ROLE OF BIOCHAR AS AMENDMENT FOR POLLUTED MATRIXES: IMPACT ON THE CONTAMINANTS BEHAVIOUR IN TWO CASE STUDIES.

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1 ROLE OF BIOCHAR AS AMENDMENT FOR POLLUTED MATRIXES: IMPACT ON THE CONTAMINANTS BEHAVIOUR IN TWO CASE STUDIES. Guido Fellet Department of Agriculture and Environmental Sciences, University of Udine, Udine, Italy

2 Contaminated Sites in Europe More than 80,000 sites cleaned up over the last 30 years; About 500,000 sites in EU still require soil cleanup; The rehabilitation of industrial sites received funding through EU Structural Funds; the total budget for this purpose is billion EUR allocated for the years If current investigation trends continue, the number of sites needing remediation will increase by 50% by PAHs 13,3% BTEX 6% Phenols 3,6% Chlorinated hydrocarbons Others 2,4% 3,6% Mineral Oil 33,7% Contaminants affecting soil in EU European Environmental Agency, Progress in management of contaminated sites (CSI 015) HM 37,3%

3 Contaminated Sites in Italy Site area (ha) 57 sites

4 Soil Remediation Technologies DIG AND DUMP Chemical and physical processes Thermal treatments Biological processes THERMAL TREATMENT

5 Phytoextraction Phytostabilization Immobilization Plant cultivation dominated by contaminant removal Strong mobilisation Soft/natural mobilisation Gentle Remediation No mobilisation extreme very high high to medium Plant cultivation not directly aimed to contaminant removal Soft/natural immobilisation Not directly aimed at the reduction of contaminant transfer into plants medium to low Aimed at the reduction of contaminant transfer into plants Smart immobilisation Plant concentration and contaminant removal low Strong immobilisation very low redrawn from: SUMATECS project (Sustainable Management of Trace Element Contaminated Sites). Final Research Report, 2008

6 What about using biochar? ph increase (Uchimiya et al., 2010) Soil aggregation and water retention improvement (Glaser et al., 2002) Increase of the long term C pool (Namgay et al., 2010) Increase the nutrients retention and availability (Lehmann et al., 2003) Influence on mobility and bioavailability of trace elements (Beesley et al., 2010) Using Biochar for remediation of polluted sites can at the same time: 1.Sequester C 2.Deal with the organic residues issue

7 Case study 1: mining site Pollutant Mg kg 1 (ppm) Cadmium 24 ± 0.66 Lead 3218 ± 185 Thallium 118 ± 9.3 Zinc 13,672 ± 336 Cave del Predil

8 Effects on Trace Elements behaviour After application of BC from pruning residues on mine tailings: Cd, Zn, and Pb BIOVAILABILITY to plants decreased Al, Cd, Pb, Zn and Cr TCLP 1 MOBILITY decreased WHC and CEC increased P and K and other nutrients were provided Effects of BC from manure on metallophytes: Significant biomass increase Reduced metal uptake (Cd, Pd and Zn) Minimum Translocation to aboveground biomass (TF<1) 1 USEPA, EPA Method 1311: TCLP Toxicity Characteristic Leaching Procedure. In: Test Methods for Evaluating Solid Waste. 3rd ed. Washington, DC.

9 Case study 2: industrial site Pollutant Mg kg 1(ppm) Cadmium 730 ± 111 Lead 8,314 ± 862 Zinc 38,912 ± 1,871 Crotone

10 Effects on TE behaviour After application of 3 BCs (pruning residues, fir wood, manure) on industrial wastes: Cd LEACHING decreased no effects on Pb LEACHING but increased for manure BC no effects on Zn LEACHING but decreased for manure BC Cpw decreased for Cd and Zn 1 USEPA, EPA Method 1311: TCLP Toxicity Characteristic Leaching Procedure. In: Test Methods for Evaluating Solid Waste. 3rd ed. Washington, DC.

11 Recent studies on inorganic pollutants Element Mobility Bioavailability Reference As Increase Increase Cd Decrease* Decrease** Beesley et al., 2010 Zheng et al., 2012 Beesley et al., 2010*, ** Beesley e Marmiroli, 2011* Uchimiya et al., 2010* Fellet et al., 2011** Park et al., 2011*, ** Cr Decrease Fellet et al., 2011 Cu Decrease* Increase** Decrease*** Increase**** Beesley et al., 2010**, **** Beesley e Dickinson, 2011** Karami et al., 2011* Uchimiya et al., 2010* Fellet et al., 2011**, **** Park et al., 2011**, *** Ni Decrease Uchimiya et al., 2010 Pb Decrease* Increase*** Decrease** Zn Decrease* Decrease** Karami et al., 2011* Fellet et al., 2011*, ** Park et al., 2011*, ** Zheng et al., 2012*** Beesley et al., 2010* Beesley e Marmiroli, 2011* Fellet et al., 2011** Zheng et al., 2012*

12 Biochar as amendment may be used to: ameliorate the substrate condition in terms of fertility for plants reduce the pollutants (TE but also organic elements) transfer into the food chain from polluted sites But, the mechanisms of TE retention depend on a variety of parameters that vary with the soil type and the biochar type. What happens in the long term? Conclusion