Plant responses to a phytomanaged urban technosol contaminated by trace elements and polycyclic aromatic hydrocarbons

Abstract

Medicago sativa was cultivated at a former harbor facility near Bordeaux (France) to phytomanage a soil contaminated by trace elements (TE) and polycyclic aromatic hydrocarbons (PAH). In parallel, a biotest with Phaseolus vulgaris was carried out on potted soils from 18 sub-sites to assess their phytotoxicity. Total soil TE and PAH concentrations, TE concentrations in the soil pore water, the foliar ionome of M. sativa (at the end of the first growth season) and of Populus nigra growing in situ, the root and shoot biomass and the foliar ionome of P. vulgaris were determined. Despite high total soil TE, soluble TE concentrations were generally low, mainly due to alkaline soil pH (7.8-8.6). Shoot dry weight (DW) yield and foliar ionome of P. vulgaris did not reflect the soil contamination, but its root DW yield decreased at highest soil TE and/or PAH concentrations. Foliar ionomes of M. sativa and P. nigra growing in situ were generally similar to the ones at uncontaminated sites. M. sativa contributed to bioavailable TE stripping by shoot removal (in g ha(-1) harvest(-1)): As 0.9, Cd 0.3, Cr 0.4, Cu 16.1, Ni 2.6, Pb 4, and Zn 134. After 1 year, 72 plant species were identified in the plant community across three subsets: (I) plant community developed on bare soil sowed with M. sativa; (II) plant community developed in unharvested plots dominated by grasses; and (III) plant community developed on unsowed bare soil. The shoot DW yield (in mg ha(-1) harvest(-1)) varied from 1.1 (subset I) to 6.9 (subset II). For subset III, the specific richness was the lowest in plots with the highest phytotoxicity for P. vulgaris.

Implementation of Omics Research to Enhance Phytoremediation Efficiency - a Review

“…Therefore, due to the high cost, contaminated lands owned by private companies are more often abandoned and not properly cleaned up [7]. Hence, the implementation of more cost-efficient methods of soil remediation, such as phytoextraction of metals or phytodegradation of organic pollutants could potentially be a promising solution, especially in large areas contaminated in the past via various range of anthropogenic sources [16]. In order to achieve satisfactory results, investigation of the specific, best suitable plant species for given process is a necessity [17].…”

“…Through recent decades, the amount of PAHs in the environment is constantly increasing. One example of plant efficiency in PAHs degradation is Populus nigra which was shown to reduce the range of PAHs such as pyrene, benzopyrene, anthracene, phenanthrene, and chrysene [16].…”

Selenium and Other Trace Element Mobility in Waste Products and Weathered Sediments at Parys Mountain Copper Mine, Anglesey, UK

“…Compositionally similar and extensively extracted base metal sulphide ore deposits in Norway have been classified as "significantly" or "highly" polluted as a result of mining activities releasing Cu, Zn, Fe, Pb, and Cd [62,88,89]. The soil guideline values [90] for inorganic As is 640 ppm for commercial land use, and levels for residential and allotment land use is lower. Parys Mountain deposits show consistently higher concentrations of As across deposits than the guideline values.…”

“…In former mine workings across Europe, including sites associated with sulphide mineralisation, technosols have been developed and utilised in order to reduce the threat of contamination posed by tailings [1,90,91]. Technosols are man-made soils, often made up of stock materials such as carbonates, biochars, and crop residues, and have been shown to reduce acidity, immobilise metals, and improve soil quality, fertility, and structure.…”

Using Native Woody Plants for Phytomanagement of Urban Technosols Contaminated by Wood Pole Preservatives

“…Technosols also frequently suffer from varying levels of contamination with a mixture of trace metals and organic compounds, which add stress to plant growth and survival. [ 4 ]…”