FLOCCULATION OF SUSPENDED SEDIMENT IN RIVERS OF SOUTHEASTERN CANADA

Flocculation has been studied extensively within marine science and sa nitary engineering and the controlling processes are generally well kn own. Less research, however, has focused on flocculation within the fr eshwater river environment. Consequently the occurrence, importance an d controlling mechanisms are poorly understood. We examine the suspend ed sediment characteristics of six rivers in southeastern Canada in or der to determine the nature and significance of flocculation in fine-g rained suspended sediment transport and the factors that may influence it. While flocs may not always comprise the majority of particles in transport, they always represent more than 90% of the total volume of sediment transported. Independent variables that may influence floccul ation, such as temperature, pH, major ions, dissolved and particulate organic carbon, suspended solids concentration and bacteria were measu red in conjunction with floc size for one of the rivers. Particulate o rganic carbon concentration, suspended solids concentration and attach ed bacteria may be important controlling factors of riverine flocculat ion.