Abstract
Chromium is a reactive and toxic heavy metal that enters the soil through various anthropogenic activities and moves through food chain affecting adversely the higher trophic levels including humans. While engineering techniques to remediate metal contaminated sites are costly and energy intensive, phytoremediation with suitable plant species is a low cost, easy and eco-friendly technique, which uses solar energy in the process. Using suitable non-edible plants makes the process of remediation safe and sustainable. The present study was therefore, carried out to study growth, Cr tolerance and phytoremediation potential of three ornamental plant species Sansevieria trifasciata, Canna indica (L) and Nephrolepis exaltata (L) for removal of chromium from soil. Pot culture experiments were conducted in greenhouse using soils artificially spiked with chromium (Cr250, Cr500, Cr750 mg/kg soil). Tolerance to different concentrations of Cr varied with the plant species as reflected by the trends and magnitude of change in aboveground and belowground biomass. Leaf chlorophyll and carotenoid were quite tolerant at Cr250 for all the species, and up to Cr500 for Sansevieria. The antioxidant enzyme superoxide dismutase (SOD) showed elevated activity in aboveground parts at Cr250, while catalase (CAT) activity declined in response to the metal. All the three species showed significant accumulation of Cr, and more so in the belowground parts. Total Cr phytoextraction was the highest in N. exaltata, followed by C. indica and S. trifasciata. In all the three species, bioconcentration factor (BCF) was >1, indicating the suitability of these species for phytoremediation of chromium contaminated soils.
Highlights
Various anthropogenic activities as well as geological processes lead to chromium contamination of soils and being non-biodegradable, the metal persists in the soil system for years, affecting soil quality and plant life
Cr250 did not show any significant adverse effect on aboveground biomass of Canna and Nephrolepis, while in case of Sansevieria,Cr250 as well as Cr500 had no adverse effect till 30d
The decline was more in C. indica, (32-86%), followed by Chlorophyll
Summary
Various anthropogenic activities as well as geological processes lead to chromium contamination of soils and being non-biodegradable, the metal persists in the soil system for years, affecting soil quality and plant life. Use of chromium in several industries like electroplating, manufacturing alloy products, nuclear reactor vessels, leather tanning, textile and dye synthesis leads to its discharge in the wastewaters and sludge that impacts both aquatic and terrestrial ecosystems.[1] Out of the two forms of chromium, Cr (III) occurs naturally in soil and is used by organisms as a micro-nutrient for their growth and development,[2] whereas Cr(VI) is a potent toxin that is produced by various anthropogenic activities and by natural oxidation of Cr(III). Various conventional methods used for removal of contaminants at large scale are expensive and affect soil constitution and its fertility.[4] While using a method for soil decontamination, it is important to see that it does not lead to pollution of other environmental components such as air or water. Phytoextraction and phytostabilization are the two important strategies that are useful for the phytoremediation of metal contaminated soils
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
