Evaluation of ecological potency in bamboo species for phytoremediation and eco-rejuvenation of fly ash-degraded land: a two-year field study.

Ecological restoration of fly ash-degraded soils is a major concern for developing countries like India. So far, various physicochemical techniques have been employed to restore these polluted lands, but the limitations of cost, inefficiency, and secondary pollutant generation have forced ecologists to look for alternative approaches. Phytoremediation has been widely employed to replace these techniques, and to produce an economic asset along with the restoration of fly ash-degraded land, through bamboo species which serve as a parallel factor increasing the overall efficiency of bio methods, becomes very interesting. Four bamboo species, Bambusa balcooa, B. vulgaris 'wamin', B. bambos, and B. vulgaris, were planted at abandoned fly ash dumpsite. After two years of plantation, there was a significant improvement in all the physicochemical characteristics of the fly ash dumpsite. Phytoremediation indices in terms of bioconcentration factor (BCF) (1.26 and 1.72) and translocation factor (TF) (1.98 and 1.25) presented that B. bambos is the ideal species for the phytoextraction of Cr and Zn, while B. balcooa is an ideal species for the phytostabilization of lead (Pb), arsenic (As), and zinc (Zn), B. vulgaris 'wamin' for the phytostabilization of copper (Cu), nickel (Ni), Zn, and As and B. vulgaris for phytostabilization of Cu, chromium (Cr), and Ni, respectively. There was a significant improvement in biomass production in all the bamboo species being highest in B. balcooa (1087 kg ha⁻¹) after two years of establishment on the fly ash dumpsite. Further, B. balcooa was found as the ideal bamboo species for sequestration of atmospheric carbon dioxide (CO₂) (8217 tonnes C ha⁻¹ year⁻¹). This work further suggests that B. balcooa is an excellent species for eco-restoration with a reliable air pollution tolerance index (APTI) (16.65). Principal component analysis demonstrated that B. bambos is the most potent bamboo species for phytoremediation of fly ash dumpsites owing to its high biomass capacity, positively correlated with hyperaccumulation of heavy metals. However, the fate of heavy metals after litter decomposition needs to be examined in detail to make this study a widespread approach. [ABSTRACT FROM AUTHOR]