Effects of Biochars on ecotoxicological indicators...Potential Toxic Elements and Organic Pollutants...

Effects of Biochars on ecotoxicological indicators

Biochar Code Feedstocks Production

Scale

Pyrolysis

Temperature

BC1 R1501017 PmW-BC Poultry manure and wood Pilot 500

BC2 R1502004 D1-BC Digestate of corn and rye Pilot 500

BC3 R1504035 D2-BC Digestate from a biogas plant Industrial 700

BC4 R1504036 W1-BC Forestry Residues Industrial 650

BC5 R1505058 W2-BC Forestry Residues Pilot 500

BC6 R1505059 WC-BCX Vegetable and forestry wastes; refuse

compost

Pilot 500

BC7 R1505060 D3-BC Digestate from a biogas plant Pilot 500

BC8 R1505061 Pig-BC Pig manure Pilot 500

Biochars characteristics

Feedstock and origins:

Ecotoxicological risk assessment


Potential Toxic Elements and Organic Pollutants

Potential Toxic Elements (PTE) • Heavy metals present in feedstocks are not destroyed by pyrolysis

Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Mercury (Hg), Molybdenum (Mo), Nickel (Ni), Lead (Pb), Selenium (Se), Zinc (Zn)

Potential Organic Pollutants (POP): • Polychlorinated biphenyls (PCBs) : present in feedstock • Polycyclic aromatic hydrocarbons (PAHs) and Dioxins and furans (PCDDs and

PCDFs) : produced during pyrolisis

Potential Toxic Elements - Contents

As, Hg, Se: for all biochars, below the LOQ (Limit of Quantification) Others heavy metals : levels are low One biochar stood out from the others : Pig-BC

Pig manure generally contains various heavy metals such as copper and zinc

Parameter Biochar

Arsenic As mg/kg dry wt < 4,07 < 4,05 < 4 < 4,06 < 4 < 4 < 4,04 < 4

Cadmium Cd mg/kg dry wt 0,7 < 0,2 0,2 < 0,2 0,2 0,5 0,89 0,8

Chromium Cr mg/kg dry wt 26,7 18,2 20,3 17,2 4,5 30,4 20 21,7

Copper Cu mg/kg dry wt 93 92,7 96 13,2 14,7 48,3 164 894,2

Mercury Hg mg/kg dry wt < 0,01 < 0,01 < 0,01 < 0,01 < 0,01 < 0,01 < 0,01 < 0,01

Molybdenum Mo mg/kg dry wt 5,56 3,96 4,66 1,93 < 0,4 2,7 5,11 10,85

Nickel Ni mg/kg dry wt 16,8 11,3 7,5 17,4 3,3 11,4 13 17,1

Lead Pb mg/kg dry wt 8,7 < 5,1 20,1 7,1 < 5 64,9 < 5 6,5

Selenium Se mg/kg dry wt < 3,06 < 3,04 < 1,5 < 3,04 < 1,5 < 1,5 < 3,03 1,7

Zinc Zn mg/kg dry wt 413,8 494,1 360,3 177,8 215,9 222,1 971,5 1475,8

D3-BC Pig-BCD1-BC PmW-BCD2-BC W1-BC W2-BC WC-BCX

Potential Toxic Elements - Contents

Comparison with limits defined by 3 guidelines and 1 french regulation All the biochars are below these limits

International Biochar Initiative (IBI) Standards V2 : http://www.biochar-international.org/sites/default/files/IBI_Biochar_Standards_V2%200_final_2014.pdf European Biochar Certificate (EBC) Guidelines V6.1 : http://www.european-biochar.org/biochar/media/doc/ebc-guidelines.pdf Biochar Quality Mandate (BQM) Version for public consultation V1.0 : http://www.geos.ed.ac.uk/homes/sshackle/BQM.pdf Arrêté du 8 janvier 1998 fixant les prescriptions techniques applicables aux épandages de boues : http://www.legifrance.gouv.fr/affichTexte.do?cidTexte=JORFTEXT000000570287

Parameter GuidelinesInternational Biochar

Initiative (IBI)

European Biochar

Certificate (EBC)

Biochar Quality

Mandate (BQM)

