Removal of Cyanide-Contaminated Water by Vetiver Grasses

Abstract

Vetiver grass and it usages have been widely investigated in many researches as the preferred plant species due to its known efficiency, low cost, the ease of availability and spread. This research aimed to use four different vetiver grass ( Vetiveria zizanioides) ecotypes to remove cyanide (CN -)-contaminated water for improve its quality. Growth capability, tolerance and removal efficiency were evaluated. The results showed that the vetiver grass had a 100% survival rate for one month after planting. Songkhlar3 had the longest leaves, followed by Surat-Thani, Sri Lanka and Monto, respectively. Root lengths of all ecotypes showed no significant differences (p ≤ 0.05). All vetiver grass ecotypes could potentially purify CN - -contaminated water at lower concentrations of ≤ 35 mg CN - /L. The Monto ecotype had the highest CN - removal efficiency at all CN - concentration levels, showing 100% CN - removal from the 5-45 mg CN - /L contaminated water samples within 2-5 weeks growth. The tolerance of vetiver grass to CN - was a more important factor than growth rate when selecting a vetiver grass ecotype for CN - phytoremediation.