Bacteria Attached to Granular Activated Carbon in Drinking Water

摘要

Laboratory and field studies were undertaken to answer basic questions about the influence of granular activated carbon (GAC) on the bacteriological quality of drinking water. A sampling apparatus consisting of a 47-mm Swinnex/and a 16-layer filter was developed to trap filter fines from large volumes of water. A desorption technique combined with optimal culturing procedures allowed for the enumeration of particle-associated bacteria. GAC-attached bacteria were resistant to 2.0 mg/l chlorine after 1 hr of exposure. Enteric pathogens were capable of colonizing laboratory-scale GAC filters. Their colonization potential and longevity depended on the presence of autochthonous river water organisms. GAC filter particles were found in effluents from properly operated treatment facilities. Several operational variables (increased bed depth, turbidity of applied water, and filtration rate) did correlate positively with the presence of fines in filter effluents. Bed age was not associated with breakthrough.