Seidel, Alexander

Alex Seidel is a multi-disciplinary engineer with Brown and Caldwell, with experience in the wastewater and solid waste industries. He is skilled in...

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About Seidel, Alexander

Alex Seidel is a multi-disciplinary engineer with Brown and Caldwell, with experience in the wastewater and solid waste industries. He is skilled in pilot-scale research, advanced equipment design, and manufacturing for science and industry. He is most passionate about developing holistic solutions in the solids and energy space, with interests in digestion, emerging contaminants, and wastewater process RD.

Seidel, Alexander

Titles from this speaker

Impact of Carbon Choice for PdN in Integrated PdNA System with Methanol Polishing

Abstract

This paper compares the impacts of three external carbon sources (fermentate, acetate, and methanol) when applied to a pilot system modeling a method for implementing integrated partial denitrification-anammox (PdNA) for nitrogen removal at DC Water’s Blue Plains Advanced Wastewater Resource Recovery Facility (WRRF).

This paper compares the impacts of three external carbon sources (fermentate, acetate, and methanol) when applied to a pilot system modeling a method for implementing integrated partial denitrification-anammox (PdNA) for nitrogen removal at DC Water's Blue Plains Advanced Wastewater Resource Recovery Facility (WRRF).

SpeakerSeidel, Alexander

Presentation time

14:30:00

15:00:00

Session time

13:30:00

15:00:00

SessionLessons Learned from Early PdNA Implementation

Session locationRoom S504a - Level 5

TopicIntermediate Level, Nutrients, Research and Innovation

Author(s)

Seidel, Alex

Author(s)A. Seidel 1; M. Ladipo-Obasa 2 ; R. Riffat 3; C. Bott 4; H. De Clippeleir 5; A. Seidel 1;

Author affiliation(s)George Washington University 1; George Washington University 2 ; George Washington University 3; Hampton Roads Sanitation District 4; DC Water 5; George Washington University, Washington, DC 1;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159089

Volume / Issue

Content sourceWEFTEC

Word count14

IntensiCarb for Anaerobic Digestion Intensification: A Techno-economic Analysis

Abstract

Intensicarb® is a vacuum-based sludge concentration technology, that when installed to intensify anaerobic digestion at a Water Resource Recovery Facility (WRRF) could decrease hydraulic retention times (HRT) while maintaining solids retention times (SRT), providing various benefits towards process intensification. Previous work has demonstrated Intensicarb® feasibility for fermentation intensification (Okoye et al. 2022) and digestion intensification (Khadir et al. 2024) at lab scale as well as its economic feasibility for use as fermentation intensification for onsite WRRF supplemental carbon production (Armenta et al. 2023). This study presents a techno-economic analysis (TEA) of the Intensicarb® process when used to intensify mesophilic anaerobic digestion (MAD) at WRRFs of multiple sizes (10 million gallons per day (MGD), 50 MGD, and 250 MGD of influent flow). Significant reductions of overall lifecycle costs, including reductions in process volume and facility footprint were seen for all 3 facility sizes analyzed. Methodology Three facility sizes were evaluated, based on 10, 50, and 250 MGD influent flows, representing small, medium, and large facilities. This was correlated to digester solids loadings of 11,000, 54,000, and 270,000 lb/day respectively. Four scenarios of increasing intensification were developed and evaluated for each facility size. These scenarios were based on the decoupling of HRT and SRT provided by the IntensiCarb® technology. Average operating SRT was assumed to be 30 days for all scenarios, and the HRT was changed from 30 days (conventional MAD), to 15, 7.5, and 5 days with IntensiCarb®. These were designated as intensification factors (IFs) 1, 2, 4, and 6. Simplified process diagrams showing the conventional MAD process and MAD with IntensiCarb® are shown in Figures 1 and 2, respectively. Flows and loads used in each scenario were developed in Excel (Microsoft), with the assumption that volatile solids destruction was constant over the range of intensification studied (Khadir et al. 2024). Further assumptions are shown in Tables 1 and 2. These parameters were then used to develop the TEA, using a Net Present Cost approach and assuming a 30-year project lifespan. A nominal discount rate of 6% and an escalation rate of 3% were assumed (Construction Cost Index 2019-2022 2022; Guidelines and Discount Rates for Benefit-Cost Analysis of Federal Programs 2023). Costs associated with this TEA were developed based on vendor budgetary estimates for vacuum evaporators from PRAB and IWE, and AD tank mixers from Anaergia. Other equipment estimates, including conventional concrete AD tanks and associated pumps were developed based on previous Brown and Caldwell designs. Operational costs outside of labor, including electrical energy costs for pumping and mixing, sludge heating energy costs, and rehabilitation and replacement costs were developed based on the process modeling outputs and the budgetary estimates outlined above. A sensitivity analysis based on several key unit costs was developed to better estimate lifecycle costs for sites in North America with different operating costs. To simplify the analysis and provide a more conservative estimate of IntensiCarb®'s potential cost savings, two key potential benefits of the IntensiCarb® process were not included in this analysis. These were biogas recovery enhancement, and reduction of nitrogen levels in the sludge (Muller et al. 2024). Additionally, vendor estimates were used to develop physical layouts for all scenarios, which were compared on a volume and footprint basis to determine any physical space savings provided by the Intensicarb® technology. Results and Discussion The results of the TEA indicated significant reductions in process volume and footprint, particularly in larger facilities, leading to potential cost savings. These results are shown in Figure 3. The economic analysis showed that higher intensification factors generally result in lower life cycle costs, with the most substantial savings observed at intensification factors of 4 and 6. However, the benefits diminish at higher intensification levels for midsize plants due to the discrete sizes of evaporator equipment available. Life cycle costs for the 50 MGD facility are shown in Figure 4. The study concludes that IntensiCarb® technology is viable at small, medium, and large scales, with the largest savings seen at IF 6 for all sizes (27%, 26%, 16% NPC savings over conventional MAD seen at IF 6 for the small, medium, and large facilities respectively). Through a sensitivity analysis, key factors driving life cycle costs were identified, with natural gas, electricity prices, and IntensiCarb® facility construction costs causing the most impact on NPC. The baseline values for these costs, as well as their identified upper and lower bounds, are shown in Table 3. Future work should focus on empirical testing and theoretical analysis to refine cost assumptions and explore additional benefits like biogas quality improvement and nutrient recovery.

