Modelo semi-empírico para obtenção do coeficiente de reoxigenação superficial em canais hidráulicos

Abstract

The oxygen transfer process through the air-water interface in free surface flows can be numerically quantified by the coefficient of surface reoxygenation . There are many empirical predictive equations in the scientific literature that consider only two water body hydraulic parameters, such as flow velocity and depth. Some studies have demonstrated that 14 parameters are important in the oxygen transfer process through the air-water interface. Since only two parameters were considered, the predictive equations available in the literature commonly predict very different results for the same hydraulic conditions. The present work aims at the generation of new data in order to contribute to the understanding of the reoxygenation process, including one more parameter in the analysis: channel bed roughness. The study of the influence of the water velocity, depth and roughness in hydraulic channel flows on was performed aiming at developing a predictive semi-empirical model. A hydraulic recirculating channel was used to simulate the reoxygenation process in water bodies. The results show that, for a certain range of values, the roughness of the bed significantly interferes in the reoxygenation process. The model developed can be used to predict the in flows with the same hydrodynamic and geometric characteristics established in this study.

The effect of SDS surfactant on surface reaeration coefficient: a laboratory scale approach

“…Even in the current context, which imposes the study of gases linked to the effects of atmospheric warming, special attention should still be maintained for oxygen transfer (Janzen et al, 2008;Menezes et al, 2015;Costa et al, 2015;Harano et al, 2018). In practice, the interest in this subject relates to the modeling of dissolved oxygen (DO) dynamics downstream from organic sources of pollution; since the biodegradation process of organic waste causes the decay of DO concentration (Costa and Texeira, 2011;Gonçalves et al, 2012;Mateus et al, 2015;Gonçalves and Esposto, 2019).…”

Estimativa do coeficiente de transferência de massa de oxigênio com o uso da técnica das sondas solúveis flutuantes: um estudo de laboratório

“…A avaliação e a previsão da concentração de OD por meio de modelos de qualidade da água são, na maioria dos casos, sensíveis ao K L e sua estimativa correta define indiretamente a quantidade de resíduos orgânicos que pode ser lançada no corpo d'água sem comprometimento da qualidade da água (KALBURGI et al, 2015). DORIA, 2002;COSTA et al, 2015;MARADEI et al, 2015;GONÇALVES et al, 2017). No entanto, esses modelos produzem pobres estimativas, quando aplicados em condições de escoamentos diferentes das quais eles foram originados; sendo verificados erros de estimativa de 40 a 50% (PALUMBO; BROWN, 2014).…”