https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 Surface tailored organobentonite enhances bacterial proliferation and phenanthrene biodegradation under cadmium co-contamination https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29856 Mycobacterium gilvum VF1 in the presence of a palmitic acid (PA)-grafted Arquad® 2HT-75-based organobentonite in cadmium (Cd)-phenanthrene co-contaminated water. The PA-grafted organobentonite (ABP) adsorbed a slightly greater quantity of Cd than bentonite at up to 30 mg L− 1 metal concentration, but its highly negative surface charge imparted by carboxylic groups indicated the potential of being a significantly superior adsorbent of Cd at higher metal concentrations. In systems co-contained with Cd (5 and 10 mg L− 1), the Arquad® 2HT-75-modified bentonite (AB) and PA-grafted organobentonite (ABP) resulted in a significantly higher (72–78%) degradation of phenanthrene than bentonite (62%) by the bacterium. The growth and proliferation of bacteria were supported by ABP which not only eliminated Cd toxicity through adsorption but also created a congenial microenvironment for bacterial survival. The macromolecules produced during ABP–bacteria interaction could form a stable clay-bacterial cluster by overcoming the electrostatic repulsion among individual components. Findings of this study provide new insights for designing clay modulated PAH bioremediation technologies in mixed-contaminated water and soil.]]> Sat 24 Mar 2018 07:40:45 AEDT ]]> Bacterial mineralization of phenanthrene on thermally activated palygorskite: a C-14 radiotracer study https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30893 14C-labelled phenanthrene and a model bacterium Burkholderia sartisoli, we studied the mineralization of phenanthrene on the surface of a moderately heat-treated (up to 400 °C) palygorskite. The heat treatment at 400 °C induced a reduction of binding sites (e.g., by the elimination of organic matter and/or channel shrinkage) in the palygorskite and thus imparted a weaker sequestration of phenanthrene on its surface and within the pores. As a result, a supplement with the thermally modified palygorskite (400 °C) significantly increased (20–30%; p < 0.05) the biomineralization of total phenanthrene in a simulated soil slurry system. These results are highly promising to develop a clay mineral based technology for the bioremediation of PAH contaminants in water and soil environments.]]> Sat 24 Mar 2018 07:30:39 AEDT ]]> Structural changes in smectite due to interaction with a biosurfactant-producing bacterium Pseudoxanthomonas kaohsiungensis https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30892 Sat 24 Mar 2018 07:30:38 AEDT ]]>