AWWA ACE90138 ✓ Most Recent

It has been demonstrated that, even after saturation of the adsorbent power of granular activated carbon (GAC), GAC filters remain efficient in the cutting down the amount of dissolved organic carbon thanks to the activity of bacteria which colonize the carbon. Even if the results obtained in a plant using this type of biological filtration are more than satisfactory, the management and optimization of the operation of these filters raises certain questions: What is the operational balance of such filters? What becomes of the organic matter eliminated during filtration? What is the effect of the washing required for the proper operation of the filters? How can activated carbon filters used for biological purposes be dimensioned in an optimum manner? What are the filtration rate and contact time which give the best performances? What is the dependence of their operation upon seasonal temperature variations? By bringing new filters into operation, what is the duration of the biological colonization phase of the medium? What is the quality of the filtered water during that period? Thanks to the development of microbiological methodologies adapted to the study of GAC filters, answers have been given following the studies carried out on the first generation of GAC filters at Choisy-le-Roi and on pilots, for more than a year, at Neuilly-sur- Marne. See more