TRACE-METAL IONS IN GANGA WATER-SYSTEM

Our observation gives the total influx of metal calculated on the basis of a formula derived as follows: C= 0.83 Cp + 0.17C. Influx of metal = C ̄ X volume of water discharge annually Where C̄ is the average cocentration of metal in river water, Cp is the concentration of metal at peak flow, C is the average concentration of metal between moderate and lean flows. The discharge constants 0.83 and 0.17 are for peak and rest of the year flows, respectively. Our data here show that the river Ganges at Uluberia (80 Km upstream from the mouth of Bay of Bengal) transports 0.00005 million tons (MT) of As and Cd, 0.015 MT of Cr, 0.007 MT of Cu, 4.1 MT of Fe, 0.014 MT Pb, 0.056 MT of Mn, 0.005 MT of Ni and 0.14 MT of Zn each year. The quantity of trace metals are dictated by the weathering of rocks and minerals, soil erosion, industrial activities and influxes from various tributaries. Most of the metals were found highest during peak flow followed by moderate flow and lean flow. Trace metal composition of the river Ganges is comparable to that of Rhine and less than those of the Amazon and the Mississipi. © 1990.