Arrêté 8 janvier 1998

Epandage boues STEP

Arsenic As mg/kg dry wt 12-100 - 10-100 -

Cadmium Cd mg/kg dry wt 1,4-39 < 1-1,5 3-39 10

Chromium Cr mg/kg dry wt 64-1200 < 80-90 15-100 1000

Copper Cu mg/kg dry wt 63-1500 < 100 40-1500 1000

Mercury Hg mg/kg dry wt 1-17 < 1 1-17 10

Molybdenum Mo mg/kg dry wt 5-20 - 10-75 -

Nickel Ni mg/kg dry wt 47-600 < 30-50 10-600 200

Lead Pb mg/kg dry wt 70-500 < 120-150 60-500 800

Selenium Se mg/kg dry wt 2-36 - 5-100 -

Zinc Zn mg/kg dry wt 200-7000 < 400 150-2800 3000

http://www.biochar-international.org/sites/default/files/IBI_Biochar_Standards_V2 0_final_2014.pdf




http://www.european-biochar.org/biochar/media/doc/ebc-guidelines.pdf






http://www.geos.ed.ac.uk/homes/sshackle/BQM.pdf

http://www.geos.ed.ac.uk/homes/sshackle/BQM.pdf

http://www.legifrance.gouv.fr/affichTexte.do?cidTexte=JORFTEXT000000570287



Potential Toxic Elements - Fluxes

Fluxes of heavy metals for a application dose of 5 tons dw/ha

1) Comparison with limits defined by french regulation for the fertilizers registration

All the biochars are below except Pig-BC for copper and zinc

( CuFlux= 4471 g/ha > MaxFlux = 1000 g/ha ; ZnFlux= 7380g/ha > MaxFlux = 3000g/ha)

2) Ecotoxicological risk assessment characterized by Risk Characterization Ratio (RCR)

RCR << 1 for all heavy metals in Biochars

PEC

PNEC RCR =

Predicted Environmental Concentration Concentration of the toxicant that might be expected to be found in an ecosystem

Calculated value (flux)

Predicted No Effect Concentration Concentration of the toxicant below wich adverse effects are unlikely to occur

Estimated value (toxicity data) RCR < 1 : No risk RCR >> 2 : Confirmed risk

Potential Organic PollutantsParameter Biochar

Congeners 28 mg/kg dry wt < 0,01 < 0,01 < 0,01 < 0,01 < 0,01 < 0,01 < 0,01 < 0,01







Sum of 7 PCB mg/kg dry wt < 0,07 < 0,07 < 0,07 < 0,07 < 0,07 < 0,07 < 0,07 < 0,07

Acenaphtene mg/kg dry wt 0,038 0,046 0,01 < 0,01 0,036 0,015 < 0,01 0,041

Acenaphtylene mg/kg dry wt < 0,01 < 0,01 0,01 < 0,01 < 0,01 < 0,01 0,01 0,012

Anthracene mg/kg dry wt 0,044 < 0,01 0,1 < 0,01 0,08 0,033 0,031 0,08

Benzo(a)anthracene mg/kg dry wt 0,013 < 0,01 0,049 < 0,01 0,026 0,018 0,017 0,039

Benzo(a)pyrene mg/kg dry wt < 0,01 < 0,01 0,032 < 0,01 0,015 0,019 0,024 0,053

Benzo(b)fluoranthène mg/kg dry wt < 0,01 < 0,01 0,024 < 0,01 < 0,01 < 0,01 0,012 0,021

Benzo(k)fluoranthène mg/kg dry wt < 0,01 < 0,01 0,019 < 0,01 < 0,01 < 0,01 < 0,01 0,012

Benzo(ghi)perylene mg/kg dry wt < 0,01 < 0,01 0,023 < 0,01 < 0,01 0,015 0,02 0,016

Chryseme mg/kg dry wt 0,018 < 0,01 0,06 < 0,01 0,026 0,019 0,03 0,13

Dibenzo(ah)anthrocene mg/kg dry wt < 0,01 < 0,01 0,033 < 0,01 < 0,01 < 0,01 < 0,01 < 0,01

