Abstract
The presence of microbial contaminants in urban stormwater is a significant concern for public health; however, their removal by traditional stormwater biofilters has been reported as inconsistent and inadequate. Recent work has explored the use of biochar to improve performance of stormwater biofilters under simplified conditions that do not consider potential effects of biofilm development on filter media. The present study investigates the role of biofilm on microbial contaminant removal performance of stormwater biofilters. Pseudomonas aeruginosa biofilms were formed in laboratory-scale sand and biochar-modified sand packed columns, which were then challenged with Escherichia coli laden synthetic stormwater containing natural organic matter. Results suggests that the presence of biofilm influences the removal of E. coli. However, the nature of the influence depends on the specific surface area and the relative hydrophobicity of filter media. The distribution of attached bacteria within the columns indicates that removal by filter media varies along the length of the column: the inlet was the primary removal zone regardless of experimental conditions. Findings from this research inform the design of field-scale biofilters for better and consistent performance in removing microbial contaminants from urban stormwater.
Highlights
Low-impact development (LID) includes natural treatment systems designed to capture, treat, and recycle urban stormwater to restore the urban hydrologic regime to the pre-urbanization stage
The effect of biofilm on the stormwater biofilters performance in removing E. coli depends on the type of filter media
The presence of high level of natural organic matter in stormwater will facilitate transport of E. coli through the subsurface
Summary
Low-impact development (LID) includes natural treatment systems designed to capture, treat, and recycle urban stormwater to restore the urban hydrologic regime to the pre-urbanization stage. Stormwater biofilters are a common type of LID. They can remove contaminants from stormwater via porous media filtration and other processes and discharge the filtrate to the underlying groundwater aquifer or via a drain to surface waters. Removal of fecal indicator bacteria (FIB), common stormwater pollutants, in conventional biofilters is reported to be inadequate and inconsistent [3]. A number of recent studies [4,5,6] has explored the use of biochar—a pyrogenic carbon compound produced via anoxic pyrolysis of waste biomass—as an alternative biofilter medium. Biochar is attractive for this purpose because it has high porosity and specific surface
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
