<b>Chemical composition of wet precipitation in Ibadan, Nigeria</b>

• Main Authors: P.C. Onianwa, O.O. Odukoya, H.A. Alabi
• Format: Article
• Language: English
• Published: Chemical Society of Ethiopia 2002-12-01
• Series: Bulletin of the Chemical Society of Ethiopia
• Online Access: http://www.ajol.info/index.php/bcse/article/view/20936

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 6.6 plus or minus 0.3. Average concentrations (&mu;eq/L) for all the sampling points and sampling periods were: SO₄^2- (46 plus or minus 22), NO₃^- (1.6 plus or minus 0.3), Cl^- (11 plus or minus 13), PO₄^3- (3.2 plus or minus 1.8), Na (11.7 plus or minus 7.9), K (5.6 plus or minus 4.4), Ca (30 plus or minus 26), and Mg (1.2 plus or minus 8.8). 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: SO₄^2- (390), NO₃^- (16.8), Cl^- (67.6), PO₄^3- (17.5), Na (46.6), K (37.9), Ca (104), and Mg (21.5).