Decay process of free residual chlorine concentration affected by travel time in water distribution systems

  • Luciano de Oliveira Escola de Engenharia Civil e Ambiental. Programa de Pós-graduação em Engenharia Ambiental e Sanitária. Universidade Federal de Goiás (UFG), Avenida Universitária, n° 1488, CEP: 74605-220, Goiânia, GO, Brazil.
  • Diana Rosa dos Reis Programa de Pós-graduação em Engenharia Agrícola. Universidade Estadual de Goiás (UEG), BR 153, Km 99, Zona Rural, CEP: 75132-903, Anápolis, GO, Brazil.
  • Nora Katia Saavedra del Aguila Hoffmann Departamento de Hidráulica e Saneamento. Programa de Pós-graduação em Engenharia Ambiental e Sanitária. Escola de Engenharia Civil e Ambiental da Universidade Federal de Goiás (EECA-UFG), Avenida Universitária, n° 1488, CEP: 74605-220, Goiânia, GO, Brazil.
DOI: https://doi.org/10.4136/ambi-agua.2830

Abstract

Chlorination is the most widely used method for disinfecting water for human consumption. While the chlorinated water travels through a distribution system, the concentration of free residual chlorine (FRC) declines depending on the natural water characteristics. This study investigated FRC decay in two types of water sources – ground and surface water – with varied concentrations of organic compounds. The travel time variable depended on water consumption patterns of both distribution systems which attend low density populations and their initial project needs. Based on mathematical simulation techniques of water quality models, the study also investigated the effects of water temperature and total organic carbon (TOC) on the kinetic constants (kb) of chlorine decay. Results show that travel time in the most critical locations in the water networks and the minimum disinfectant concentrations required at the entry points were 40 hours and 0.27-0.28 mg L-1 at Vale dos Pássaros housing complex, and 144 hours and 0.30-0.36 mg L-1 at Terras Alphaville housing complex.

Keywords: disinfection, TOC, water quality.


Published
31/05/2022
Issue
Vol. 17 No. 3 (2022)
Section
Papers

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