Abstract |
The surfaces of granular activated carbon (GAC), sand, and anthracite particles were found to be populated to the same levels with heterotrophic plate count (HPC) bacteria. GAC supported a greater number of Klebsiella oxytoca than the other two filter media. In a study of operating drinking water filters, GAC-filtered water contained particles with attached HPC and coliform bacteria to a greater extent than sand and anthracite treated waters. Statistical analyses revealed that GAC age does not affect the occurrence of populated filter particles in the filtered water. However, greater GAC bed depth, increased applied water turbidity, and elevated filtration rate all were implicated in the presence of populated filtration media particles in drinking water. (Copyright (c) Proc. of American Water Works Assoc. Water Quality Tech Conf., Houston, TX, 12/8-11/85, p. 473-482.) |