Phytoextraction and the economic perspective of phytomining of heavy metals

Abstract. The world rapid growing population, expanding economics and anthropogenic activities contribute to heavy metals pollution, which are non-biodegradable, persistent and threaten the environment. The rising level of heavy metals in environment emphasizes on indigenous technologies, but conventional technologies are too expensive, laborious and result in secondary pollution. Phytoremediation/phytoextraction is a plant based technology, which is environmental friendly, economic and effective for heavy metals remediation. The global market of phytoremediation is 34–54 billion US$ and is expanding in the developed countries, providing an opportunity for this green technology. Suitability of phytoextraction depends on biomass production, accumulation rate and tolerance to target metals. Metals uptake can be enhanced by exploring effective hyperaccumulators, expanding phytomining operations and extending molecular studies on accumulation mechanism, tolerance and sensitivity of heavy metals. Hyperaccumulator plants achieve greater performance at low cost than conventional technologies for in situ metal removal. Phytomining generate revenue and provide new research area for biofortification of food and feed, biofuel and metal rich biochar production in future. This review highlights the sources of heavy metals and its effects on plants, enhancing phytoremediation process and increasing economic benefits of phytomining.