Indirect caffeine modeling in an urban river

Abstract

Caffeine is used worldwide as a chemical tracer to identify anthropic pressures on urban water resources. Nevertheless, its quantification demands great financial investments. This research created a model that would indirectly determine a range of possible caffeine concentrations along an urban river, without the need for extensive laboratory work. The model is based on Canonical Correlation Analysis (CCA), which can correlate two sets of different-sized independent and dependent variables in order to generate a single empirical equation. This equation takes as input the concentrations of ammonia nitrogen and orthophosphate, as well as the total population and the population inhabiting irregular housing areas. From the model’s results, it was possible to elaborate a spectrum of possible concentrations of caffeine along the Atuba River (Curitiba-Brazil). The tendency of water quality degradation of this river was also predicted. This model could become a useful preliminary analysis for water resource managers and researchers alike.
 Keywords: caffeine, canonical correlation analysis, water quality modeling.

Representative water quality parameters in a critical water basin: elements for planning and management

“…This leads to a complexity in modeling water resources, which is worse in urban areas where land cover and land use are more dynamic than those present in rural scenarios. In this context, it is possible to highlight the discharge of contaminants of emerging concern, such as caffeine and female sex hormones (Peixoto et al, 2022;Mizukawa et al, 2019;Mizukawa, 2016;Kramer et al, 2015). These compounds can be associated directly with human activity and although they are present in aquatic environments in very low concentrations (in the order of nano and micrograms per liter), chronic exposure to these compounds is frequently associated with endocrine disruption, carcinogenicity, and overall environmental imbalance.…”