A study on arsenic uptaking capacity of water hyacinth

Water hyacinths are free-floating aqueous weeds which can accumulate metals. They have fibrous roots and obtain all of their nutrients from the water. Determination of arsenic uptaking capacity of water hyacinth in arsenic-contaminated water is the main objective of the study. Total of 1350 grams wet water hyacinths were taken from adaptation tank which was collected from the Lake of Shahjalal University of Science and Technology (SUST) campus and were maintained in 27 L tap water supplemented with 0.4, 0.5, 0.6, 0.8, 1.0 and 1.5 mg/L of As in three glass tanks and the test durations were 0, 6, 12, 24, 36, 48 and 72 hours. Samples were collected from three glass tanks and arsenic remained in the solution was measured by Silver Di-ethyl Di-thyo Carbamate (SDDC) method. It was found that the remaining concentration reached below the permissible limit 0.05 mg/L (Bangladesh drinking water quality standard) on or before 48 hours for initial concentration 0.4, 0.5 and 0.6 mg/L of As. But for higher initial concentration (0.8, 1.0 and 1.5 mg/L) the remaining concentration started to increase after 48 hours. So the gross effective floating period for water hyacinth is 48 hours up to initial concentration 0.6 mg/L