PHYTOREMEDIATION OF CD AND NI CONTAMINATED WASTEWATERS BY MISCANTHUS

Transcription

1 PHYTOREMEDIATION OF CD AND NI CONTAMINATED WASTEWATERS BY MISCANTHUS João Lino Ana L. Fernando July 2014

2 Biomass CONTEXT Celulose, hemicelulose and lignin, as main components Great abundance Low economic value Raw material for the production of bioenergy, biofuels and high value biobased materials Hemicelulose Lignin Energy crop systems Industrial cultivation of annual or perennial plant species for the production of bioenergy Viable substitute to non-renewable energy sources Energy crops offer ecological advantages over fossil fuels Celulose Sugar, Oil and Lignocellulosic 2

3 CONTEXT Miscanthus spp. Is a woody rhizomatous C 4 grass Productive lifetime of, at least, years High yields and low moisture content High water and nitrogen use efficiencies Phytoremediation - use of vegetation for the decontamination of different matrices Combination of phytoremediation and wastewater irrigation Reduction in the use of freshwater resources Large amount of generated biomass Promising, cost-effective and ecological-friendly alternative to conventional treatment methods Reduction of cultivation and environmental costs Reduce the disposal of pollutant effluents into surface water bodies 3

4 AIM OF THE STUDY Study the phytoremediation response of three Miscanthus genotypes Miscanthus x giganteus Miscanthus floridulus Miscanthus sinensis Evaluate quality and biomass productivity Irrigated with piggery wastewaters contaminated with Cd/Ni Evaluation of percolated waters Soil analysis 4

5 EXPERIMENTAL LAYOUT 0.2 mg/dm 3 Cd 2.0 mg/dm 3 Ni 2 rhyzomes/pot M x giganteus M. sinensis M. floridulus April 2013 to December 2014 Full irrigation 950 mm No plants replicates 6 g N.m g P 2 O 5.m g K 2 O.m -2 o o Plants were harvested at the end of the growth season Aerial productivity and biomass quality were monitored o The percolated waters and the soils were also sampled at the end of the growing season 5

6 Biomass Productivity: RESULTS - PRODUCTIVITY 1349 g/m 2 Statistical differences between Miscanthus species and contaminations M. x giganteus had better productivity t test M. sinensis and M. floridulus growth was positively affected by the cadmium/nickel wastewaters 6

7 Ash Content: RESULTS BIOMASS QUALITY Leaves > Stems/Panicle Stems from wastewater irrigated pots presented higher ash content than control There weren t found any statistical differences between the different types of irrigation 7

8 RESULTS BIOMASS QUALITY Cd Content: In terms of Cd accumulation, no significant differences were observed among genotypes and fractions 8

9 RESULTS BIOMASS QUALITY Ni Content: The results for the Ni content were quite similar to the ones obtained in Cd content Leaves showed statistical differences between irrigations (p = 0,0103; t test) There weren t found any significant differences among genotypes for Ni content 9

10 RESULTS PERCOLATED WATERS Cd Content: Ni Content: % removal was significant (98-99%) No significant differences among the three different genotypes % removal was significant M. x giganteus and M. sinensis were more efficient on the removal (96-98%) M. floridulus, which showed a removal of 58% 10

11 Cd Content (soil): RESULTS SOILS M. floridulus irrigated with WWCd presented a higher accumulation than the other two M. floridulus shows a lower capability to trap Cd Ni Content (soil): No significant differences were observed among genotypes Accumulation of Cd/Ni in the soils is mostly in the upper layer (0-20cm) 11

12 CONCLUSIONS The irrigation with wastewaters contaminated with Cd and Ni did not affect the productivity of the three studied Miscanthus genotypes. In the three genotypes, the biomass irrigated with wastewaters contaminated with Ni presented higher productivity than control plants. The three studied Miscanthus genotypes showed cadmium and nickel accumulation capacity In the biomass, the accumulation occurred more in leaves than in stems, concerning Ni. But, concerning Cd, differences among fractions were not identified. Miscanthus-soil systems accomplished 98-99% removal of Cd and 58-98% removal of Ni from wastewaters. Cd/Ni accumulation in the top soil shows irrigation with wastewaters should be clearly controlled in order to avoid negative impacts on the environment. 12

13 FUTURE PROPOSALS Scale-up (field) Understand the biomass capability in the biorefinerie concept Phytoremediation response to minimal and high [Cd] / [Ni] Phytoremediation response to a mixture of Cd and Ni Quality of the rhizomatous system

14 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 Obrigado Thank you 14