Abstract:
The possibility of using phytoremediation by a weed plant species in Thailand to remove chromium (Cr) from soil and water was studied. A weed plant species was studied because it has no economic value and is a burden on the environment as agricultural waste. Phyllanthus reticulatus Poir., which has an ability to accumulate total chromium (TCr) was chosen for the study. This plant species was planted in pots which had a Cr concentration of 0 and 100 mg/kg. TCr accumulation capacity of the roots, stems and leaves on this plant was 390.57, 61.47 and 58.67 mg/kg of plant on a dry weight basis after 30 days, respectively, at a pulse hexavalent chromium [Cr(VI)] concentration. The trivalent chromium [Cr(III)] uptake by Phyllanthus reticulatus occurred mainly in roots, stems and leaves and measuring 291.35, 3.43 and 3.35 mg/kg of plant on a dry weight basis, respectively. After 30 days of dosing, Phyllanthus reticulatus had Cr(VI) accumulation in roots, stems and leaves of 99.21, 58.04 and 55.32 mg/kg of plant on a dry weight basis of the Cr(VI) input, respectively. Aside from using phytoremediation, Cr removal with Phyllanthus reticulatus using hydroponics was also studied. Artificial wastewater was derived by using potassium dichromate, with concentration of 5, 10 and 15 mg/L. Phyllanthus reticulatus had TCr accumulation in the roots, leaves and stems of 6,616.12, 14.46 and 0 mg/kg, respectively, of plant on a dry weight basis after 60 days with Cr(VI) concentration at 15 mg/L. The Cr(III) uptake by Phyllanthus reticulatus occurred mainly in roots, leaves and stems and registered 5,790.03, 8.04 and 0 mg/kg, respectively, after 60 days of dosing. Cr(VI) accumulation capacity of the roots, stems and leaves in this plant was 826.15, 6.41 and 0 mg/kg, respectively, after 60 days. The results on Cr accumulation and translocation in the plant tissues suggest that Cr was removed mainly via phytoextraction. Thus Phyllanthus reticulatus is suitable for the remediation of Cr contaminated soil and water.