AWWA QTC98288

This paper presents data obtained from bench-scale and pilot-scale studies that specifically look at the interactions of distribution biofilms under the influence of low disinfectant residuals and phosphorus based corrosion inhibitors. Although the use of disinfectants increases corrosion product formation, there will be a disinfectant residual level in which the mass transfer limitations will begin to be overcome which results in deeper penetration into the biofilm/corrosion product matrix. Deeper disinfectant penetration increases microbial inactivation and reduces biofilm density. This disinfectant level will increase in corrosion product mass, but will reduce biofilm density. This disinfectant level can be defined as the threshold residual and will change depending on the pipe material and water quality. The use of phosphorus based corrosion inhibitors changes the type of corrosion products normally found on pipe materials. The use of corrosion inhibitors reduces the amount of geothite formed on a pipe suface along with changing the electrostatic surface characteristics of these materials. The electrostatic surface charge is of significance because the charge regulates the rate of adsorption of humic substances to the pipe surface along with the electrostatic adhesion properties of microorganisms with the surface.

Product Details

Published:

01/01/1998

ISBN(s):

0898679796

Number of Pages:

17

File Size:

1 file , 200 KB