【作者】 王维；

【导师】 敖良根； 陈垚；

【作者基本信息】 重庆交通大学 ， 土木水利硕士（专业学位）， 2023， 硕士

【摘要】 药物类污染物（PhACs）是一类较为典型的新兴污染物,广泛存在于自然水体、土壤、垃圾渗滤液等环境介质中,对饮用水安全、人类健康和生态环境形成了极大威胁。现有技术不仅难以对其进行高效去除,还存在高能耗、二次污染和实际应用效果差等问题。为此,本研究基于过氧乙酸（PAA）的高级氧化技术提出了一种新型的电活化过氧乙酸（EC/PAA）体系,研究了单独电（EC）、单独过氧乙酸（PAA）、电活化过氧乙酸（EC/PAA）三种体系对典型PhACs（卡马西平,CBZ）的去除性能,系统评估了EC和PAA之间的协同效率和矿化效能,并考察了PAA投加量、电流密度、p H、初始CBZ浓度对EC/PAA体系去除效能的影响。通过自由基淬灭、电化学、电子顺磁共振技术（EPR）等实验确定了该体系中的活性物质种类,并识别了中间产物,揭示了EC/PAA体系的内在反应机理和污染物可能的主要降解路径,并探究了该体系的潜在应用价值。研究成果可为后续开展基于PAA高级氧化技术的相关研究提供一定理论基础。论文的主要研究结论如下:（1）EC、PAA之间具有良好的协同作用,协同系数为2.19。在CBZ初始浓度为10 mg L^-1,PAA投加量为10 mmol L^-1,电流密度为20 m A cm^-2的条件下,EC/PAA体系较其他体系具有更好的降解效果,能够在120 min内去除94.2%的CBZ,反应速率高达0.02308 min^-1,TOC的去除率为64.3%,并且能在较低的能耗下,达到污染物的高效降解。该体系受溶液初始p H值影响比较大,因为溶液p H值高于PAA的p Ka（8.2）时,PAA会发生自分解作用,因此该体系在酸性或中性的条件下能有较高的去除效果。（2）EC/PAA体系可以促进羟基自由基（·OH）、有机自由基（R-O·）、超氧阴离子(O₂^·-)和单线态氧（¹O₂）等活性物质的产生。其中,·OH和R-O·主要通过阴极直接为PAA供给电子,导致PAA发生α-H裂变而产生;而¹O₂则通过体系中H₂O₂与·OH反应而产生。通过探针法和捕获实验两种方法发现,EC/PAA体系中·OH贡献率分别为40.2%和52.04%,由于捕获实验忽略了过量叔丁醇（TBA）在捕获·OH时PAA的消耗作用导致该方法计算出的贡献率过高。通过对EC/PAA体系中CBZ降解中间产物进行检测分析发现,CBZ首先生成了羟基化、羧基化和氢原子提取产物,随后通过脱氢、脱羧、加聚、断键、重组等作用生成不同的中间降解产物,并进一步被氧化为H₂O、CO₂等产物。（3）EC/PAA体系在超纯水、自来水和地表水作为背景水体时,CBZ的去除率分别为94.2%、84.1%和74.2%。这可能是由于地表水中含有的天然有机物（如HA）和一些无机离子(如Cl^-、HCO₃^-、PO₄^3-)通过竞争副反应消耗了·OH和R-O·等活性物质,从而削弱该体系的氧化效率。虽然EC/PAA体系对地表水和自来水中CBZ的降解能力不及超纯水,但总体上对CBZ的去除效果也能保持在70%以上。其中,水中碳酸氢根离子（HCO₃^-）、磷酸根离子(PO₄^3-)、氯离子（Cl^-）和腐殖酸（HA）的存在均会抑制EC/PAA体系对CBZ的降解能力。此外,EC/PAA体系还可用于磺胺甲噁挫（SMX）、萘普生（NPX）和环丙沙星（CIP）等多种难降解有机污染物的去除,均具有良好的协同作用和去除效能,表明该体系具有良好的应用潜力。更多还原

