Wet deposition of total nitrogen, dissolved organic carbon and heavy metals investigating role of long-range transport at two sites in Delhi

Abstract

Precipitation is one of the signi cant phenomena for various nitrogen, carbon and metal fractions depositions. In the current study, Total nitrogen (TN), Dissolved organic carbon (DOC) and metal concentrations were measured during different seasons in 2018 and 2019 to nd out their potential sources at two sites in Delhi region having distinct land use pattern. The total nitrogen (TN) mean concentration was found to be 16 mg/l and 7 mg/l for DG and JN site respectively. Whereas the dissolved organic carbon (DOC) mean concentration was found to be 3.8 mg/l and 2.5 mg/l at DG and JN site respectively. The sequence for the metal concentrations was recorded as Ca>Na>K>Mg> Fe>Al>Cu>Mn>Zn>As for DG site whereas at JN site recorded different sequence i.e., Ca> Na> K>Mg>Fe>Al>Mn>Zn>Cu>As. Different source can be attributed to the in uence of anthropogenic activities (agriculture, animal husbandry) on nitrogenous species and biomass burning on dissolved organic carbon species. The wind rose plots indicated that local and regional sources located in the north-western direction in uenced the wet deposition of the species while air-mass back trajectory analysis implied the in uence of air masses originating from the Bay of Bengal, This study bridges the data gap in the less studied part of the Delhi region and provides new information for policy makers to deal with pollution control.