Mitigation of Arsenic by Water Hyacinths (Eichhornia crassipes) Plant

Abstract

Water hyacinth (Eichhornia crassipes) plant removes arsenic remarkably both from artificial arsenic solution and naturally arsenic contaminated ground water. Two clay containers (locally known as "Chari"), one with water hyacinth plant in distilled water as a control and another with water hyacinth plant in artificial arsenic solution (0.3 mg/l) was used to set up the experiment. The arsenic concentration of the water was tested over multiple trails using a Hach colorimetric test kit. It was observed that water hyacinth reduced arsenic level from 0.3 mg/l to 0.01 mg/l for one trail, 0.05 mg/l for two trails and lost all ability to remove arsenic after five trails. Again, water hyacinth plant was placed in a clay container in which naturally arsenic contaminated (0.8 mg/l) ground water was used for a period of one month. Sampling was conducted in every two successive days. Rate of arsenic extraction through water hyacinth plant was higher in first two weeks and after that it seems to be constant. All laboratory tests were performed by SDDC method to determine arsenic content in root, bladder and leaves of hyacinth plant. About 40–50% arsenic was removed through water hyacinth from arsenic contaminated ground water. Roots, bladders and leaves of hyacinth plant absorbed most of the removed arsenic.