Full Description

A water quality model of a distribution system providesan alternative to extensive grab sampling of chlorineresiduals and disinfection byproduct concentrations,but the accuracy of such models depends on theinput of a chlorine-decay rate relationship and thespecific rate constant for reaction with pipe-wall material.This has proven difficult to quantify in currentlyavailable distribution system modeling software. Unlikesmall coupons of pipe material that are used in otherbench-scale tests of chlorine-decay rate, the pipe sectionreactor (PSR) proposed in this article uses an undisturbedsection of the actual pipe material filled withtest water and a variable-speed stirrer blade to simulatea range of water velocities.Results are given for chlorine-decay rate tests on oldcast-iron pipe and new ductile-iron pipe. With furthertesting of the PSR, rate models and rate constants will beavailable for use in water quality models to replace empiricalapproaches. This should improve the accuracy of chlorineresidual predictions, with less reliance on field calibration.Accurate predictions of chlorine residual throughoutthe distribution system are essential to determine wherelow residuals exist and thus to comply with the Stage 2Disinfectants/Disinfection Byproducts Rule. Includes 19 references, tables, figures.

Product Details

Edition: Vol. 97 - No. 1 Published: 01/01/2005 Number of Pages: 12 File Size: 1 file , 200 KB