Experimental Studies on Nitrogen Compounds Fate and Transport in Groundwater Systems -Impacts of Wastewater Irrigation

English Abstract:

Abstract:Inorder to meet the water demand by population growth and urbanization, many countries started using untreated or partially treated wastewater for irrigation, groundwater recharge, landscaping and other purposes. On the other hand, the use of nitrogen-based fertilizers in agriculture has helped to feed millions of people but it’s also disrupted the nitrogen cycle, and resulted in nitrate contamination in groundwater creating various health issues. A scientific investigation on the nitrogen dynamics in the subsurface, its sources, sinks, transformations and transport is essential to device proper wastewater reuse strategies and to ensure safe groundwater. The major nitrogen transformation process in soil like adsorption, chemical and biological transformations namely nitrification and denitrification, plant uptake and others will control the final release of nitrates into the groundwater. Therefore, it is very important to study the fate and transport of nitrogen species from fertilizer and/or wastewater irrigation in order to predict the spatial and temporal distributions of concentrations in the vadose zone and groundwater. In this aspect, experimental evidences are needed to quantify the individual reaction rates of all the processes by batch and bench scale column studies. The data from batch experiments will be used to propose a mathematical model for simulating the processes of nitrogen dynamics spatially and temporally in real scenario. Finally, a comprehensive, replicating the field conditions will be helpful in validating the model and thereby applying it for predictions, scenario analysis and guidelines development for wastewater irrigation and fertilizer management.

Keywords: Nitrogen compounds, Transport, Biotransformation, Nitrification, Denitrification