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"Phytoremediation Potential of Some Plants for Nickel-Contaminated Soils" (Invited Lecture) 4th International Conference of the Chemical Societies of the South-East European Countries on Chemical Sciences in Changing Times: Visions, Challenges and Solutions Faculty of Technology and Metallurgy, Belgrade, Serbia and Montenegro,
A. Cullaj ; Florian Kongoli ¹ ; A. Hasko ;
¹FLOGEN Technologies Inc,1255 Laird Blvd., Ste.388, Mont-Royal, Quebec, Canada

Keywords: soil contamination, heavy metals, remediation, fhytoremediation, phytoextraction, biotechnology, mineral recovery, Ni, nickel, smelting, refinery, Atomic Absorption Spectrometry, Alyssum, Bornmuellera, genus, Cruciferae, Alyssum murale var. chlorocarpum Hausskn and Alyssum markgrafii O.E. Schulz

ABSTRACT

Phytoremediation is a new low cost alternative technique for remediation of contaminated soils from heavy metals that are emitted by ferrous and nonferrous mining and extracting processes. This is based on the ability of some plants to accumulate very high concentrations of metals from soils and thus providing the basis for a remediation of the contaminated sites. This technique as an emerging branch of natural biotechnology, has several advantages compared to the sophisticated physicochemical techniques of soil remediation. It is not only environmentally friendly and low cost but furthermore plants can accumulate metals to such levels that the mineral recovery maybe feasible even in conventional smelting or refining processes. The aim of this paper is to present for the first time data of the wild plants species growing in nickel-containing serpentine soils in Albania, in order to identify the nickel-tolerant and hyperaccumulator species that could be used for phytoremediation and phytoextraction purposes. In this work, the potential of many plants to accumulate nickel has been investigated in order to identify the species which offer the best phytoremedial potential for nickel contaminated soils in Albania. Field surveys have been made in five nickel-containing sites in order to identify the nickel tolerant species that have spontaneously grown in contaminated soils. Atomic Absorption Spectrometry measurements were carried out on 145 different plants collected. 16 of them were identified as having an hyper ability to accumulate nickel since they contained more than 10 000 mg Ni per kg (DW). Seven taxa are of Alyssum genus and one of Bornmuellera genus of Cruciferae. The taxa showing the highest accumulation of this metal is Alyssum murale var. chlorocarpum with 28 600 ?g/g or 2.86% and Alyssum markgrafii O.E. Schulz with 23 700 mg/kg or 2.37%. In order to optimize the phytoremediation and phytoextraction processes further biological and chemical studies were carried out to determine the parts of the plants that accumulate the highest amount of nickel and the best biological cycle during which they accumulate the highest amount. The results show that the greatest accumulation of nickel occurred in the leaf material (2.86%) and the least in the roots (0.43%). The investigation of the biological cycle of the genus Alyssum showed that: (1) the seeds germinated between 5º C to 30 ºC and more in 25 º C; (2) 62.9 % of seeds germinated at A.m. var. chlorocarpum; (3) the emergence is almost continue from March to April; (4) the anthesis occurs from May to July; (5) the ripening of the fruit takes place 30 days after flowering; (6) the dissemination of fruits occurs from September to October. The above-mentioned esults are obtained for the wild species that grow spontaneously in nickelcontaining oils. However, the cultivation of selected Alyssum genotypes in the conditioned soils can lead to adequate hyper-accumulation of metals in the plants in order to make feasible the recovery of the metals from these plants. Some of the soil conditions that increase the accumulating ability for nickel and it phytoextraction might be a low pH of the soil (at a range of 4.5 to 6.2), low exchangeable calcium concentration and relatively high magnesium concentration and the addition of ammonium-containing fertilizer and chelating agents. Due to these special characteristics it is reaffirmed that Alyssum murale var. chlorocarpum, as a nickel hyperaccumulator, is the most promising plant to be used for feasible phytoremedation and phytoextraction purposes.

Cite this article as:
A. Cullaj, Florian Kongoli, A. Hasko (2004). "Phytoremediation Potential of Some Plants for Nickel-Contaminated Soils". 4th International Conference of the Chemical Societies of the South-East European Countries on Chemical Sciences in Changing Times: Visions, Challenges and Solutions Faculty of Technology and Metallurgy, Belgrade, Serbia and Montenegro.

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