Transport of the colloid matter of riverine runoff through estuaries

A procedure for separating the colloid component of natural waters is proposed. It was shown that this component is the main form of matter transfer in Ob River runoff, because the mass of colloid substance is two orders of magnitude higher than that of particulate matter in the outer part of the estuary. Simulation and field experiments revealed the influence of nature and concentration of organic matter on their ability to stabilize or flocculate clay particles with an increase in salinity, thus affecting the range of transfer of riverine runoff matter. It was shown that the interaction of humic acids and clay particles, as well as the increase in hydrophobic properties of a flocculant, improve flocculation efficiency. Criteria are proposed to recognize in the estuarine region areas of pronounced contribution of flocculation processes to sedimentation of fine particles. It is shown that the newly formed organic matter produced by biota under saline stress might be flocculants of fine particulate matter.