Bacterra? by Filterra~? Advanced Bioretention System Discussion of the Benefits, Mechanisms and Efficiencies for Bacteria Removal

摘要

With the growing concern about bacterial impairment of recreational waters associated with stormwater runoff, extensive laboratory and field studies were conducted by Filterra?, division of Americast, Inc., in 2006-07 to determine an optimum blend for bacteria removal. This bioretention BMP blend is currently designed to remove typical stormwater pollutants such as TSS, phosphorus, nitrogen and heavy metals. A specialized treatment media has now been developed to remove fecal coliform and other pathogens from urban stormwater runoff. This new product has been trade marked Bacterra. Field and laboratory tests have shown removal rates between 77% and 99% removal, with significant log reductions. It is believed that the media goes through a maturation process where it develops a complex microbiological ecosystem that enhances predation, capture and destruction of fecal coliform. Physical, chemical and biological processes are all believed to contribute to the removal process, but sorption is believed to be the primary removal mechanism. This study does not support conventional thinking that it has been assumed that long contact times are needed to effectively remove bacteria from stormwater runoff using bioretention media. Our study demonstrates that the high flow through rate can achieve high bacteria removal efficiencies. This paper summarizes the research effort and findings in the development of a bacteria high flow bioretention media stormwater treatment technology.