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Brevundimonas diminuta was isolated from the oil-contaminated seawater in Dalian, China. The effects of salinity and nutrients (nitrogen and external carbon) on diesel oil biodegradation were investigated. This strain could utilize diesel oil as the sole source of carbon and energy and gave a biodegradation rate of 45% over 6 d under the salinity of 3.38% (w/w). Under the saline condition, nutrient addition has been proved to be an effective strategy to enhance oil biodegradation in marine environment. The addition of soluble starch and methanol exhibited a significant stimulative effect on oil biodegradation. The optimum external carbon source was soluble starch. Based on this, the optimum carbon source to external carbon source (C/EC) ratio in the test range was 2:1. Under the optimum conditions, diesel oil biodegradation rate increased from 44 to 65%. The optimum nitrogen source and C/N ratio were found to be NaNO3 and 20:1, respectively. Under the optimum condition, the diesel oil biodegradation rate increased to 88%. The polymeric compounds formed in the culture after nitrogen addition comprise a number of amphoteric functional groups. The results suggest that B. diminuta has considerable ability for bioremediation process of oil in marine environment. [ABSTRACT FROM AUTHOR]

Bamboo charcoal (BC) was used as starting material to prepare iron-modified bamboo charcoal (Fe-MBC) by its impregnation in FeCl3 and HNO3 solutions simultaneously, followed by microwave heating. The material can be used as an adsorbent for Pb(II) contaminants removal in water. The composites were prepared with Fe molar concentration of 0.5,1.0 and 2.0 mol/L and characterized by means of N2 adsorption-desorption isotherms. X-ray diffraction spectroscopy (XRD), scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM-EDS), Fourier transform infrared (FT-IR) and point of zero charge (pHpzc) measurements. Nitrogen adsorption analyses showed that the BET specific surface area and total pore volume increased with iron impregnation. The adsorbent with Fe molar concentration of 2 mol/L (2Fe-MBC) exhibited the highest surface area and produced the best pore structure. The Pb(II) adsorption process of 2Fe-MBC and BC were evaluated in batch experiments and 2Fe-MBC showed an excellent adsorption capability for removal Pb(n). The adsorption of Pb(II) strongly depended on solution pH, with maximum values at pH 5.0. The ionic strength had a significant effect on the adsorption at pH < 6.0. The adsorption isotherms followed the Langmuir isotherm model well, and the maximum adsorption capacity for Pb(II) was 200.38 mg/g for 2Fe-MBC. The adsorption processes were well fitted by a pseudo second-order kinetic model. Thermodynamic parameters showed that the adsorption of Pb(II) onto Fe-MBC was feasible, spontaneous, and exothermic under the studied conditions, and the ion exchange mechanism played an significant role. These results have important implications for the design of low-cost and effective adsorbents in the removal of Pb(n) from wastewater. [ABSTRACT FROM AUTHOR]