Phytoremediation of Salt (& PHC) Impacted Soils Using Biochar Augmentation; Implications of Salt Tolerance Mechanisms

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1 Phytoremediation of Salt (& PHC) Impacted Soils Using Biochar Augmentation; Implications of Salt Tolerance Mechanisms Dr. Barbara A. Zeeb Canada Research Chair Biotechnologies & Environment Dept. Chemistry & Chemical Engineering Royal Military College of Canada Kingston, ON CANADA RPIC Federal Contaminated Sites National Workshop Stream C - Remediation 26 April, 2016; 10:30-11 am

2 Salinization Causes Natural processes Landfilling of high salt Currently content estimated wastes that Canada has >7.2 million ha of salinized soils Consequences Land degradation Reduction in plant growth & yield Reduction water quality Toxic to aquatic, microbial, veg communities The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again. Landfilling Waste Weathering Agricultural Practices The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.

3 Phytotechnologies the application of plants to engineering and science problems remediating environmental contaminants (phytoremediation) ecorestoration & habitat creation carbon sequestration

4 Mechanisms of Phytoremediation 1. Accumulate 2. Excrete

5 Biochar carbon rich by-product of pyrolysis The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.

6 Phytotechnologies Phytoextraction! Use vegetation to mobilize salts into above ground tissues Accumulation Biochar! Improve soil structure! Improve seed germination! Improve plant growth Uptake 6

7 Halophytes 2. Accumulation Na + Cl - 1. Exclusion 3. Excretion

8 The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again. Adapted from Yensen & Biel 2006

9 Cement Kiln Dust (CKD) Landfill! Operating Cement Plant in Bath, ON! 30 min west of Kingston! CKD landfilled from ! Saline sodic material, slightly alkaline, low TOC! Project Objectives: i) improve aesthetics & ii) reduce [salt]

10 CKD Site Characterization Electrical Conductivity (ds/m) Sodium Absorption Ratio Chloride (µg/g) MOE Guideline < Soil Characterization Saline: >4 Sodic: >13 Average: ~100 CKD Site

11 Objectives 1. Compare the phytoextraction efficiency of 3 halophytes P. australis P. nuttalliana S. pectinata 2. Investigate different salt tolerance mechanisms & their ability to remove salt from soil 3. Role of biochar augmentation

12 Phytoextraction of Chloride with Phragmites australis 12

13 Phytoextraction Phragmites australis = accumulator species large, perennial grass growth prolifically effectively extracts Cl - from soils July 2013 Oct 2013 July 2014

14 Temporal Study

15 Remediation Timeframe Total chloride in top 10 cm of soil: 464 ± 193 kg Based on yearly extractions of kg 3-9 years McSorley, K., Rutter, A. Cumming, R., and Zeeb, B.A Phytoextraction of chloride from a cement kiln dust (CKD) contaminated landfill with Phragmites australis. J. Waste Management (accepted Oct 2015).

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17 Field Trial Addition of 60 lbs of biochar (5% w/w) Planted 36 seedlings per plot

18 5% Biochar Buffer Zone Control S. pectinata A. elongatum P. nuttalliana A. elongatum & P. nuttalliana seeds

19 Biochar Effects Significant in uptake of Na + in P. nuttalliana & K + and Cl - in S. pectinata No uptake of divalent cations Improved germination of P. nuttalliana by 67% 5% Biochar Control

20 Accumulation Conventional phytoextraction calculation i.e. [shoot ion] x biomass at harvest P. australis has highest phytoextraction potential 20

21 Implications of Salt Tolerance Mechanisms on Extraction Efficiency excreted salts 82X mag salt glands S. pectinata growing in RMC lab 2200X mag

22 Characterization of Excreted Salts! EDS for identification of salts excreted on stem & leaf surfaces of S. pectinata! Cl - and K + main ions excreted! Mean weekly excretion! Cl ± 1200 µg/g! K ± 940 µg/g

23 Salt Excretion When considering excretion in lieu of accumulation: Cl - removal increased 160% K + removal increased 30% S. pectinata highest salt phytoextraction potential native to Ontario McSorley, K., Rutter, A. Cumming, R., and Zeeb, B.A. Chloride Accumulation vs Excretion: Variations in phytoextraction potential of three halophytic grass species growing in a salinized landfill. J. Waste Management (submitted April 2016).

24 Fate of Salts! Potential for wind dispersion and dilution! haloconduction theory! micro (Cl - ) and macro (K + ) nutrients released by S. pectinata & wind dispersed! potential beneficial effects! Further research needed to determine extent of redistribution

25 Summary P. australis can extract 65 ± 4 kg/km 2 Cl - /season! remediate site in 3-9 years Biochar can be used for assisted re-vegetation at the CKD landfill germination of P. nuttalliana by 67% Salt tolerance mechanisms affect phytoextraction efficiency Salt excretion with S. pectinata most efficient

26 Acknowledgements Co-Authors: Dr. Allison Rutter, Queen s University Kaitlin McSorley, Pinchin Envt. Rob Cumming, Lafarge, Canada