Multi-Metal Effluent Removal By Centella Asiatica (L) Urban: Prospects In Phytoremediation

The search for an efficient plant for simultaneous extraction of ten trace elements from industrial effluent has lead us to Centella asiatica, a native species, known for medicinal properties. After 28-d of trial, it could effectively lower toxic metals such as Cd (14%-54%), Cr (2%-43%), Cu (18%-81%), Pb (35%-90%), Ni (13%-59%) and Zn (20%-81%) from test solutions that comprised of the effluent from a pulp and paper mill that was appropriately diluted with 30% Hoagland's solution The plant demonstrated favourable attributes such as augmentation of key antioxidant enzymes (SOD, CAT, APX and GPX) for combating oxidative stress. Plants showed improved growth and worked well in the lowest effluent dose (25%, v/v). Scanning electron microscopy along with energy dispersive X-ray microanalysis of the root showed the localization of all the trace elements, Pb (weight %, 11-28) and Cd (weight %, 3.1-6.8) peaks indicated that adsorbed metals predominantly remained in the root at 75% and 100% (v/v) exposures. The phytoremediation trials were validated by bioassays in Clarias batrachus reared in phytoremediated effluents; fish showed lower metal burden, most toxic trace metals were within the safe levels, which was suggestive of the accomplishment of phytoremediation and utilities for bio-monitoring purposes. (C) 2021 Elsevier B.V. All rights reserved.