Applying SEM-EDX and XRD Techniques to Demonstrate the Overgrowth of Atmospheric Soot and Its Coalescence with Crystal Silicate Particles in Delhi — Oak Academic Publishing
Research ArticleOpen AccessGoogle Scholar indexed
Applying SEM-EDX and XRD Techniques to Demonstrate the Overgrowth of Atmospheric Soot and Its Coalescence with Crystal Silicate Particles in Delhi
Scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) and X-ray diffraction (XRD) systems were used to demonstrate the overgrowth of soot to fractal like structure and its subsequent coalescence with crystal shaped silicate particles. Sample was obtained from a very clean area of Delhi at a height of 16 m from ground with the help of a five stage cascade impactor in the winters of 2006. Impactor collects particles in five different size ranges (i.e. ≥10.9, 10.9 - 5.4, 5.4 - 1.6, 1.6 - 0.7 and ≤0.7 μm). In the present investigation only the particles collected in the size range 1.6 - 0.7 μm (D50 = 0.980 μm) have been considered. It has clearly been observed that the soot particles tend to grow or rather agglomerate in a fractal like structure. During this process they incorporate other chemically and structurally different particles (crystal silicate in the present investigation) to make multi phase and multi chemical amorphous aggregates. These aggregates are formed during/after its collection on the sampling substrate and may be as many as hundred times more than the expected size interval (D50 or cut off range).
KeywordsScanning Electron MicroscopeEnergy Dispersive X-RaySootAerosolsOvergrowthDelhi
A. Gelencser, “Carbonaceous Aerosol,” Springer, Berlin, 2004, p. 350.
M. Z. Jacobson, “Strong Radiative Heating Due to the Mixing State of Black Carbon in Atmospheric Aerosols,” Nature, Vol. 409, No. 6821, 2001, pp. 695-697. doi:10.1038/35055518
J. E. Penner, S. Y. Zhang and C. C. Chuang, “Soot and Smoke Aerosol May Not Warm Climate,” Journal of Geophysical Research, Vol. 108, No. D21, 2003, p. 4657. doi:10.1029/2003JD003409
A. Petzold, J. Strom, F. P. Schroder and B. Karcher, “Carbonaceous Aerosol in Jet Engine Exhaust: Emission Characteristics and Implications for Heterogeneous Chemical Reactions,” Atmospheric Environment, Vol. 33, No. 17, 1999, pp. 2689-2698. doi:10.1016/S1352-2310(98)00314-8
D. W. Dockery, C. A. Pope, X. P. Xu, J. D. Spengler, J. H. Ware, M. E. Fay, B. G. Ferris and F. E. Speizer, “An Association between Air Pollution and Mortality in Six US Cities,” New England Journal of Medicine, Vol. 329, No. 24, 1993, pp. 1753-1759. doi:10.1056/NEJM199312093292401
W. L. Chameides and M. Bergin, “Climate Change-Soot Takes Center Stage,” Science, Vol. 297, No. 5590, 2002, pp. 2214-2215. doi:10.1126/science.1076866
A. Hunt, J. L. Abraham, B. Judson and C. L. Berry, “Toxicological and Epidemiologic Clues from the Characterization of the 1952 London Smog Fine Particulate Matter in Archival Autopsy Lung Tissues,” Environmental Health Perspective, Vol. 111, No. 9, 2003, pp. 1209-1214. doi:10.1289/ehp.6114
K. Fassi-Fihri and S. R. Rosset, “Internal and External Mixing in Atmospheric Aerosols by Coagulation: Impact on the Optical and Hygroscopic Properties of the Sulphate-Soot System,” Atmospheric Environment, Vol. 31, No. 10, 1997, pp. 1393-1402. doi:10.1016/S1352-2310(96)00341-X
A. Braun, A. Wirick, A. Kubatova, B. S. Mun and F. E. Huggins, “Photochemically Induced Decarboxylation in Diesel Soot Extracts,” Atmospheric Environment, Vol. 40, No. 30, 2006, pp. 5837-5844. doi:10.1016/j.atmosenv.2006.05.024
