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Tetracycline (TC), as a typical micro-pollutant in natural environment, has attracted much attention. The peroxymonosulfate (PMS)-based advanced oxidation process is regarded as a promising technology for TC treatment, while its potential practical application is mainly dependent on the oxidant yield derived from activating PMS by catalysts. Therefore, the development of improved activators which are characterized by adequate activity and stability for PMS decomposition is in high demand. In this paper, the high-efficiency K2−xMn8O16 nanowire hydrogels (KNH) with high stability was synthesized through a simple hydrothermal method and then an enhanced PMS/KNH system for antibiotic degradation via multiple strategies was established. For removal of low-concentration TC, a high degradation of nearly 95% could be achieved by activating PMS in a wide pH rang. More than that, a further catalytic mechanism of this PMS/KNH system was also put forward, thus providing a guideline for designing and fabricating transition-metal catalysts to activate PMS. [ABSTRACT FROM AUTHOR]

Cancer is a leading cause of human mortality around the globe. In this study, mechanism-based SAR (Structure-Activity Relationship) was employed to investigate the carcinogenicity of aromatic amines and nitroaromatics based on CPDB. Principal component analysis and cluster analysis were used to construct the SAR model. Principle component analysis generated three principal components from 12 mechanism-based descriptors. The extracted principal components were later used for cluster analysis, which divided the selected 55 chemicals into six clusters. The three principal components were proposed to describe the "transport", "reactivity" and "electrophilicity" properties of the chemicals. Cluster analysis indicated that the relevant "transport" properties positively correlated with the carcinogenic potential and were contributing factors in determining the carcinogenicity of the studied chemicals. The mechanism-based SAR analysis suggested the electron donating groups, electron withdrawing groups and planarity are significant factors in determining the carcinogenic potency for studied aromatic compounds. The present study may provide insights into the relationship between the three proposed properties and the carcinogenesis of aromatic amines and nitroaromatics. • Three properties (transport, reactivity and electrophilicity) of the chemicals about the carcinogenicity are screened out. • Cluster analysis indicated the relevant "transport" properties positively correlated with the carcinogenic potential. • The properties of electrophilicity significantly influenced the carcinogenic potency for studied aromatic compounds. [ABSTRACT FROM AUTHOR]