A mobile strategy for water participatory monitoring

The increase in industrialization and urbanization processes has directly affected the quality of water resources worldwide, generating impacts on public health and aggravating the availability of clean water. This study presents AQUA, a mobile application designed as a monitoring tool for urban rivers using colorimetric chemical tests. AQUA enables the analysis and storage of georeferenced data on pollutant levels across specific areas. Tests for ammonia (NH3-N), orthophosphate (PO43--P), iron, and nitrite (NO2-N) were miniaturized and submitted to analytical validation, reaching satisfactory values according to the National Institute of Metrology, Quality, and Technology (INMETRO) guidelines, and presenting results comparable with the classic methodologies using UV-VIS spectrophotometer. The limit values of quantification were below the maximum thresholds established by Brazilian law for surface water quality. Nine urban rivers in Foz do Iguaçu (a city in the State of Paraná) were assessed, with high NH3-N and NO2-N levels, likely indicating untreated sewage discharges. The generated georeferenced pollution map provides a valuable tool for water quality control in local communities. Overall, this strategy enables participatory water quality monitoring in a cost-effective, flexible, and accessible manner, contributing to Sustainable Development Goal 6 by promoting water availability and sustainable management.