Improving Energy Efficiency and Performance of Wastewater Recycling
This project’s intent is to test and demonstrate, the controlled operation of intensive high-rate algal ponds for year-round wastewater treatment. This includes low-cost harvesting of the algal biomass by a combined algal settling and membrane
MicroBio Engineering, Inc.
Recipient
San Luis Obispo, CA
Recipient Location
17th
Senate District
30th
Assembly District
$1,394,862
Amount Spent
Active
Project Status
Project Update
The project was completed in 2024. The advancements made over the course of this project set RNEW on a trajectory to provide a nature-based solution for municipal wastewater treatment that is particularly well suited for rural communities in need of conventional pond upgrades to meet lower nutrient discharge limits. This solution uses less electricity with fewer associated GHG emissions than traditional alternatives. Additionally, RNEW can be operated in a manner to use less electricity during periods of peak demand, freeing up electricity for essential functions especially during periods of peak demand.
Optimization of the RNEW process was able to decrease the amount of aeration needed by 15% over 3 years. Because of this ability to provide treatment with limited use of aeration, the electricity consumption of Recycle Nutrients Energy and Water (RNEW) is much lower than a facility of the same size using activated sludge would be. In fact, implementation of RNEW with optimization could result in up to a 66% reduction in annual energy use for a wastewater treatment facility. Based on the data collected, the savings in energy consumption for a 0.6 MGD facility like the Delhi CWD WWTP (used for this project) was projected to be about 700,000 kWh annually.
The Issue
Standard wastewater treatment methods have high power demands and are not efficient in their handling of nutrients. Algal-based wastewater treatment has the potential to simultaneously lower costs and improve process sustainability. Algal-based treatment can reduce and shape power use while also recycling nutrients and producing biofuel feedstocks from wastewater. However, algal-based wastewater treatment has reduced treatment performance in winter months, and this project is researching methods to maximize performance year-round.
Project Innovation
This project will advance the RNEW (Recycle Nutrients Energy and Water) process, which will overcome the seasonal limitation of current wastewater treatment pond processes and incorporate two-stage algae biomass harvesting by settling and filtration. The products resulting from this process are unrestricted reuse water and biomass that can be used to generate biofuels, fertilizers, and bioplastics. RNEW is suitable for both small and large communities and industries. Besides application in new facilities, aspects of the RNEW process can be used in retrofits. The technological and scientific knowledge being advanced by this project are the controlled operation of intensive high-rate algal ponds for year-round wastewater treatment. This includes low-cost harvesting of the algal biomass by a combined algal settling and membrane separation for recovery of energy, fertilizers, and reclaimed water.
Project Goals
Develop a low energy intensity wastewater treatment (WWT) process to reduce the electrical demand of WWT in California.
Develop a low-cost WWT technology so disadvantaged communities can upgrade facilities to meet discharge requirements.
Ensure that the WWT technology is robust for all seasons, reliable and can meet discharge limits year-round.
Project Benefits
This project will advance the science and engineering of algae wastewater treatment systems, to enable California wastewater plants to reduce net electricity consumption while improving plant performance and lower overall costs. The RNEW® technology has a projected 50% lower electricity consumption and 50% lower annualized capital and operating costs than the conventional activated sludge process. RNEW® can produce water that meets California's Title 22 recycled water standards.
Consumer Appeal
Consumer Appeal
The project seeks to improve the cost effectiveness of RNEW(r), to expand availability of recycled water and lower peak demand on the electrical grid.
Affordability
Affordability
The RNEW(r) technology has a projected 50% lower electricity consumption and 50% lower annualized capital and operating costs than conventional activated sludge.
Environmental Sustainability
Environmental Sustainability
If widely adopted, the estimated annual greenhouse gas emissions reduction for all cities within the San Joaquin Valley (with a population >100,000) is ~47,000 mt CO2eq per year.
Key Project Members
Dr. John Benemann
Chief Executive Officer
MicroBio Engineering Inc.
Shelley Blackwell, M.S.
Senior Scientist
MicroBio Engineering Inc.
John Coyne
Senior Environmental Engineer
MicroBio Engineering Inc
Dr. Tryg Lundquist
Professor
California Polytechnic State University, San Luis Obispo
Subrecipients
Cal Poly Corporation
Match Partners
MicroBio Engineering, Inc.
