Coliform Attachment to Suspended Particles in Stormwater

摘要

Fractional filtration and settling tests showed significant numbers of fecal coliforms (FC), Klebsiella sp. (KS) and Pseudomonas aeruginosa (PA) (15-30% of cells), to be associated with stormwater suspended particles. Most of these were associated with the 30-52 and greater-than 52 micron fractions. The percentages of total filtered microorganisms retained on the 30 and 52 micron screens were for FC, KS, PA, and gram negative bacteria (GNB) were 80, 75, 68, and 87%, respectively. While large particles settled rapidly, sufficient numbers of single bacteria or aggregates less than 5 microns remain (above 50% of cells) to contribute to waterborne pollution. FC may not be ideal indicators of adsorption/settleability, but should be viewed as conservative indicators.