Study On Biological Toxicity Of Norfloxacin And Its Products By Ozonation

The threat to the ecological environment and human health is more and more serious in the water environment.Ozone is a powerful oxidant,which can effectively remove the parent substance.However,the production of toxic byproducts is the main problem of the application of ozone technology.This topic choose norfloxacin to study,ozone oxidation technology,mainly studied the intermediate product from the degradation and the degradation process of ozone on norfloxacin in the biodegradability;to photobacterium phosphoreum emission rate for toxicity assessment methods,through the study of norfloxacin and ozone oxidation of norfloxacin the intermediate product of luminescent bacteria inhibition on toxicity changes before and after ozone oxidation,and speculate the possible intermediates;using zebrafish as the subjects of biological toxicity,research on norfloxacin and ozone oxidation of norfloxacin intermediate on the mortality of zebrafish and micronucleus rate,to examine the toxicity of ozone oxidation of the intermediate product of norfloxacin.The results are as follows:The initial concentration of ozone oxidation for norfloxacin was 5mg/L,the removal rate increased with the increase of ozone dosage increased.By the influence of pH on the removal rate,can be found,the oxidation effect of ozone on norfloxacin than pH 3 environment in pH 11 environment,but the removal rate is not always increased,when the ozone dosage is more than 10 mg /L,the removal rate tended to be stable.Determination of norfloxacin in the process of ozone oxidation index can be found,when the oxidation of p H3 and ozone dosage is 20mg/L,the DOC removal efficiency of the ozone oxidation process of norfloxacin solution,UV₂₅₄ pH in different oxidation conditions,are gradually decreased,compared with the removal of UV₂₅₄ and under the condition of pH 11 and the other two conditions for slightly worse results,along with the increase of ozone dose,norfloxacin N atom in oxidized gradually from norfloxacin free,ammonia and NO3—exist in the form of.After ozonation,the biodegradability of the solution increased gradually,which indicated that the intermediate products were easy to be biodegraded.Inhibitory rate and norfloxacin concentration there is a strong correlation between the initial concentration of Vibrio fischeri,norfloxacin 500mg/L,norfloxacin inhibition of luminescence of Vibrio fischeri rate is about 65%.The ozone oxidation of norfloxacin intermediate on luminosity of luminescent bacteria inhibition studies showed that oxidation of pH11 condition solution after oxidation of Vibrio fischeri luminescence inhibition rate increasing with time has been increased,inhibition of the same oxidation time were lower than the results of pH3 and p H7.The micronucleus rate of zebrafish showed an upward trend with the increase of norfloxacin concentration,indicating that the higher the concentration of norfloxacin,the higher the mutation rate,the greater the toxicity.In 250 mg/L solution for norfloxacin solution,with the increase of ozone concentration,norfloxacin intermediate effect on micronucleus rate of zebrafish decreases sharply when the ozone dosage is 2.5 mg/L,the micronucleus rate of zebrafish was 2 per thousand,and with the increase of ozone dosage,when reaching 10 mg/L micronucleus rate basically stable.