Impact of basidiomycete fungi on the wettability of soil contaminated with a hydrophobic polycyclic aromatic hydrocarbon

Polyaromatic hydrocarbons (PAHs) present a challenge to bioremediation because they are hydrophobic, thus influencing the water availability and repellency of soil. The addition of different concentrations of the PAH, anthracene, showed it to induce moderate levels of repellency. We investigated the efficacy of three basidiomycete fungal species on improving the wettability of soil by reducing repellency caused by contamination of soil with 7 ppm anthracene. A microcosm system was used that enabled determination of the impact of fungi on wettability at three locations down a 30 mm deep repacked soil core. Before incubation with fungi, the contaminated soil had a repellency of R = 3.12 ± 0.08 (s.e.). After 28 days incubation, Coriolus versicolor caused a significant reduction in repellency to R = 1.79 ± 0.35 (P <0.001) for the top section of the soil in a microcosm. Phanerochaete chrysosporium and Phlebia radiata did not influence repellency. None of the fungi had an effect at 20 mm depth

Thematic Issue on the Hydrological Effects of the Vegetation-Soil Complex

Peer reviewedPublisher PD

Two Roses

https://digitalcommons.library.umaine.edu/mmb-me/1285/thumbnail.jp

Two Roses

https://digitalcommons.library.umaine.edu/mmb-me/1286/thumbnail.jp

Contrasting ability of deep and shallow rooting rice genotypes to grow through plough pans containing simulated biopores and cracks

Fundings: Commonwealth Scholarship Commission Open access via Springer agreement Acknowledgements This study was funded by the Commonwealth Scholarship Commission in the UK. We thank all people that contributed to this work. In particular, Luke Harrold, Rong Qu, Yehia Hazzazi, Licida Maria Giuliani and Istiaq Ahmed with their stimulating discussion during and after setting experiment. We are highly grateful to Annette Rafan, Dr. Stewart J Chalmers and Jaime Buckingham for providing technical supportPeer reviewedPublisher PD

Preface : Biohydrology – walking on drylands and swimming through pores

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Combined turnover of carbon and soil aggregates using rare earth oxides and isotopically labelled carbon as tracers

This work was granted by the China-UK jointed Red Soil Critical Zone project from National Natural Science Foundation of China (NSFC: 41571130053, 41371235) and from Natural Environmental Research Council (NERC: Code: NE/N007611/1).Peer reviewedPublisher PD

Counterion Condensation on Spheres in the Salt-free Limit

A highly-charged spherical colloid in a salt-free environment exerts such a powerful attraction on its counterions that a certain fraction condenses onto the surface of a particle. The degree of condensation depends on the curvature of the surface. So, for instance, condensation is triggered on a highly-charged sphere only if the radius exceeds a certain critical radius \collrad^{*}. \collrad^{*} is expected to be a simple function of the volume fraction of particles. To test these predictions, we prepare spherical particles which contain a covalently-bound ionic liquid, which is engineered to dissociate efficiently in a low-dielectric medium. By varying the proportion of ionic liquid to monomer we synthesise nonpolar dispersions of highly-charged spheres which contain essentially no free co-ions. The only ions in the system are counterions generated by the dissociation of surface-bound groups. We study the electrophoretic mobility of this salt-free system as a function of the colloid volume fraction, the particle radius, and the bare charge density and find evidence for extensive counterion condensation. At low electric fields, we observe excellent agreement with Poisson-Boltzmann predictions for counterion condensation on spheres. At high electric fields however, where ion advection is dominant, the electrophoretic mobility is enhanced significantly which we attribute to hydrodynamic stripping of the condensed layer of counterions from the surface of the particle.Comment: 13 pages, 9 figures and two table