为了在大型复杂网络中分配饮用水时保持其生物稳定性，必须满足高标准——即低细菌密度和低水平的可生物降解有机碳。法国巴黎Choisy le Roi处理厂采用二级颗粒活性炭（GAC）过滤（无需碳再生）。通过这种过滤可以有效去除溶解的有机碳，这主要是因为可生物降解的有机碳减少了。为了研究这种去除过程中涉及的微生物过程，已经开发了基于放射性标记示踪剂的新方法，以测量与GAC相关的细菌生物量和活性。包括26个参考文献、表格和图表。

To maintain the biological stability of drinking water during distribution in large, complex networks, high standards have to be met--namely, low bacterial densities and low levels of biodegradable organic carbon. Second-stage granular activated carbon (GAC) filtration (without regeneration of carbon) is used for this purpose at the Choisy-le-Roi, Paris, France, treatment plant. Effective removal of dissolved organic carbon has been observed with such filtration--mainly because of a reduction in the biodegradable organic carbon. To study the microbial processes involved in this removal, new methods based on the use of radio-labeled tracers have been developed in order to measure the bacterial biomass and activity associated with GAC. Includes 26 references, tables, figures.