Study on Chromium-Binding Capacity of Callitriche cophocarpa in an Aquatic Environment

Joanna Augustynowicz,Andrzej Waloszek,Sylwester Smoleń,Joanna Kyzioł-Komosińska

doi:10.1007/s00244-012-9853-5

Abstract

The aim of the present study was to investigate the binding strength of chromium (Cr) ions to aquatic macrophyte Callitriche cophocarpa. Shoots of the plants were incubated in a natural water solution containing Cr(III) or Cr(VI) at a concentration ranging from 0.5 to 4 mM under laboratory conditions. We found that C. cophocarpa has an extremely high capacity to bind Cr. The average level of accumulation reached 28,385 or 7,315 mg kg−1 dry weight for plants incubated with Cr(III) or Cr(VI), respectively. Shoots incubated in a 0.5 mM concentration of Cr(III) for 5 days removed almost 100 % of the metal from solution. The major pool of the bound Cr(III) ions follows the strongest mechanism of metal-binding to an organic matter. In contrast, we found that only 25 % of Cr(VI) ions are bound into the metallo-organic compounds and 57 % of Cr(VI) exists in an easily remobilizable form. Activity of a photosynthetic electron transport (as F V/F M) was evaluated with respect to the Cr-binding mechanism. Our results contribute to the development of knowledge on processes controlling bioremediation of heavy-metallic compounds in aquatic systems.

Highlights

The aim of the present study was to investigate the binding strength of chromium (Cr) ions to aquatic macrophyte Callitriche cophocarpa
Different methods of chemical Sequential extraction (SE) are used to fractionate metals in various environmentally reactive or hydromorphic phases of soil (Jaradat et al 2006; Jain et al 2008; Romaguera et al 2008), sediment (Alomary and Belhadj 2007) and solid wastes (Ayari et al 2008; Soco and Kalembkiewicz 2009). These chemical SE methods can differentiate between the following fractions: metals retained in a pore solution and adsorbed onto surface of particles, exchangeable species, metals bound to carbonates or manganese (Mn) and iron (Fe) oxides, metals bound to an organic matter and sulphides, and a residual phase of metals bound in lithogenic minerals
SE may be applied to homogenous materials, e.g., organic matter, such as peat and plants, e.g., mosses (Mouvet and Claveri 1999; KyziołKomosinska et al 2006)

Summary

Introduction

The aim of the present study was to investigate the binding strength of chromium (Cr) ions to aquatic macrophyte Callitriche cophocarpa. Fungi, algae, and higher plants are promising biosorbents of Cr. Studies of organic and inorganic materials for their applicability as sorbents in the removal of heavy metal ions from water and wastewater must consider the sorption capacity of the investigated materials and the mechanisms by which metals are bound. Different methods of chemical SE are used to fractionate metals in various environmentally reactive or hydromorphic phases of soil (Jaradat et al 2006; Jain et al 2008; Romaguera et al 2008), sediment (Alomary and Belhadj 2007) and solid wastes (Ayari et al 2008; Soco and Kalembkiewicz 2009) These chemical SE methods can differentiate between the following fractions: metals retained in a pore solution and adsorbed onto surface of particles, exchangeable species, metals bound to carbonates or manganese (Mn) and iron (Fe) oxides, metals bound to an organic matter and sulphides, and a residual phase of metals bound in lithogenic minerals. SE may be applied to homogenous materials, e.g., organic matter, such as peat and plants, e.g., mosses (Mouvet and Claveri 1999; KyziołKomosinska et al 2006)

Objectives

Methods

Results