https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 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 ]]> Enhanced Recovery of Nonextractable Benzo[a]pyrene Residues in Contrasting Soils Using Exhaustive Methanolic and Nonmethanolic Alkaline Treatments https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:44583 0.05). Approximately 40% of B[a]P NERs in the sandy-clay-loam organic matter-rich soil was recovered by the exhaustive alkaline extractions after 180 d of aging, compared to only 10% using conventional methanolic saponification. However, the amounts of B[a]P NERs recovered depend on soil properties and the amounts of NERs in soils. A significant correlation (R2 = 0.69, p < 0.001) was also observed between the amounts of B[a]P recovered by each of the seven alkaline extractions in the contrasting soils and corresponding NERs at 180 d of aging, indicating a potential association warranting further investigations. Extraction techniques that estimate the amounts of PAH NERs recoverable in soil can help give a better understanding of the fate of NERs in soil.]]> Mon 17 Oct 2022 11:44:39 AEDT ]]>