Fluoranthene mg/kg dry wt 0,04 < 0,01 0,125 < 0,01 0,045 0,021 0,031 0,085

Fluorene mg/kg dry wt 0,076 < 0,01 0,13 < 0,01 0,15 0,08 0,067 0,15

Indeno(123CD)pyrene mg/kg dry wt < 0,01 < 0,01 < 0,01 < 0,01 < 0,01 < 0,01 0,013 < 0,01

Naphtalene mg/kg dry wt 0,198 0,32 0,31 0,041 0,32 0,1 0,254 0,35

Phenanthrene mg/kg dry wt 0,147 < 0,01 0,309 < 0,01 0,277 0,09 0,085 0,262

Pyrene mg/kg dry wt 0,04 < 0,01 0,14 < 0,01 0,086 0,033 0,037 0,099

Sum of 16 HAP mg/kg dry wt 0,649 0,436 1,379 0,116 1,091 0,468 0,646 1,36

1,2,3,4,6,7,8-Heptachlorodibenzodioxin ng/kg dry wt 0,1504 0,065 0,2 0,222 0,116 0,114 0,1342 0,0787

1,2,3,4,6,7,8-Heptachlorodibenzofuran ng/kg dry wt 0,1387 0,072 0,056 0,08 0,074 0,059 0,0471 0,0494

1,2,3,4,7,8,9-Heptachlorodibenzofuran ng/kg dry wt 0,0263 0,015 < 0,011 0,024 < 0,017 < 0,023 < 0,0098 0,0122

1,2,3,4,7,8-Hexachlorodibenzofuran ng/kg dry wt 0,0436 0,03 0,023 0,051 < 0,03 < 0,017 0,0244 0,0287

1,2,3,6,7,8-Hexachlorodibenzodioxin ng/kg dry wt 0,0389 < 0,01 < 0,022 < 0,028 < 0,055 < 0,045 0,0331 0,0133

1,2,3,6,7,8-Hexachlorodibenzofuran ng/kg dry wt 0,0334 0,019 < 0,013 0,033 < 0,03 < 0,017 0,0155 0,0106

1,2,3,7,8,9-Hexachlorodibenzodioxin ng/kg dry wt 0,0237 < 0,01 < 0,022 < 0,027 < 0,054 < 0,045 0,0663 0,0138

1,2,3,7,8,9-Hexachlorodibenzofuran ng/kg dry wt < 0,0133 < 0,008 < 0,015 < 0,027 < 0,032 < 0,02 < 0,0125 < 0,0047

2,3,4,6,7,8-Hexachlorodibenzofuran ng/kg dry wt 0,026 0,01 < 0,014 < 0,026 < 0,031 < 0,017 < 0,012 0,008

1,2,3,7,8-Pentachlorodibenzodioxin ng/kg dry wt 0,0176 0,014 0,03 0,051 < 0,03 < 0,026 0,0716 0,0184

1,2,3,7,8-Pentachlorodibenzofuran ng/kg dry wt 0,0277 0,019 0,015 < 0,032 < 0,023 0,016 0,017 0,023

2,3,4,6,7,8-Pentachlorodibenzofuran ng/kg dry wt 0,0318 0,028 0,027 0,06 0,035 0,022 0,0292 0,0308

1,2,3,4,7,8-Hexachlorodibenzodioxin ng/kg dry wt < 0,0114 < 0,01 < 0,022 < 0,026 < 0,052 < 0,043 < 0,0137 < 0,01

2,3,7,8-Tetrachlorodibenzodioxin ng/kg dry wt 0,0217 < 0,005 < 0,011 0,027 < 0,019 < 0,018 0,0502 0,0114

2,3,7,8-Tetrachlorodibenzofuran ng/kg dry wt 0,0489 0,035 0,041 0,063 0,051 0,033 0,0396 0,0799

Octachlorodibenzodioxin ng/kg dry wt 0,0483 0,195 0,463 0,885 0,535 0,231 0,3428 0,2255

Octachlorodibenzofuran ng/kg dry wt 0,1664 0,061 0,123 0,097 0,129 0,078 0,0601 0,0481

