الفهرس | Only 14 pages are availabe for public view |
Abstract Due to large production of both low level radioactive liquid and toxic industrial wastes, aquatic plants are used to absorb undesirable ions from waste solutions. The present work illustrates, the uptake of so111e metal ions existed in low level liquid radioactive or industrial wastes namely U VI, Th IV, Ce Ill, Fe Ill, KMn04, Cu II, Pb II, Ni II, Cd II and phenol by Eichornia crassipes or Potamogeton crispus plant. The uptake process was performed for each metal ions, and in presence of some additives then for groups of metals, which represent, the radioactive and toxic wastes. The changes in photosynthetic pigments of the leaf, toxicity index and the carbohydrate contents of Eichornia crassipes and Potamogeton crispus plants before, during and after the uptake process were determined. The obtained results were supported by applying electron microscope techniques to examine the photosynthetic apparatus. The effects of some environmental parameters such as pH, temperature, concentration, interference of some additives and plant age on the uptake and accumulation of the studied elements by the two aquatic plants were also investigated. The variation in mineral composition of Eichornia crassipes plant at different sites along lsmailia canal compared with the mineral composition in water at these sites showed that, Fe, Ni, Cd and Pb ions were accumulated in roots in greater amounts than in shoots, while a reverse pattern was shown concerning Cu ions accumulation. In addition, the distribution ofMn ions was shown to be nearly the same in both shoots and roots of Eichomia crassipes plants. It is of interest to mention here that one gram of Eichomia roots can accumulate 8.2, 7.2, 3.4, 1.6 and 1.2 times from Fe, Mn, Cd, Ni and Pb ions respectively as those recorded in water. These absorbed metal ions did not affect the photosynthetic pigment contents and the carbohydrate levels indicating that this plant is tolerant to the absorbed concentrations of metal ions. The two examined plants revealed specific pattern for the uptake of studied metal ions, with regard to time. They could be used as bioindicator to monitor their existence in fresh water environment. They can detect such metal ions if possible radioactive contamination in the surrounding . environmental water is occurred. Eichomia crassipes and Potamogeton crispus could be used eventually for treatment of low level liquid radioactive or toxic wastes. It can be recommended that the treated plants with the studied metal ions should be collected directly after 10 hours of the beginning of the u a . |