R. J. Samson, G. W. Mulholland and J. W. Gentry, “Structural Analysis of Soot Agglomerates,” Langmuir, Vol. 3, No. 2, 1987, pp. 272-281. doi:10.1021/la00074a022
A. Schmidt-Ott, “In Situ Measurement of the Fractal Dimensionality of Ultrafine Aerosol Particles,” Applied Physics Letters, Vol. 52, No. 12, 1988, pp. 954-956. doi:10.1063/1.99239
A. Schmidt-Ott, “New Approaches to in Situ Characterization of Ultrafine Agglomerates,” Journal of Aerosols Science, Vol. 19, No. 5, 1988, pp. 553-563. doi:10.1016/0021-8502(88)90207-8
C. Xiong and S. K. Friedlander, “Morphological Properties of Atmospheric Aerosol Aggregates,” PNAS, Vol. 98, No. 21, 2001, pp. 11851-11856. doi:10.1073/pnas.211376098
K. Wittmaack, N. Menzel, H. Wehnes and U. Heinzmann, “Phase Separation and Regrowth of Aerosol Matter Collected after Size Fractionation in an Impactor,” Atmospheric Environment, Vol. 36, No. 39, 2002, pp. 5877- 5886. doi:10.1016/S1352-2310(02)00827-0
M. Chiaradia and F. Cupelin, “Behaviour of Airborne Lead and Temporal Variations of Its Source Effects in Geneva (Switzerland): Comparison of Anthropogenic versus Natural Processes,” Atmospheric Environment, Vol. 34, No. 6, 2000, pp. 959-971. doi:10.1016/S1352-2310(99)00213-7
M. Wentzel, H. Gorzawski, K. H. Naumann, H. Saatho and S. Weinbruch, “Transmission Electron Microscopical and Aerosol Dynamical Characterization of Soot Aerosols,” Aerosols Science, Vol. 34, No. 10, 2003, pp. 1347- 1370. doi:10.1016/S0021-8502(03)00360-4
C. Van Gulijk, J. C. M. Marijnissen, M. Makkee, J. A. Moulijn and A. Schmidt-Ott, “Measuring Diesel Soot with a Scanning Mobility Particle Sizer and an Electrical Low- Pressure Impactor: Performance Assessment with a Model for Fractal-Like Agglomerates,” Aerosols Science, Vol. 35, No. 5, 2004, pp. 633-655. doi:10.1016/j.jaerosci.2003.11.004
M. Maricq, “Coagulation Dynamics of Fractal-Like Soot Aggregates,” Aerosols Science, Vol. 38, No. 2, 2007, pp. 141-156. doi:10.1016/j.jaerosci.2006.11.004
“Economic Survey of Delhi,” Planning Department, Go- vernment of NCT of Delhi, Delhi Secretariat, New Delhi, 2005-2006.
G. Cressey and P. F. Schofield, “Rapid Whole-Pattern Profile Stripping Method for the Quantification of Multiphase Samples,” Powder Diffraction, Vol. 11, No. 1, 1996, pp. 35-39
A. Srivastava and V. K. Jain, “Seasonal Trends in Coarse and Fine Particle Sources in Delhi by the chemical Mass Balance Receptor Model,” Journal of Hazardous Materials, Vol. 144, No. 1-2, 2007, pp. 283-291. doi:10.1016/j.jhazmat.2006.10.030
A. Srivastava and V. K. Jain, “Size Distribution and Source Identification of Suspended Particulate Matters in Atmospheric Aerosols over Delhi,” Chemosphere, Vol. 68, 2007, pp. 579-589. doi:10.1016/j.chemosphere.2006.12.046
S. Balachandran, B. R. Meena and P. S. Khillare, “Particle Size Distribution and Its Elemental Composition in the Ambient Air of Delhi,” Environment International, Vol. 26, No. 1-2, 2000, pp. 49-54. doi:10.1016/S0160-4120(00)00077-5
A. Schmidt-Ott, U. Baltensperger, H. W. Faggeler and D. T. Jost, “Scaling Behavior of Physical Parameters Describing Agglomerates,” Journal of Aerosols Science, Vol. 21, No. 6, 1990, pp. 711-717. doi:10.1016/0021-8502(90)90037-X
G. Skillas, S. Futzel, H. Burtscher, U. Baltensperger and K. Siegmann, “High Fractal-Like Dimensions of Diesel Soot Agglomerates,” Journal of Aerosols Science, Vol. 29, No. 4, 1998, pp. 411-419. doi:10.1016/S0021-8502(97)00448-5