B. Holden et al., THE EFFECT OF CHANGING INTER PROCESS AND FINAL DISINFECTION REAGENTS ON CORROSION AND BIOFILM GROWTH IN DISTRIBUTION PIPES, Water science and technology, 32(8), 1995, pp. 213-220
Citations number
7
Categorie Soggetti
Water Resources","Environmental Sciences","Engineering, Civil
Anglian Water are currently up-rating the treatment process on all the
ir surface water sources to include ozone to aid clarification and add
itional GAC contact time for the removal of micropollutants such as pe
sticides and trihalomethanes in the water. The final disinfection for
the high quality water is by either chloramination or chlorination and
pumped into a distribution network containing pipes of various materi
als. To investigate the effect on the distribution network of changing
from pre-chlorination to an advanced water treatment process, a pipe
rig was constructed at Grafham Water Works which included sections of
a 60 year old cast iron main and new plastic MDPE pipework. The work w
as carried out in conjunction with University College London and inves
tigated parameters including assimilable organic carbon (AOC), total o
rganic carbon (TOC) and temperature and monitored their effect on the
biofilm growth and corrosion rates. The biofilm growth and corrosion r
ates on the coupons inserted into the cast iron pipes of the rig were
found to be related to their orientation on the main. Temperature had
a significant effect and correlated to bacterial activity. During the
period of investigation Grafham main works also changed over from pre-
chlorination to ozonation and samples were taken from the actual distr
ibution system pre and post the process changes, The results from thes
e findings agreed with the pipe rig model, with the overall conclusion
that the change from pre-chlorination to ozonation would have little
effect on the corrosion and biofilm growth in distribution.