Wet And Dry Deposition Studies Of Aerosol Hazes Around A Major Sawdust Open Burning Area
Keywords:
Dry Deposition, Wet Deposition, Deposition Velocity, Scavenging RatioAbstract
The continuous generation of aerosol species from natural and anthropogenic sources around saw dust open burning sites necessitates extensive deposition study of such areas. This work used the concepts of deposition velocity and scavenging ratio to study the removal mechanisms of heavy metal constituents of the aerosol in a sawdust open burning area. The aerosol concentration of the area was determined using gravimetry method with a high volume sampler fitted with a two-filter holder and exposed filters. A sampling period of 6-hours was adopted. Twenty seven deposition gauges were deployed to the sampling site to measure the flux of settleable particulate matter. Aerosol samplings and deposition flux rates measurements were carried out in the area in the wet (July, 2008; May, 2009) and dry (October, 2008; February, 2009) seasons. The measured average deposition flux rates in wet were evaluated to be 1.092 x 10-3 µgm-2s-1 in July, 2008; 1.388 x10-3 µgm-2s-1 in May, 2009 while that of dry season were evaluated to be 1.587 x 10-3 µgm-2s-1 in October, 2008 and 1.933 x 10-3 µgm-2s-1 in February, 2009. The calculated deposition velocities for the trace metals in the area had values between 3.87 x 10-7 – 2.11 x 10-4 m/s while the estimated scavenging ratios were found to be between 0.82 – 1224.31 in the study area. The results showed that Cd, Pb, and Sb are better removed through gravitational settling of particles while Fe, Mn, Cr and Ti are scavenged by precipitation.
References
E. Furimsky, Characterization of Trace Element Emissions from Coal Combustion by Equilibrium Calculations, Fuel Processing Technology, 63, 2000, 29-44
J. Mohn, R. Figi, P. Graf, E. Gujer, R. Haag, P. Honegger, P. Mattrel, O. Nagel, P. Schmid, C. Seiler, C. Schreiner, E. Steinhauser, M. Zennegg, L. Emmenegger. Wood Combustion – Clean Energy In: proceedings of 5th International Conference on Emission Monitoring, Odence, Denmark, September, 2002.
K.G. Westerland, Metal Emissions from Stockholm Traffics – Wear of Brake Linings; Report from SLB – Analysis, Environment and Health Protection Administration in Stockholm, Stockholm, 2001.
W. L. Flower, L. W. Peng, M. P. Bonin, N. B. French, H. A. Johnsen, D. K. Ottesen, R. F. Renzi, L. V. Westbrook. A Laser-based Techniques to Continuously Monitor Metal Aerosol Emissions, Fuel Processing Technology, 39,1994, 277 – 284
R. M. Harrison, In: R. M. Harrison, R. Perry (Eds.), Handbook of Air Pollution Analysis, Champman and Hall, London, 1986.
J. H. Seinfeld and S. N. Pandis, Atmospheric Chemistry and Physics of Air Pollution, Willey Inter- science, New York, 1998.
J.E. Jonson and E. Berge, Some Preliminary Results on transport and Deposition of Nitrogen Compounds by Use of the Multi-layer Eularian Model. EMEP/MSC-W Note 1/95. The Norwegian Meteorological Institutes, Oslo, Norway, 1995.
H. A. Jacobson, J.E. Jonson, E. Berge, Status of Development of the Multi-layer Eularian Model, (a) Model description; (b) New Method for Calculating Mixing Heights; (c) Model Results for Sulphur Transport and deposition in Europe for 1992 in 50km Grid. EMEP/MSC-W Note 3/95. The Norwegian Meteorological Institutes, Oslo, Norway, 1995.
J.W. Erissman, W.A.J. Van Pul, and G.P. Wyers, Parameterization of Surface Resistance for the Quantification of Atmospheric Deposition of Acidifying pollutants and Ozone. Atmospheric Environment, 28(16), 1994, 2595-2607
O. Seland, A. Van Pul, A. Sorteberg, and J.P. Tuovinen, Implementation of a Resistance Dry Deposition Module and a Variable Local Correction Factor in the Langrangian EMEP Model. EMEP/MSC-W Reports 3/95. The Norwegian Meteorological Institute, Oslo, Norway, 1995.
H.A. Jacobson, J.E. Jonson, E. Berge. Transport and Deposition Calculations of Sulphur and Nitrogen Compounds in Europe for 1992 in the 50km Grid by Use of the Multi-layer Eularian Model. EMEP/MSC-W Note 2/96. The Norwegian Meteorological Institutes, Oslo, Norway, 1996.
E. Berge. Preliminary Estimates of Sulphur transport and Depositions in Europe with a Regional Scale Multi-layer Eulerian Model. EMEP/MSC-W Note 1/93. The Norwegian Meteorological Institute, Oslo, Norway, 1993.
B. Herut, M. Nimmo, A. Medway, R. Chester, M.D. Krom. Dry Atmospheric Inputs of Trace Metals at the Mediterranean Coast or Israel (SE Mediterranean), Sources and Fluxes”, Atmospheric Environment, vol. 35, 2001, 803-813.
F. A. Akeredolu, Lecture Note on Advanced Topics in Environmental Engineering, Unpublished, Department of Chemical Engineering, Obafemi Awolowo University, 2006.
N. Jarostz, B. Loubet, B. Durand, A. McCartney, X. Foeillassar and L. Huber, Field Measurements of Airborne Concentration and Deposition Rate of Maize Pollen, Agricultural and Forest Biology, 119, 2003, 37-51
G. Geroza, A. Finco, S. Meren, R. Marzuoli and B. Denti, Interractions Among Vegetation and Ozone, Water and Nitrogen Fluxes in a Coastal Mediterranean Marquis Ecosystem Biogenic Discursion, 6, 2009,1453-1455
M.A. Abegunde, Description and Characteristics of Physical Environment of Lagos State, Unpublished, B. Sc Thesis, Department of Geography, Lagos State University, 1986.
P.K. Hopke, Y. Xie, T. Raunema, S. Biegalski, S. Landsberger, W. Maenhaut, P. Artaxo, D. Cohen, Characterization of the Gent Stacked Filter Unit PM10 Sampler, Aerosol Science and Technology 27,1997,726-735.
S.C. Lee, Ho, C.K. Chan, J.C. Yu, J.C. Chow, and X.H. Yao, Characterization of Chemical Species in Pm2..5 and Pm10 Aerosols in Hongkong. Atmospheric Environment 37, 2003, 31-39.
C. Liousse, J.E. Penner, C. Chuang, J.J. Walton, H. Eddleman, and H. Cachier. A Global Three-Dimensional Model Study of Carboneous Aerosols. Journal of Geographycal Research 101 (D14), 1996, 19411-19422.
W.F. Cooke and J.J.N. Wilson, A Black Carbon Aerosol Models. Journal of Geophysical Research 101 (D14), 1996,19395-19409.
J.E. Penner, H. Eddleman, and T. Novakov, Towards the Development of a Global Inventory for Black Carbon Emissions, Atmospheric Environment 27A, 1993, 1277-1295.
I. Tegen, and I. Fung, Contribution to the Atmospheric Mineral Aerosol Load from Land Surface Modification. Journal of Geophysical Research 100 (D9), 1994, 18707- 18726.
M. Sakata and K. Marumoto, Annual Changes in Wet Deposition Fluxes of Trace metals and Scavenging of Mercury by Precipitation in an Urban Area, CRIEPI Report No T03015 (in Japanese), 2004.
