The role of reversibility in flocculation of heavy metals in the estuarine zone

After discover of flocculation process in estuaries, there was a significant change in calculation of dissolved metals load entering sea and other saline water environments through rivers. In other words, due to mixing of fresh and saline water in an estuarine zone, a significant amount of heavy metals flocculate and settle in the estuarine zone. In the present research, the flocculation process of heavy metals in Shfarud River is investigated during estuarine mixing with Caspian Sea water. Results indicated that that Cd, Cr, Co and Ni lose their initial load by 86, 74, 62 and 52 percent, respectively. Furthermore, an updated method, which is considered as one achievement, was used to simulate the estuary in this research. Actually, it is showed that flocculation process could be a reversible process. In other words, due to continuous chemical and physical change of estuary environment, flocs of metals might return to dissolve phase.