Tetracycline Hydrochloride Removal By Chlamydomonas Reinhardtii In Aquatic Environment

An increasing number of trace organic pollutants in water environment has very adverse effects on aquatic ecosystems and human health,particularly the antibiotic organic pollutants has become a hot focus in recent years.In the world antibiotics not only for human and animal infectious disease treatment,but also used as growth promoters of livestock.Most of the drugs taken from humans and animals are not metabolized in the living body and eventually enter the water environment.Due to the particularity of antibiotics may cause drug resistance of microbial community,they exist in the environment of concentration and its environmental behavior are more and more getting attention.Rhine Chlamydomonas(Chlamydomonas reinhartii FACHB-265)is a kind of freshwater algae,because its are widely distributed in the environment,easy to cultivate,and has the ability of degradation of pollutants,as the research object of this paper.Based on the Rhine chlamydomonas as the research object: To study the illumination condition,the Rhine chlamydomonas of tetracycline hydrochloride,removing of photodegradation.Study living algae and algae to tetracycline hydrochloride to remove algae,the active ingredient as well as to examine the effects of the generation of hydroxyl radicals to tetracycline hydrochloride to remove the influence of tetracycline hydrochloride for water environment pollution of bioremediation to provide theory and practice basis.The main research results are as follows:(1)The removal of tetracycline hydrochloride from live algae and dead algae cells of Chlamydomonas reinhardtii under the condition of light showed that the removal rate of tetracycline was higher than that of live algae.On the one hand due to the death of algae cells after the destruction of cells to be released,the leakage of light in the role of light to accelerate the removal of tetracycline hydrochloride;the other side of the Chlamydomonas reinhardtii cells rupture,algal cells cell wall broken,many internal functional groups exposed to antibiotics combined,and thus removal rate is better.(2)Under the condition of shading,the removal of tetracycline from live algae and dead algae cells of Chlamydomonas reinhardtii showed that the removal rate of tetracycline was higher than that of live algae group.As the Chlamydomonas reinhardtii cell death,algae cell wall broken more,there are more internal functional groups exposed to antibiotics combined,and thus remove the effect better.At the 8th hour,At 8h,the concentration of Chlamydo-monas reinhardtii(>106cell/L),the live algae group to remove tetracycline hydrochloride effect is relatively better.As the cells of the dead algae rupture,the activity is lost and the metabolism can not be carried out,while the live algae group can be metabolized,and the removal rate of tetracycline hydrochloride in the live algae group is higher.(3)For the adsorption of tetracycline hydrochloride,the adsorption rate increased rapidly in a short time,and the adsorption had stabilized at 30 min.The amount of tetracycline adsorbed by Chlamydomonas reinhardtii was increased slowly with the passage of time,indicating that the rapid adsorption of cell surface has been completed.(4)In the light conditions,the extracellular waste can promote the removal of tetracyc-line hydrochloride.The concentration of tetracycline hydrochloride in the supernatant of the cells decreased continuously.At the 8th hour,23.2% of the tetracycline hydrochloride was degraded in the supernatant group,which was significantly higher than that in the blank control group(16.5%).This proves that algae rupture and leakage of extracellular substances promote the degradation of tetracycline hydrochloride.(5)Chlamydomonas reinhardtii live algae and dead algae cells can promote the formation of oxygen free radicals in water.The generation of hydroxyl radicals in the culture medium of the algae was much higher than that of the live algae cells,and the free radicals of the live algae and the dead algae cells were generated under the white light,which was much higher than that of the blank control group.When the treatment group added tetracycline hydrochloride,the generation of hydroxyl radicals was significantly reduced.At the 8th hour,the content of hydroxyl radicals in the experimental group of tetracycline hydrochloride was only 48.5% and 53.3% of the tetracycline hydrochloride group.Because the generated hydroxyl radicals are reduced by the reaction with tetracycline hydrochloride.