TITLE:
Chemical Composition and Source Characterization of Hailstones in Dhaka, Bangladesh
AUTHORS:
Rasheda Aktar Samiha, Morshad Ahmed, Mohammad Shohel, Abdus Salam
KEYWORDS:
Hailstone, Water Soluble Ion, Trace Metal, Source Apportionment
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.6 No.9,
September
5,
2018
ABSTRACT: A comprehensive analysis on the chemical composition and source apportionment of hailstone samples were conducted in Dhaka, Bangladesh. pH, electrical conductivity (EC), total dissolved solids (TDS), water soluble ions (Na+, K+, Ca2+, Mg2+, Cl-, SO42-, NO3-, HCO3-) and trace metals (Zn, Fe, Cu, Mn) of hailstone were determined. The result revealed that the average pH, EC, TDS were 6.95 ± 0.54, 356.3 ± 150.6 μS·cm-1 and 17.5 ± 2.89 mg·L-1, respectively. The water soluble ions followed the order: Ca2+ > Cl-1 > SO42- > HCO3- > Na+ > Mg2+ > K+ > NO3-. The concentrations of trace metals ranged in order with Zn > Fe > Cu, while the concentration of Mn was below detection limit. Sodium adsorption ratio (SAR) was 0.20 ± 0.09 meqL-1 which indicates it is benign to plants and safe for irrigation. The order of neutralization factor (calculated with average concentrations) found in hailstone was NFCa(1.16) > NFMg (0.36) > NFK(0.32) which were originated from earth crust. Notable correlation was found in between soil tracers Ca2+ and Mg2+ (r = 0.87), indicating their common source dust. Enrichment factor analysis revealed that Ca2+, Mg2+ and K+ are mainly from crust, whereas NO3- and SO42- are mainly attributable to anthropogenic origins. Further source contribution analysis revealed that anthropogenic actions accounted for 99.2% of total NO3- and 89.6% of total SO42-, while 99.2% of total Ca2+ and 95% Mg2+ were from crustal source.