Utilization of Water Hyacinth (Eichhorniacrassipes) for Phytoremediation of Hexavalent Chromium in Simulated Wastewater

One of the most common sources of contamination in surface water is the discharge of waste water containing heavy metals from different industrial applications.Methods in the removal of contaminants like hexavalent chromium, Cr+6 ,that are available nowadays are too costly and difficult to operate efficiently. A new approach to solve such problem is Phytoremediation or the use of green plants in the removal of contaminants from wastewater that contains heavy metals.In this study, the effectiveness of water hyacinth (Eichhorniacrassipes) was evaluated for its capability in removing hexavalent chromium from simulated wastewater.The effect of a co-ion, specifically Cu2+ ions, on the percentage removal of Cr6+ was also studied. Diphenyl carbazide colorimetric method was used to quantify the amount of Cr6+ left after treatment with water hyacinth.The percentage removal of Cr6+ was determined under varying conditions. The parameters varied were concentration of Cr6+ (3, 6, & 9 mg/L), contact time (4, 8, and 12 days) and concentration of Cu2+ (0, 4, and 8 mg/L). Results showed that the percentage removal of Cr6+ is directly proportional to the initial concentration of Cr6+ and contact time but inversely proportional to the concentration of co-ions which is Cu2+ ions. Results and statistical data showed that the optimum condition for phytoremediation of Cr6+ using water hyacinth is 12 days of contact time, and initial concentrations of 9 mg/L and 4 mg/L of Cr6+ and Cu2+ respectively.Overall results indicated that Eichhorniacrassipes can be used for phytoremediation of Cr+6contaminated wastewater.

Keywords: chromium, phyto remediation, water hyacinth, wastewater treatment,