The Effect Of UV Photolysis Intermediates On The Biodegradation Of Sulfamethoxazole

Sulfamethoxazole(SMX)is one of the most important sulfonamides,which are detected in environment every year.The components may alter ecosystems in the natural environment,and pose a risk to human health when they bio-accumulate through the food chain,since many pharmaceuticals existed in natural environments are recalcitrant to be biodegraded by microorganisms.Due to large special drug usage,every year there are a large number of drugs into the environment in the system,to the natural environment,especially the water environmental system bring adverse effect.Therefore,the conventional activated sludge systems would be easily broken,once pharmaceuticals,like antibiotic drugs,enter into the systems by the way of municipal wastewater.It is significant to use some effective methods for alleviating the inhibition of antibiotic drugs to microorganism,and accelerating their removal rate.The degradation of sulfa drugs common methods include physical and chemical method,advanced oxidation and biological method.According to chemical oxidation treatment wastewater containing sulfa drugs efficiency is higher,but the degradation is not complete,also may have an adverse effect on the environment generated in the middle of the product.And a single biological degradation efficiency is low,also tend to be biological inhibition led to the decrease of the biological activity.Solution by UV light or photocatalytic method as a biological pretreatment,can obviously improve the sulfonamide biological sex,and improve their degradation rate.This experimental study delving into SMX generated in the process of ultraviolet irradiation in the middle of the product,to explore the photolysis of SMX.Ultraviolet solution as a pretreatment method applied in the process of biodegradation of SMX,to explore the influence of ultraviolet light SMX to biodegradation process,especially to explore the various intermediate of ultraviolet solution to generate the SMX biodegradation process.According to the existing literature,exploring foreign electronic promoting effect of SMX biodegradation,and attempts to delve into the electronic flow and distribution.The results showed that:(1)by adopting the method of ultraviolet irradiation SMX preprocessing,able to quickly and efficiently destroy the SMX molecular structure,weakening of its inhibitory effect on microorganism,light intermediate in aminobenzene sulfonic acid(ABS)and 3-amino-5-methyl isopropyl pbo(ISO).N,S part of the molecular structure of SMX release in the form of root and ammonium sulfate,and as the SMXdegradation,ion concentration increased.(2)UV pretreatment solution,can effectively promote the biodegradation process of SMX.The initial concentration of 60 mg/L SMX after UV irradiation treatment 9 min,reduced to 30 mg/L,the concentration of the mixed solution to biodegradation,SMX degradation rate compared with direct biodegradable 30 mg/L SMX,increased by 37.5%.And initial concentration of 100 mg/L SMX after UV irradiation processing 27 min,its concentration down to 30 mg/L,the mixed solution to biodegradation SMX degradation rate is directly 30 mg/L SMX biodegradation rate of 1.88 times.Ultraviolet irradiation pretreatment is beneficial to save the time of experiment,to accelerate the process of experiment,save energy,etc.(3)To the SMX biodegradation respectively to join in the process of ABS,ISO,and ABS and mixture of ISO,have great influence to the biodegradation process of SMX.Plus 0.0215 mM ABS,can make the SMX biodegradation rate increased by40.34%.Plus 0.0215 mM ABS ISO and 0.0874 mM of mixed solution,can make the SMX biodegradation rate increased by 37.5%.ISO plus 0.0874 mM,suppresses the SMX biodegradation process,the degradation rate was reduced by 18.75%.(4)Aacetic acid as external electron donor to SMX biodegradation process,can accelerate the degradation rate,and join the relatively high concentration of acetic acid,namely to join the electronic equivalent of number is large,the degradation rate of SMX also quickly.When the acetic acid and provide the same amount of electronic equivalent number of ABS,the molecular structure of the acetic acid compared to simple,the promoting effect of SMX biodegradation process is more obvious.ABS as plus electron donor,join to SMX in biodegradation process,itself consumes electronic in the reaction system,which will compete with the SMX exist a certain amount of electronic effect.To sum up,through ultraviolet sulfamethoxazole after solution not only can make the microbial inhibitory ease,at the same time can effectively improve the biodegradation rate of sulfamethoxazole,through in-depth discussion SMX degradation under UV irradiation,and different ways to know the photolysis and biodegradable,for better degradation of sulfamethoxazole and similar experience and theoretical reference for the refractory organic compounds.