Flocculate

I. P. Roberts When applied to clay soils it [lime] binds the small particles together, or flocculates them.

For example when the Mississippi water flows into the saline water of the Gulf of Mexico, much of the matter that was held suspended in the river-water is flocculated at once, so that it can subside. Such action as this is one prime cause of the formation of deltas, for the flocculation of fine mud by salt is common to all rivers that reach the sea.