Demonstration of Advanced Sludge Separation Treatment Technologies for Decarbonization of Wastewater Treatment Plants

Advanced Sludge Separation Treatment Technologies for Decarbonization of Wastewater Treatment Plants

Caliskaner Water Technologies, Inc.

Recipient

Woodland, CA

Recipient Location

3rd

Senate District

4th

Assembly District

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$190,957

Amount Spent

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Active

Project Status

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Project Update

The project team’s primary technical focus has been on Task 2 – Design Fabrication and Installation of Advanced Sludge Separation Technologies and Task 3 - Monitoring of Baseline Sludge Treatment System. Two of the three technologies were deployed on-site, and a performance assessment of these technologies is currently being initiated (Task 4). The project is progressing as planned, with milestones expected to be met.

The Issue

For many cities and towns, wastewater treatment plants (WWTPs) are the largest energy consumers that account for up to 3 percent of global electricity consumption and are among the most significant GHG emitters at nearly 1.57 percent of global GHG emissions. The incumbent technology, Anaerobic Digestion (AD), is a significant source of GHG emissions and is often economically unfeasible for facilities smaller than 5 million gallons per day (MGD). Furthermore, conventional sludge thickening systems rely on gravitational forces and polymers, resulting in solids capture rates of only 60-80% and higher GHG footprints compared with advanced alternatives. Current processes also fail to fully capture the latent chemical energy—approximately 1.8 kWh per pound of chemical oxygen demand—present in raw wastewater. Consequently, there is a critical need for innovative technologies that can replace inefficient incumbent processes to achieve decarbonization and move WWTPs toward net energy production.

Project Innovation

This project demonstrates three innovative Advanced Sludge Separation Treatment (ASST) technologies: the Biosolids Filtration Thickener (BFT), Suspended Air Floatation (SAF), and Ultra-Super Critical Water Oxidation (Ultra-SCWO). Unlike conventional thickening methods that rely on gravity and polymers, the BFT and SAF systems achieve higher solids capture rates (up to 99%) often without chemical additions, significantly reducing energy consumption and facility footprint. Specifically, the SAF technology uses micron-sized encapsulated air bubbles formed at atmospheric pressure, thereby eliminating the need for the energy-intensive pressurization systems used in conventional dissolved air flotation. The Ultra-SCWO system aims to replace traditional anaerobic digestion by destroying nearly all organics within seconds rather than days, thereby eliminating the need to dispose of high-volume solids. By integrating these high-efficiency technologies, wastewater treatment plants can transition to net energy production while effectively degrading organic matter.

Project Goals

Demonstrate and evaluate innovative advanced sludge separation treatment (ASST) technologies

Quantify and prove specific environmental and operational benefits for wastewater treatment plants

Promote the adoption of these high-efficiency technologies to help achieve California’s statutory decarbonization goals

Project Benefits

The implementation of ASST technologies aims to enable WWTPs to shift from energy sinks to energy producers while reducing GHG emissions by 30-45%. Advanced thickening via BFT and SAF systems achieves up to 99 percent solids capture and 40-90 percent energy savings by eliminating the need for chemical reagents and reducing footprint. The Ultra-SCWO system further advances treatment by destroying virtually all organics within seconds and generating significantly fewer byproducts, thereby eliminating the need for disposal. Beyond energy benefits, these innovations provide critical environmental protection by destroying emerging contaminants, including PFAS, microplastics, and pharmaceuticals. WWTPs utilizing these systems can achieve a 60 percent reduction in treatment footprint and at least a 15 percent decrease in operational and maintenance costs. The process also significantly reduces the volume of solid by-products—up to seven times less than conventional methods —thereby lowering transportation and disposal costs. By lowering peak electrical loads and increasing energy self-sufficiency, the project enhances grid reliability and strengthens facility resilience against outages. Finally, implementing these technologies in disadvantaged communities provides economic benefits through local operator training and infrastructure improvements that help lower ratepayer burdens.