基于Cu掺杂BiOBr光阴极的生物光电化学系统降解典型抗生素的特性及微生物群落响应

Degradation of typical antibiotics and microbial community response in a biophotoelectrochemical system with a Cu-doped BiOBr photocathode

抗生素难以生物降解且会诱导产生抗性基因,对生态环境和人体健康均造成威胁,因此,抗生素废水的高效处理意义重大.本研究制备了Cu掺杂的BiOBr光阴极,并与生物阳极耦合,构建生物光电化学系统(biophotoelectrochemical system,BPES),用于降解抗生素.结果表明,Cu-BiOBr较BiOBr具有更优异的光电化学性能.光照条件下的BPES在48 h内对初始浓度为20 mg·L^(-1)的阿莫西林(AMX)的去除率达91.38%.此外,适当曝气可提高BPES对AMX的去除.当AMX与盐酸四环素(TC),磺胺甲恶唑(SMX)在BPES中共降解时,降解过程均受到不同程度的抑制.根据鉴定的AMX的降解中间产物,推断了AMX的降解路径.BPES的阳极生物膜上的微生物主要以电活性细菌Geobacter为主,其对抗生素具有较高耐受性以及降解能力.

Antibiotics are difficult to be biodegraded,and they can induce resistance genes;therefore,efficient treatment of antibiotics wastewater is of great significance.In this study,the Cu-doped BiOBr(Cu-BiOBr)photocathode was prepared and coupled with a bioanode to constructed a biophotoelectrochemical system(BPES)for antibiotics degradation.Results showed that the Cu-BiOBr exhibited superior photochemical performance as compared with the BiOBr.In the light-illuminated BPES,the removal of amoxicillin(AMX,initial concentrationof 20 mg·L^(-1))reached 91.38%within 48 h.In addition,providing suitable aeration in the BPES could promote AMX removal.When AMX,tetracycline hydrochloride(TC),and sulfamethoxazole(SMX)were co-existed in the BPES,degradation process of each antibiotic was inhibited to some extent.Possible degradation pathways of AMX in BPES were proposed according to the identified degradation intermediates.The dominated microorganisms on the anodic biofilm of the BPESs treating different antibiotic wastewater were electro-active bacteria--Geobacter,which showed relatively high resistance towards antibiotics and certain degradation ability.