Indicadores de consumo de água e análise comparativa entre o aproveitamento de águas pluviais e o reúso de águas cinzas em edificações de ensino do Campus Darcy Ribeiro - UnB

Abstract

This work has characterized the end-uses of water of higher education buildings in Darcy Ribeiro Campus
- University of Brasilia and with this, a comparative analysis of the performance of rainwater harvesting
(RWH) and greywater reuse (GWR) systems for non-potable uses was made. The study was divided into
three stages. In the first stage, water consumption indicators were generated based on billed water
consumption, built area and population for each building analyzed. Water end-uses for toilet flushing,
lavatories, drinking fountains, floor washing and irrigation were estimated through the use of
questionnaires (directed to students, teachers and employees) and structured interviews (to managers
and maintenance teams). In the second stage, a series of simulations were carried out to verify water
savings for different RWH and GWR systems based on three non-potable scenarios: i) Irrigation and floor
washing (Scenario 1); ii) Toilet flushing (Scenario 2); and iii) Irrigation, floor washing and toilet flushing
(Scenario 3). In the final stage, a comparative analysis of the performance, based on water reductions
was carried out. Results showed that for the first scenario, both systems are capable of supplying water
demand. However, most systems were not capable of fully supplying water demand for Scenarios 2 and
3. In general, rainwater harvesting stood out as the best option, promoting higher water savings raging
from 137 to 19,510 m3/year, depending on the size of the building.