This paper was presented at the WEF Residuals & Biosolids and Innovations in Treatment Technology Joint Conference, May 6-9, 2025.

SpeakerSeidel, Alexander

Presentation time

09:10:00

09:30:00

Session time

08:30:00

11:45:00

SessionInnovations in Sludge Management: Enhancing Anaerobic Digestion and Phosphorus Control

Session number10

Session locationBaltimore Convention Center, Baltimore, Maryland, USA

TopicAerobic Digestion, Anaerobic Digestion, Biogas Utilization, Biosolids, Biosolids treatment, Class A, Dewaterability, Phosphorus recovery, struvite, electrochemical, Pilot Scale, Process Intensification, Resource Recovery, Solids Pre-Treatment, Sustainability, thermophilic, THP, CAMBI

Author(s)

Seidel, Alexander, Armenta, Maxwell, Kakar, Farokh, Al-Omari, Ahmed, Khadir, Ali, Sheculski, Chris, Santoro, Domenico, Nakhla, George, Bell, Katie, Muller, Chris

Author(s)A. Seidel1, M. Armenta1, F. Kakar1, A. Al-Omari1, A. Khadir2, C. Sheculski3, D. Santoro2, 4, G. Nakhla3, K. Bell 1, C. Muller1

Author affiliation(s)Brown and Caldwell, 1 University of Western Ontario, Canada, 2Trojan Technologies, 3USP Technologies, 4

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date May 2025

DOI10.2175/193864718825159759

Volume / Issue

Content sourceResiduals and Biosolids Conference

Word count9

Description: Moving Towards PdNA Demonstration at Blue Plains AWWTP Using Primary Sludge...

Moving Towards PdNA Demonstration at Blue Plains AWWTP Using Primary Sludge Fermentate

Abstract

This paper shows the drivers and implementation approach we plan to use for partial denitrification anammox (PdNA) integration in the existing nutrient removal system at Blue Plains advanced wastewater treatment plant. Keywords: short-cut nitrogen removal, mainstream nitrogen removal, operations, process control, PdNA, fermentate, facilities planning, infrastructure Learning Objective: Understanding the specific application needs for implementation of partial denitrification anammox technology when using fermentate as a carbon source.

