AC25 Biosolids and Energy Track Bundle

CWEA Member: $85.00
Non-Member: $110.00

2.0 contact hours towards CWEA's ECI, certifications.
This series includes the following 50 minute sessions. 

Session 1: Advancing Solids Thickening Through Suspended Air Application
In a recent project funded by California Energy Commission (CEC), an innovative thickening process -Suspended Air Flotation (SAF®)- was selected to be tested at demonstration scale. SAF® process presents a compelling alternative to traditional thickening methods considering its potential to reduce energy consumption and to separate emerging contaminants such as Per- and polyfluoroalkyl substances (PFAS).

The SAF technique employs a suspension of micron-sized air bubbles, ranging from 7 to 50 µm, in water to attain a volumetric air content of 40 to 50%. These bubbles are coated with a thin layer of soap film derived from an electrically charged anionic or cationic surfactant. The charged bubbles offer a substantial interfacial area for the adsorption of oppositely charged flocculated wastewater solids. In practice, suspensions of charged bubbles are introduced into the flotation tank to interact with wastewater solids. The solids then ascend to the surface and are skimmed off. The clarified effluent is recirculated to the headworks.
SAF enhances traditional thickening methods like Dissolved Air Flotation (DAF) by eliminating the need for dissolved air, thus obviating the requirement for pressurization systems, recirculation pumps, compressors, and airlines, leading to considerable energy savings. SAF's capability to manage high solids loads also results in substantial footprint and power savings, high solids recovery (up to 99%), and a high solids loading rate (up to 40 lb/ft2/hr). Moreover, no polymer is needed to thicken sludge to 4% solids. Owing to these benefits, adopting SAF technology can lead to an energy savings of up to 90% compared to its conventional counterparts, such as DAF.
This presentation will assess this novel technology, its performance, present results from case studies, and elaborate on the potential of this technology for PFAS separation.

Learning Objectives:
Define the suspended air flotation technology (SAF) and difference between dissolved air flotation (DAF) technology
Demonstrate the advancements of SAF technology for various case studies including thickening of Advanced primary treatment solids and secondary solids
List the important criteria for the design and operational challenges of the SAF technology"

Session 2: Anaerobic Digestion of Organics: Industry Drivers Overview of Two Case Studies for CHP and RNG
This presentation will discuss the diversion of organics, such as food waste and the co-digestion of these wastes with anaerobic digestion which generated biogas, a beneficial byproduct. Doing so allows reduction in landfill volumes and stabilization of the waste suitable for land application. The stabilization process, when accomplished with anaerobic digestion, generates biogas, a beneficial byproduct.

The presentation will include an overview of industry trends, including regional trends in State of California for organics diversion requirements. Other industry drivers that will be covered will include greenhouse gas emissions reductions, state and federal financial incentives, and drivers for renewable energy production.

When organic waste is diverted to a wastewater treatment facility, the organics can be co-mingled with municipally generated sludge in anaerobic digestion (i.e., co-digestion). This allows for existing infrastructure to be utilized for both wastewater treatment and landfill diversion while generating a biosolids product and digester gas. The produced biogas can be utilized as a fuel source for a process heating boiler or in a combined heat and power system or renewable natural gas.

Finally, the presentation will include case study overviews of two functioning wastewater treatment facilities with anaerobic digestion, both which are receiving significant quantities of organic wastes to generate biogas from co-digestion. One facility is utilizing biogas produced in a combined heat & power (CHP) for use at the facility and has achieved net zero operations beginning in 2022. The second facility facility has a very large high strength waste program with over 19,000 loads received annually. The biogas from this facility is processing the biogas into renewable natural gas (RNG) for pipeline injection which generates over $6M annually.
Learning Objectives:
1. Gain understanding of the industry drivers for organics diversion and resource recovery programs.
2. Learn about two functioning full-scale wastewater treatment facilities with anaerobic digestion, both which are receiving significant quantities of organic wastes to generate biogas from co-digestion.
3. Define the concept the organics diversion, such as food waste and the co-digestion of these wastes with anaerobic digestion which generated biogas and potential value of this renewable fuel."

