Determination of the potential of Pistia stratiotes L. in removing nickel from the environment by utilizing its rhizofiltration capacity

Abstract

The aim of this study is to explain the biological response and rhizofiltration capacity of Pistia stratiotes, which is an aquatic macrophyte, in alleviating heavy metal stress. In our study, Pistia species were exposed to Nickel (Ni) at different concentrations over seven days. The potential of the aquatic macrophytes in accumulating heavy metals in the water and in removing them from the environment was evaluated by determining the bio-concentration factors (BCF). Selected biological parameters in the leaves of Pistia stratiotes, including metal accumulation, photosynthetic pigment amount, lipid peroxidation activity, and growth rates were measured at the end of the seven-day period. The highest amount of Ni accumulation in P. stratiotes occurred at a concentration of 20 mg l-1. The amount of chlorophyll a (chl a) in P. stratiotes reached a value of 0.087 mg g-1 at the Ni concentration of 20 mg l-1. The relative growth rate (RGR) of P. stratiotes showed a negative correlation with the increases in the concentration levels of the metal. Malondialdehyde (MDA) levels increased to 8.214 nmol/g at the concentration of 20 mg l-1, depending on Ni concentration and time. In our study, the use of P. stratiotes has been determined to be an appropriate plant as an effective Ni accumulator to be utilized with the purpose of rhizofiltration.