Comparative Study of Chrysopogon nitrigana (Vetiver Grass) and Cymbopogon citratus (Lemon Grass) for Heavy Metal Removal from Industrial Effluent

Abstract

The introduction of foreign materials such as the heavy metals into the environment is attributed to the major reason of environmental adulteration, a major hazard to life and the total ecosystem. Plants have shown great potency in the biosorption of these toxic elements from the environment. Two terrestrial plants; Cymbopogon citratus (lemon grass) and Chrysopogon nitrigana (vetiver grass) have been used in the present study for the uptake of four heavy metals (cadmium, lead, copper and chromium) from a heavy metal containing effluent. Two treatments were employed which include; 50% (TRT 1) and 25% (TRT 2), the effluent concentrations used in the hydroponic system to culture the plants for the heavy metal bioaccumulation. Cymbopogon citratus significantly (P<0.05) reduced the concentrations of the four heavy metals in the range of 38% - 99% and Chrysopogon nitrigana 12% - 98% for both treatments respectively. Slight growth rate was observed for both plants few weeks after exposure to the effluent after which, no notable growth was observed further. The data obtained from this study revealed that both plants have the capacity to take up heavy metals from polluted effluents however, Cymbopogn citratus (lemon grass) was more efficient in the uptake of all the four studied heavy metals when compared to its counterpart, Chrysopogon nitrigana (vetiver grass).