The Removal Mechanism Of Typical Chloramphenicol And Sulfa Antibiotics By Chlorella

Pharmaceutical compounds(PC)are a class of organic compounds whose residues are ubiquitous in the aquatic environment.At present,the drug compounds that flow into the water mainly include endocrine disrupting substances,antibiotics,pesticides,hormones,etc.,and these compounds continue to enter the environment and appear to be "sustained",so we also call such pollutants for "fake" persistent environmental pollutants.At present,the way to remove these pollutants in the industry is mainly the oxidation method.Although this method can effectively remove the drug contaminants,it requires excessive financial and material resources;ultraviolet photolysis and photolysis of the catalyst are required.The cost is large;and the adsorption method of the adsorbent only changes the shape of the pollutant,and there is no real degradation,and it will cause secondary pollution.In this paper,microalgae biodegradation is used to purify antibiotics,and the growth characteristics and antibiotic purification effects and mechanisms are explored.After investigation,we found that the use of microalgae to purify antibiotics of chloramphenicol antibiotics and sulfa antibiotics is feasible.1)During the culture period,florfenicol(FF)was found to inhibit the growth of chlorella,while in UTEX-1602,the inhibitory effect of FF was stronger at high concentrations(126.15 mg/L and 159.22 mg/L).When UTEX-1602 has almost no growth,Chlorella L38 can still grow at high concentrations,indicating that L38 is more tolerant to FF.Through investigation,it was found that chlorella L38 degraded FF by defluorination and side chain disconnection,and the maximum removal rate of FF reached 97.03%(46.05 mg/L).2)During the culture period,both strains of chlorella can effectively degrade thiamphenicol(TAP),and the removal rate of TAP reached 97.01%(46.21 mg/L).Meanwhile,TAP was found to affect microalgae.Changes in the content of chlorophyll and carotenoids and changes in enzymes in the ROS system.The degradation mode of TAP is mainly caused by hydroxylation reaction,side chain breaking,oxidation reaction and dechlorination reaction.3)Compared with chloramphenicol antibiotics,the highest bioremoval rate of sulfa antibiotics,sulfadially dipyrimidine(SDM),is only about 55.03%,and SDM affects microalgae.Changes in the content of chlorophyll and carotenoids.Through these,we found that chlorella is more suitable for direct purification of low concentrations of sulfa antibiotics.In summary,it is known that chlorella L38 is suitable for degrading FF,and chlorella UTEX-1602 is suitable for TAP.In contrast,SDM is not suitable for direct degradation by chlorella.