Os instrumentos legais e as tecnologias utilizadas no aproveitamento de águas pluviais em edificações: uma revisão de literatura

Abstract

The continuous increase in the demand for water is one of the main environmental problems today. Stimulated by population growth, the urban expansion of large cities and the industrial sector enlargement, this water resource has become much more consumed. Due to pollution and poor soil use, it becomes increasingly difficult to find sources with satisfactory quality to be selected as supply. Moreover, the current model of potable water supplying allocates it for necessary purposes such as human consumption and personal hygiene, and for less noble purposes such as flushing toilets, washing clothes or irrigating gardens, thus generating waste of this essential resource. Therefore, nowadays the search for alternative sources and water reuse practices is increasing, and among them, the reuse of rainwater stands out. In this sense, through a literature review, the present work has as one of its objectives to present in detail the typical operation of a rainwater reuse system, discussing about its stages and processes, and mainly analyzing the technologies present in the market, most likely to be used. For this purpose, bibliographic databases such as Google Scholar and SciELO were used in order to find final papers, dissertations, theses and scientific articles about the research topic. Furthermore, the current configuration of the legal framework on this subject was also analyzed, making a survey of the current federal, state and municipal laws and technical standards, putting together all those that were found in legislative portals and in other means of research. Thus, according to this study, it was found that the use of a rainwater reuse system works as an essential sustainable practice to help solving problems related to the water scarcity or the urban floods occurrence. Among the technologies found, we can mention the green roofs, different models of self-cleaning filters for coarse materials, different configurations for first flush devices, slow filters with granular filtering material, devices with different chlorination mechanisms (floating chlorinator, tablet chlorinator and chlorine dosing pumps), ultraviolet radiation reactors, ozone generators and modular cisterns. However, it is important that the legislation on this subject be further expanded and that knowledge about this technique be more disseminated. For this, it is necessary to invest in more specific laws and regulations, as well as in programs towards the raising environmental awareness.