New soil remediation strategies targeted at reduction of PACs contaminant exposure and mobility

1. New soil remediation strategies targeted at reduction of PACs contaminant exposure and mobility Geoffrey Marchal National Environmental Research Institute Aarhus University

2. I. Concept & hypothesis Two and three ring PAC are weakly bound to soil particles and 4-7 ring PAC are strongly bound to organic soil particles. • Environmental Fate • Polycyclic aromatic compounds (PACs) do not dissolve easily in water and they bind to particles, and settle to the bottom of lakes and rivers. • Due to their lipophilic nature and their affinity for organic carbon, PACs become sequestered to the soil matrixfor a long time. Phenanthridine Benz[a]anthracene Fluoranthene PhD Studentship REMTEC presentation 10/09 - 09

3. I. Concept & hypothesis New bioremediation concepts for the reduction of environmental and human risks will be developed and validated by turning the limitation of existing remediation technology (limited bioavailability) into an advantage (reduction of mobility and uptake). BIOSTABILISATION A number of soil amendments will be investigated for their potential to facilitate chemical degradation | Biodegradation | transformation into non accessible forms while, if possible, at the same time improving other core functions of the soil. PhD Studentship REMTEC presentation 10/09 - 09

4. I. Concept & hypothesis 1. Biochara: biomass-derived black carbon (incomplete combustion) made from wood-char.2. Charcoalb: 1 – 100 µm particles made from incomplete combustion of organic matter with identifiable morphological features of the original fuel.3. Activated carbon: Activated carbon (particule size 0.15 to 1 mm) is a form of carbon that has been processed to make it extremely porous and thus to have a very large surface area available for adsorption or chemical reactions.4. Black carbonb: the remnants carbon rich matter of incomplete combustion.And also Compost and Artificial humus Soils amendments: a. Lehmann J et al. . 2006 Bio-char sequestration in terrestrial ecosystems – a review. Mitigation and Adaptation Strategies for Global Change 11, 403 - 427. b. Cornelissen G et al. . 2005. Extensive Sorption of Organic Compounds to Black Carbon, Coal, and Kerogen in Sediments and Soils: Mechanisms and Consequences for Distribution, Bioaccumulation, and Biodegradation. Environmental science and technology 39, 6881-6895. PhD Studentship REMTEC presentation 10/09 - 09

5. I. Concept & hypothesis TOPSOIL (1a) add stable organic matters (1a’) add high porous matters (1b) bind and sequester PACs (2) transform to increase inaccessibility (2’) sequester PACs inside pores (3) increase hydrophobicity (3’) block pores by oil/lipid/bacteria (4) increase stabilization by interaction with mineral surfaces (5) Transform into highly recalcitrant matter PhD Studentship REMTEC presentation 10/09 - 09

6. I. Concept & hypothesis • add amendment • bind and sequester PACs • sequester PACs inside pores • Decrease chemical activity and mobility of PACs in soil. • Increase PACs concentration on amendment. Chemical activity on amendment? • growth of PACs degrader bacteria increase on amendment loaded with PACs • PACs degrader fungi hyphae grow into pores of amendment • Decrease total concentration of PACs SOIL amendment bacteria Fungi PACs bacteria and fungi can reach PACs PhD Studentship REMTEC presentation 10/09 - 09

7. II. Experimental Approach First Experiment - Screening of soil amendments: We study the sequestration capacities of amendment. The purpose of this experiment is to screen and to select different amendments for the future experiments. Mass balance study: measure PAC trapped to amendment and not trapped to amendment simple system: cyclodextrin solution (140 mg L-1) 14C labeled single PAC specific C-amendment • Soil amendments : • Biochar • Activated carbon • Charcoal • PACs : • Anthracene • Fluoranthene • Phenanthrene • Compost • Artificial humus • Phenanthridine • Pyrene PhD Studentship REMTEC presentation 10/09 - 09

8. III. General Method step 2 step 3 Filter each vials Measure 14C in the solution Measure 14C on the filter (amendment) Shake vials for 0, 2, 6, 12, 24, 48, 72, and 144h at room temperature 0 24 48 72 144 step 1 Add amendment with cyclodextrin solution Calculation of mass balance estimate PACs sequestration capacity of amendment Evaporation of methanol solution Loading vials with 14C labeled PAC methanol solution PhD Studentship REMTEC presentation 10/09 - 09

9. V. Future Prospect 2nd experiment: Screening of soil amendments with bacteria. Repetition of first experiment with bacteria and/or fungi 3th experiment: Studying interaction among a few selected amendments with effects on chemical activity and indigenous bacteria extracted from soil. 4th experiment: “fungal highway”: study capacity of hyphae to improve bacterial biodegradation of inaccessible PAC sequester into pores of amendment. PhD Studentship REMTEC presentation 10/09 - 09

10. IV. PhD Project Description QUESTION ? PhD Studentship REMTEC presentation 10/09 - 09

11. The End Thank you for your attention PhD Studentship REMTEC presentation 10/09 - 09