中文摘要：
近年来,药品和个人的护理品(PPCPs)的实际使用在逐年大幅度地增加,而在饮用水处理领域中关于其在水中的迁移转化也逐渐成为了热点,同时也有许多报道表明PPCPs是许多臭氧消毒副产物的重要前体物,目前已发现PPCPs在氯及氯胺作用下会直接生成消毒副产物N-亚硝基二甲胺(NDMA),但目前对于PPCPs在臭氧的氧化作用下直接生成的N-亚硝基二甲胺(NDMA)的形成机制及其相关影响因素的研究还较少。本文首先建立了降低人力及时间成本的且适合实际操作的利用在线固相萃取-高效液相色谱法检测水中痕量NDMA的分析方法,采用固相萃取柱Hypersil GOLD a Q(4.6×100mm,3μm)和分析柱Thermo Acclaim PAⅡ(4.6x250mm,5μm),进样体积为2500μL,检测波长为228nm,目标物在不同浓度下的加标回收率在98%-105.7%之间;相对标准偏差在1.91%-7.19%之间。选取五类抗生素药物(大环内酯类、青霉素类、四环素类、磺胺类、喹诺酮类)中的20种,进一步考察经由O3氧化后的NDMA生成特性进行研究,并重点地关注药物在O3氧化时氧化剂的剂量、p H、温度和O3氧化反应时间等多种臭氧氧化因素对NDMA生成时产生的影响。结果表明,这20种化合物都有可能生成NDMA,但不同的目标物有着不同的生成情况。在p H=7.5,药物投量均为2μM,O3投量为0.5mg/L时,NDMA生成的浓度范围分别为410.2～899.4ng/L(大环内酯类)、252.1～501.0ng/L(磺胺类)、185.4～589.6ng/L(四环素类)、79.0～292.6ng/L(青霉素类)和85.4～163.2ng/L(喹诺酮类)。除此之外,氧化剂量、p H和温度均高时会直接影响氧化剂NDMA的生成,在一定的范围内,使用氧化剂的剂量越大,NDMA生成量越大,但由于氧化剂的降解反应特性,在氧化剂过量时,又可能会降解剩余的NDMA;中性偏碱性的条件对NDMA生成有促进作用;温度高会加剧分子运动的速度,会增加NDMA的生成。选取五种抗生素药物(克拉霉素、青霉素V、金霉素、磺胺嘧啶、诺氟沙星)中的五种药物进行臭氧降解反应效果、动力学的相关研究,考察了臭氧降解反应物初始浓度、初始p H值、臭氧流量、降解反应温度等相关性因素对臭氧反应降解速率的直接影响,发现臭氧氧化降解药物的过程遵循伪一级反应动力学,反应速率常数最大可达1.3245min-1。对中间产物及降解反应路径进行了分析与推测,对反应机理进行初探。
英文摘要：
In recent years,the actual use of pharmaceuticals and personal care products(PPCPs)has been increasing substantially year by year.In the field of drinking water treatment technology,its role in water and its migration and transformation have gradually become a hot spot,and there are also Many reports indicate that PPCPs may be important precursors of many ozone disinfection by-products.It has been found that PPCPs may directly generate highly toxic disinfection by-product Nnitrosodimethylamine(NDMA)in chlorine and chloramine,but At present,there are few studies on the formation mechanism and related influencing factors of Nnitrosodimethylamine(NDMA)directly generated by PPCPs under the oxidation of ozone.This article first establishes an analytical method that uses on-line solid phase extraction-high performance liquid chromatography to detect trace amounts of NDMA in water,which reduces labor and time costs and is suitable for practical operation.It uses a solid phase extraction column Hypersil GOLD a Q(4.6×100mm,3μm)And analytical column Thermo Acclaim PA Ⅱ(4.6x250 mm,5μm),the injection volume is 2500μL,the detection wavelength is 228 nm,the recovery rate of the target at different concentrations is between 98%-105.7%;the relative standard deviation is 1.91%-7.19%.20 types of antibiotics(macrolides,penicillins,tetracyclines,sulfonamides,quinolones)was selected,and the characteristics of NDMA formation after ozone oxidationwas further investigated.And then this article focus on drugs in ozone oxidation and the related effects of various ozone oxidation factors such as the dose of oxidant,p H,temperature and ozone oxidation reaction time on the generation of NDMA.The results show that these 20 antibiotics generate NDMA,but different antibiotics have different generation trends and amounts.At p H=7.5,the drug dosage is 2μM,and the ozone dosage is 0.5mg/L,the concentration range generated by NDMA is 410.2～899.4 ng/L(Macrolide),252.1～501.0 ng/L(Sulfonamides),185.4～589.6 ng/L(Tetracyclines),79.0～292.6 ng/L(Penicillins)and 85.4～163.2 ng/L(Quinolones).In addition,when the amount of oxidant,p H and temperature are high,it will directly affect the production of oxidant NDMA.Within a certain range,the larger the dose of oxidant used,the greater the amount of NDMA generated,but due to the degradation reaction characteristics of oxidant,When the oxidant is excessive,it may degrade to form the remaining NDMA;the neutral and alkaline conditions are conducive to the generation of NDMA;when the temperature of the oxidant is high,the speed of the oxidant molecule movement will be greatly aggravated,and the generation of NDMA will be greatly increased.Five antibiotics(Clarithromycin,Penicillin V,Chlortetracycline,Sulfadiazine,Norfloxacin)were selected to study the effects and kinetics of ozone degradation reaction,and the initial concentration of ozone degradation reactants was investigated,The initial p H value,ozone flow rate,degradation reaction temperature and other related factors have a direct impact on the ozone reaction degradation rate.It is found that the process of ozone oxidative degradation of drugs follows pseudo-first-order reaction kinetics,and the maximum reaction rate constant can reach 1.3245min-1.The analysis speculates on the intermediate products and degradation reaction paths,and makes a preliminary exploration of the reaction mechanism.
