Event Title

The Effects of Fungal Cultivation on Bacteria Removal in Stormwater Biofiltration Systems

Presentation Abstract

Pathogens from nonpoint sources are the leading cause of water quality impairments in US surface waters. Pathogen contaminated waterways cause millions of waterborne illnesses, tens of thousands of beach closure and advisory days each year, and pose a serious threats to coastal shellfish harvesting—a critical economic activity in Washington State. Incorporating fungi into stormwater Best Management Practices—a concept known as mycofiltration—is a simple and low-cost method for improving the pollutant removal capacity of stormwater treatment installations. This study assessed the feasibility of using mycofiltration to remove E. coli from synthetic stormwater as part of a Phase I EPA Small Business Innovate Research (SBIR) grant. Six fungal species grown on a range of substrates were put through cycles of saturation, drying, heating, and freezing. The most resilient fungi included Irpex lacteus, Stropharia rugoso-annulata and Pleurotus ostreatus. These species were grown in MycoFiltersTM consisting of 25 L plastic containers. Replicate MycoFilters were loaded with de-chlorinated tap water spiked with ~700 cfu/100 mL of E. coli (ATCC 11775) at low (0.5 L/min) and high (2.2 L/min) hydraulic loading. Influent and effluent was monitored for fecal coliform and E. coli using the EPA approved Colisan C MF chromogenic media method. Biological monitoring was more of a challenge than anticipated due to the complex microbiology of the mycofiltration media. Results generally confirmed that MycoFilters had the capacity improve E. coli removal relative to control media, with better removal at lower hydraulic loading. Results also indicated, that organic lignocellulosic media such as straw and wood chips can, in some cases, export bacteria that cause false positives for fecal coliform and E. coli. Results highlight the problematic aspects of using traditional microbial indicator methods, such as enzyme-linked chromogenic media, to assess the capacity for biologically rich treatment systems like mycofiltration to remove pathogens from polluted waters.

Session Title

Session S-08B: Stormwater Quality, Impacts, Treatment Solutions

Conference Track

Stormwater

Conference Name

Salish Sea Ecosystem Conference (2014 : Seattle, Wash.)

Document Type

Event

Start Date

1-5-2014 5:00 PM

End Date

1-5-2014 6:30 PM

Location

Room 6C

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Type

Text

Language

English

Format

application/pdf

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May 1st, 5:00 PM May 1st, 6:30 PM

The Effects of Fungal Cultivation on Bacteria Removal in Stormwater Biofiltration Systems

Room 6C

Pathogens from nonpoint sources are the leading cause of water quality impairments in US surface waters. Pathogen contaminated waterways cause millions of waterborne illnesses, tens of thousands of beach closure and advisory days each year, and pose a serious threats to coastal shellfish harvesting—a critical economic activity in Washington State. Incorporating fungi into stormwater Best Management Practices—a concept known as mycofiltration—is a simple and low-cost method for improving the pollutant removal capacity of stormwater treatment installations. This study assessed the feasibility of using mycofiltration to remove E. coli from synthetic stormwater as part of a Phase I EPA Small Business Innovate Research (SBIR) grant. Six fungal species grown on a range of substrates were put through cycles of saturation, drying, heating, and freezing. The most resilient fungi included Irpex lacteus, Stropharia rugoso-annulata and Pleurotus ostreatus. These species were grown in MycoFiltersTM consisting of 25 L plastic containers. Replicate MycoFilters were loaded with de-chlorinated tap water spiked with ~700 cfu/100 mL of E. coli (ATCC 11775) at low (0.5 L/min) and high (2.2 L/min) hydraulic loading. Influent and effluent was monitored for fecal coliform and E. coli using the EPA approved Colisan C MF chromogenic media method. Biological monitoring was more of a challenge than anticipated due to the complex microbiology of the mycofiltration media. Results generally confirmed that MycoFilters had the capacity improve E. coli removal relative to control media, with better removal at lower hydraulic loading. Results also indicated, that organic lignocellulosic media such as straw and wood chips can, in some cases, export bacteria that cause false positives for fecal coliform and E. coli. Results highlight the problematic aspects of using traditional microbial indicator methods, such as enzyme-linked chromogenic media, to assess the capacity for biologically rich treatment systems like mycofiltration to remove pathogens from polluted waters.