Journal Article

Phytoremediation of Cu and Zn by vetiver grass in mine soils amended with humic acids

Moliner, Ana, Vargas, Carmen, Pérez-Esteban, Javier, Masaguer, Alberto, Escolástico, Consuelo

2016

Overview

Phytoremediation of contaminated mine soils requires the use of fast-growing, deep-rooted, high-biomass, and metal-tolerant plants with the application of soil amendments that promote metal uptake by plants. A pot experiment was performed to evaluate the combined use of vetiver grass ( Chrysopogon zizanioides ) and humic acid for phytoremediation of Cu and Zn in mine soils. Vetiver plants were grown in soil samples collected from two mine sites of Spain mixed with a commercial humic acid derived from leonardite at doses of 0, 2, 10, and 20 g kg −1 . Plant metal concentrations and biomass were measured and metal bioavailability in soils was determined by a low molecular weight organic acid extraction. Results showed that humic acid addition decreased organic acid-extractable metals in soil. Although this extraction method is used to estimate bioavailability of metals, it was not a good estimator under these conditions due to competition with the strong chelators in the added humic acid. High doses of humic acid also promoted root growth and increased Cu concentrations in plants due to formation of soluble metal-organic complexes, which enhanced removal of this metal from soil and its accumulation in roots. Although humic acid was not able to improve Zn uptake, it managed to reduce translocation of Zn and Cu to aerial parts of plants. Vetiver resulted unsuitable for phytoextraction, but our study showed that the combined use of this species with humic acid at 10–20 g kg −1 could be an effective strategy for phytostabilization of mine soils.

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V
• Subject: Acids / aerial parts / Aquatic Pollution / Atmospheric Protection/Air Quality Control/Air Pollution / Bioavailability / Biodegradation, Environmental / biomass / Bioremediation / chelating agents / Chrysopogon / Chrysopogon - metabolism / Chrysopogon zizanioides / copper / Copper - analysis / Copper - metabolism / Earth and Environmental Science / Ecotoxicology / Environment / Environmental Chemistry / Environmental Health / Environmental science / Grasses / Heavy metals / Humic acids / Humic Substances - analysis / Metal concentrations / metal tolerance / Metals / Mines / Mining / Molecular weight / Organic acids / Phytoremediation / Plant growth / Research Article / root growth / roots / soil / Soil amendment / soil amendments / Soil contamination / Soil erosion / Soil Pollutants - analysis / Soil Pollutants - metabolism / soil sampling / Soil sciences / soil treatment / Spain / Studies / Translocation / Waste Water Technology / Water Management / Water Pollution Control / Zinc / Zinc - analysis / Zinc - metabolism