Relative abundance and relationships between aniline, phenol and catechol degraders were investigated in unpolluted and polluted fresh waters in Osaka prefecture, Japan. Phenol and catechol degraders were found more f...Relative abundance and relationships between aniline, phenol and catechol degraders were investigated in unpolluted and polluted fresh waters in Osaka prefecture, Japan. Phenol and catechol degraders were found more frequently compared to aniline degraders. The results indicate that these degraders were more abundant in polluted waters than in unpolluted waters. Aniline degraders isolated from the Ina River water showed a higher capability of degrading catechol than phenol. Analysis on sequence homology among these three kinds of degraders indicated a possible relationship between aniline degraders and certain strains of both catechol and phenol degraders.展开更多
Catalytic ozonation is progressively becoming an attractive technique for quick water purification but efficient and stable catalysts remains elusive. Here we solvothermally synthesized highly-dispersed Co3O4 nanocrys...Catalytic ozonation is progressively becoming an attractive technique for quick water purification but efficient and stable catalysts remains elusive. Here we solvothermally synthesized highly-dispersed Co3O4 nanocrystals over microscale nitrogen-doping graphene （NG） nanosheets and tested it as a synthetic catalyst in the ozonation of phenol in aqueous solutions. Transmission electron microscopy, powder X-ray diffraction, Fourier transform infrared spectra and X-ray photoelectron spectroscopy were used to determine its morphology, crystallinity, elemental composition and molecular bonds, respectively. The comparative experiments confirmed the highest catalytic activity and oxidation degree （AOSC） of Co3O4/NG among four nanocomposites （G, NG, Co3O4/G, and Co3OJNG）. Co3O4/NG also has exhibited the highest degradation rate： complete conversion of a near-saturated concentration of phenol （941.1 mg/L） was achieved within 30 min under ambient conditions with only a small dosage of Co3O4/NG （50 mg/L） and ozone （4 mg/L, flow rate： 0.5 L/min）. It also resulted in 34.6% chemical oxygen demand （CODcr） and 24.2% total organic carbon （TOC） reduction. In this work, graphene nanosheets not only functioned as a support for Co3O4 nanocrystals but also functioned as a co-catalyst for the enhancement in phenol removal efficiency. The surface nitridation and Co3O4 modification treatment further improved the removal rate of the phenol pollutants and brought in the higher oxidation degree. Our finding may open new perspectives for pursuing exceptional activity for catalytic ozonation reaction.展开更多
文摘Relative abundance and relationships between aniline, phenol and catechol degraders were investigated in unpolluted and polluted fresh waters in Osaka prefecture, Japan. Phenol and catechol degraders were found more frequently compared to aniline degraders. The results indicate that these degraders were more abundant in polluted waters than in unpolluted waters. Aniline degraders isolated from the Ina River water showed a higher capability of degrading catechol than phenol. Analysis on sequence homology among these three kinds of degraders indicated a possible relationship between aniline degraders and certain strains of both catechol and phenol degraders.
基金supported by the research fund of Hanyang University (HY-2013 year)
文摘Catalytic ozonation is progressively becoming an attractive technique for quick water purification but efficient and stable catalysts remains elusive. Here we solvothermally synthesized highly-dispersed Co3O4 nanocrystals over microscale nitrogen-doping graphene （NG） nanosheets and tested it as a synthetic catalyst in the ozonation of phenol in aqueous solutions. Transmission electron microscopy, powder X-ray diffraction, Fourier transform infrared spectra and X-ray photoelectron spectroscopy were used to determine its morphology, crystallinity, elemental composition and molecular bonds, respectively. The comparative experiments confirmed the highest catalytic activity and oxidation degree （AOSC） of Co3O4/NG among four nanocomposites （G, NG, Co3O4/G, and Co3OJNG）. Co3O4/NG also has exhibited the highest degradation rate： complete conversion of a near-saturated concentration of phenol （941.1 mg/L） was achieved within 30 min under ambient conditions with only a small dosage of Co3O4/NG （50 mg/L） and ozone （4 mg/L, flow rate： 0.5 L/min）. It also resulted in 34.6% chemical oxygen demand （CODcr） and 24.2% total organic carbon （TOC） reduction. In this work, graphene nanosheets not only functioned as a support for Co3O4 nanocrystals but also functioned as a co-catalyst for the enhancement in phenol removal efficiency. The surface nitridation and Co3O4 modification treatment further improved the removal rate of the phenol pollutants and brought in the higher oxidation degree. Our finding may open new perspectives for pursuing exceptional activity for catalytic ozonation reaction.
