Influence of compost and biochar on microbial communities and the sorption/degradation of PAHs and NSO-substituted PAHs in contaminated soils

Author(s)
Gabriel Sigmund, Caroline Poyntner, Guadalupe Pinar, Mélanie Kah, Thilo Hofmann
Abstract

Diffusely contaminated soils often remain untreated as classical remediation approaches would be disproportionately expensive. Adding compost can accelerate the biodegradation of organic contaminants and adding biochar can immobilize contaminants through sorption. The combined use of compost and biochar to reduce polycyclic aromatic hydrocarbon (PAH) and NSO-substituted PAH contamination has, however, not previously been systematically investigated. We have therefore investigated the processes involved (i) through sorption batch experiments, (ii) by monitoring changes in bacterial, fungal and archaeal communities using denaturing gradient gel electrophoresis, and (iii) through degradation experiments with fluorene, phenanthrene, pyrene, carbazole, dibenzothiophene, and dibenzofuran. Sorption coefficients for organic contaminants in soils increased tenfold following 10% compost addition and up to a hundredfold with further addition of 5% biochar. The rate of PAH and NSO-PAH degradation increased up to twofold following compost addition despite increased sorption, probably due to the introduction of additional microbial species into the autochthonous soil communities. In contrast, degradation of PAHs and NSO-PAHs in soil-compost-biochar mixtures slowed down up to tenfold due to the additional sorption, although some degradation still occurred. The combined use of biochar and compost may therefore provide a strategy for immobilizing PAHs and NSO-PAHs and facilitating degradation of remaining accessible contaminant fractions.

Organisation(s)
External organisation(s)
University of Natural Resources and Life Sciences
Journal
Journal of Hazardous Materials
Volume
345
Pages
107-113
No. of pages
7
ISSN
0304-3894
DOI
https://doi.org/10.1016/j.jhazmat.2017.11.010
Publication date
11-2017
Peer reviewed
Yes
Austrian Fields of Science 2012
104023 Environmental chemistry, 104002 Analytical chemistry, 105906 Environmental geosciences
Keywords
ASJC Scopus subject areas
Pollution, Waste Management and Disposal, Health, Toxicology and Mutagenesis, Environmental Engineering, Environmental Chemistry
Portal url
https://ucrisportal.univie.ac.at/en/publications/c8a24255-e624-415a-a683-2bc5a56463ab