Engineers Apply Water Monitoring System to Preserve Filtering Membrane

Reverse-Osmosis filters
Drexel engineers and American Water are using a new test of seawater to help slow the destructive growth of biofilm on Reverse-Osmosis filters like the ones pictured here.

Researchers in Drexel University’s Environmental Engineering Department are collaborating with American Water to apply a new test that is intended to extend the lifespan of seawater filtering membranes by predicting the growth of damaging biofilm on them. The test, called Bioluminescent Saltwater Assimilable Organic Carbon (AOC), will help to measure the amount of biodegradable organic matter in seawater and enable researchers to predict the level of biological fouling –formation of biofilm- that could occur on the filtering membrane. American Water developed the AOC test, which will also help to reduce Reverse-Osmosis (RO) membrane fouling in the water desalination process.

“This research will enable engineers to design and operate systems more economically and to use energy efficiently,” said Dr. Charles Haas, LD Betz Professor of Environmental Engineering, department head of Civil, Architectural and Environmental Engineering and Principal Investigator of the project. “With population growth, increasing urbanization and climate change, providing adequate clean water for people is becoming a critical problem. Advances in technology are enabling more efficient production of drinking water from salt water.”

Haas is partnering with American Water’s Dr. Mark LeChevallier, co-principal investigator to monitor and reduce the biological fouling. The project is supported by doctoral student of environmental engineering Lauren Weinrich, senior analyst for American Water’s Innovation and Environmental Stewardship department.

The team’s research will help the desalination industry improve membrane operations by monitoring and controlling biodegradable matter in the pretreatment process. The results of the research will reduce RO membrane desalination that is continually on the rise and plagued with membrane fouling, which often increases the cost of operating, maintaining and replacing the membrane filters.

“The saltwater AOC test is a novel method that will further increase our understanding of the impact of pretreatment in seawater. Results are determined in a short turnaround time and growth parameters will be used in pretreatment monitoring and modeling applications,” said Weinrich.

The research is supported by a grant from the WateReuse Foundation.  Drexel University will be conducting the research in cooperation with The American Water Works Company, Inc. The total value of the project is $248,170.

AOC testing will be done at the Innovation laboratories at American Water in New Jersey.