[Growth characteristics and control of iron bacteria on cast iron in drinking water distribution systems].
This study investigated the growth characteristics of iron bacteria on cast iron and relationship between suspended and attached iron bacteria. The steady-state growth of iron bacteria would need 12 d and iron bacteria level in effluents increased 1 lg. Hydraulics influence on iron bacteria level and detachment rate of steady-state attached iron bacteria was not significant. But it could affect the time of attached iron bacteria on cast-iron coupons reaching to steady state. When the chlorine residual was 0.3 mg/L, the iron bacteria growth could be controlled effectively and suspended and attached iron bacteria levels both decreased 1 lg. When the chlorine residual was more than 1.0 mg/L, it could not inactivate the iron bacteria of internal corrosion scale yet. There was little effect on inhibiting the iron bacteria growth that the chlorine residual was 0.05 mg/L in drinking water quality standard of China. The iron bacteria on coupons reached to steady state without disinfectant and then increased the chlorine residual to 1.25 mg/L, the attached iron bacteria level could decrease 2 lg to 3 lg. Under steady-state, the suspended iron bacteria levels were linearly dependent on the attached iron bacteria. The control of iron bacteria in drinking water distribution systems was advanced: maintaining the chlorine residual (0.3 mg/L), flushing the pipeline with high dosage disinfectant, adopting corrosion-resistant pipe materials and renovating the old pipe loop.
Wang
Yang
Y
Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China. wangyang00@mails.tsinghua.edu.cn
Zhang
Xiao-Jian
XJ
Chen
Yu-Qiao
YQ
Lu
Pin-Pin
PP
Chen
Chao
C
D001419:Bacteria / Q000254:growth & development*; D019149:Bioreactors / Q000382:microbiology; D017606:Chlorine Compounds / Q000494:pharmacology; D003343:Corrosion; D004202:Disinfectants / Q000494:pharmacology; D007501:Iron / Q000737:chemistry*; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*; D014881:Water Supply
D017606:Chlorine Compounds; D004202:Disinfectants; D007501:Iron