The Research Of Decontamination For Heavy Metals Of Seawater By Halophyte From Coastal Area

Phytoremediation is a new technique to clean up contaminated soils by some accumulators or hyperaccumulators which can absorb exceptionally large amount of heavy metals from the environment and translocate them into plants. Presently, the researches of phytoremediation for heavy metals focus on fresh water and inland soil but not estuary. The major objectives of this study were testing the salinity tolerance of different halophytes in Laizhou coastal area, then choosing the durable plant to identify the tolerance and heavy metal bioaccumulation of Pb, Cd, Cu, Zn by halophytes both in static and dynamic experimentations. Based on the data, the main results can be summarized below.1. The germination rate of Suaeda salsa, Suaeda heteroptera Kitag, Kochia scoparia was high, while that of Artemisia annua, Apocynum venetum and Datura innoxia was too low. Moreover, compared with Suaeda heteroptera Kitag and Kochia scoparia, Suaeda salsa has higher salinity endurance and can grow in the seawater with the salinity below 10.2. Suaeda Salsa seedlings can normally grew in low concentrations (Environmental quality standard for surface water(â…¤)) of separate Pb, Cd, Cu, Zn. In all experiment levels, the bioaccumulation of heavy metals in plant increased with the increasing concentrations of heavy metals in the water, and the contents of heavy metals in roots were higher than that in shoots.3. The following eightweek study of the tolerance and heavy metal bioaccumulation of separate Pb, Cd, Cu, Zn by Suaeda Salsa indicated that the plant can grow normally in seawater at a salinity of 10 under low concentrations of heavy metals(Sea water quality standardâ…£)conditions. The bioaccumulation of heavy metals in roots and shoots increased with the increase of heavy metals in the seawater. As the biomass increased, the gross heavy metals in plant was higher than that in fresh water.4. Suaeda Salsa can also endure salt and heavy metals mixed stresses in the dynamic experimentation. The concentration of heavy metals in seawater at a salinity of 10 descended obviously.The removal rates of Cd, Cu, Zn were more than 75%, separately.5. Analyzing the tolerance and accumulation of salinity and heavy metals by Suaeda Salsa both in static and dynamic experimentations.Suaeda Salsa was considered to have potential for phytoremediation of estuary containing heavy metals.