The Experts below are selected from a list of 9309 Experts worldwide ranked by ideXlab platform

Sakayu Shimizu - One of the best experts on this subject based on the ideXlab platform.

Eiji Sakuradani - One of the best experts on this subject based on the ideXlab platform.

Hua Zhong - One of the best experts on this subject based on the ideXlab platform.

  • heterogeneous fenton like catalyst for treatment of rhamnolipid solubilized Hexadecane wastewater
    Chemosphere, 2019
    Co-Authors: Yang Liu, Hua Zhong, Zhifeng Liu, Guangming Zeng, Min Cheng, Ming Chen, Chengyun Zhou, Weiping Xiong, Binbin Shao
    Abstract:

    Abstract The treatment of wastewater containing hydrophobic organic pollutants solubilized by surfactants is of great environmental importance. In this work, the removal of rhamnolipid-solubilized Hexadecane via a salicylic acid-methanol-acetone modified steel converter slag (SMA-SCS) catalyzed Fenton-like process was studied. First, we investigated the adsorption of rhamnolipid and Hexadecane onto SCS and SMA-modified SCS. Compared to that of SCS, SMA-SCS exhibited better adsorption performance with maximum adsorption capacities of 0.23 and 0.28 mg/g for Hexadecane and rhamnolipid, respectively. Degradation experiments showed that Hexadecane was more readily degraded by the Fenton-like process than rhamnolipid. Up to 81.1% of Hexadecane removal was achieved over 20 g/L of SMA-SCS within 24 h, whereas only 36% of rhamnolipid was degraded. On the other hand, the results indicated that increased rhamnolipid concentration had a negative effect on the degradation of Hexadecane. During the oxidation reaction, the pH value of solution remained between 6.0 and 6.72. All these results demonstrated that the SMA-SCS/H2O2 Fenton-like process could be a cost-effective and promising approach for the treatment of surfactant-solubilized hydrophobic organic compounds.

  • effect of low concentration rhamnolipid on adsorption of pseudomonas aeruginosa atcc 9027 on hydrophilic and hydrophobic surfaces
    Journal of Hazardous Materials, 2015
    Co-Authors: Hua Zhong, Yang Liu, Zhifeng Liu, Yongbing Jiang, Guangming Zeng, Liuxia Liu, Xin Yang, Mingyong Lai
    Abstract:

    The effects of low-concentration monorhamnolipid (monoRL) on the adsorption of Pseudomonas aeruginosa ATCC 9027 grown on glucose or Hexadecane to glass beads with hydrophobic or hydrophilic surfaces was investigated using batch adsorption experiments. Results showed that adsorption isotherms of the cells on both types of glass beads fitted the Freundlich equation better than the Langmuir equation. The Kf of the Freundlich equation for adsorption of Hexadecane-grown cell to glass beads with hydrophobic surface was remarkably higher than that for adsorption of Hexadecane-grown cell to glass beads with hydrophilic surface, or glucose-grown cell to glass beads with either hydrophilic or hydrophobic surface. Furthermore, it decreased with the increasing monoRL concentration. For both groups of cells, the zeta potential was close to each other and stable with the increase of monoRL concentration. The surface hydrophobicity of Hexadecane-grown cells, however, was significantly higher than that of the glucose-grown cells and it decreased with the increase of monoRL concentration. The results indicate the importance of hydrophobic interaction on adsorption of bacterial cells to surfaces and monoRL plays a role in reducing the bacterial adsorption by affecting cell surface hydrophobicity.

  • degradation of pseudo solubilized and mass Hexadecane by a pseudomonas aeruginosa with treatment of rhamnolipid biosurfactant
    International Biodeterioration & Biodegradation, 2014
    Co-Authors: Hua Zhong, Yang Liu, Zhifeng Liu, Yongbing Jiang, Fei Tan, Guangming Zeng, Xingzhong Yuan, Ming Yan, Qiuya Niu
    Abstract:

    Degradation of rhamnolipid-solubilized Hexadecane and mass Hexadecane as a separate phase by Pseudomonas aeruginosa CCTCC AB93066 treated with rhamnolipid biosurfactant was studied for better understanding on the roles of rhamnolipid in hydrocarbon biodegradation. The results of Hexadecane solubilization experiment showed that solubility of Hexadecane was linearly related to the concentration of rhamnolipid below or above its critical micelle concentration (CMC), and the ability of monorhamnolipid (monoRL) to solubilize Hexadecane was stronger at concentration below CMC than above CMC. MonoRL was then used for treating cells in degradation experiment. Results showed that 75 μM (1 CMC) monoRL treatment had a small inhibitory effect on cell growth on glucose or mass Hexadecane, however 750 μM (10 CMC) monoRL treatment accelerated degradation of mass Hexadecane by reducing the lag phase of cell growth for 36 h; this effect was not caused by initial cell surface hydrophobicity enhancement. No degradation of Hexadecane solubilized by 750 μM monoRL was observed for the cells treated with or without monoRL, indicating that the pseudo-solubilized Hexadecane is not available to cells. It is inferred from the data that the effectiveness of rhamnolipid to accelerate degradation of hydrocarbons by enhancing solubilization of the hydrocarbons may not always be guaranteed, which is of importance for evaluation of rhamnolipid biosurfactant application to hydrocarbon-contaminated sites during remediation.

  • effect of monorhamnolipid on the degradation of n Hexadecane by candida tropicalis and the association with cell surface properties
    Applied Microbiology and Biotechnology, 2011
    Co-Authors: Guangming Zeng, Hua Zhong, Zhifeng Liu, Xingzhong Yuan, Ying Ding, Jing Wang, Meifang Zhou
    Abstract:

    The effect of monorhamnolipid (monoRL) on the degradation of n-Hexadecane by Candida tropicalis was investigated in this study. The concentration of Hexadecane, cell growth, cell surface hydrophobicity (CSH), cell surface zeta potential (CSZP), and FT-IR spectra of cellular envelope were tested to determine the mechanisms. MonoRL at the initial concentrations of 11.4, 19, and 38 mg/l improved the degradation of Hexadecane, and 19 mg/l was the best concentration. However, 114 mg/l monoRL suppressed the biodegradation probably because of the reduced bioavailability of Hexadecane caused by the micelles. The presence of monoRL changed the cell surface properties, which was demonstrated by the increased CSH, the increased CSZP, and the changed FT-IR spectra of cellular envelope at 680 and 620 cm−1. The changes of cell surface properties may be a reason for the enhanced biodegradation of Hexadecane by the yeast. The results indicate the potential application of monoRL in the bioremediation of hydrocarbons.

Yasushi Takimura - One of the best experts on this subject based on the ideXlab platform.

Yusuke Natsume - One of the best experts on this subject based on the ideXlab platform.