Session 3: Resilient Resource Recovery at the Encina Water Pollution Control Facility
Encina Wastewater Authority's plan for resilient resource recovery at the Encina Water Pollution Control Facility will be presented. The plan focusses on having a reliable energy supply to treat wastewater and recover biosolids and energy for beneficial use. Having adequate anaerobic digestion capacity and enhancing its performance for more biogas is an integral part of the plan. Converting solids to biogas decreases the amount of biosolids sent to the dryer and reduces its energy demand. Using biogas to fuel combined heat and power (CHP) units and/or producing renewable natural gas (RNG) while complying with increasingly stringent air permit regulations will be discussed. Ultra-low emissions CHP units being considered include non-combustion fuel cells and flameless-combustion linear generators. The microbial hydrolysis process (MHP) using the hyper-thermophilic bacteria caldicellulosiruptor bescii will enhance the anaerobic digestion project to convert cellulose into biogas. Recuperative thickening will increase the capacity of the existing digesters by increasing the solids retention time (SRT). The reduction in solids concentration in the digesters because of the increased volatile solids reduction (VSR) from the addition of the MHP will balance the increase in solids concentration from the operation of recuperative thickening. The resulting solids concentration will be low enough to enable effective mixing with the existing digester mixing system. The enhanced anaerobic digestion system will produce more biogas and less biosolids. Producing more biogas and fueling ultra-low emission CHP units will contribute to energy resiliency by decreasing the dependence on utility supplied natural gas and electricity.

Learning Objectives:
Upon completion, participants will be able to list the components in a resilient water resource recovery facility.
Upon completion, participants will be able to describe how anaerobic digestion is an integral part of resilient resource recovery.
Upon completion, participants will be able to define the microbial hydrolysis process and explain how it enhances anaerobic digestion."

Session 4: Maximizing Biosolids Value: Post-Upgrade Optimization and Market Development
This presentation explores the optimization of new solids handling facilities and the creation of marketable biosolids products, drawing insights from two major utilities: Hampton Roads Sanitation District (HRSD) and JEA.

HRSD’s Atlantic Treatment Plant (ATP) transitioned from Class B to Class A biosolids production by commissioning a Cambi thermal hydrolysis process (THP) skid in mid-2020. This transition resulted in increased solids capacity and improved final dewatering performance. The presentation will delve into the startup and optimization process, highlighting lessons learned and how these upgrades have prepared HRSD to adapt to future regulatory changes.

Initial startup required ATP to disinfect digesters and all associated piping. The first digester was filled with heated disinfected non-potable water and seed from DC Water’s digesters. The approach to ramping up thermally hydrolyzed sludge feed started at 50% of DC Water’s loading rate and increased over several weeks.
Using existing dewatering centrifuges, the final dewatering cake solids improved from 14-16% total solids (TS) to 30% TS after THP implementation and optimization. Curing pilots using the 30% cake and a windrow turner determined the most efficient method for producing a low-odor, aerobically cured product. Lessons from 2023 pilot studies have been applied to full-scale curing operations initiated in early 2024.

JEA, one of Florida’s largest utilities, has proactively planned for the future of their biosolids program. In 2017, JEA’s master plan recommended decommissioning the old thermal drying system and outsourcing Class B dewatered cake processing to a third-party. However, this dependence led to uncertainties in costs and regulatory compliance.

In 2020, JEA revised their strategy, recommending a new regional biosolids handling facility at the Buckman Water Reclamation Facility (BWRF). This facility, designed to handle solids from all 12 JEA-owned water reclamation facilities, includes advanced thickening and dewatering equipment, two large thermal drum drying systems, and infrastructure for high-quality pellet production. These upgrades provide JEA with the flexibility to pivot as regulatory drivers change and new market opportunities arise.

The presentation will discuss innovative strategies employed by JEA, including a pilot of an in-line high-shear dynamic mixer to re-wet dewatered cake solids, reducing transportation costs and capital expenses.
Learning Objectives:
Describe the startup and optimization process of thermal hydrolysis and its impact on biosolids capacity and quality.
Explain approaches to evaluating and upgrading biosolids handling facilities, focusing on infrastructure, process reliability, and market development.
Identify key lessons learned in the production and market development for biosolids products."

Registrants who view the live webinar to see the slides and hear the audio and then enter the correct attention check code (directions below) will receive 2.0 contact hours towards CWEA's certification:ECI

To receive your contact hours for viewing the recording, you will need to view each video in the series. Upon completion of the last video in the series, the system will automatically unlock the attention check code for you view. The two (2) different attention check codes that will be displayed, and you will need to enter these codes as 1st attention check code – 2nd attention check code (XXXX-XXXX) in the Attention Check Code component under the "Contents" tab.  

Please note, all user activity of CWEA certification holders on the Online Wastewater Education Network is subject to the CWEA Code of Ethics standards for professional conduct and ethics. Certification holders should receive credit for a training only once within the same contact hour period. Any attempt to undermine the certification process may be subject to ethics procedures and possible sanctions. It is not possible to receive contact hours for both attending the live webinar and viewing the recording.  

Once you have entered the correct attendance check codes, you will be able to create and download an electronic certificate of completion under the "Contents" tab.