Caracterização físico-química e análise da estrutura da comunidade microbiana na água da chuva de um sistema de aproveitamento de água

Abstract

This work aims to analyze the operation of a rainwater harvesting system (RWHS) in a private educational institution, installed in the district of Vila Kosmos, in the city of Rio de Janeiro, based on water consumption data, physical chemical characterization and analysis of the microbial community structure observed in rainwater. The quantitative aspects of the stored volume were also evaluated, regarding the economic benefits related to the use of rainwater instead of drinking water. The methodology consists of collecting and analyzing samples of the quality of rainwater stored in the points of direct precipitation (PD), first-flush (FF), reservoir (RR) and tap available to cleaning services (TL) of the institution, in the period between March 2019 and February 2020. The study of the microbial community structure is carried out through the analysis of the gene that encodes the RNAr 16S, from the genetic coding by the polymerase chain reaction (PCR) technique of the bacterial community present in the rainwater, with dendograms obtained by the software BioNumerics. The results indicate variability and complex bacterial community present in rainwater in the FF, RR and TL samples. In general, the quality of the water used for non-potable purposes in the institution meets the limits established by NBR 15,527 / 2019, as well as the consumption data suggest a 10% savings from the use of rainwater and present economic benefits in short term, according to the cost involved in the installation and the turnaround time. It is concluded that the use of rainwater use systems in educational institutions, in a planned way, can reduce up to 0,35 m³/year.person. There is a need for expanded studies on the assessment of microbial community structure present in rainwater, in order to obtain possible standardization effects on the distribution of structures in the bacterial community, especially with the increase in sample collection periods.