Biochar has a charcoal polycyclic aromatic structure which allows its long half-life in soil, making it an ideal tool for C sequestration and for adsorption of organic pollutants, but at the same time raises concerns about possible adverse impacts on soil biota. Two biochars were tested under laboratory-controlled conditions on Eisenia andrei earthworms: a biochar produced at low temperature from wine tree cuttings (WTB) and a commercial low tar hardwood lump charcoal (HLB). The avoidance test (48-h exposure) showed that earthworms avoid biochar-treated soil with rates higher than 16 t ha−1 for HLB and 64 t ha−1 for WTB. After 42 days, toxic effects on earthworms were observed even at application rates (100 t ha−1) that are generally considered beneficial for most crops. The concentration of HLB and WTB required to kill half of earthworms’ population (LC50; 95 % confidence limits) in the synthetic OECD soil was 338 and 580 t ha−1, respectively. Accumulation of polycyclic aromatic hydrocarbons (PAH) in earthworms exposed to the two biochar types at 100 t ha−1 was tested in two soils of different texture. In biochar-treated soils, the average earthworm survival rates were about 64 % in the sandy and 78 % clay-loam soils. PAH accumulation was larger in the sandy soil and largest in soils amended with HLB. PAH with less than four rings were preferentially scavenged from the soil by biochars, and this behaviour may mask that of the more dangerous components (i.e. four to five rings), which are preferentially accumulated. Earthworms can accumulate PAH as a consequence of exposure to biochar-treated soils and transfer them along the food chain. Soil type and biochar quality are both relevant in determining PAH transfer.

Bioaccumulation of polycyclic aromatic hydrocarbons and survival of earthworms (Eisenia andrei) exposed to biochar amended soils

MALEV, OLGA;CONTIN, MARCO;LICEN, SABINA;BARBIERI, PIERLUIGI;
2016

Abstract

Biochar has a charcoal polycyclic aromatic structure which allows its long half-life in soil, making it an ideal tool for C sequestration and for adsorption of organic pollutants, but at the same time raises concerns about possible adverse impacts on soil biota. Two biochars were tested under laboratory-controlled conditions on Eisenia andrei earthworms: a biochar produced at low temperature from wine tree cuttings (WTB) and a commercial low tar hardwood lump charcoal (HLB). The avoidance test (48-h exposure) showed that earthworms avoid biochar-treated soil with rates higher than 16 t ha−1 for HLB and 64 t ha−1 for WTB. After 42 days, toxic effects on earthworms were observed even at application rates (100 t ha−1) that are generally considered beneficial for most crops. The concentration of HLB and WTB required to kill half of earthworms’ population (LC50; 95 % confidence limits) in the synthetic OECD soil was 338 and 580 t ha−1, respectively. Accumulation of polycyclic aromatic hydrocarbons (PAH) in earthworms exposed to the two biochar types at 100 t ha−1 was tested in two soils of different texture. In biochar-treated soils, the average earthworm survival rates were about 64 % in the sandy and 78 % clay-loam soils. PAH accumulation was larger in the sandy soil and largest in soils amended with HLB. PAH with less than four rings were preferentially scavenged from the soil by biochars, and this behaviour may mask that of the more dangerous components (i.e. four to five rings), which are preferentially accumulated. Earthworms can accumulate PAH as a consequence of exposure to biochar-treated soils and transfer them along the food chain. Soil type and biochar quality are both relevant in determining PAH transfer.
Pubblicato
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL
https://link.springer.com/article/10.1007/s11356-015-5568-2
File in questo prodotto:
File Dimensione Formato  
Contin PAHS Biochar earthworms 2016.pdf

non disponibili

Tipologia: Documento in Versione Editoriale
Licenza: Copyright Editore
Dimensione 578.54 kB
Formato Adobe PDF
578.54 kB Adobe PDF   Visualizza/Apri   Richiedi una copia
3904_11368_2905347_EUT.pdf

accesso aperto

Tipologia: Bozza finale post-referaggio (post-print)
Licenza: Digital Rights Management non definito
Dimensione 544.42 kB
Formato Adobe PDF
544.42 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11368/2905347
Citazioni
  • ???jsp.display-item.citation.pmc??? 3
  • Scopus 28
  • ???jsp.display-item.citation.isi??? 29
social impact