Phytoextraction with Maize of Soil Contaminated with Copper after Application of Mineral and Organic Amendments

Abstract

This study aimed to determine the possibility to increase the the effect of different amendments (compost, bentonite and zeolite) on the shoot yield and the concentration of trace elements in shoots of maize (Zea mays L.) on soil contaminated with Cu. The yield of shoots and concentration of the trace elements in shoots of maize depended on Cu dose and amendment incorporation into the sandy soil. Cu-spiked soil caused an increase the yield of shoots (only to 100 mg Cu/kg of soil), in the concentration of Cu, Co, Mn, Ni and Fe in shoots of maize and, to a smaller degree, in the concentration of Zn and bioconcentration factor (BCF) of all elements except copper, compared to the control soil without Cu. Under the influence of 150 and 200 mg Cu per kg of soil, a decrease in yield of shoots of maize was observed. Compost, bentonite and zeolite increased the yield of shoots and reduced the concentration of Cu, Co, Mn, Fe and Zn in shoots of maize. Bentonite had a more positive effect than compost and zeolite on the yield of shoots and the concentration of Co, Mn and Zn in shoots of maize. The effect of these amendments on the Cu and Fe concentration in shoots of maize was reverse. A reverse effect of these amendments (especially bentonite and zeolite) on the Ni concentration in plants was observed. The amendments applied to soil, especially compost, increased the BCF of Ni and, to a small degree, BCF of Cu in shoots of maize, compared to the control series. Compost, zeolite and especially bentonite are very good amendments in the restoration of maize growth in polluted areas.

Phytoremediation Capability and Copper Uptake of Maize (Zea mays L.) in Copper Contaminated Soils

“…For instance, copper concentrations in Z. mays roots and shoots in T4 were 435.8 mg kg −1 and 831.5 mg kg −1 with a significant enhancement of 7.8 and 10.2 times, respectively, compared to T1 (p < 0.05). This is consistent with the literature in which an increase in copper content of soil from 20 mg kg −1 to 100 mg kg −1 caused a reduction in maize growth and an increase in copper uptake from soil [49]. This might be attributed to the higher availability of copper in soil to be up taken by plant roots.…”

Mineral Materials as a Neutralizing Agent Used on Soil Contaminated with Copper

“…There are a number of mechanisms that can reduce the stressful effects of metals on plant growth. Among them, there is the mechanism of metal ion sequestration through their accumulation and inactivation in forms related to organic and inorganic components contained in cells, e.g., oxalates or phenolic compounds [28,52]. With an excess of harmful ions in the cytoplasm, the plant can integrate them into the structure of cell walls through secondary transport [48].…”

“…The durability of these bonds depends on the soil pH, amount and type of minerals, redox potential, sorption capacity and organic matter content [7,27]. A method that allows reduction of the harmfulness of heavy metals is the addition of neutralizing materials to the soil [3,[28][29][30] so as to bind metals in insoluble metal-mineral or organo-metallic forms, which-under favorable conditions-may remain in the soil in harmless forms for a long period [9,31]. The most common neutralizing materials are zeolites, bentonite, clay, lime, and also organic materials, like compost, tree bark, farmyard manure and peat [3,23,30].…”

Phytoavailability of Cd, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Tl and Zn in Arable Crop Systems Amended for 13 to 15 Years with Organic Waste Products

“…A number of studies have examined the role of OWP, especially sewage sludge, as a source of TE contamination of soil, but only limited works reported the beneficial effect of organic amendments as a way for reducing TE mobility in soils [22]. These studies focused mostly on contaminated soils [28,29], but rarely on uncontaminated agricultural soils at the field scale [12,30].…”