Aerobic Granular Sludge (AGS) - An Innovation for Increased Performance and Capacity within Existing Footprint
By developing granular sludge that settle significantly better than conventional flocculent activated sludge, the innovative aerobic granular sludge process has gained tremendous interests in its capability of holding 2-3 times the biomass inventory of an activated sludge process within the same space, increasing capacity, enhancing nutrient removal, while offering energy savings.
The workshop will provide the attendees with the state of the art of the aerobic granular sludge process, and feature leading practitioners from forward-thinking municipalities/utilities, academia, consulting fields, and innovative technology providers.
The objectives of the workshop are to provide the attendees with the state of the art of the aerobic granular sludge process, including its fundamentals, worldwide applications, case studies, challenges of and design approaches to full-scale implementations, highlights of researches, and initiatives in pacific Northwest.
The workshop will also provide an opportunity through panel discussions to exchange ideas with respect to the development, assessment and implementation of aerobic granular sludge technology in existing infrastructure.
10:00 - 10:05 am: Welcome & Introductions, Dr. L. Lei, Facilitator, Jacobs
10:05 - 11:05 am: State of Art of Aerobic Granular Sludge Process and Initiatives in Pacific Northwest, Dr. H. Dave Stensel, Univ. of Washington; Dr. B. Figdore, HDR
11:00 - 12:00 pm: Approaching Aerobic Granular Sludge in Continuous Flow Processes using inDENSE® Technology. Dr. S. Murthy. NEWhub.
12:00 - 1:00 pm: Lunch Break
1:00 - 1:20: Collecting Attendee's Questions on Aerobic Granular Sludge Processes, Dr. L. Lei, Facilitator, Jacobs
1:20 - 2:15 pm: Molecular Biology Findings and Implications for Aerobic Granular Sludge Processes, Dr. M. Winkler, Univ. of Washington
2:15 - 3:00 pm: Aqua-Aerobic Systems, Inc. AquaNereda® Aerobic Granular Sludge: Worldwide Operational Experience in Full Scale Plants and the First plant in USA, Mr. M. de los Santos, Aqua-Aerobic Systems, Inc.
3:00 - 3:15 pm: Refreshment Break
3:15 - 4:15 pm: Design and Case Studies of Aerobic Granular Sludge Plants, Mr. B. Johnson, P.E., BCEE, IWA Fellow, Jacobs
4:15 - 5:00 pm: Panel Discussions, All Speakers
Speakers and presentations featured:
Dr. H David Stensel. Univ. of Washington. State of Art of Aerobic Granular Sludge Process and Initiatives in Pacific Northwest. The objectives of this presentation are to provide the attendees with a background on the fundamentals of granular activated sludge and the current progress on a pilot plant study by the University of Washington and King County to evaluate the use of sidestream granular sludge bioaugmentation to enable mainstream nitrogen removal in a short-solids retention time (SRT) flocculent activated sludge process.
The outline of the presentation is as follows:
- Characteristics of Granular versus flocculent activated sludge
- Advantages for granular versus flocculent activated sludge and combined granular/flocculent activated sludge
- Selective pressures for granular sludge growth
- Types of granular sludge applications
- Sidestream growth of granular sludge for bioaugmentation of ammonia removal
- UW/King County granular sludge bioaugmentation pilot plant project
i. Seed source and “baby granules”
ii. Start up operation and performance of sidestream granular sludge system treating anaerobic digestion centrate
iii. Performance of mainstream treatment system after granular sludge addition
Dr. Sudhir Murthy. NEWhub. Approaching Aerobic Granular Sludge in Continuous Flow Processes using the inDENSE® Technology. The use of hydrocyclones in combination with an anaerobic zone metabolic selector for densification and bioP is an innovative approach for low capital cost investment for wastewater treatment plants to improve both phosphorus removal performance and increase process capacity simultaneously. Hydrocyclones retain phosphorus-accumulating organisms in the underflow leading to stabilization in treatment systems with seasonal variation by maintaining the biomass population. In some process configurations, it can lead to granulation.
This presentation highlights the implementations of hydrocyclones and performance enhancement at Hampton Roads Sanitation District’s (HRSD) James River Wastewater Treatment Plant (JRTP) and Urbanna Wastewater Treatment Plant (UBTP), VA and the Soyen plant near Munich, Germany. The three plants have very different configurations.
The JRTP is rated at 20 MGD, utilizes a 4-stage Bardenpho configuration with an IFAS system, and had historically poor settleability prior to the hydrocyclone installation, with SVI values of 140± 34 mL/g, not associated with filaments, nutrient deficiencies, or poor monovalent to divalent cation ratios. The influent wastewater characteristics, such as soluble chemical oxygen demand (sCOD) of 250 to 350 mg L-1, are favorable and allow for seasonal biological phosphorus removal without a formal anaerobic selector.