PCBs

PAHs

Dioxins

Furans

D3-BC Pig-BCD1-BC PmW-BCD2-BC W1-BC W2-BC WC-BCX

PCBs below the LOQ

Contents All the biochars are

below limits defined by 3 guidelines and 1 french regulation

Fluxes Below limits defined by french regulation

RCR < 2 for all POP in Biochars


Global approach - Soil improver

ISO 11-269-2 : Effects of contaminated soils on the emergence and early growth of higher plants

Biochars tested : D1-BC ; D2-BC ; PmW-BC Plant test : barley (Hordeum vulgare) and cress (Lepidium sativum) Application doses : 1 – 5 – 10 – 50 t dw/ha Emergence 7 days after seedling Dry weight 14 days after 70% emergence of the seedling in the control group Emergence and biomasses are compared to those of untreated control plants and percentage of inhibition are calculated Toxicity threshold : 25 % inhibition



No negative impact at 1, 5 and 10 t/ha ; At 50 t/ha, only on cress emergence


ISO 11-268-2 : Determination of effects on reproduction of Eisenia fetida/Eisenia andrei

Biochars tested : D1-BC ; D2-BC ; PmW-BC Test indicators : Eisenia fetida and Eisenia andrei Application doses : 1 – 5 – 10 – 50 t dw/ha Mortality and biomasses of adults eartworms 28 days after exposure Reproduction (numbers of juvenils) 56 days after exposure Biomasses and numbers of juvenils are compared to those of untreated control and expressed as inhibition percentage Toxicity threshold : 20 % inhibiton for biomasses 50 % inhibition for numbers of juvenils



% Mortality after 28 days Doses D1-BC D2-BC PmW-BC

Dose 1 0 0 0

Dose 5 0 0 0

Dose 10 0 0 0

Dose 50 0 3 0

Control 0 0 0

No negative impact at 1, 5, 10 and 50 t/ha

Global approach - Component growing media


Biochar tested : W1-BC Plant test : barley (Hordeum vulgare) and cress (Lepidium sativum) Application doses : 5 – 10 – 20 % (volum/volum) Emergence 7 days after seedling Dry weight 14 days after 70% emergence of the seedling in the control group Emergence and biomasses are compared to those of untreated control plants and percentage of inhibition are calculated Toxicity threshold : 25 % inhibition


No negative impact on emergence


No negative impact on barley growth

Cress growth Dose 10% (v/v) : - 47% growth Dose 20% (v/v) : - 54% growth


Biochars tested : D1-BC ; D2-BC ; W1-BC Test indicator : Eisenia fetida and Eisenia andrei Application doses : 5 – 10 – 20 % (volum/volum) Mortality and biomasses of adults eartworms 28 days after exposure Reproduction (numbers of juvenils) 56 days after exposure Biomasses and numbers of juvenils are compared to those of untreated control and expressed as inhibition percentage Toxicity threshold : 20 % inhibition for biomasses 50 % inhibition for numbers of juvenils



% Mortality after 28 days

Negative impact at all application doses - High mortality rate - Biomass loss - No reproduction


Doses D1-BC D2-BC W1-BC

Dose 5% 100 23 0

Dose 10% 100 48 8

Dose 20% 100 100 50

Control 0 0 0


Leaching

Batch Leaching (EN ISO TS 21268-2 )

90g dw Biochar

900ml lixiviant (CaCl2 1mM)

24 hours agitation at 10 rpm

Liquid/Solid (L/S) Ratio = 10

Upward Leaching (EN ISO TS 21268-3 )

3,5 kg dw soil + 6g dw Biochar

(dose soil improver: 5 t dw/ha)

Lixiviant (CaCl2 1mM)

Upward flow = 49 ml/hours

L/S Ratio = 10

2,5 kg dw soil + 3,25g dw

Biochar (dose soil improver)

600 ml watering: rainfall

episode simulation 80mm

L/S Ratio = 0,25

Downward Leaching (Lysimetric essay)

Liquid/Solid Ratio L/kg Volume of eluate L

Eluate 1 0,1 ± 0,02 0,367

Eluate 2 0,1 ± 0,02 0,367

Eluate 3 0,3 ± 0,05 1,101

Eluate 4 0,5 ± 0,01 1,835

Eluate 5 1,0 ± 0,2 3,67

Eluate 6 3,0 ± 0,2 11,01

Eluate 7 5,0 ± 0,2 18,349

Potential Toxic Elements

1) Analysis of heavy metals concentration in aqueous extract Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Mercury (Hg), Molybdenum (Mo), Nickel (Ni), Lead (Pb), Selenium (Se), Zinc (Zn)

