Modelagem do decaimento de cloro: estudo de caso para rede do Guajiru, em Caucaia

Abstract

One of the biggest challenges faced by sanitation management entities is the difficulty of ensuring the distribution of water for human supply within potability standards. In this context, chlorination is the most widely used process for water disinfection for this purpose, given the advantage of non-conservative chlorine behavior. Visualizing, therefore, modeling as an efficient tool to manage residual chlorine in water distribution systems, this work aimed to study the behavior of chlorine decay within the Guajiru supply network in Caucaia / CE. For this, simulations were performed with the support of EPANET 2.0 software. Knowing this, the analyzes were conducted in two scenarios, the first of them in steady state and the second in transient regime, allowing to reach conclusions about the behavior of the phenomenon in the studied system. Thus, this work was able to define values for the parameters governing chlorine decay for all stretches of the network under study. Moreover, from the simulations employed, it was noted that for steady flow, the system takes at least 16 hours to reach a steady state of chlorine concentrations for each node, while for transient flow, a Stable behavior can be viewed in 9 hours of simulation. Moreover, for both scenarios it was noted that chlorine takes 8 hours to be present on all nodes of the network and that, after reaching steady state, the average concentration of each node of the transient regime resembles those of the operating network. on a permanent basis. Finally, a reduction in chlorine concentration imposed on water after treatment was proposed in order to reduce CAGECE expenses, with a value of 1.4 mg / L of initial chlorine concentration found, representing a 30% reduction. over the 2.0 mg / L commonly used.