Modelling of chlorine residual in the water distribution network of Macao

Abstract

A study of chlorine modelling in sand filtered water (before postchlorination) of the Macao treatment plant indicates that the chlorine consumption in sand filtered water can be divided into two phases: an initial chlorine consumption during the first hour which corresponds to the contact time in the reservoir of the treatment plant and a long‐term chlorine consumption after one hour in the network which is interpreted in terms of an apparent first‐order equation. According to the experiments performed on the steel and asbestos cement pipes (diameter > 250 mm), the chlorine consumption by pipes is negligible. More experiments need to be performed to verify the eventual influence of water velocity and diameter of pipe on the chlorine consumption by pipe itself. The chlorine disappearance in the network of Macao can be modelled as first order equation with an average apparent kinetic constant 1.3 ± 0.3 × 10−3 min−1 using the Piccolo‐Quality software. © 1992 Taylor and Francis Group, LLC.