2) Calculation of efficiency of extraction for each metals quantity biochar x heavy metal content x concentration 3) Evaluation of Predicted Environmental Concentration (PEC) in 2 compartments Infiltration of surface water in groundwater (50%) and in river (50%) 5 tons dw/ha x heavy metal content x efficiency of extraction Groundwater Daily flow : 540 m3 Annual flow : 197 100 m3

River Daily flow : 86 400 m3 Annual flow : 31 536 000 m3

Stormy episode during 24 hours Rain during 1 year 4) Calculation of Risk Characterization Ratio (RCR)


Batch leaching 6 Biochars

PTE D1-BC D2-BC D3-BC W2-BC WC-BXC Pig-BC D1-BC D2-BC D3-BC W2-BC WC-BXC Pig-BC

As 0,0044 - - - - - - - - - - - -

Cd 0,00075 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000

Cr 0,0041 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000

Cu 0,0016 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,001 0,000 0,000 0,026

Hg 0,00024 - - - - - - - - - - - -

Ni 0,0005 0,000 0,000 0,000 0,000 0,000 0,000 0,004 0,000 0,000 0,000 0,000 0,004

Pb 0,005 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000

Se 0,00088 - - - - - - - - - - - -

Zn 0,0086 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,001 0,000 0,001

Rain during 1 year

PNEC

mg/LRCR River RCR Groundwater

PTE D1-BC D2-BC D3-BC W2-BC WC-BXC Pig-BC D1-BC D2-BC D3-BC W2-BC WC-BXC Pig-BC

As 0,0044 - - - - - - - - - - - -

Cd 0,00075 0,000 0,000 0,000 0,000 0,000 0,000 0,075 0,044 0,022 0,022 0,022 0,022

Cr 0,0041 0,000 0,000 0,000 0,000 0,000 0,000 0,068 0,022 0,008 0,003 0,029 0,008

Cu 0,0016 0,001 0,000 0,002 0,001 0,001 0,060 0,122 0,031 0,278 0,148 0,081 9,549

Hg 0,00024 - - - - - - - - - - - -

Ni 0,0005 0,009 0,001 0,001 0,001 0,001 0,009 1,481 0,093 0,093 0,093 0,093 1,389

Pb 0,005 0,000 0,000 0,000 0,000 0,000 0,000 0,030 0,005 0,002 0,005 0,002 0,002

Se 0,00088 - - - - - - - - - - - -

Zn 0,0086 0,000 0,001 0,000 0,003 0,000 0,002 0,027 0,108 0,013 0,431 0,065 0,323

Stormy episode during 24 hours

PNEC

mg/LRCR River RCR Groundwater

RCR > 2 for copper in Pig-BC Confirmed risk in the most critical scenario


Upward leaching 2 Biochars (D1-BC, D2-BC) Downward leaching 1 Biochar (D1-BC), 2 leachings

