ABSTRACT
Groundwater pollution is a growing concern everywhere in the world. The basic problems are twofold: extensive usage of groundwater leading to overdrafts and declining groundwater levels, and pollution of fresh groundwater leading to undesirable effects on users or curtailment of groundwater usage. Nitrates are one of the most problematic and widespread of the vast number of potential groundwater contaminants. The ammonification, synthesis, nitrification, and denitrification processes are the primary mechanisms employed in the treatment of contaminated groundwater for nitrogen control and/or removal. The transport mechanisms primarily responsible for the movement of nitrogen through the environment include precipitation, dustfall, sedimentation in water systems, wind, groundwater movement, stream flow, overland runoff, and volatilization. Synthesis and denitrification rarely remove all nitrates added to the soil from fertilizers and nitrified wastewater effluents. Accordingly, nitrates leached from soil are a major groundwater quality problem in many areas in the US and elsewhere around the world.
