Estudo de viabilidade econômica do uso de mictório seco

Abstract

The problem of water scarcity has worsened over time, causing rationing in several regions, especially in large urban centers. To ensure availability with a focus on sustainable development, it is necessary to develop policies for the rational use of water and the use of water-saving appliances appears as one of the alternatives for the conservation and efficient use of water. Among water-saving appliances, waterless urinals appear as a more efficient solution, since they do not use water in the discharge process and can be a good alternative to mitigate the effects of water scarcity. If on the one hand the waterless urinals bring economic benefits for water saving, on the other hand there are the cost of purchasing the sanitary appliance and the operating costs that are the seal responsible to replace the water seal and the cartridge that packs it. In this work an economic feasibility study of the use of waterless urinal was developed. The study was divided in three scenarios and in each of them the use of the waterless urinal was compared with a corresponding sanitary appliance. The scenario 1 evaluated the replacement of the conventional urinal by waterless urinal (saving of 1.0 L / use). The scenario 2 evaluated the use of waterless urinal in comparison to a double-acting sanitary basin (saving of 3.0 L / use). And in scenario 3, it verified the viability of the use of waterless urinal in comparison to a sanitary basin of single drive (economy of 6.0 L / use). In the residential category, it also considered the different tariffs charged by the water supply concessionaire. The economic indicators were: return period (PR), net present value (NPV), benefit / cost ratio (B / C) and internal rate of return (TIR), both for a project life of 20 years and reference values to the city of João Pessoa-PB Brazil, according to the average number of uses per day. For the residential category, the use of waterless urinal is not feasible in scenario 1. In scenario 2, there is viability from intermediate charging (average standard) and uses above 17 uses / day. This value is 10 uses / day for the highest value tariff (high standard). In scenario 3, the use of dry urinal becomes economically viable for use above 10 uses / day, for the popular rate, 6 uses for the average standard rate and 4 uses / day for the high standard rate. For the commercial, industrial and public categories, economic viability occurs in all cases. For these categories, scenario 1 was the one that presented higher values of uses per day to become viable. These values were 39 uses / day, for the commercial category, 29 uses / day, for the industrial category and 30 uses / day for the public category. In scenario 2, economic viability occurs for much smaller amounts of use. These values are: 7 uses / day for the commercial category, and 6 uses / day for the industrial and public category. In the last scenario, the result was the same for both categories, being necessary values above only 3 uses / day to exist economic viability