电子束辐照降解水体中磺胺间甲氧嘧啶

中国环境科学 2018,38(7)：2520~2526 China Environmental Science 电子束辐照降解水体中磺胺间甲氧嘧啶

张洋1,2,付兴明2,罗敏2*,肖扬1,2,马玲玲2,徐殿斗2,宋浩军2,顾建忠1,吴明红1,徐刚1**(1.上海大学环境与化学工程学院,上海 200444；2.中国科学院高能物理研究所,核技术应用研究中心,北京 100049)

摘要：应用电子束辐照初步探索了去除水体中磺胺间甲氧嘧啶(SMM)10mg/L的过程.研究了吸收剂量、自由基清除剂、无机盐等对辐照降解的影响.通过实验数据和模拟计算,推测了降解机理和降解路径,并对降解产物进行了毒性评估.结果表明,当吸收剂量为3.0kGy时,去除率高于99%,辐照降解效率高.在辐照降解过程中,还原消除占主导作用.降解反应遵循一级动力学方程.碳酸根、硫酸根和硝酸根等无机阴离子在一定的程度上会抑制SMM的降解.根据超高效液相色谱-质谱(UHPLC-MS)对降解产物的分析,结合高斯理论模拟,推断出9种可能的降解产物和相应的降解途径.费氏弧菌的毒性测试显示,辐照降解中间体毒性先升高后降低,在吸收剂量为2.0kGy达到最高值.

关键词：电子束辐照；磺胺间甲氧嘧啶；降解产物；降解途径；毒理

中图分类号：X505 文献标识码：A 文章编号：1000-6923(2018)07-2520-07

Studies on the degradation of sulfamonomethoxine by electron beam irradiation in aqueous solution. ZHAN G Yang1,2, FU Xing-ming2, LUO Min2*, XIAO Yang1,2, MA Ling-ling2, XU Dian-dou2, SONG Hao-jun2, GU Jian-zhong1, WU Ming-hong1, XU Gang1**(1.Colloge of Environment and Chemical Engineering, Shanghai University, Shanghai 200444, China；2.Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China). China Environmental Science, 2018,38(7)：2520~2526

Abstract：The process of removing sulfamonomethoxine (SMM) 10mg/L in aqueous systems was preliminarily explored by electron beam irradiation (EBI). Several factors such as absorbed dose, radical scavenger and inorganic salts affecting on the removal efficiency were examined. Degradation mechanism and pathway were proposed through both experimental data and simulation calculation. The toxicity of degradation products was also evaluated. The removal rate of SMM was 99% at 3.0kGy. The data demonstrated that reduction elimination reaction played the key role. SMM degradation fitted the first-order kinetic equation. The degradation efficiency of SMM was inhibited to a certain extent when there were some inorganic ions (CO32−, SO42−, and NO3−). N ine kinds of possible degradation products and corresponding degradation pathways were deduced from the analysis of the degradation products by ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) with the assistance of theoretical calculation results by Gaussian 03 software as well. The toxicity test of Vibrio fernuli showed that the toxicity of the irradiated intermediates increased first and then decreased and reached the maximum at the absorption dose of 2.0kGy.

Key words：electron beam irradiation；sulfamonomethoxine；transformationproducts；degradation pathways；toxicity

磺胺间甲氧嘧啶(SMM)是磺胺类药物的一种,因抗菌效果好,被大量应用于治疗和预防兽禽的疾病[1].该药品难以被动物完全吸收,会以母体或代谢物的形式残留于动物体内及排泄物中,最终进入土壤、水体等环境介质,并循环进入农作物,对环境和人体健康造成危险[2-3].现有研究表明磺胺类药物在人体内蓄积到一定程度会破坏人的正常免疫机能、造血系统、脑神经系统和消化系统[4-5],且会导致微生物产生抗性基因,对生物体的生育能力和甲状腺造成影响[6].

有研究报道SMM会抑制水生生物的生长[7].国内外一些河流、地下水都检测出磺胺类药物,浓度达到ng/L[8−11]的级别.因此残留SMM的水环境行为备受关注.目前报道的污水处理厂传统生物工艺法对磺胺类药物的去除率最高只有60%[12−14].其他去除水中SMM的方法有Fenton氧化法[15]、过硫酸盐高级氧化法[16]、光催化[17]等.这些方法需要消耗大量的试剂,容易引起二次污染,处理的条件苛刻,且不适合处理大量废水.因此,研发去除水体中SMM的环境友好的高效方法非常重要.

近年来,辐照法因其操作简单、降解率高、且不引入二次污染等优点,在去除水体中难降解污染物方面受到人们的日益关注.γ射线和电子束辐照降解水体中的磺胺嘧啶、甲砜霉素、氟苯尼考、邻苯二甲酸二甲酯、卡马西平、双酚A等有机污染物时,在低于5.0kGy的剂量下,均有较好效果[18−23].电子束辐照在去除水体中有机污染物领域已展现出良好的应用收稿日期：2017-12-10

基金项目：国家自然科学基金资助项目(11405184,11575210,91643206);北京市自然科学基金资助项目(2173063)

* 责任作者, 副研究员, minluo@; ** 研究员, xugang@