PTE

D1-BC

Upward

Leaching

D1-BC

Downward

Leaching 1

D1-BC

Downward

Leaching 2

D2-BC

Upward

Leaching

D1-BC

Upward

Leaching

D1-BC

Downward

Leaching 1

D1-BC

Downward

Leaching 2

D2-BC

Upward

Leaching

As 0,0044 - 0,000 - - - 0,003 - -

Cd 0,00075 0,000 0,000 0,000 - 0,006 0,002 0,000 -

Cr 0,0041 0,000 0,000 0,000 - 0,002 0,000 0,000 -

Cu 0,0016 - 0,000 - - - 0,018 - -

Hg 0,00024 - 0,000 0,000 - - 0,002 0,000 -

Ni 0,0005 0,000 0,000 0,000 - 0,075 0,008 0,000 -

Pb 0,005 0,000 0,000 0,000 - 0,013 0,000 0,000 -

Se 0,00088 0,000 0,000 0,000 - 0,026 0,001 0,000 -

Zn 0,0086 - 0,000 0,000 - - 0,007 0,010 -

Rain during 1 year

PNEC

mg/L

RCR River RCR Groundwater

PTE

D1-BC

Upward

Leaching

D1-BC

Downward

Leaching 1

D1-BC

Downward

Leaching 2

D2-BC

Upward

Leaching

D1-BC

Upward

Leaching

D1-BC

Downward

Leaching 1

D1-BC

Downward

Leaching 2

D2-BC

Upward

Leaching

As 0,0044 - 0,006 - - - 1,034 - -

Cd 0,00075 0,014 0,005 0,000 - 2,242 0,728 0,014 -

Cr 0,0041 0,005 0,001 0,000 - 0,727 0,093 0,004 -

Cu 0,0016 - 0,041 - - - 6,603 - -

Hg 0,00024 - 0,004 0,000 - - 0,637 0,012 -

Ni 0,0005 0,171 0,019 0,000 - 27,307 3,058 0,059 -

Pb 0,005 0,029 0,000 0,000 - 4,614 0,076 0,001 -

Se 0,00088 0,060 0,003 0,000 - 9,541 0,434 0,008 -

Zn 0,0086 - 0,017 0,023 - - 2,667 3,740 -

Stormy episode during 24 hours

PNEC

mg/L

RCR River RCR Groundwater

Upward leaching L/S = 10

Downward leaching L/S = 0,25

RCR > 2 for several heavy metals

Confirmed risk in the most critical scenario


Global approach

ISO 8692 : Fresh water algal growth inhibition test with unicellular green algae

Aqueous extract by : - batch leaching (6 Biochars) - downward leaching (Mix Soil + 1 Biochar) - upward leaching (Mix Soil + 1 Biochar) Test indicator : Pseudokirchneriella subcapitata Tested doses : range of concentration of aqueous extract Growth 72 hours after exposure Growth are compared to those of untreated control and percentage of inhibition are calculated Toxicity threshold : 15 % inhibition

Global approach

ISO 6341: Determination of the inhibition of the mobility of Daphnia magna Straus

Aqueous extract by : - batch leaching (6 Biochars) - downward leaching (Mix Soil + 1 Biochar) - upward leaching (Mix Soil + 1 Biochar) Test indicator : Daphnia magna Straus Tested doses : range of concentration of aqueous extract Immobilization of D. magna after 24 and 48 hours exposure Immobilization are compared to those of untreated control and percentage of inhibition are calculated Toxicity threshold : 20 % inhibition

Global approach

Aqueous extract by batch leaching

Inhibition algae growth:

Pig-BC > D1-BC > WC-BCX > D3-BC > D2-BC > W2-BC

Inhibition daphnia mobility:

Pig-BC > D1-BC > D2-BC > D3-BC > WC-BCX > W2-BC

Global approach

Aqueous extract by downward leaching

Inhibition algae growth: No ecotoxicity for D1-BC leaching, soil leaching present more effect !

Inhibition daphnia mobility:

No ecotoxicity

Global approach

Aqueous extract by upward leaching

Inhibition daphnia mobility: No ecotoxicity

Inhibition algae growth:

No ecotoxicity for soil and mix soil + D1-BC

Conclusion

Terrestrial Risks - Particular attention should be given to heavy metals content in feedstocks - Use as soil improver :

No risks are identified on tested indicators at 5 and 10 tons dw/ha PTE : confirmed risk in the most critical scenario : « Terms of use » should be

defined - Use as growing media component : confirmed risk starts at dose 5 % (v/v)

Aquatic Risks - Particular attention should be given to heavy metals content in feedstocks - Confirmed risk in the most critical scenario : « Terms of use » should be defined - Aqueous extracts from batch leaching : confirmed effects are identified

Coloration of extract inhibits growth ? tests on other indicators? - Aqueous extracs from up/down leaching : no risks are identified on tested indicators

Biochars should not present an ecotoxic risk in defined usage

Thank you for your attention

Date post:	26-May-2020
Category:	Documents
Upload:	others
View:	5 times
Download:	0 times

Effects of Biochars on ecotoxicological indicators...Potential Toxic Elements and Organic Pollutants...

Documents