Factors affecting bacterial growth in drinking water distribution system.
OBJECTIVE
To define the influence of some parameters, including assimilable organic carbon (AOC), chloramine residual, etc. on the bacterial growth in drinking water distribution systems.


METHODS
Three typical water treatment plants in a northern city (City T) of China and their corresponding distribution systems were investigated. Some parameters of the water samples, such as heterotrophic plate content (HPC), AOC, COD(Mn), TOC, and phosphate were measured.


RESULTS
The AOC in most water samples were more than 100 microg/L, or even more than 200 microg/L in some cases. The HPC in distribution systems increased significantly with the decrease of residual chlorine. When the residual chlorine was less than 0.1 mg/L, the magnitude order of HPC was 10(4) CFU/mL; when it was 0.5-0.7 mg/L, the HPC was about 500 CFU/mL.


CONCLUSIONS
For controlling the biostability of drinking water, the controlling of AOC and residual chlorine should be considered simultaneously. The influence of phosphors on the AOC tests of water is not significant. Phosphors may not be the limiting nutrient in the water distribution systems.
Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China. luw02@mails.tsinghua.edu.cn
Wei
W
Lu
Xiao-Jian
XJ
Zhang
D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development; D002244:Carbon / Q000032:analysis / Q000378:metabolism; D002681:China; D002700:Chloramines / Q000494:pharmacology; D002713:Chlorine / Q000494:pharmacology; D004202:Disinfectants / Q000494:pharmacology*; D004355:Drug Stability; D009930:Organic Chemicals / Q000032:analysis; D010710:Phosphates / Q000032:analysis / Q000378:metabolism; D010758:Phosphorus / Q000494:pharmacology; D011157:Population Dynamics; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods; D014881:Water Supply
D002700:Chloramines; D004202:Disinfectants; D009930:Organic Chemicals; D010710:Phosphates; D010758:Phosphorus; D002713:Chlorine; D002244:Carbon