Aquaculture America 2024

February 18 - 21, 2024

San Antonio, Texas

AN OPEN-SOURCE METHOD FOR DEWATERING MICROALGAE CULTURES FOR USE IN LIVE FEED PRODUCTION

 Natalie  A. Neiman* , Shawna Chamberlin, Robert Holmberg, Andrew L. Rhyne

Center for Economic and Environmental Development 

Roger Williams University 

One Old Ferry Road

Bristol, RI 02809

nneiman183@g.rwu.edu

 



Microalgae cultur ing is an essential contributor to aquaculture and other industries in biotechnology. These cultures are used in the  Roger Williams University Aquaculture and Aquarium Science Lab (RWU AASL)  and Luther Hx . Blount Shellfish Hatchery to sustain filter-feeding organisms, as well as provide adequate shading in larval tanks during the culturing process . Microalgae production is a costly and time-consuming process, so it is essential to optimize growth and storage methods. Using microfiltration (MF) and ultrafiltration (UF), the total volume of liquid the microalgae cells are suspended in can be significantly reduced, creating a dewatered, cell-dense output that can be stored and fed when necessary. Utilization of MF and UF is preferable for cell viability compared to other methods of dewatering. There are several different components that affect the efficiency of these filtration processes and  this project details  ideal methods for dewatering microalgae using a single-pump small-scale crossflow filtration system.

 To fully capture the changes occurring to the algae population during filtering, a mathematical  model was developed. This model aims to test the effects of  parameters such as flow rate, culture volume, and pressure on cell count and viability. Modeling also simulated the impacts of shear stress within the MF or UF system on the microalgal cells, as high stress dramatically reduces cell viability. S imulated parameters must be  repeatedly tested  to ensure the most viable  biomass concentration. Upon dewatering, the  decrease in culture volume and increase in  cell density of the retentate  allows for  the  compact storage of microalgae

 Establishing best practices for microalgae filtration fosters the creation of a time and cost-efficient method of feeding the organisms grown in the RWU AASL and Hatchery. This will also provide a convenient method for acquiring concentrated microalgae for use in commercial hatcheries or other industry locations.