Desenvolvimento de aplicativo computacional para simulação e otimização de remoção biológica de nutrientes (nitrogênio e fósforo) em águas residuárias.

Abstract

The accumulation of phosphorus and nitrogen in reservoirs of public drinking water supplies can lead to its deterioration , caused by extreme algae proliferation, that in addition to competing with other aquatic beings for the available dissolved oxygen, can liberate toxic substances causing disease of many organisms. They also cause unpleasant flavor and odor, having therefore great importance in questions of public health and for the environment. This dissertation has the objective of developing computational applications for simulation and optimization of wastewater treatment plants for biological removal of nutrients (N and P). There are several conFigurations that can be used for biological nutrient removal (BNR). The main difference between these is the way the anaerobic zone is protected from nitrate introduction, avoiding that the quickly biodegradable materials are consumed by microorganisms of low mass fraction of phosphorus. The software is divided in two parts, optimization and simulation. In the optimization the smallest volume of the system to effect the removal of nutrients is identified for any particular configuration and set of operational conditions. The simulation, as the proper name already says, has the objective to imitate the real functioning of the BNR. The software allows to extract data like oxygen consumption, removal of organic material and nutrients, production and composition of sludge, volume of the units and financial costs, sludge age among others. The adopted language is based on events and objects, which it allowed the use of friendly graphical interface and easy understanding, as well as the use of images for exhibition of the adopted systems and stirage of input and output data in text files and graphical presentation for the removal of phosphorus. In preliminary tests the software proved to be efficient in the simulation of nutrients and organic material removal, as well as in the indication of the optimal volumes of the units used in any configuration, showing that it can be used for the selection and sizing of the configurations evaluated in this text.