| || || Atmospheric deposition -- Fiji -- Measurement|
| || || A study of atmospheric deposition of nutrients and flux measurements in Fiji|
Author: Singh, Joslin Ashna
Institution: University of the South Pacific.
Subject: Atmospheric deposition -- Fiji -- Measurement
Call No.: pac TD 427 .A84 S54 2012
Copyright:10-20% of this thesis may be copied without the authors written permission
Abstract: This thesis investigates the deposition of nutrients; nitrate, sulphate and phosphate in aerosols and rainwater. Data was collected simultaneously at Koronivia; the windward side and Lautoka; the leeward side of Viti Levu, Fiji from September 2007 to September 2008. This sampling period coincided with two dry and one wet season. High Performance Ion Chromatographic technique was employed to determine the concentration of nutrients in both sets of samples. The precision of the aerosol data at KRS and LKA respectively was calculated to be: 0.61 % & 4.73 % RSD for nitrate, 0.44 % & 3.50 % RSD for sulphate and 5.03 % & 3.66 % RSD. Whereas for rainwater: 6.20 % & 3.58 % RSD for nitrate, 0.37 % and 2.99 % RSD for sulphate and 4.01 % & 3.79 % RSD for phosphate. Seasonality was observed to influence the nutrient flux at both the sites. Higher deposition of all nutrients was observed during the dry and winter season of 2008 at LKA; for aerosols and rainwater except for SO4 2- in rainwater which was greater during the wet and summer season of 2008. Whereas, at KRS, the aerosol flux of NO3 - and SO4 2- was greater during the dry and winter season of 2008 and PO4 3- during the wet and summer season of 2008. While for rainwater flux at KRS, NO3 - and PO4 3- were greater during the wet and summer season of 2008 and SO4 2- during the dry and winter season of 2007. The annual nutrient fluxes in aerosol samples were; 1,280 ± 3.1 mg/m3, 11,577 ± 30 mg/m3, and 122.3 ± 0.57 mg/m3 at KRS and 3,655 ± 8.5 mg/m3, 10,679 ± 25 mg/m3 and 310.73 ± 0.90 mg/m3 at LKA for NO3 -, SO4 2- and PO4 3- respectively. On the other hand, the nutrient fluxes in rainwater samples were; 397.9 ± 2.0 μeq/L, 8,824 ± 42 μeq/L, and 35.77 ± 0.4 μeq/L at KRS and 7,218 ± 28 μeq/L, 18,730 ± 69 μeq/L and 6,991 ± 42 μeq/L at LKA for NO3 -, SO4 2- and PO4 3- respectively. This study indicates that the dry deposition is the predominant pathway for nutrient flux at KRS while the wet deposition predominates at LKA.