[Relation between phosphorus and bacterial regrowth in drinking water].

In the experiment, a bioassay called Bacterial Regrowth Potential (BRP) was used to investigate the effect of phosphorus on bacterial regrowth in the water sample that was made from some raw water taken from a reservoir located in northern China. It was shown that BRP of water sample increased about 100%-235% when 50 micrograms/L PO4(3-) -P (as NaH2PO4) was added alone. BRP of water sample with various inorganic nutrients (including phosphate) addition had the similar increase compared with BRP of water sample with only 50 micrograms/L PO4(3-) -P addition and BRP of water sample with acetate-C of 1 mg/L addition increased only 30%-40%. These results were clear evidence of phosphorus limitation on bacteria regrowth in the water sample investigated in the experiment. This observation offered novel possibility to restrict microbial regrowth in water distribution system by developing technologies to remove phosphorus efficiently from drinking water.