Fitoekstrakcijski potencial hiperakumulacijskih vrst rodu Noccaea za odstranjevanje Zn in Cd iz zmerno onesnaženih tal

Drnovšek, Nika (author), Pongrac, Paula (mentor)

Prekomerno kopičenje težkih kovin v kmetijskih tleh predstavlja globalno težavo, saj le-te škodljivo vplivajo na kakovost in količino pridelka in s tem prek prehrane tudi na zdravje ljudi. Obetavna metoda za remediacijo tal je fitoekstrakcija, ki izkorišča sposobnost hiperakumulacijskih rastlin, da iz zemlje privzemajo velike koncentracije težkih kovin in jih akumulirajo v svojih nadzemnih delih. Med hiperakumulacijske rastline spadata tudi dve vrsti iz rodu Noccaea, in sicer N. caerulescens in N. praecox, ki rasteta tudi v Sloveniji. Cilj dela je preučiti privzem cinka (Zn) in kadmija (Cd) iz zmerno onesnaženih tal s hiperkaumulacijskima vrstama N. caerulescens in N. praecox, raziskati vpliv izvorne lokacije semen na privzem Zn in Cd ter oceniti potencial proučevanih vrst za fitoekstrakcijo Zn in Cd iz zmerno onesnažene kmetijske zemlje iz Celjske kotline. V lončnem poskusu smo v kontroliranih razmerah gojili rastline vrste N. caerulescens in N. praecox, semena katerih smo nabrali na neonesnaženi lokaciji v vasi Lokovec in vrsto N. praecox, semena katere smo nabrali na s Cd, Zn in Pb onesnaženi lokaciji v Žerjavu. Izmerili smo pH in dostopne frakcije Cd in Zn v proučevanem substratu, rastlinam pa smo izmerili biomaso in koncentracijo Cd in Zn. Vrsta N. caerulescens iz Lokovca je v poganjkih kopičila manj Cd od vrste N. praecox iz Lokovca, v privzemu Zn pa med vrstama ni bilo razlik. Koncentracije Zn so bile v vrsti N. praecox iz Lokovca večje kot v vrsti N. praecox iz Žerjava. V koreninah so bile koncentracije Cd večje pri vrsti N. praecox iz Žerjava kot pri vrsti N. praecox iz Lokovca, medtem ko v poganjkih med tema dvema vrstama ni bilo statističnih razlik v koncentracijah Cd. Ugotovili smo, da bi pri letnem pridelku 5 t ha-1 s preučevanimi vrstami koncentracijo Cd v zmerno onesnaženi zemlji v manj kot 20 letih znižali pod mejno vrednost nevarnih snovi v tleh. Za znižanje koncentracije Zn bi z vrstama N. caerulescens in N. praecox iz Lokovca potrebovali približno 80 let, medtem ko bi z vrsto N. praecox iz Žerjava potrebovali več kot 200 let.

• Language: Slovenian
• Keywords: kadmij, cink, fitoekstrakcija, hiperakumulacija, Noccaea caerulescens, Noccaea praecox
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Year: 2024
• PID: 20.500.12556/RUL-159663
• COBISS.SI-ID: 202225923
• Publication date in RUL: 18.07.2024

Secondary language

• Language: English
• Title: Phytoextraction potential of hyperaccumulators from genus Noccaea for removal of Zn and Cd from moderately contaminated soil

Abstract

Excessive accumulation of heavy metals in agricultural soils is a global problem, as they have harmful effect on the quality and quantity of crops and, through food webs, on human health. A promising method for soil remediation is phytoextraction, which exploits the ability of hyperaccumulating plants to take up large concentrations of heavy metals from the soil and accumulate them in their aerial parts. Two species from the genus Noccaea, namely N. caerulescens and N. praecox, which also grow in Slovenia, are also hyperaccumulating plants. The aim of the work was to evaluate the uptake of zinc (Zn) and cadmium (Cd) from moderately polluted soils by the hyperaccumulating species N. caerulescens and N. praecox, to investigate the influence of the source location of the seeds on the uptake of Zn and Cd and to assess the potential of the studied species for phytoextraction of Zn and Cd from moderately polluted agricultural soil from the Celje basin. Plants were grown in pots under controlled conditions from seeds collected at an unpolluted location in Lokovec and at Cd-, Zn-, and Pb-contaminated location in Žerjav. pH and phytoavailable fractions of Cd and Zn in the substrate were determined, and the biomass and concentration of Cd and Zn in the plants were measured. N. caerulescens from Lokovec accumulated less Cd in the shoots than N. praecox from Lokovec, however there was no difference in Zn uptake between the two species. Concentrations of Zn were higher in N. praecox from Lokovec than in N. praecox from Žerjav. In roots Cd concentrations were higher in N. praecox from Žerjav than in N. praecox from Lokovec, while there was no statistical difference in Cd concentrations between these two species in shoots. We found that with an annual yield of 5 t ha-1 the studied species, could lower the concentration of Cd in moderately polluted soil below the permissible limit value of contaminants in ground in less than 20 years. It would take N. caerulescens and N. praecox from Lokovec approximately 80 years to lower the concentration of Zn below the permissible limit value, while the N. praecox from Žerjav would need more than 200 years.

• Keywords: cadmium, zinc, phytoextraction, hyperaccumulation, Noccaea caerulescens, Noccaea praecox