Abundance and variation of gaseous NH in relation with inorganic fertilizers and soil moisture during Kharif and Rabi season.

In an agricultural country like India, inorganic fertilizers are the major contributors of atmospheric NH in rural areas affecting soil, vegetation and water bodies. In this study, day-night and seasonal variation of ammonia emissions were measured from July 2017 to June 2018 during Kharif and Rabi crop seasons at a rural agricultural site in Jhajjar district of Haryana. Also, NH emission inventory is prepared for the amount of fertilizers applied during its basal and top dressing.

Seasonal variations of dustfall fluxes and biochemical parameters in the foliage of selected indoor plants in Delhi, India.

This study reports the seasonal variations in dry deposition of coarse and fine particles on the foliar surfaces of common indoor plants viz. and along with their biochemical changes in the urban households of metropolitan Delhi. The dustfall fluxes were significantly higher at the industrial site as compared to residential site and temporal variations indicated higher dustfall fluxes during the winter months as compared to other seasons.

Wet deposition of total dissolved nitrogen in Indo-Gangetic Plain (India).

Very limited information on the magnitude and environmental impacts of both inorganic and organic forms of nitrogen (N) wet deposition is available in India. Molar concentrations of inorganic (NH and NO) and organic N in rainwater were monitored at three different land use sites in Indo-Gangetic Plain (IGP) during the monsoon period (June-September) of 2017. It has been observed that dissolved organic N (DON) contributed significantly to the total dissolved N (TDN) ranging from 5 to 60%.

Gaseous and particulate reactive nitrogen species in the indoor air of selected households in New Delhi.

The present study reports the indoor abundance of inorganic trace gases (NH, NO and SO) and their corresponding particulates (NH, NO and SO) along with other major ionic species present in the aerosol form (Cl, F, Na, K, Ca and Mg), in the urban households of megacity Delhi (India). Two different households (DH site and MH site) were selected in the city based on the variation in the land use patterns of the locations in which they were situated. Trace gases followed the order NH > SO > NO at both the sites with NH contributing about 90% and 85% to the total Nr species at DH and MH sites, respectively.

Characterisation of emission from open-field burning of crop residue during harvesting period in north-west India.

Open-field crop residue burning is one of the important sources of atmospheric pollution in north-west India during the harvesting period. In this work, we studied NO and SO concentrations and physical and chemical properties of aerosols from open-field combustion of rice and wheat residue. NO and SO were analysed using UV-spectrophotometer and ion chromatography (IC) respectively.

Industrial dust sulphate and its effects on biochemical and morphological characteristics of Morus (Morus alba) plant in NCR Delhi.

Abundance of CaCO3 rich soil dust is a typical feature of atmospheric environment in the Indian region. During prevailing dry weather conditions, dustfall is deposited onto the foliar surfaces of plant affecting their morphology, stomata and the levels of biochemical constituents. This study reports the chemical characteristics of dustfall, its effect on foliar morphology and biochemical constituents of a medicinal plant (Morus alba) at two sites which are differentiated on the basis of landuse pattern, viz.

Spatial and temporal patterns of air pollutants in rural and urban areas of India.

In this study, we analysed spatial and temporal patterns of Suspended Particulate Matter (SPM) concentrations across India. We have also assessed MODIS-derived aerosol optical depth (AOD) variations to characterize the air quality and relate it to SPM, NO2 and SO2 in different areas. In addition, the pollutant concentrations have been mapped using geospatial techniques.

Precipitation and aerosol studies in India.

In India, rain water and atmospheric aerosols are observed to be alkaline in nature due to the influence of soil-derived particles which are rich in components like Ca and Mg. These components increase the neutralization potential of rain water and have a greater influence at rural site compared to urban site. However, if there are continuous rains, the concentration of crustal components becomes lower resulting in lower pH of rain water.

Identification of the nature and source of atmospheric aerosols near the Taj Mahal (India).

The chemical composition of aerosol samples collected at Agra near the Taj Mahal during April 1991-June 1992 was identified by wet chemical analysis. The average concentration of suspended particulate matter (SPM) was 368.5 µg m(-3), ranging between 83 and 1305 µg m(-3), depending upon the season.

Factors affecting alkaline nature of rain water in Agra (India).

Rain water was collected and analysed from a reference site, Dayalbagh and Taj Ganj, near the Taj Mahal in Agra. The ionic components Ca, Mg, Na, K, NH(4), Pb, Fe, Zn, SO(4), HCO(3), Cl and F were analysed along with pH, alkalinity and conductance. The average pH of rain water at both sites is 7.