There is little information about the influence of organic solvents for low water-solubility organic compounds on Photobacterium phosphoreum toxicity test,though it appears likely that much of data were obtained by us...There is little information about the influence of organic solvents for low water-solubility organic compounds on Photobacterium phosphoreum toxicity test,though it appears likely that much of data were obtained by using solutions prepared with cosolvents or surfactants.In this study the influence of five stock solvents,including dimethyl sulphoxide（DMSO）,acetone,aether,ethanol,tetrahydrofuran,on Photobacterium phosphoreum toxicity test was measured and different effective concentration values were obtained.DMSO was selected as the most suitable solvent for organic compounds with low water-solubility according to its good characteristics and less toxicity effect on Photobacterium phospherum.Chlorobenzene and nitrobenzene with proper solubility were selected to verify the effect of DMSO on Photobacterium phosphoreum toxicity.It was demonstrated that DMSO(concentration no higher than 0.20 mol·L-1) had little effect on the toxicity of organic chemicals with relative error no more than 10%.The successful application of DMSO as cosolvent provided a good example and a good idea to improve traditional acute toxicity test of Photobacterium phosphoreum,and broadened the application to identifying the toxicity of low water-solubility organic compounds.展开更多
Comprehensive evaluation of effluents is of great importance for environmental impact assessment.In this paper,three kinds of chromeplating effluents were characterized by determining pH,conductivity and COD values.Th...Comprehensive evaluation of effluents is of great importance for environmental impact assessment.In this paper,three kinds of chromeplating effluents were characterized by determining pH,conductivity and COD values.The toxicity of these effluents to Photobacterium phosphoreum was also determined.According to the toxicity category standard,their order of toxicity intensity was obtained.Although there was a correlation between EC50,COD and conductivity to some extent,it was inappropriate to represent quantitatively the damages to organisms only by the physico-chemical properties of the chromeplating effluents.It was indicated that a combination of physico-chemical characterization and comprehensive toxicity analysis could provide the correct information for effluent discharge standards.In this study,causative toxic compound types in three kinds of electroplating effluents were also analyzed preliminarily according to conductivity,COD and EC50 values.It can provide the basis for toxicity identification evaluation of electroplating effluents.展开更多
The mass production and wide usage of surfactants and aromatic compounds disturb seriously the natural ecosystem of physical,chemical and biological processes.The study on the mechanisms of joint toxicity can indicate...The mass production and wide usage of surfactants and aromatic compounds disturb seriously the natural ecosystem of physical,chemical and biological processes.The study on the mechanisms of joint toxicity can indicate the characterization of real environmental behavior and assessment of joint ecological effect.The toxicity to Photobacterium phosphoreum of different mixture systems of cationic surfactant of dodecyl dimethyl benzyl ammonium chloride (DDBAC) and three substituted aromatic compounds according to equi-concentration ratio of 1∶1,as well as individual toxicity,were determined respectively.They were evaluated by toxicity unit (TU),additive index (AI),similarity parameter (λ),and mixtures toxicity index (MTI).Four evaluating methods were compared and the modes of joint action of different systems were analyzed.It was shown that coherent results were obtained by four different evaluating methods in most situations.Conclusions can be drawn that the joint effects of different mixture systems were synergistic.Mechanisms of joint toxicity action could be discussed according to luminescence principle of Photobacterium phosphoreum and molecule structures of the mixture components.展开更多
文摘There is little information about the influence of organic solvents for low water-solubility organic compounds on Photobacterium phosphoreum toxicity test,though it appears likely that much of data were obtained by using solutions prepared with cosolvents or surfactants.In this study the influence of five stock solvents,including dimethyl sulphoxide（DMSO）,acetone,aether,ethanol,tetrahydrofuran,on Photobacterium phosphoreum toxicity test was measured and different effective concentration values were obtained.DMSO was selected as the most suitable solvent for organic compounds with low water-solubility according to its good characteristics and less toxicity effect on Photobacterium phospherum.Chlorobenzene and nitrobenzene with proper solubility were selected to verify the effect of DMSO on Photobacterium phosphoreum toxicity.It was demonstrated that DMSO(concentration no higher than 0.20 mol·L-1) had little effect on the toxicity of organic chemicals with relative error no more than 10%.The successful application of DMSO as cosolvent provided a good example and a good idea to improve traditional acute toxicity test of Photobacterium phosphoreum,and broadened the application to identifying the toxicity of low water-solubility organic compounds.
文摘Comprehensive evaluation of effluents is of great importance for environmental impact assessment.In this paper,three kinds of chromeplating effluents were characterized by determining pH,conductivity and COD values.The toxicity of these effluents to Photobacterium phosphoreum was also determined.According to the toxicity category standard,their order of toxicity intensity was obtained.Although there was a correlation between EC50,COD and conductivity to some extent,it was inappropriate to represent quantitatively the damages to organisms only by the physico-chemical properties of the chromeplating effluents.It was indicated that a combination of physico-chemical characterization and comprehensive toxicity analysis could provide the correct information for effluent discharge standards.In this study,causative toxic compound types in three kinds of electroplating effluents were also analyzed preliminarily according to conductivity,COD and EC50 values.It can provide the basis for toxicity identification evaluation of electroplating effluents.
文摘The mass production and wide usage of surfactants and aromatic compounds disturb seriously the natural ecosystem of physical,chemical and biological processes.The study on the mechanisms of joint toxicity can indicate the characterization of real environmental behavior and assessment of joint ecological effect.The toxicity to Photobacterium phosphoreum of different mixture systems of cationic surfactant of dodecyl dimethyl benzyl ammonium chloride (DDBAC) and three substituted aromatic compounds according to equi-concentration ratio of 1∶1,as well as individual toxicity,were determined respectively.They were evaluated by toxicity unit (TU),additive index (AI),similarity parameter (λ),and mixtures toxicity index (MTI).Four evaluating methods were compared and the modes of joint action of different systems were analyzed.It was shown that coherent results were obtained by four different evaluating methods in most situations.Conclusions can be drawn that the joint effects of different mixture systems were synergistic.Mechanisms of joint toxicity action could be discussed according to luminescence principle of Photobacterium phosphoreum and molecule structures of the mixture components.
