Phytoremediation and Bioenergy Production Efficiency of Medicinal and Aromatic Plants

The cultivation of aromatic and medicinal plants for their direct as well as indirect uses is a common practice from ancient time. There are several medicinal plants which have not only the tolerance ability against the environmental contaminants but also may extract them from the polluted sites. Essential oil-bearing crops like peppermint (Mentha sps.), tulsi (Ocimum basilicum L.), industrial hemp (Cannabis sativa L.), Cymbopogon citratus etc., have been found to bear substantial efficiency to accumulate toxic metals e.g., Cd, As, Ni, Cu, Fe, etc. Generally the process used to extract the essential oil is steam distillation which has the least chance to allow the contaminants to move in oil. After harvesting the oil, residual biomass may be utilized for energy production. This energy may be produced by direct burning of biomass or production of biogas through the gasification of biomass. This integrated approach will not only reduce the cost of petroleum oil but also will help to develop a sustainable model which will help in mitigation of many environmental issues like reduction of greenhouse gases, pollution alleviation etc.