Phytoremediation response of Miscanthus to Zn contaminated soils

Transcription

1 Phytoremediation response of Miscanthus to Zn contaminated soils Sara Boléo *, Maria Paula Duarte, Ana Luísa Fernando, Universidade Nova de Lisboa - Faculdade de Ciências e Tecnologia Departamento de Ciências e Tecnologia da Biomassa, UBIA Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 1

2 Context Energy crop systems Renewable sources of energy biomass demand for bioenergy Menace to food security But - Intensive use of land Water resources depletion Mineral resources depletion (fertilisers) Soil nutrient depletion Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 2

3 Context Contaminated land use Surplus land sustainable option low cost approach to restore or attenuate and stabilize contaminated sites while bringing additional revenue to owners Land-use conflict with food crops diminished Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 3

4 Aim of the study to merge energy crop production with waste management 3 Miscanthus genotypes M. sinensis M. floridulus M. x giganteus Soils contaminated with Zn Phytoremediation Different water regimens Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 4

5 Miscanthus genus C 4 perenial, woody, rhyzomatous, bamboo-like grasses Native from tropical and subtropical regions of Asia and Southeast Africa species (Poaceae) Forms tuffs with high shoot density 1,5 7 m height Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 5

6 Miscanthus genus why? Non-food crop High yields: 9-27 Mg.ha -1 in Europe Life span of years Root system: Deep and long Drought tolerant High nutrient efficiency Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 6

7 Miscanthus genus why? Economic value : high fiber content stems 22% lignin 36% -cellulose 24% hemicellulose 2 nd generation biofuels Bioenergy (p.e. combustion, gasification) Bio-products: pulp paste, bioplastics, fibre Phytoremediation good results Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 7

8 Zn ions why? Ubiquous Human activities Excess heavy metal could be a threat to human health - by entering the food chain to environment - by affecting the ecosystems services Problematic in soil due to their mobility: Risk of polluting ground and surface water - Run-off, Leaching Previous studies showed good results Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 8

9 Tasks Evaluate the growth, productivity and quality of the biomass. Assess soil and percolates quality throughout the process. Understand the dynamic of Zn in soil-plant system. Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 9

10 Experimental layout M. X giganteus M. sinensis M. floridulus With replicates Control Zn I 450 mg Zn.kg -1 d.m. Zn II 900 mg Zn.kg -1 d.m. 12kg soil / pot H 2 O H 2 O Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 10

11 Experimental layout Plantation May st yr harvest Jan nd year harvest Dez 2013 Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 11

12 Analysis - Biomass Aerial Biomass analyses (stems, leaves, panicules, litter) At the end of each vegetative cycle Morphological analyses Productivity Organic matter Nitrogen and Phosphorus Ashes and different metals Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 12

13 Analysis - Biomass Belowground Biomass analyses (roots and rhyzomes) At the end of 3 years Morphological analyses Productivity Organic matter Nitrogen and Phosphorus Ashes and different metals Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 13

14 Analysis Plant stress Process of Metal accumulation in the plants and its relation to Metal plant toxicity threshold to metabolism, we will analyze in leaves, during the growth period: Photopigments: chlorophyll a, b, carotenes Activity of Enzymes involved in desactivation mechanisms of ROS (Reactive Oxygen Species): - SOD Superoxide dismutase - CAT - Catalase - POD - Peroxidase Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 14

15 Analysis - Biomass To access biomass quality quality and suitability for application in biorefinaries chains: In stems (3 rd year) Fiber content Heat capacity Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 15

16 Analysis - Soils At the end of each growing cycle, 0-20 cm and cm With soils in vases with and without plants Soil organic matter, ph, Conductivity Total N and P,NO3, NO2, NH4, PO4 and metals Metals speciation extractability with different extraction solutions Soil Ecotoxicity (Microtox) and microbial population analyses Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 16

17 Analysis - Leachates Along each growing cycle To vases with and without plants ph, Conductivity, BOD Total N and P, NO 3-, NO 2-, NH 4-, PO 4-3 and metals Metals speciation extractability with different extraction solutions Microbial population analyses Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 17

18 Miscanthus productivity (g dry matter/ m-2) Results Productivity-2 yrs M. x giganteus M. x g. : > M. floridulus > > M. H 2 sinensis O M. s. & M.f.: > Control > Zn H 2 I O > Zn II Control ZnI ZnII M. giganteus M. sinensis M. floridulus M. giganteus M. sinensis M. floridulus 1st year 2nd year Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 18

19 Zinc content (mg Zn/kg dry mass) Results Zn content 1st yr M. x giganteus > M. floridulus > M. sinensis Control Zn I Zn II 50 0 M. giganteus M. sinensis M. floridulus M. giganteus M. sinensis M. floridulus stems leaves Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 19

20 Nitrogen content (% dry mass) Results Nitrogen -1st yr M. x giganteus > M. floridulus > Leaves 0,90 0,80 sinensis 0,70 0,60 0,50 0,40 0,30 0,20 Contro Zn I Zn II 0,10 0,00 M. giganteus M. sinensis M. floridulus M. giganteus M. sinensis M. floridulus stems leaves Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 20

21 Phosphorus content (g P/ kg dry mass) Results - Phosphorus-1st yr 1,20 1,00 M. x giganteus > M. floridulus > M. sinensis Leaves 0,80 0,60 0,40 0,20 Control Zn I Zn II 0,00 M. giganteus M. sinensis M. floridulus M. giganteus stems M. sinensis M. floridulus leaves Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 21

22 Expected results It is expected that the energy crop Miscanthus is able to merge high levels of decontamination of soil at low inputs of irrigation with high yields. Biomass can be used for the production of fiber, byproducts and bioenergy. Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 22

23 Aknowledgements This work was supported by the European Union (project Optimization of perennial grasses for biomass production, OPTIMA, Grant Agreement No: , Collaborative project, FP7-KBBE Thank you for your attention Suer School : Lignocellulosic Crops as Feedstock for Future Biorefineries 23