SpeakerLadipo-Obasa, Mojolaoluwa

Presentation time

08:30:00

09:00:00

Session time

08:30:00

10:00:00

SessionPdNA Whole Plant Considerations

Session locationRoom S504a - Level 5

TopicIntermediate Level, Nutrients

Author(s)

Ladipo-Obasa, Mojolaoluwa

Author(s)M. Ladipo-Obasa 1; S. Fuentes 2 ; A. Seidel 3; R. Riffat 4; H. Azam 5; R. Suzuki 6; N. Passarelli 6; A. Tesfaye 6; D. Parker 7; C. Bott 8; H. De Clippeleir 9; M. Ladipo-Obasa 1;

Author affiliation(s)DC Water and Sewer Authority, Department of Civil & Environmental Engineering, The George Washington University 1; DC Water and Sewer Authority, Department of Civil & Environmental Engineering, The University of the District of Columbia 2 ; DC Water and Sewer Authority, Department of Civil & Environmental Engineering, The George Washington University 3; Department of Civil & Environmental Engineering, The George Washington University 4; Department of Civil & Environmental Engineering, The University of the District of Columbia 5; DC Water and Sewer Authority 6; DC Water and Sewer Authority 6; DC Water and Sewer Authority 6; DC Water and Sewer Authority 7; Hampton Roads Sanitation District 8; DC Water and Sewer Authority 9; 1;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159155

Volume / Issue

Content sourceWEFTEC

Word count13

PFAS Assessment of a Rotary Drum Dryer

Abstract

Introduction Biosolids drying is gaining interest as a volume reduction strategy in regions where biosolids management outlets are becoming increasingly constrained due to concerns over per- and polyfluoroalkyl substances (PFAS). However, no studies as of yet have been conducted on the fate of PFAS through a thermal dryer system. Synagro partnered with Brown and Caldwell to conduct a PFAS mass balance through a centrifuge dewatering and rotary drum dryer facility to evaluate the fate of PFAS through the system and assess potential points of PFAS transfer to the environment. Methodology A three-day PFAS sampling event was conducted the week of April 17, 2023. Process samples were taken at all inputs and outputs to the system with composite sampling over a four hour period each day. An overview of the dewatering and dryer system and PFAS sampling points is provided in Figure 1. The dewatering and dryer system was operated at roughly 2,300 dry pounds of total solids per hour for the duration of the test. Gas-phase sampling was conducted by a commercial stack sampler using an OTM-45 PFAS sampling train at the stack and prior to the regenerative thermal oxidizer emissions (RTO) control device. In addition, a fourth run was conducted on the final day of the week when the dryer was down, but the scrubber was kept in operation to evaluate if PFAS were released from cooling water in the scrubber. The PFAS data was received in October 2023 and are currently being evaluated using the data quality analysis plan developed under the Brown and Caldwell lead Water Research Foundation Tailored Collaboration program project (WRF 5111). Results and Discussion PFAS sampling data is under review and will be available for detailed comparison by 2024 WEF RBC. An initial review of preliminary findings is provided in Tables 1, 2 and 3 attached with the following findings below. - Individual PFAS were transferred from biosolids to the gas phase at a transfer rate of 50% to 92% through the dryer. - No widespread trend of PFAS accumulation in the scrubber water was observed. Individual PFAS showed a modest increase from 10% to 20%. - Eighteen individual PFAS were detected in the gas phase from the dryer, prior to treatment in the RTO, - HFPO-DA and trace amounts of three PFAS were detected in the emissions from the RTO. Field QC and prior study findings indicate HFPO-DA detection may be due to contamination/interference, more work is required to verify. - More work required to refine liquid sludge analysis and develop system-wide PFAS mass balance. Conclusions This study is the first to present data demonstrating PFAS transfer from solids phase to the process air during thermal drying of biosolids. The data suggests the thermal oxidizer is capable of providing effective PFAS destruction or removal from the gas phase. More analysis will be conducted to present PFAS partitioning through the dewatering system and evaluate the aggregate PFAS mass balance through the dewatering and drying process.

This paper was presented at the WEF Residuals and Biosolids Conference, June 18-21, 2024.

Presentation time

10:45:00

11:15:00

Session time

10:45:00

11:45:00

SessionDryer

Session number15

Session locationOklahoma City Convention Center, Oklahoma City, Oklahoma

TopicDrying, PFAS

Author(s)

Ross, John

Author(s)J. Ross1, A. Seidel1, L. Winchell1, M. Wells2, D. Song 3,

Author affiliation(s)Brown and Caldwell 1; Brown and Caldwell 1; Brown and Caldwell 1; EnviroChem Services 2; Synagro Technologies, Inc.3;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Jun 2024

DOI10.2175/193864718825159466

Volume / Issue

Content sourceResiduals and Biosolids Conference

Word count8

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Seidel, Alexander

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