Modelagem hidráulica de parâmetros de qualidade da água e trihalometanosna região sul de Palmas-TO

Abstract

Chlorination of public water supply is the most common and widely used system for disinfection; Brazilian law has mandatory parameters for the presence of free residual chlorine in water supply systems, ranging from 0.2mgL-1 to 2.0mgL-1. The major problem associated with chlorination is the presence of solubilized organic matter in water, which reacting with free residual chlorine forms halogenated by-products known as trihalomethanes (Bromodichloromethane, Dibromochloromethane, Bromoform, Chloroform). In this context, the use of hydraulic models for water quality emerges as a tool to identify distribution network locations with high detention time and consequently higher trihalomethane formation rate. This study evaluated the chlorine decay patterns and trihalomethane formation throughout the water distribution network in the southern region of the city of Palmas-TO. With data associated with an adequate geographic information system it was possible to understand the chlorine decay patterns and all the formation and diffusion of the trihalomethanes originated in the network. Trihalomethane concentrations were found to be significantly higher in September; and chlorine, despite higher concentrations, tends to decline more rapidly this month. The results have proved useful as benchmarks for future interventions in the system aiming at an increase in operating efficiency.