Biotreatment of restaurant wastewater with an oily high concentration by newly isolated bacteria from oily sludge.

High concentration restaurant oily wastewater from restaurants and food processing industries discharged into water environment usually results in environment pollution and inhibits the activity of microorganisms in biological wastewater treatment systems. In this study, 75 strains from oily sludge were isolated with oil degradation activity for edible oil-contained wastewater. Eight isolates were able to grow well in liquid cultures with edible oil as the sole carbon source and discovered with high efficient oil-degrading ability. Seven out of eight isolates were identified as Acinetobacter and one isolate as Kluyvera cryocrescens, based on their 16S rRNA gene sequences. Three highly efficient oil degrading bacteria (Acinetobacter dijkshoorniae LYC46-2, Kluyvera cryocrescens LYC50-1a and Acinetobacter pittii LYC73-4b) were selected and their degradation characteristic were examined, the results showed that the three isolates were effective under pH range from 7.0 to 10.0, and temperature from 25 to 35 °C. For degradation of 2-4% (v/v) of vegetable oil, > 85% degradation percentage were obtained within 30 h. Degradation of the higher concentration oil (6-8%, v/v) result in 50-70% degradation percentage within 72 h, and the degradation percentage for the isolated strains were decreased about 50% for the degradation of 10% oil (< 45%) compared to 2% oil. Different type of oils were also tested, > 90% of degradation percentage were obtained by the three isolates, implied that these strains are capable of removing various oils efficiently. These results suggested that Acinetobacter dijkshoorniae LYC46-2, Kluyvera cryocrescens LYC50-1a and Acinetobacter pittii LYC73-4b are potential species could be efficiently used for high concentration restaurant oily wastewater treatment and might be applicable to a wastewater treatment system for the removal of oil.

[Determination of 235U/238U isotope ratios in camphor tree bark samples by MC-ICP-MS after separation of uranium from matrix elements].

Twelve camphor (cinnamomum camphora) tree bark samples were collected from Hiroshima and Kyoto, and the matrix element composition and morphology of the outer surface of these camphor tree bark samples were studied by EDXS and SEM respectively. After a dry decomposition, DOWEX 1-X8 anion exchange resin was used to separate uranium from matrix elements in these camphor tree bark samples. Finally, 235U/238 U isotope ratios in purified uranium solutions were determined by MC-ICP-MS. It was demonstrated that the outer surface of these camphor tree bark samples is porous and rough, with Al, Ca, Fe, K, Mg, Si, C, O and S as its matrix element composition. Uranium in these camphor tree bark samples can be efficiently separated and quantitatively recovered from the matrix element composition. Compared with those collected from Kyoto, the camphor tree bark samples collected from Hiroshima have significantly higher uranium contents, which may be due to the increased aerosol mass concentration during the city reconstruction. Moreover, the 235 U/23.U isotope ratios in a few camphor tree bark samples collected from Hiroshima are slightly higher than 0.007 25.