PROSPECTS FOR THE MANAGEMENT OF REACTIVE NITROGEN IN THE SANITATION SECTOR
Reactive Nitrogen Biogeochemical Flow. Industrial Ecology. Sustainable
Sanitation. System Dynamics
The main goal of this thesis was to expand the understanding of existent
interactions that influence on reactive nitrogen flows in sanitation sector and its
interactions with related sectors. Firstly, the research was focussed on
highlighting sustainability challenges and issues that involve the reactive nitrogen
use from sanitation sector through human urine. The reactive nitrogen use by
human urine is an alternative of nitrogen resource management that can contribute
either on the security of water-energy-food nexus or on the mitigation of global
environmental impacts. In the second phase of research, the variables that influence
the reactive nitrogen management through resource flows in sanitation sector were
identified and evaluated using the Systems Dynamics approach. A conceptual
model was developed to encompass the variables of the Livestock Production,
Crop Production and Population subsystems. The integrated evaluation of the
proposed variables can support the decision-making of the reactive nitrogen
management. In the last phase, a hypothetic model of Stock and Flow was
developed using the software Vensim PLE Plus Version 6.3 to assess the progress
of nitrogen resource management options. The simulated results indicated the
potential of nitrogen fertilizer substitution by existing reactive nitrogen sources from
sanitation sector, thus reducing the inert nitrogen conversion to reactive nitrogen as
well as the reactive nitrogen emissions to environment. Among the proposed actions,
the urine segregation and stabilization of protein consumption were the most efficient
actions of nitrogen resource management. Therefore, the sanitation sector can
improve its environmental performance as well as contribute to achieving the
Sustainable Development Goals.