Particulate heavy metal transport in the lower Paraiba do Sul River basin, southeastern, Brazil

In the present study an attempt has been made to calculate the mass transfers of suspended particulate matter and associated heavy metal within the lower portion of the Paraiba do Sul River drainage basin and the contribution of its tributaries. The highest metal loads were related with the highest water flows and, consequently, with the highest suspended particulate matter loads, which increased both by surface runoff and sediment resuspension. The highest flow month for the total transported load contributed between 34 and 66% of the total metal transported per year. The total load transported during the entirerainy season ranges from 82 to 93% of the total transported load. The importance of the tributary input for the total transported load ofthe Paraiba do Sul River was generally lower than 10%, although in some months, when the Paraiba do Sul River had low water discharge andstrong local rain occurred, this increased upto 40%. [ABSTRACT FROM AUTHOR]