Assessment of medicinal plants colonizing abundantly on metal-enriched fly ash deposits: phytoremediation prospective

Abstract

Heavy metal-enriched fly ash (FA) deposits are recognized as hazardous contaminated sites on the earth, which pollute our ecosystems. Consequently, the present investigation was carried out to explore the phytoremediation potential of naturally growing medicinal plants in the FA dumpsite. This present study chose two native medicinal plants i.e., Bacopa monnieri and Acmella oleracea found to be naturally colonizing abundantly on FA dumpsite to assess heavy metal accumulation. FA sample of B. monnieri thriving sites found to have metal content in order Mn (216.6)> Cr (39.27)> Zn (20.8)> Ni (16.1)> Cu (15.03)> Co (6.7)> Pb (5.43) whereas for A. oleracea FA dumpsites, the order of metal availability was Mn (750.3)> B (54.5)>Cr (37.2)>Zn (31.33)> Cu (18.7)> Ni (16.93)> Co (7.7)>Pb (4.23). In B. monnieri, higher concentrations of Cr and Mn were observed in the shoot in comparison to the root, indicative of its potential as a hyperaccumulator plant. Conversely, in A. oleracea, greater amounts of Pb were detected in the shoot relative to the root. Hence, it is recommended that B. monnieri and A. oleracea grow on such heavy metal-enriched substrates should be avoided for medicinal purposes; however, these plants can be used for phytoremediation purposes.

HIGHLIGHTS

• Fly ash phytoremediation through natural colonizer plant species is limited.

• Native colonizing plant species on fly ash has a pivotal role in phytoremediation.

• Naturally colonizing medicinal plants were dominant over the Fly ash dumpsites.

• Bacopa monnieri and Acmella oleracea have phytoremediation potential on fly ash.

• Indeed, fly ash-grown medicinal plants should not be used by local communities.

Keywords:

• Eco-restoration
• fly ash
• heavy metal
• medicinal plants
• phytoremediation

Acknowledgment

The authors are thankful to the Director, CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nagpur, India for encouraging and providing necessary facilities. Mrs. Swati Yadav is thankful to the Council of Scientific and Industrial Research (CSIR), Government of India for providing JRF fellowship (31/016(0136)/2019-EMR-I) and to the Academy of Scientific and Innovative Research (AcSIR), CSIR-HRDG for the support of the doctoral study, and this work is a part of her Ph.D. thesis under AcSIR.

Author contributions

SY: methodology, investigation, formal analysis, data curation, writing-original draft; VCP: conceptualization, visualization, supervision, writing–review and editing; LS: supervision, writing–review and editing

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data availability

The authors confirm that the data supporting the findings of this study are available within the article.