基于超高分辨质谱的溶解性有机质分子转化机理分析  

Molecular Insights into the Transformation Mechanisms of Dissolved Organic Matter Based on Ultrahigh Resolution Mass Spectrometry

作　　者：成受明[1] 周波[1] Cheng Shouming;Zhou Bo(College of Architecture&Environment,Sichuan University,Chengdu 610065)

机构地区：[1]四川大学建筑与环境学院,成都610065

出　　处：《化学学报》2022年第8期1106-1114,共9页Acta Chimica Sinica

基　　金：国家自然科学基金(No.51878422);成都市科技局项目(No.2021-YF05-00350-SN)资助。

摘　　要：本研究对比分析了不同处理工艺对制药废水中溶解性有机质(DOM)的降解,通过三维荧光图谱(EEM)、总有机碳(TOC)、zeta电位以及动态光散射技术进行表征分析,并利用超高分辨质谱进一步探究了过硫酸钾(PS),碳纳米管(CNTs),CNTs/PS工艺诱导的DOM分子转化机制.结果表明,PS通过静电聚合作用和氧化作用对DOM中的缩合芳香类化合物(76%)和蛋白质/多肽类(65%)去除较大,CNTs通过吸附作用对不饱和水平较低的含氧化合物(木质素类、蛋白质/多肽类和氨基糖类(90%))的去除最为显著,而CNTs/PS则是通过吸附作用、电子转移以及单线态氧(^(1)O_(2))的生成以实现不同组分的DOM的高效去除.化学参数定量分布以及线性拟合分析表明,PS和CNTs/PS体系对于DOM分子的化学参数分布影响较小,而CNTs的吸附作用会导致残留分子的平均氧碳比(O/C)、芳香指数(AI_(mod))、等价双键(DBE)和碳的名义氧化态(NOSC)数值增加,且氧原子对DBE的贡献作用增大.本研究结果为进一步理解DOM在水环境中的去除和分子转化提供了理论依据.In this study,the removal of dissolved organic matter(DOM)in pharmaceutical wastewater effluent by five treatment processes[including ultraviolet(UV),UV/HO,potassium persulfate(PS),carbon nano tubes(CNTs)and CNTs/PS]was investigated,which was characterized by excitation-emission matrix spectra spectroscopy(EEM),total dissolved carbon(TOC),zeta potential and dynamic light scattering analysis,while the transformation mechanism of DOM fractionations induced by PS,CNTs and CNTs/PS processes was further explored by ultra-high-resolution mass spectrometry(UPLC-Q-TOF-MS).The results suggested that the PS,CNTs and CNTs/PS processes proved to have the best treatment effect for the removal of DOM via EEM analysis,with TOC removal of 128,204 and 243 mg/L,respectively.Zeta potential and dynamic light scattering analysis indicated that DOM molecules were removed by PS process through electrostatic polymerization and oxidation,and by CNTs process via adsorption,while CNTs/PS process degraded DOM by combining adsorption,electron transfer and the generation of strongly oxidizing singlet oxygen(^(1)O_(2)).Molecular characterization analysis demonstrated that the condensed aromatic compounds(76%)and proteins/lipids(65%)in DOM were the most vulnerable to PS attack,and the adsorption of CNTs was more effective for oxygenated compounds with lower levels of unsaturation(such as lignin,protein polypeptides and amino sugars(90%)),while the CNTs/PS process achieved indiscriminate degradation of various DOM molecules,which was a complement and enhancement to the separate CNT and PS treatment processes.In terms of different elemental compositions,the PS process had little effect on the elemental composition of the residual DOM molecules,while the CNTs and CNTs/PS processes showed a more obvious effect on the removal of CHON and CHONS molecules.Furthermore,by combining the quantitative distribution of chemical parameters of DOM molecules and linear fitting analysis,PS and CNTs/PS system had little effect on the distribution of chemical para

关 键 词：溶解性有机质 过硫酸钾 碳纳米管 高分辨质谱 分子转化 

分 类 号：X787[环境科学与工程—环境工程] O657.63[理学—分析化学]