A Preliminary Modeling Study of Biofilm Accumulation in the Water Recovery System



Journal Title

Journal ISSN

Volume Title


2020 International Conference on Environmental Systems


Bacterial biofilms are ubiquitous in wastewater systems on earth and in spacecraft, such as in the International Space Station (ISS) wastewater processing assembly (WPA), where they cause problems in the tank, solenoid valves, and pipelines. Downstream filter applications, tank cycling, and regular biocide water flushing have been used to control biofilm accumulation on board the ISS. Biofilm control is expected to be a challenge for long-term missions with a dormancy period of up to a year, as stagnant water systems are highly susceptible to biofilm growth. Flushing of the system with biocidal water has been proposed to avoid biomass problems for long-term missions. To validate the proposed flush method, a mathematical model, based on the metabolism maintenance rate of bacteria, is being developed to understand the current biofilm accumulation rate in the ISS WPA system and to calculate the biomass production rate under dormancy-like conditions. This method of quantification of biofilm can be applied as a function of nutrient inputs to guide the selection and optimization of biofilm mitigation approaches. The method can also be helpful in understanding, defining, quantifying, visualizing, and simulating the state of the water processing system during operation and after dormancy.


Angie Diaz, Amentum, US
Wenyan Li, Amentum, USA
Tesia Irwin, The Bionetics Corporation, USA
Luz Calle, National Aeronautics and Space Administration (NASA), USA
Geoffrey Angle, GeoControl Systems Inc., USA
Yo-Ann Velez Justiniano, Aerodyne Industries, USA
Mononita Nur, National Aeronautics and Space Administration (NASA), USA
Michael Callahan, National Aeronautics and Space Administration (NASA), USA
ICES303: Physio-Chemical Life Support- Water Recovery & Management Systems- Technology and Process Development
The proceedings for the 2020 International Conference on Environmental Systems were published from July 31, 2020. The technical papers were not presented in person due to the inability to hold the event as scheduled in Lisbon, Portugal because of the COVID-19 global pandemic.


biofilm, wastewater, nutrient, modeling