Strong Ionization Degradation Of Lincomycin In Water And Its Effects To Zebarfish Embryos Growth

Lincomycin（LIN）is used as a typical antibiotic in the treatment of human and animal diseases which was detected in the water around the world.LIN will enhance the resistance of water organisms,and affect their growth and development.In addition,it will cause human anaphylactic shock,and affect the urinary system,cardiovascular system and nervous system.It is difficult to degrade by the common sewage degradation techniques because of its stable structure.Therefore,it is essential to develop an efficient,fast and green water treatment technology for the protection of the ecological environment in China.In this study,LIN was taken as the target pollutant,and its degradation was studied by strong ionization dielectric barrier discharge（SIDBD）pilot scale water treatment system.The principle and yield of active particles in the SIDBD system were explored,the influence of various factors on the degradation efficiency of LIN in the SIDBD system was investigated and the optimal degradation conditions for the LIN.The degradation products and pathways of LIN were analyzed by Ultraviolet-visible spectrophotometer（UV-Vis）,Total organic carbon（TOC）,Chemical oxygen demand（COD）,and Liquid Chromatography-Mass（LC-MS）,et al.The zebrafish was used as a model organism to study the effects of LIN degradation on the growth of zebrafish embryos,and the biological safety of SIDBD degradation technology was investigated.The main research results were as followed:（1）The mechanism of producing active particles in the SIDBD system was explored,and the yield of active particles was detected and analyzed.Experiments showed the presence of O₃and·OH in an aqueous solution,and no H₂O₂was present.The concentration of O₃was 22.27 mg/L and·OH was 0.019 mmol/L.The energy consumption of the SIDBD water treatment system is 0.33 k Wh/m³.（2）Analysis to p H,conductivity,TOC and COD after degradation showed that the p H and conductivity of LIN decrease with the degradation.The degradation efficiency of LIN was much greater than the degradation efficiency of TOC and COD.The reaction kinetic constant was 0.086 mg/min in the 15 mg/L LIN solution by the analysis of reaction kinetics.（3）The influence law of each factor on the efficiency of LIN degradation had been determined.The results showed that the degradation efficiency was positively correlated with voltage and negatively correlated with the initial concentration.The degradation efficiency p H=7.88 was more than p H=4.33 and p H=11.31.Experiments showed that the addition of inorganic ions had a significant effect on the degradation effect of LIN.In addition HCO₃^-and CO₃^2-inhibited the degradation efficiency of LIN were more than Cl^-.According to the orthogonal test results,the influence of LIN degradation efficiency was applied voltage stronger than initial concentration and p H.It can be determined that the optimal experimental conditions by SIDBD were initial concentration of LIN at 10 mg/L,applied voltage of 3.6 k V and p H value of 7.88.（4）Through High performance Liquid Chromatography（HPLC）,LC-MS,UV-Vis and other means analyze the degradation process of LIN.There were mainly desulfurization（-S）,hydroxylation（+OH）,deamidation（-NHR）and sensitization in the degradation process of LIN by SIDBD.C₁₆H₂₉N₂O₅（m/z=329）、C₁₃H₁₈N₂O₂（m/z=238）、C₁₇H₃₂N₂O₆（m/z=346）,C₁₅H₂₃N₂O₄（m/z=260）,C₁₀H₁₇N₂O（m/z=184）and small molecule products were produced by LIN.（5）The effect of different concentrations of LIN on the growth and development of zebrafish embryos was observed by the comparative experiments of the control group,10 mg/L,20 mg/L,30 mg/L,40 mg/L,50 mg/L and the LIN solution after 1 h of degradation.It showed that there was no significant lethal effect on zebrafish.The presence of LIN in an aqueous solution obviously affected the growth and development of zebrafish embryos.Survivability was inhibited by low concentration and promoted by high concentration.Fetal movement,heartbeat,and body length gradually decreased with the increasing concentration of LIN.High concentrations inhibited the swimming speed,distance,and behavioral trajectory density in juvenile zebrafish.In addition,the experiment showed zebrafish embryos were no significant change in LIN concentration at 10 mg/L,distinct cysts in the yolk at 20 mg/L,and notochord distortion at 30 mg/L.Malformations in the midbrain and hindbrain regions of the embryo became heavier with the increasing of concentration.LIN was both neurotoxic and developmentally toxic in zebrafish embryos.The experiment showed that the notochord of the control and the water embryos obtained after 1 h were normal.There was no significant difference between the treated water indicators and the Control groups.It showed that the degraded LIN had no obvious toxicity to the zebrafish embryos growth and development.It was harmless to the environment.