Abstract:
Remediation of heavy metal contaminated soil and water has been investigated through various methods,
most of these have been shown to be expensive and sometimes result in the generation of toxic sludge. In situ
methods such as phytoremediation have therefore been explored for their green, economical and less
environmentally disruptive advantages. This study investigates the use of vetiver grass in the remediation of
chromium(VI) from wastewater. The grass is known to grow in both soil and water. The efficiency of the vetiver
grass in the removal of Cr(VI) was examined using 2 L solutions of varying concentrations. The initial
concentrations of Cr(VI) chosen for the study were 5 ppm, 10 ppm, 30 ppm and 70 ppm. In a seven (7) week
period, 87 % reduction in Cr(VI) concentration was observed in the 5 ppm bucket, while 51 % Cr(VI) removal
was measured in the 10 ppm bucket. The 30 ppm bucket had a removal efficiency of 28 % in 5 weeks and
12 % removal efficiency in 4 weeks was measured in the 70 ppm bucket. The absorption of chromium was
higher in the roots than the leaves at 5 ppm and 10 ppm, whereas it was higher in the leaves than in the roots
at 30 ppm and 70 ppm. The results show the potential of vetiver grass in phytoextraction of chromium and its
hyperaccumulator potential for other heavy metals.
