Remediation of heavy metals by microalgae: Productivity impact and end fate of contaminants

Transcription

1 Remediation of heavy metals by microalgae: Productivity impact and end fate of contaminants Eric Torres, Derek Hess, Brian McNeil, Jason C. Quinn Mechanical & Aerospace Engineering Utah State University 1

2 Acknowledgments NSF Katerine Napan, Ph. D. Utah Water Research Laboratory Joan McLean Tessa Guy BioEnergy Center 2

3 Outline Introduction Methods Results 3

4 Previous Work Harvest Density (g/l) Scenedesmus obliquus with 10 heavy metals 0X 1X 2X 5X 10X Distribution (%) As Cd Co Cr Cu Hg Ni Pb Se Zn Metals Concentration Harvest Density (g/l) X Nannochloropsis salina with 14 heavy metals 0X 1X 2X 5X 10X Distribution (%) As Cd Co Cr Cu Hg Ni Pb Sb V Napan, et.al. Metals Concentration 4

5 Contaminated Water Systems Industrial waste Coal-fired power plants Produced Water Mine tailings- Animas River, CO 5

6 Outline Introduction Methods Results 6

7 Experimental Design Nannochloropsis salina 7

8 Metal Concentrations Metal 1X, mg/l 10X, mg/l 40X, mg/l As Cd Cr Co Cu Pb Ni Hg Se Zn X 10X 1X As Cd Ghana Cr Goldmine Co Cu Mexican Pb Reservoir Ni Hg Se Zn Egytian Lake Pikeville Coal Mine, KY Isabella Mine, TN Produced water, Thailand Quartzite Mine, Slovakia Coal power plant 8

9 Cultivation System 32 cups 3 light levels ph maintained at 7.5 -/ /- 0.5 C Evaporation control 9

10 Outline Introduction Methods Results 10

11 Results 11 1 Productivity (% of Control) Light Level Metal Conc. 11

12 Cd 11 1 Productivity (% of Control) Light Level Metal Conc. Minimal effect on growth High sorption 12

13 Co 11 1 Productivity (% of Control) Light Level Metal Conc. Minimal effect on growth High sorption 13

14 Pb 11 1 Productivity (% of Control) Light Level Metal Conc. Minimal effect on growth High sorption 14

15 Zn 11 1 Productivity (% of Control) Light Level Metal Conc. Adverse effects at 40X metals concentrations High sorption 15

16 Cd, Co, Pb, Zn 11 1 Productivity (% of Control) Light Level Metal Conc. Minimal effect on growth High sorption 16

17 Sorption mg/g mg/g Cd mg/g Cd % Sorbed Co mg/g Co % Sorbed mg/g mg/g Pb mg/g Pb % Sorbed Zn mg/g Zn % Sorbed Growth Dilution- decreasing mg/g but increasing % sorbed 17

18 As Light Level Productivity (% of Control) Metal Conc Adverse effects at 40X metals concentrations Low sorption 18

19 Cr Light Level Productivity (% of Control) Metal Conc Adverse effects at 40X metals concentrations Low sorption 19

20 Se Light Level Productivity (% of Control) Metal Conc Minimal effect on growth Low sorption 20

21 As, Cr, Se Light Level Productivity (% of Control) Metal Conc Minimal effect on growth except at 40X Low sorption 21

22 Sorption mg/g mg/g As mg/g As % Sorbed Cr mg/g Cr % Sorbed mg/g Growth Dilutiondecreasing mg/g but increasing % sorbed Se mg/g Se % Sorbed 22

23 Hg Light Level Productivity (% of Control) Metal Conc. We expect Hg to mostly volalatize Not yet performed metal analysis Minimal effect on growth 23

24 Cu Light Level Productivity (% of Control) Metal Conc. Kills algae at 40X metals concentrations Moderate sorption at 40X 24

25 Ni Light Level Productivity (% of Control) Metal Conc. Adverse effects in all occurrences Low sorption 25

26 Sorption mg/g Cu saturating at 40X, no growth Control Cu Cu mg/g Cu % Sorbed mg/g Ni mg/g Ni % Sorbed Growth Dilution- decreasing mg/g but increasing % sorbed Ni 26

27 Summary As Cr Se Cd, Co, Pb, and Zn have high sorption capacities As, Cr, and Se have low sorption capacities Ni and Cu have adverse effects on growth Productivity (% of Control) 2-2 Cd Co Pb Zn Cu Ni 10 2 None of the metals increased growth beyond the mg/g control Growth dilution present in many of the systems 0 mg/g As mg/g As % Sorbed Cu mg/g Dead algae can be effective against Cu 27

28 Thank You Contact Information: Eric Torres 28

29 Hg, Cu, Ni Light Level Productivity (% of Control) Metal Conc. Minimal effect on growth High sorption 29

30 Work by Others Little information exists on heavy metals removal by N. Salina One study 1 shows >9 removal of Cd and Zn Very little or no information on As, Cr, Co, Cu, Pb, Ni, Hg, Se Hess work here? Or would That be a spoiler for his presentation? 30