Phytoremediation of Zn or Cu Contaminated Wastewater using Arundo donax L.

Transcription

1 Summer School Lignocellulosic Crops as Feedstock for Future Biorefineries Phytoremediation of Zn or Cu Contaminated Wastewater using Arundo donax L. Jorge Costa, Ana Luisa Fernando Lisbon, July 2014

2 Context Energy crop systems Renewable source of energy But - Intensive use of land Water resources depletion Mineral resources depletion (fertilizers) Soil nutrient depletion Land use competition 2

3 Context Wastewaters (WW) Large volumes Nutrient rich N, P, K, etc, but also contaminants such as heavy metals It takes energy and other resources to treat 3

4 Context Reuse of WW in the irrigation of energy crops Merge energy crop production with WW management Offers dual goals fiber and bioenergy production environmental benefits water remediation carbon sequestration 4

5 Context Arundo donax L. Yields of up to 40 t/ha (dm), can be increased if subjected to genetic improvement. Very aggressive plant, with capacity to suppress any vegetation under their canopies. Very high density in the wild ranging from 50 to 74 stems/m 2. Extremely resistant to crop plagues. Deep and extensive radicular system 5

6 Context Yielding high quality lignocellulosic material Energy Raw material cover building material fishing rods walking sticks pulp/paper production 6

7 Aim of the study To evaluate The effect of reuse of wastewater contaminated with zinc or copper on yield and quality of giant reed (Arundo donax L.) To determine the effectiveness of phytoremediation in terms of heavy metal removing from wastewater under different water regimes 7

8 Methodology Assembling the trials 28 cm 12 kg 10 mm mesh size sieve Soil collected at the rhizome extraction site 3 g N/m 2 (urea, 46% N); 3 g N/m 2 (NH 4 NO 3 + CaCO 3, 27% N); 17 g K 2 O/m 2 (K 2 SO 4 51% K 2 O); 23 g P 2 O 5 /m 2 (superphosphate, 18% P 2 O 5 ). Zn/Cu Sinthetic treated wastewater produced from piggery wastewater 8

9 Methodology DL 236/98 WWZnI - 10 mg Zn. dm -3 WWZnII - 20 mg Zn. dm -3 DL 236/98 WWCuI - 1 mg Cu.dm -3 WWCuII - 2 mg Cu.dm -3 Tap water Control WWZnI WWZnII Tap water Control WWCuI WWCuII Irrigation regime mm/year Replicates 9

10 Methodology Part of the Trial site and vase layout. 10

11 Average Stem Diameter (mm) Results First year results Stems height and diameter Average stem height (cm) 120,00 100,00 80,00 60,00 40,00 20,00 0,00 950mm 475mm 238mm Water regime Control ZnI ZnII CuI CuII Height with Zn, but not with Cu in high water regime = or Height in medium and low water regimes 10,00 9,00 8,00 7,00 6,00 5,00 4,00 3,00 2,00 1,00 0,00 950mm 475mm 238mm Water regime Control ZnI ZnII CuI CuII diameter in medium and low water regimes 11

12 Results First year results - Biomass Productivity % % stems in WWCuI stems leaves stem yields in WWZnI, WWZnII, WWCuII Control WWZnI WWZnII WWCuI WWCuII % leaves production Zn/Cu contamination increases productivity in medium and low H 2 O regime 12

13 Results First year results Zn content Zn with Zn contamination 13

14 Results First year results Cu content Cu with Cu contamination, in leaves Cu with Cu contamination, in stems with 950mm, but not with medium and low water regime 14

15 Copper content in percolates (mg/l) Zinc content in percolates (mg/l) Results First year results Percolates 2,0000 1,8000 1,6000 1,4000 1,2000 1,0000 0,8000 0,6000 0,4000 0,2000 0, Water regime Control WW ZnI WW ZnII Most of Zn was retained by the soil and by Arundo 0,3500 0,3000 0,2500 0,2000 0,1500 0,1000 Control WW CuI WW CuII 0,0500 Most of Cu was retained by the soil and by Arundo 0, Water regime 15

16 Conclusions Contaminated WW can be used as a water source for energy purpose crops irrigation By using WW in water scarce regions it is possible to save tap water for other applications After the establishment period Arundo can offer interesting biomass production for energy purposes specially when irrigated with WW 180 % Stems leaves Control ZnI ZnII CuI CuII Arundo can be cropped in different WW availability due to insignificant parameter differences in all water regimes Minimize the use of fertilizers due to nutrient loads present in WW 16

17 Acknowledgments This work was supported by the European Union (Project Optimization of perennial grasses for biomass production (OPTIMA), Grant Agreement No: , Collaborative project, FP7-KBBE PhD and MSc colleagues 17