AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Chemical Source Profiles for Airborne Crustal Material Over a Region in Central India
RAMYA SUNDER RAMAN, Rohit Sirvaiya, Masood Ayub Kaloo, Indian Institute of Science Education and Research, Bhopal
Abstract Number: 288 Working Group: Source Apportionment
Abstract Recently, source apportionment of ambient aerosol over locations in India utilizing receptor modeling techniques have been performed by various investigators. Source apportionment studies that use the Chemical Mass Balance (CMB) model are compelled to utilize the USEPA ‘fingerprints’, which are often inappropriate for aerosol measured over locations in India. Thus, the current study is aimed at generating source profiles for crustal material over a region in Central India. A novelty of this study is the characterization of light attenuation along with chemical species abundances in source profiles. This inclusion will help assess whether or not the differences in light attenuating species between sources can help enhance source-resolution by receptor models.
Aerosols from various crustal sources at different locations in and around Bhopal were collected using standard methods. The aerosol from each location for each source category (e.g., paved and unpaved road dust, agricultural tilling, construction, demolition, storage piles) was then sieved and re-suspended in a chamber (fabricated based on the UC Davis re-suspension chamber design). A composite aerosol for each source type (e.g., paved road dust) was obtained by compositing the aerosol collected from different locations. Once composite samples representative of different crustal sources were obtained, dried and sieved, they were resuspended to permit sampling them on to filter substrates. The resuspended aerosol was collected using a MiniVol® sampler. Both PM$_10 and PM$_2.5 inlets were used to permit the sampling of crustal material in both size fractions. Subsequent to the collection of samples on to filter substrates (Teflon and Quartz Fiber), the filters were subjected to chemical analyses including organic and elemental carbon (OC/EC), inorganic anions/cations, and trace element concentrations. Teflon filters were also used to quantify the light attenuated at two different wavelengths (870 nm and 320 nm) using an optical transmissometer (Magee Scientific, OT21).
The source profiles (chemical species and light attenuation) for PM$_10 and PM$_2.5 aerosols from different locations and source categories, and profiles for aerosol samples composited by source type from different locations will be discussed. Variability within source profiles from the same source category and size bin will also be outlined.
Acknowledgement: This work is funded by the Department of Science and Technology (DST) Government of India vide grant SR/FTP/ES-146/2010