紫外辐射加速磺胺甲恶唑(SM X)的生物降解

UV Irradiation for Accelerated Biodegradation of Sulfamethoxazole (SM X)

分别采用紫外辐射光解(Ph)、生物降解(B)以及光解与生物降解同步耦合(Ph&B)3种方法对磺胺甲恶唑(SMX)进行间歇降解,比较不同浓度的SMX在不同降解方法下的降解速率及矿化程度。通过比较SMX的初始浓度对初始降解速率和平均降解速率的影响,发现SMX对微生物具有较强的抑制作用,而紫外辐射则可以缓解其对生物膜的抑制作用,从而加快SMX的降解速率。方法Ph&B降解SMX的平均速率是方法Ph的2倍,方法B的4倍。在SMX生物降解过程中,氮素对微生物的活性有较大的影响。而在紫外辐射光解作用下,SMX结构中的氮素会部分脱落,并被微生物部分利用。此外,采用方法Ph&B时,紫外辐射与生物膜的协同作用可以提高SMX的矿化程度,矿化程度分别是方法Ph的8.4倍,方法B的2.2倍。

Three protocols,UV photolysis alone（Ph）,biodegradation alone（B）,and intimately coupled photolysis and biodegradation（PhB）,were respectively used for degradation of sulfamethoxazole（SMX） in batch to test SMX degradation rates and mineralization degree.SMX was more inhibition to biofilm by comparing with the effect of initial SMX concentration on initial SMX degradation rate and average degradation rate,but the inhibition could be relieved by means of UV irradiation,which resulted in accelerated degradation of SMX.The average SMX degradation rate by PhB was twice as that by Ph and 4 times as that by B.The nitrogen has significant effect on bioactivity of biofilm degrading SMX,while the released nitrogen from SMX under UV irradiation was assimilated by biofilm partly.In addition,when protocol PhB was used for degradation of SMX,the mineralization degree could be increased due to synergy of photolysis and biodegradation,and the degree was 8.4 times as protocol Ph and 2.2 times as protocol B.