertiary treatment phase was operated to test the feasibility of achieving TN limits < 3 mg/L using partial nitrification/denitrification/anammox. The results indicate that it is feasible to achieve methanol-driven PdNA in tertiary MBBR with low nitrogen concentrations in the long term.

SpeakerSun, Yewei

Presentation time

08:30:00

08:55:00

Session time

08:30:00

10:00:00

TopicAdvanced Level, Municipal Wastewater Treatment Design, Nutrients, Research and Innovation

Author(s)

Sun, Yewei

Author(s)Jiefu Wang1; Wendell Khunjar2; Yewei Sun2; Greg Pace2; Ankit Pathak2; Michael McGrath3; Mujahid Ali3; Zhi-Wu Wang1

Author affiliation(s)Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA1; Hazen and Sawyer, Fairfax, VA2; Norman M. Cole Jr., Pollution Control Plant, Lorton, VA3

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2022

DOI10.2175/193864718825158495

Volume / Issue

Content sourceWEFTEC

Word count21

Description: Successful Full-scale Demonstration of Nitrogen Removal in a High Purity Oxygen...

Successful Full-scale Demonstration of Nitrogen Removal in a High Purity Oxygen Facility with No Infrastructure Modification

Abstract

The Los Angeles County Sanitation Districts (Districts) have been exploring options for implementing nitrogen removal at the Joint Water Pollution Control Plant (JWPCP), a 400-MGD capacity high purity oxygen activated sludge (HPOAS) facility, due to potential reuse and regulatory drivers. This paper summarizes a fullscale demonstration of a novel concept of utilizing HPOAS for nitrogen removal with no infrastructure modification. This approach has proven successful at providing robust nitrogen removal and provides a significant benefit to the JWPCP and potentially other HPOAS facilities.

The Los Angeles County Sanitation Districts are exploring nitrogen removal options at the Joint Water Pollution Control Plant (JWPCP), a 400-MGD capacity high purity oxygen activated sludge (HPOAS) facility, to address potential reuse and regulatory drivers. Through a full-scale demonstration of the high-purity oxygen Ludzack-Ettinger (HPOLE) process, robust nitrogen removal was achieve, indicating that HPOLE provides a significant benefit to the JWPCP and is scalable to other HPOAS facilities.

SpeakerDanker, Bryce

Presentation time

13:30:00

14:00:00

Session time

13:30:00

15:00:00

SessionSweat Your Assets Off: BNR Optimization

Session locationRoom S403b - Level 4

TopicIntermediate Level, Nutrients

Author(s)

Danker, Bryce

Author(s)B. Danker 1; P. Pitt 2 ; R. Latimer 3; P. Hsia 4; M. Liu 4; B. Mansell 5; G. Caro 5; S. Patel 5; K. Panesar 5; W. Khunjar 6; Y. Sun 7; H. Noteboom 8; N. Melitas 4; B. Danker 1;

Author affiliation(s)Hazen & Sawyer 1; Hazen & Sawyer 2 ; Hazen & Sawyer 3; Los Angeles County Sanitation Districts 4; Los Angeles County Sanitation Districts 4; Los Angeles County Sanitation Districts 5; Los Angeles County Sanitation Districts 5; Los Angeles County Sanitation Districts 5; Los Angeles County Sanitation Districts 5; Hazen & Sawyer 6; Hazen & Sawyer 7; Hazen & Sawyer 8; Los Angeles County Sanitation Districts 4; Hazen & Sawyer 1;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159005

Volume / Issue

Content sourceWEFTEC

Word count17

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Sun, Yewei

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