PHYSICO-CHEMICAL CHARACTERISTICS OF TIN MINING POND WATER USED FOR IRRIGATION IN PLATEAU STATE, CENTRAL NIGERIA

The present work was conducted by monitoring the water from twelve major tin mine ponds water in Plateau State, North Central Nigeria (Bokkos, Barkin – Ladi and Jos – South) used for irrigation. Their quality was assessed in terms of physico-chemical parameters for dry and rainy seasons. The physico-chemical parameters such as; Turbidity, pH, Temperature, Electrical Conductivity (EC), Cation Exchange Capacity (CEC), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), Total alkalinity (TA), Total Hardness (TH), Dissolved Oxygen (DO), Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Phosphate (PO43-), Sulphate (SO42-), Chloride (Cl- ), Fluoride (F-), Sodium (Na+) and Potassium (K+)  were investigated to ascertain the water quality for irrigation purposes. Water quality parameters with regards to its use for the purpose of irrigation such as FAO/WHO/FEPA standards satisfy the requirement for use in agriculture. However, turbidity which ranged from18.1 – 27.4 and 15.9 – 18.8, dissolved oxygen 20.9 – 26.3 and 20.2 – 27.4 mg/L, Total alkalinity 101 – 134 and 122 – 167mg/L, total phosphate 6.3 – 8.9 and 6.5 – 10.5 mg/L, BOD 7.4 – 23.8 and 7.2 – 29.2 mg/L, potassium 1.13 – 1.18 and 3.81 – 4.63 mg/L both in dry and rainy seasons, respectively were found to be above the irrigation water standard limits. The study therefore recommends that the mining pond water should be used with caution as some of the parameters are liable to be toxic to the irrigated crops. The positive correlation exhibited among some of the parameters examined is a clear indication of a common relationship between these sources of water.