NITRATE, SULPHATE AND HEAVY METALS IN LEAVES OF SELECTED PLANTS IN BOTANICAL GARDENS OF TWO NIGERIAN UNIVERSITIES

The levels of sulphates (SO42-), nitrates (NO3-) and selected heavy metals (Pb, Cd, Fe, Mn and Cr) in leaves of six tree species taken from botanical gardens of two Nigerian Universities, University of Lagos (Unilag) and University of Ilorin (Unilorin) were investigated with the aim of assessing the potential of the trees to bio-accumulate pollutants. The tree species were; Almond tree (Terminalia catappa), Cashew tree (Anacardium occidentale), Mango tree (Mangifera indica), Orange tree (Citrus sinensis), Masquerade tree (Polyalthia longifolia) and Jungle flame tree (Ixora coccinea).The concentrations of sulphates and nitrates in the leaf samples were determined using UV/Visible spectrophotometer, while heavy metals were determined using Atomic Absorption Spectrophotometer. Almond tree leaves of the two botanical gardens have the ability to bio-accumulate both sulphates and nitrates with average .... KEY WORDS: Bio-accumulation, Sulphates, Nitrates, Heavy metals, Botanical garden