【Abstract】 Pharmaceutical contaminants（PhACs）are a class of emerging contaminants that are widely found in natural water bodies,soil,waste leachate and other environmental media,posing a great threat to drinking water safety,human health and ecological environment.Existing technologies are not only difficult to remove them efficiently,but also have problems such as high energy consumption,secondary pollution and poor practical application.To this end,a novel electro-activated peracetic acid（EC/PAA）system based on peracetic acid（PAA）advanced oxidation technology was proposed in this study,and the removal performance of three systems,sole EC,peroxyacetic acid（PAA）alone,and electro-activated peracetic acid（EC/PAA）,on typical PhACs（carbamazepine,CBZ）was investigated,and the systematic evaluation of the EC and PAA between the synergistic efficiency and mineralization efficacy between EC and PAA were systematically evaluated,and the effects of PAA dosing,current density,p H,and initial CBZ concentration on the removal efficacy of the EC/PAA system were investigated.The experiments of free radical quenching,electrochemistry and electron paramagnetic resonance technology（EPR）were used to identify the active species and intermediate products in the system,reveal the intrinsic reaction mechanism and the possible main degradation pathways of pollutants in the EC/PAA system,and explore the potential applications of the system.The research results could provide a certain theoretical basis for the subsequent research based on PAA advanced oxidation technology.The main findings of the paper are as follows:（1）EC and PAA have good synergistic effect with a synergy coefficient of 2.19.Under the conditions of initial CBZ concentration of 10 mg L^-1,PAA injection of 10mmol L^-1and current density of 20 m A cm^-2,the EC/PAA system has better degradation effect than other systems,and could remove 94.2%of CBZ in 120 min with a reaction rate of up to 0.02308 min^-1and the removal rate of TOC was 64.3%,and the system could achieve efficient degradation of pollutants with low energy consumption.The system was influenced by the initial p H of the solution,because the solution p H is higher than the p Ka of PAA（8.2）,the PAA will undergo autolysis,so the system could have a high removal effect under acidic or neutral conditions.（2）The EC/PAA system could promote the production of reactive substances such as hydroxyl radicals（·OH）,organic radicals（R-O·）,superoxide anions（O₂·^-）and singlet oxygen（¹O₂）.Among them,·OH and R-O·are mainly produced through the direct supply of electrons to PAA by the cathode,leading toα-H fission of PAA;while ¹O₂is produced through the reaction of H₂O₂with·OH in the system.The contribution of·OH in the EC/PAA system was found to be 40.2%and 52.04%by both the probe method and the capture experiment,respectively.The contribution calculated by this method was too high because the capture experiment ignored the consumption effect of excess tert-butanol（TBA）in capturing·OH by PAA.The detection and analysis of CBZ degradation intermediates in the EC/PAA system revealed that CBZ first generated hydroxylation,carboxylation and hydrogen atom extraction products,followed by different intermediate degradation products through dehydrogenation,decarboxylation,polymerization,bond breaking and recombination,which were further oxidized to H₂O,CO₂and other products.（3）The removal of CBZ by the EC/PAA system was 94.2%,84.1%and 74.2%for ultrapure water,tap water and surface water as background water bodies,respectively.This may be due to the fact that the natural organic matter（HA）and some inorganic ions(Cl^-,HCO₃^-,PO₄^3-)contained in the surface water remove·OH and R-O·through competitive reactions,thus weakening the oxidation efficiency of the system.Although the degradation of CBZ in surface water and tap water by the EC/PAA system is not as good as that of ultrapure water,the overall removal of CBZ could be maintained at more than 70%.Among them,the presence of bicarbonate ions（HCO₃^-）,phosphate ions(PO₄^3-),chloride ions（Cl^-）and humic acid（HA）in water inhibited the degradation ability of the EC/PAA system for CBZ.In addition,the EC/PAA system can also be used for the removal of a variety of refractory organic pollutants such as sulfamethoxazole（SMX）,naproxen（NPX）and ciprofloxacin（CIP）,all with good synergistic effects and removal efficacy,indicating that the system has good potential for application.更多还原