https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 Chemolithotrophic processes in the bacterial communities on the surface of mineral-enriched biochars https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:33882 Thiobacillus and a novel group within the Oxalbacteraceae were enriched only on the MEBs and they had the genetic capacity for thiosulfate oxidation. All three surface-enriched bacteria also had the capacity to fix carbon dioxide, either in a potentially strictly autotrophic or mixotrophic manner. Our results show the dominance of chemolithotrophic processes on the surface of biochar and MEB that can contribute to carbon sequestration in soil.]]> Mon 21 Jan 2019 15:50:56 AEDT ]]> Biochar and enhanced phosphate capture: mapping mechanisms to functional properties https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34692 −1 PO₄-P solution, to produce a parallel set of P-exposed biochars. Biochar exterior and/or interior surfaces were quantitatively characterised using laser-ablation (LA)-ICP-MS, X-ray diffraction, X-ray photo-electron spectroscopy (XPS) and scanning electron microscopy coupled with energy dispersive X-ray. The results highlighted the general importance of Fe minerals in P capture. XPS analysis of POCAD550 indicated lower oxidation state Fe2p3 bonding compared to POCAD450, and LA-ICP-MS indicated stronger covariation of Fe and S, even after P exposure. This suggests that low-solubility Fe/S compounds are formed during pyrolysis, are affected by process parameters and impact on P capture. Other data suggested capture roles for aluminium, calcium and silicon. Overall, our analyses suggest that a range of mechanisms for P capture are concurrently active in biochar. We highlighted the potential to manipulate these through choice of form and composition of feedstock as well as pyrolysis processing, so that biochar may be increasingly tailored towards specific functionality.]]> Fri 12 Apr 2019 14:00:53 AEST ]]>