Vpliv povečane koncentracije kovin v rastlinah na njihovo snovno in energijsko izrabo : doktorska disertacija

slovenian

doktorska dela

2013

Univerza v Mariboru, Fakulteta za strojništvo

Contaminated soils with metals are consequnce of several centuries of uncontrolled anthro-pogenic pollution in the past. Metals due to their inability to break, unlike most organic sub-stances, posing a serious threat to the environment, people and animals and therefore must be properly disposedof. One of the actions of revitalization of contaminated land with metals is the greening with energy plants in situ. he method of phyto extraction was used in the study. We observed distribution of metals in plant parts juvenile and mature hybrids PR45 D01 and PR46 W31 of oil seed rape (Brassica napus L. var. napus) in situ at different contaminated soils (Ponikva, Šentjur Medlog, Proseniško, Škofja vas, Črna na Koroškem and Mežica). The study results showed that the uptake of Cd, Pb and Zn in the upper parts of mature plants are up to 56 %, 35 % and 52 % respectively higher compared to above ground parts of the juvenile plants. The content of metals in plants mostly depends on the metal content in the soil and of soil pH value. Hybrids of oil seed rape uptake metals and As in their upper parts, especially important in the seeds. For each metal was calculated TF, this is the relationship between plant parts, and BAF, which is the ratio between the content of the target element in the above-ground part and element content in the soil. The mature hybrid PR46 W31 had TF(Cd) and BAF(Cd) > 1 and could be therefore suitable for phytoremediation on medium with metals contaminated soils. Comparison of two extracting oil methods out of oil seed rape showed that the supercritical CO2 extraction method is more suitable. Cake after a cold mechanical pressing and SC-CO2 of seeds did not contain increased levels of metals and is suitable in products for animal nutrition. Heat treatment of stables and cakes at 700 °C showed the lowest concentrations of Cd, Pb and Zn in the residue and the concentrations of Cu, Ni, Co, Mo, As and Ba are the highest. In the residues after heat treatment at 850 °C Cd, Pb and Zn were determined significantly higher than the levels of Cu Ni, Co, Mo, As and Ba. Calorific value of stem and cakes are comparable to bituminous coal, lignite and wood. he impact of increased metal content in the soil did not affect the material and energy recovery of oil seed rape. Application one of the remediation measures, that is greening, not only is the most economically viable remediation, but also brightens the appearance of the landscape and improves the quality of life of people who are exposed to contaminated areas.

08.08.2023