Change search
ReferencesLink to record
Permanent link

Direct link
Quantifying the Total and Bioavailable Polycyclic Aromatic Hydrocarbons and Dioxins in Biochars
Show others and affiliations
2012 (English)In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 5, 2830-2838 p.Article in journal (Refereed) Published
Abstract [en]

Biochar soil amendment is advocated to mitigate climate change and improve soil fertility. A concern though, is that during biochar preparation PAHs and dioxins are likely formed. These contaminants can possibly be present in the biochar matrix and even bioavailable to exposed organisms. Here we quantify total and bioavailable PAHs and dioxins in a suite of over 50 biochars produced via slow pyrolysis between 250 and 900 degrees C, using various methods and biomass from tropical, boreal, and temperate areas. These slow pyrolysis biochars, which can be produced locally on farms with minimum resources, are also compared to biochar produced using the industrial methods of fast pyrolysis and gasification. Total concentrations were measured with a Soxhlet extraction and bioavailable concentrations were measured with polyoxymethylene passive samplers. Total PAH concentrations ranged from 0.07 mu g g(-1) to 3.27 mu g g(-1) for the slow pyrolysis biochars and were dependent on biomass source, pyrolysis temperature, and time. With increasing pyrolysis time and temperature, PAH concentrations generally decreased. These total concentrations were below existing environmental quality standards for concentrations of PAHs in soils. Total PAH concentrations in the fast pyrolysis and gasification biochar were 0.3 mu g g(-1) and 45 mu g g(-1), respectively, with maximum levels exceeding some quality standards. Concentrations of bioavailable PAHs in slow pyrolysis biochars ranged from 0.17 ng L-1 to 10.0 ng L-1 which is lower than concentrations reported for relatively clean urban sediments. The gasification produced biochar sample had the highest bioavailable concentration (162 +/- 71 ng L-1). Total dioxin concentrations were low (up to 92 mu g g(-1)) and bioavailable concentrations were below the analytical limit of detection. No clear pattern of how strongly PAHs were bound to different biochars was found based on the biochars' physicochemical properties.

Place, publisher, year, edition, pages
2012. Vol. 46, no 5, 2830-2838 p.
National Category
Environmental Sciences
URN: urn:nbn:se:su:diva-76149DOI: 10.1021/es203984kISI: 000301023700047OAI: diva2:525906
10Available from: 2012-05-09 Created: 2012-05-09 Last updated: 2012-05-09Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Cornelissen, Gerard
By organisation
Department of Applied Environmental Science (ITM)
In the same journal
Environmental Science and Technology
Environmental Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 37 hits
ReferencesLink to record
Permanent link

Direct link