Análise da viabilidade de um sistema domiciliar de aproveitamento de águas pluviais na cidade do Rio de Janeiro

Abstract

The high population density, the disordered occupation of land use and the pollution of water resources have aggravated the conditions of the increase in water demand and the impacts of urban waters. Given this scenario, water availability in different regions of the country is affected in terms of water collection and distribution as conventional sources of supply. This work aims to evaluate the operation of a hybrid system for supplying conventional water and rainwater from a residential system implemented in the city of Rio de Janeiro. The methodology consists of the analysis of historical series of pluviometric data, water consumption in the building and operation of the system regarding the volumes stored, treated and distributed to the sanitary devices. The development of the automated system for the use of rainwater in an urban dwelling uses the existing hydraulic installations and reservoirs, with a focus on reducing the consumption of drinking water from traditional sources, in an integrated manner with the use of rainwater. The results of the rainwater quality achieved with the treatment employed proved promising, so that rainwater presents itself as a favorable option for urban supply in its various uses. With the use of a small roof area for catchment (82 m2) and a total reserve volume of 3.3 m3, integrated into the concessionaire's distribution network, there was a total saving of 81.4 m3 of water in twelve months, corresponding to 32.6% of total water consumption at the residence, and an annual financial savings of US$ 293.02. With an estimated useful life of 20 years and low cost of operation / maintenance, the system proved to be viable, with an estimated return on investment of five years and nine months.