Treatment of sites contaminated with perfluorinated compounds using biochar amendment
Number of Authors: 4
2016 (English)In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 142, 35-40 p.Article in journal (Refereed) Published
Per- and polyfiuorinated compounds (PFCs) have been attracting increasing attention due to their considerable persistence, bioaccumulation, and toxicity. Here, we studied the sorption behavior of three PFCs, viz. perfluorooctanesulfonic acid (PFOS), perfluorooctanecarboxylic acid (PFOA), perfluorohexanesulfonic acid (PFHxS), on one activated carbon (AC) and two biochars from different feedstocks, viz, mixed wood (MW) and paper mill waste (PMW). In addition, we explored the potential of remediating three natively PFC contaminated soils by the addition of AC or biochar. The sorption coefficient i.e. Freundlich coefficients LogK(F), (mu g/kg)/(mu g/L)(n), for the two biochars were 4.61 +/- 0.11 and 4.41 +/- 0.05 for PFOS, 3.02 +/- 0.04 and 3.01 +/- 0.01 for PFOA, and 3.21 +/- 0.07 and 3.18 +/- 0.03 for PFHxS, respectively. The AC sorbed the PFCs so strongly that aqueous concentrations were reduced to below detection limits, implying that the LogK(F) values were above 5.60. Sorption capacities decreased in the order: AC > MW > PMW, which was consistent with the material's surface area and pore size distribution. PFC sorption to MW biochar was near-linear (Freundlich exponent n(F) of 0.87-0.90), but non-linear for PMW biochar (0.64-0.73). Addition of the AC to contaminated soils resulted in almost complete removal of PFCs from the water phase and a significant (i.e. 1-3 Log unit) increase in soil-water distribution coefficient LogK(d). However, small to no reduction in pore water concentration, and no effect on LogK(d) was found for the biochars. We conclude that amendment with AC but not biochar can be a useful method for in situ remediation of PFC-contaminated soils.
Place, publisher, year, edition, pages
2016. Vol. 142, 35-40 p.
Perfluorinated compounds, Biochar, Sorption, Soil remediation, Activated carbon, PFOS
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:su:diva-125642DOI: 10.1016/j.chemosphere.2015.04.085ISI: 000365368400006PubMedID: 25956025OAI: oai:DiVA.org:su-125642DiVA: diva2:895507