Transportation, Distribution And Removal Of Heavy Metal Pollutants In The Estuary

Estuary has been affected by the drainage from upstream and the tide level from downstream for a long time. Lead to secondary pollution of heavy metals. Moreover, it cause biological death and difficulties for drinking water. In order to protect the ecosystem environment of estuary, guard the safety of drinking water and human health, it is necessary to study the pollution of heavy metals of estuaries. Therefore, this paper is based on heavy metals' pollution problems in estuary, studied on heavy metals' migration, distribution and the removal of heavy metal contaminants.Firstly, using a new water quality model (TITech-WARM (Tokyo Institute of Technology Water Reservoir model)) in the environmental field in recent years, and choosing a estuary (Kitakami Estuary in Japan) on the distribution and migration of heavy metal pollutants were studied. The results show that the heavy metal pollutants mainly migrate to the river channel and the concentration gradually increase after 8 days; and the entire river channel has covered by the heavy metal pollutants and the concentration of heavy metal pollutants with a further increasing trend after 16 days; After 24 days, the result shows the vast majority returned with the water heavy metal pollutants in the estuary and sea again, and the concentration gradually decrease. Above all, the heavy metals'distribution and migration emerge a certain concentration gradient at all times throughout the simulation process. The estuarine circulation is the driving force of this process, the heavy metal contaminants migration was driven by the movement of water flow.Secondly, a method for the estuary of heavy metals pollutants at all the times with a certain concentration gradient was proposed, which was used aerosol carbothermal reduction synthesis of iron-carbon (Fe-C) composites. In this paper, the representative heavy metal pollutant Cr (?) with widely variety of sources, the presence of varied shapes, harmfulness to ecological environment was selected to treatment. The removal mechanism of Cr (?) using this composite was studied in detail. The results showed that the Fe-C composite has good effect of absorption-reducing synergies for Cr (?), the removal efficiency up to 98.6%. The reason is that C can effectively adsorbed Cr (?), thus increasing the Cr (?) concentration near Fe. So that Cr (?) can targeted in contact with the Fe and realize synergy of absorption and reduction while overcoming the mass transfer problems.In summary, this paper combined simulation with experiment. Simulation avoids the problems of sampling cumbersome and data lag by traditional research methods, at the same time, the simulation results indicate the direction of experiment. Based on the results of simulation, proposing aerosol carbothermal reduction to synthesis Fe-C nano-composite to remove heavy metal pollutants Cr (VI) was studied. The results show that it has good ability of absorption and reduction synergies. Meanwhile, it can achieve a complete removal of heavy metal pollutants in low concentration gradient of the estuary.