AWWA WQTC58850

Assimilable organic carbon (AOC) and bacterial regrowth potential (BRP) of deionized water with addition of some necessary nutrients and drinking water produced from raw water by a pilot-scale treatment chain were analyzed. It was shown that phosphorus would be the limiting nutrient on bacterial growth in the deionized water and AOC_P17 and BRP increased in direct proportion to the increase of phosphorus concentration when the phosphorus concentration was low enough. The favorable ratio of C:P for bacteria growth in oligotrophic water environment was around 100:1.5~2.0. It was also shown that after 50ug/L PO₄ ^3--P was added to the drinking water investigated in the experiment, AOC increased by 55% and BRP increased by 123%. This result indicated the possible instance that phosphorus, the limiting nutrient on bacterial regrowth in drinking water, might exist in some areas of China. This study demonstrated the possibility and feasibility to restrict microbial growth in drinking water distribution systems by keeping TP in drinking water low enough. Includes 22 references, table, figures.