UBTP is rated at 0.10 MGD with two 0.050 MGD parallel trains operated in a Modified Ludzack-Ettinger (MLE) configuration. Previously the UBTP was an extended aeration system with poor settling sludge due to denitrification in the secondary clarifiers. Hydrocyclones were implemented at both plants as external selectors for selectively wasting poor settling flocs while retaining dense particles for improved settleability, in addition to elucidate the extent of metabolic selection with and without a formal anaerobic selector to enhance biological phosphorus removal performance.
Finally, the BIOCOS process (a modified SBR) at the Soyen plant will also be discussed, which was converted to perform Bio-P by using an external anerobic selector as well as an external hydrocyclone.
Dr. Mari Winkler. Univ. of Washington. Microbiology and Optimization of Granule Aerobic Sludge Process for Enhancing Mainstream Nitrogen Removal Capacities at Low Costs. This talk involves providing an opportunity to exchange ideas with respect to the development, assessment and implementation of aerobic granular sludge technology in existing infrastructure. A critical limitation of the aerobic granular sludge technology is that it cannot be readily adapted to most existing activated sludge process reactor geometries, which clearly limits its broader application. Therefore, it is a challenge to find new ways how to retrofit existing plants for aerobic granular sludge technology.
This talk will focus on the microbiological aspects of granule and floc competition and on the population dynamics in these systems.
In addition, this talk will focus on the enhancement of mainstream nitrogen removal capacities at minimal costs by determining optimal conditions for promoting growth of ammonium oxidizing archaea (AOA) with Anaerobic ammonium oxidizing bacteria (Anammox) within single granules using
- Controlled laboratory reactor systems
- EPS-mimetic hydrogels embedded with AOA-Anammox microbes
- High-resolution real-time sensing modes coupled with machine learning data processing for enhanced bioreactor control mechanisms.
The aim of this talk is to establish actionable roadmaps for the further development, demonstration, and implementation of granular sludge in existing treatment facilities.
Mr. Manuel de los Santos. Aqua-Aerobic Systems, Inc. AquaNereda® Aerobic Granular Sludge: Worldwide Operational Experience in Full Scale Plants and the First plant in USA. A research partnership in the Netherlands led to the development of a first technology applying aerobic granular sludge in a full-scale wastewater treatment plant. Currently, over 30 full-scale AGS plants are operational or under design/construction worldwide.
This SBR type AGS system creates proper conditions to reliably maintain a stable granule within a single tank, without the need of a carrier, secondary clarifiers, selectors, separate compartments, or return sludge pumping stations.
The layered microbial community within the granule structure enable simultaneous processes to take place in the granular biomass, including enhanced biological phosphorus reduction, and simultaneous nitrification/denitrification, and makes the system more resistant to toxic shocks and fluctuations in chemicals, load, pH, and salinity than conventional systems. The enhanced settling properties (SVI at 30-50 mL/g) allow the system to be designed for 8 g/L of MLSS, reducing footprint by up to 75% and provideing up to 50% energy savings when compared to activated sludge systems.
The AGS technology is now entering U.S. as a promising alternative for capacity increase, retrofit, treatment upgrades with limited footprint, and enhance biological nutrient removal. To validate the technology in the US, a full-scale demonstration facility is in development and an AGS pilot unit has been constructed. Additionally, a full-scale AGS application is currently in the design stages for a municipality in Alabama.
This presentation will cover details on the granular sludge technology, the advantages that it offers, its worldwide operational experience and the efforts to introduce the technology to the US market.
Mr. Bruce Johnson, P.E., BCEE, IWA Fellow, Jacobs. Design and Case Studies of Aerobic Granular Sludge Plants. The design of Aerobic Granular Sludge (AGS) facilities falls into two major categories:
- continuous feed systems where granules are encouraged to form within a conventional activated sludge system; and,
- in sequencing batch reactors or SBRs (e.g. Nereda™).
Both of these systems rely upon, and encourage, the development of aerobic granular biomass collections. These granules have the characteristics of multiple biomass populations within them (i.e. heterotrophs and autotrophs), and are more easily retained in biological treatment systems as a result of their larger settling rates/size.
Case studies of both types of the systems at Ejby Mølle WWTP (Odense, Denmark) and Central Regional Wastewater System WWTP CRWS, Trinity River Authority, Texas, will be highlighted.
While continuous feed AGS systems can be freely designed and installed by utilities, SBR AGS systems are currently patented by DHV and sold in North America exclusively by Aqua Aerobics.
This presents challenges to the North American market for two reasons:
- sole source procurement of large process systems can be challenging in some utilities
- there are currently no publicly available tools (i.e. wastewater simulators) that can capture and confirm the design parameters provided by the vendor
It is important for the responsible process engineer to have independent confirmation of performance for professional liability concerns. This presentation will discuss design experience with the Morecombe WwTW in the United Kingdom, and how it approached working with DHV and confirming their process design for this facility.