Chemical Composition of Wet Precipitation in Ibadan, Nigeria

Abstract

Rainwater samples were collected for four two-weekly periods at nine sampling points in the city of Ibadan, Nigeria, during May-July, 1999, and analysed for pH, sulphate, nitrate, chloride, phosphate, sodium, potassium, calcium, and magnesium. The rainwater was predominantly neutral with pH values ranging between 5.8 and 7.0, and averaging 6.60.3. Average concentrations (eq/L) for all the sampling points and sampling periods were: SO42- (4622), NO3- (1.60.3), Cl- (1113), PO43- (3.21.8), Na (11.77.9), K (5.64.4), Ca (3026), and Mg (1.28.8). Concentrations of the various ions in the rainwater decreased slightly with the progress of the sampling period. The deposition flux (kg km-2 month-1) was estimated as: SO42- (390), NO3- (16.8), Cl- (67.6), PO43- (17.5), Na (46.6), K (37.9), Ca (104), and Mg (21.5).


(Bulletin of The Chemical Society of Ethiopia: 2002 16 (2): 141-148)