Abstract
In the present PhD work, the reclamation of old tailing and mine waste disposal areas at the sites «Olympiada» and «Karakoli Stratoniou» of Halkidiki-Greece was investigated by using the method of phytoremediation, after chemical stabilization of soil substrates with Fe and Mn oxides and the addition of inorganic and organic materials as soil amendments. Based on previous laboratory and greenhouse experiments, the four best treatments (1, 2, 3, 4), which are mixtures of mine wastes and soil amendments, were chosen and used in the present pilot study with two other treatments (5,6) corresponding to a 100 % mine waste and a 100 % soil of the surrounding area (control). As soil amendments, by-products of pyrolusite industry rich in Mn and Fe oxides, rise husk and skeletal material were used. In addition, an inoculation with clones of the mycorrhizal fungus Glomus intraradices was applied in treatment 4. For the phytoremediation, the species Nerium oleander was used and the plants were fe ...
In the present PhD work, the reclamation of old tailing and mine waste disposal areas at the sites «Olympiada» and «Karakoli Stratoniou» of Halkidiki-Greece was investigated by using the method of phytoremediation, after chemical stabilization of soil substrates with Fe and Mn oxides and the addition of inorganic and organic materials as soil amendments. Based on previous laboratory and greenhouse experiments, the four best treatments (1, 2, 3, 4), which are mixtures of mine wastes and soil amendments, were chosen and used in the present pilot study with two other treatments (5,6) corresponding to a 100 % mine waste and a 100 % soil of the surrounding area (control). As soil amendments, by-products of pyrolusite industry rich in Mn and Fe oxides, rise husk and skeletal material were used. In addition, an inoculation with clones of the mycorrhizal fungus Glomus intraradices was applied in treatment 4. For the phytoremediation, the species Nerium oleander was used and the plants were fertilized and irrigated for two growth periods (2011, 2012). Totally, 18 experimental plots (three plots per treatment) with dimensions 5 m x 10 m (width x length) and 40 cm in thickness were established in each site. On each plot, 36 plants were planted with planting space 1 m x 1 m (totally 1296 plants for the two experimental sites). Chemical analyses for the soil substrate of each treatment and experimental site (pH measurements, determination of extracted P concentrations, of extracted with CH3COONH4 1Ν cations Ca2+, Mg2+, K+, Na+, of extracted trace elements with DTPA (Zn, Cu, Fe, Mn) and of water soluble elements Ca2+, Mg2+, Zn2+, K+, Na+, Cu2+, Fe2+, Mn2+), measurements of biometrical characteristics of Nerium oleander plants (leaf area, height of plants, weight of leaves and number of branches), determination of concentrations of the elements in the leaves of the Nerium oleander plants and in the above ground biomass of other plant species installed with natural processes as well as determination of the bioaccumulation factors were carried out. For the site «Olympiada», the survival and the good growth of plants were fully successful in all treatments. Based on biometrical characteristics, treatments 2 and 4 containing Fe and Mn oxides were the best. For the site «Karakoli», the growth of plants was successful in treatments 1,3,4 and 6, while all plants in treatment 5 (100% mine wastes) and a small number of plants in treatment 2 died during the first growth period. After the chemical stabilization of soil substrates and the growth of Nerium oleander plants for two growth periods, a quick installation of plant species with natural processes occurred. In the two experimental sites («Olympiada», «Karakoli»), 35 and 40 different plant species were recorded, respectively. The type of treatment affected the biometrical characteristics of Nerium oleander plants and the number of plant species installed with natural processes. In both experimental sites, the bioconcentration factor of trace elements in the above ground plant biomass was found, in most cases, more than 1 for different species and different trace elements and, in several cases, more than 50. Thus, a number of species may be characterized as «metallophytes», while some other species can potentially act as «hyperaccumulators». The appearance and growth of brya, two years after planting, may be considered as an indicator that the conditions of soil substrates were improved, while the development of mycorrhiza (treatment 4) favored the growth of plants.
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