Study On Toxicities Of Some Nitrobenzene And Bisphenol Compounds And Their Mixtures On Photobacterium

Toxicity test and ecologic risk assessment for the toxic chemicals are always the important parts in the environmental pollution research area. Choosing two kinds of typical toxic organic pollutants as the study objective, using microplate toxicity test method, we tested the luminescent-inhibition effecting of toxicants to the photobacterium. The two kinds of toxic organic pollutants were nitrobenzene and bisphenol compounds, which were the toxic chemicals with high toxicity, high biologic concentration and difficult to degrade.The test bacterium is the only kind of freshwater photobacterium-Vibrio Qinghaiensis sp.. The luminescent-inhibition effecting to the photobacterium was tested on the SpectraMax M5 device. After data processing, the dose-effect relations of toxicants were got, and then were transformed into function expression and related parameters through regression analysis with least square method. Different from the usual liner analysis which only could get the dose-effect relations in the limited range; this nonlinear analysis could get the whole dose-effect relations of toxicants.It don't exist pure toxic compound in the nature environment, and every toxic compound affected the living body by complex mixture forms. So, from the single compound research extended to mixture system research is the inevitable trend of eco toxicology development. At present, the mixture toxicity research major concentrated in two-two action steps, which could not reflect the mixture toxicity action in the actual environment.The luminescent-inhibition effecting of nitrobenzene and 6 kinds of its substitution to the photobacterium were determined. The results showed that the pEC₅₀ values of this 7 toxicants were: 4-Nitroaniline(4.22)>4-Nitrotoluene(3.39) >1-Chloro-3-nitrobenzene(3.30)>1-Chloro-4-nitrobenzene(3.29)>1-Chloro-2-nitrobe nzene(3.22 )>3-Nitroaniline (2.94 )>Nitrobenzene(2.66). Then, 10 kinds of bisphenol compounds were tested by microplate toxicity test method. Because of solution problem, the test compounds were separated into two groups. The toxicants in the first group were dissolved in distilled water, and the toxicants in the second group were dissolved in 20%DMSO/water. In the meanwhile, research the influence of cosolvent-DMSO. The pEC₅₀ values of toxicants in the first group were: BPA(5.17)> BPE(5.13) >BPAF(4.29)> BPF(4.25) >BPS(3.69). The pEC₅₀ values of toxicants in the second group were: BPC=4.33,BPZ=5.3,BPM=4.13,BPP=4.32,BPAP=4.27.Choosing the same kind compounds with the similar structure as mixture components, introducing CA/IA model to predict the mixture toxicity, a preliminary exploration of mixture toxicity of nitrobenzene and bisphenol compounds was made. 3 mixtures with 5 bisphenol components and 5 mixtures with 7 nitrobenzene components were designed by the traditional equivalent-effect concentration ratio method. For the further research of different concentration ratio in the whole space of mixture, a uniform table with 7 factors, 5 levels and 10 lines was designed. 10 kinds of concentration ratio mixture were arranged based on the uniform table. It is found the CA/IA model prediction results had a high reliability. The DRC of 10 uniform design mixtures were scattered and don't assemble together as equivalent-effect concentration ratio mixtures, which mean uniform design could see about the mixture toxicity of multi component mixture in a greater scope.