Search Results

Now showing 1 - 2 of 2

Accumulation of chromium and zinc from aqueous solutions using water hyacinth (Eichhornia crassipes)
(2009) Virendra Kumar Mishra; B.D. Tripathi
Under present investigation Eichhornia crassipes (water hyacinth) has been tested for removal of two important heavy metals chromium (Cr) and zinc (Zn) from metal solution. This species was grown at four concentrations of Cr and Zn, i.e. 1.0, 5.0, 10.0 and 20.0 mg l-1 in single metal solution. This plant has performed extremely well in removing the Cr and Zn from their solution and was capable of removing up to 95% of zinc and 84% of chromium during 11 days incubation period. Removal of Cr at lower concentrations (1.0 and 5.0 mg l-1) was found harmless, without any symptom of toxicity but at 10.0 and 20.0 mg l-1, plants have shown some morphological symptoms of toxicity. On the other hand E. crassipes removed Zn safely at all the four concentrations, i.e. 1.0, 5.0, 10.0 and 20.0 mg l-1. In this case morphological symptoms of toxicity were not evident in the test plant. Biochemical parameters viz. protein, sugar and chlorophyll in experimental plants have shown a decreasing trend due to accumulation of Zn and Cr. Overall this methodology is safe for the removal of Zn and Cr and can be utilized at large scale after few further investigation. © 2008 Elsevier B.V. All rights reserved.
Removal and accumulation of mercury by aquatic macrophytes from an open cast coal mine effluent
(2009) Virendra Kumar Mishra; B.D. Tripathi; Ki-Hyun Kim
In this study, the mercury (Hg) removal capacities of two aquatic macrophytes, Pistia stratiotes and Azolla pinnata, were investigated against the coal mining effluent. These plants reduced mercury from the effluent via rhizofiltration and subsequent accumulation in plant. The removal rate of P. stratiotes and A. pinnata was 80% and 68%, respectively, after 21 days of exposure to the effluent containing 10 μg L-1 of Hg. As mercury from the effluent was accumulated in the root and shoot tissues of both aquatic macrophytes, they were proven to be a root accumulator with a translocation factor of less than one during the entire study. The decreasing Hg content in effluent (from 10 to 2.0 μg L-1) was reflected by its accumulation in roots (0.57 ± 0.02 mg g-1 in P. stratiotes) and leaves of the experimental plants (0.42 ± 0.01 mg g-1, P. stratiotes). As a result, Hg concentrations in the coal mining effluent were tightly associated with those observed from macrophytes. Considering the high removal efficiencies of Hg by these aquatic macrophytes, these plants can be recommended for the actual treatment of Hg-containing waste waters. © 2009 Elsevier B.V. All rights reserved.

2009

Browse

Filters

Settings

Sort By

Results per page

Search Results