Wankmuller, David

David Wankmuller is a Process Engineer at Hazen and Sawyer with 12 years of experience in wastewater treatment facility design and process optimization. His main areas of interest include real-time process controls/optimization, sidestream deammonification, and blower/aeration design.

Titles from this speaker

Description: Application of Real-time Process Control and Post-anoxic Denitrification via...

Application of Real-time Process Control and Post-anoxic Denitrification via Internally Stored Carbon to Achieve Low TN Discharge Limits

Abstract

The North Durham Water Reclamation Facility (NDWRF) is a 20 mgd advanced biological nutrient removal (BNR) treatment facility, owned and operated by the City of Durham, NC that discharges to Falls Lake. In 2016 the facility began implementing state of the art control strategies in concert with excellent operational practices to reduce their effluent TN from approximately 6.0 mg/L in 2016 to 2.0 mg/L in 2019. From 2019 through 2022 the facility has averaged an effluent TN of 1.9 mg/L. Staff has been continuously optimizing the facility, pushing the limits of conventional treatment technologies. The NDWRF currently implements the following state of the art control strategies to reduce effluent TN and TP below typical conventional treatment limits: • Feed forward and feedback ammonia based aeration control (ABAC) • Nitrate based carbon addition • Diurnal ammonia based primary effluent equalization • Automatic SRT control utilizing solids analyzers • Sidestream Equalization This paper will i) detail the advanced control strategies the facility currently implements and the necessary operator maintenance/intervention necessary to ensure the programs run smoothly, and ii) demonstrate how process control has allowed operators to reduce supplemental carbon demand by leveraging internal carbon driven denitrification

The North Durham Water Reclamation Facility (NDWRF) is a 20 mgd advanced biological nutrient removal (BNR) treatment facility, owned and operated by the City of Durham, NC. In 2016 the facility began implementing state of the art control strategies in concert with excellent operational practices to reduce their effluent TN from approximately 6.0 mg/L in 2016 to 2.0 mg/L in 2019. From 2019 through 2022 the facility has averaged an effluent TN of 1.9 mg/L.

SpeakerWankmuller, David

Presentation time

09:10:00

09:30:00

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)

Wankmuller, David

Author(s)D. Wankmuller 1; J. Dodson 2 ; D. Wankmuller 1;

Author affiliation(s)Hazen and Sawyer 1; City of Durham 2 ; Hazen and Sawyer 1;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159063

Volume / Issue

Content sourceWEFTEC

Word count19

Description: In-Tank Carbon Generation as a Primary Benefit of RAS and MLSS Fermentation for...

In-Tank Carbon Generation as a Primary Benefit of RAS and MLSS Fermentation for Stabilizing Biological Phosphorus Removal Performance

Abstract

As effluent nutrient limits get more stringent, water resource recovery facilities (WRRFs) will continue to need to implement biological nitrogen (N) and phosphorus (P) removal. BPR systems in particular are susceptible to upset and many plants struggle to maintain BPR year-round because of a multitude of factors including, insufficient bioavailable carbon for PAOs, suboptimal aeration control, solids recycle impacts, excessive solids retention times, suboptimal pH operation, and secondary phosphorus release. Recently, it has been suggested that current BPR designs are inadequate for stable performance and that sidestream RAS fermentation is needed for stable BPR (Barnard et al., 2017). The authors propose that RAS fermentation selects for unique BPR organisms (e.g., Tetrasphaera) that can perform anoxic P uptake and also ferment in the presence of deeply anaerobic conditions redox conditions. Barnard et al., 2017 have also suggested that the influent wastewater characteristics can become irrelevant if RAS fermentation is implemented. Interestingly, recent work has shown that the microbial community in conventional BPR systems has less diversity than sidestream RAS or MLSS fermentation systems; however, the functional community (primary organisms responsible for BPR) were similar regardless of configuration (Onniss-Hayden et al., 2019). These authors were also careful to suggest that the "superior" performance of RAS/MLSS fermentation systems may be due to positive bias in their comparison of facilities. Given these findings, it is still not clear to practitioners what may be driving RAS/MLSS fermentation systems to have stable BPR. This work investigates the underlying reasons for scenarios where implementing RAS or MLSS fermentation as part of a flexible BNR design can help to stabilize BPR. Specifically, this work documents how RAS/MLSS fermentation can be used to ensure that sufficient carbon is provided to a BPR system that is subjected to shifts in wastewater characteristics in response to peak flow conditions and cold temperatures.

This work investigates the underlying reasons for scenarios where implementing RAS or MLSS fermentation as part of a flexible BNR design can help to stabilize BPR. Specifically, this work documents how RAS/MLSS fermentation can be used to ensure that sufficient carbon is provided to a BPR system that is subjected to shifts in wastewater characteristics in response to peak flow conditions and cold temperatures. Historical data, profile sampling, phosphorus release batch tests, and 48-hour fermentation batch tests were performed at two facilities to determine the carbon generation potential of the MLSS and RAS.

SpeakerWankmuller, David

Presentation time

14:00:00

14:15:00

Session time

13:30:00

15:00:00

SessionBringing It All Together: Guide to Designing and Implementing S2EBPR Processes

Session number502

TopicFacility Operations and Maintenance, Municipal Wastewater Treatment Design, Nutrients

Author(s)

David Wankmuller