二苯甲酮类紫外防晒剂光-氯联合处理 急性毒性评价及转化特征研究
文献类型：学位论文
| 作者 | 于奇 |
| 学位类别 | 硕士 |
| 答辩日期 | 2016-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 魏东斌 |
| 关键词 | 二苯甲酮，光-氯联合处理，急性毒性，转化特征 benzophenones, photo-chlorination combined treatment, acute toxicity, transformation characteristics |
| 其他题名 | The acute toxicity evaluation and transformation characteristics of BPs UV-filters in photo induction-chlorination disinfection process |
| 学位专业 | 分析化学 |
| 中文摘要 | 二苯甲酮类紫外防晒剂价格低廉，吸收紫外线效果好，应用广泛。该类化合物可通过游泳、洗涤、生活污水和工业废水排放等多种途径进入环境，在水体、动植物体及人体代谢物中频繁检出。研究表明，二苯甲酮类紫外防晒剂具有多种生物毒性，如内分泌干扰性、遗传毒性等。氯消毒是水处理工艺的必要环节，此过程中消毒剂氯可能与水体中残存的污染物发生反应生成有毒有害副产物，危害生态环境安全和人体健康。为减少消毒副产物的生成，光-氯联合处理工艺成为必然选择。环境中二苯甲酮类紫外防晒剂可能进入水处理系统，其在光-氯联合处理工艺中的转化行为值得关注。本文选取 11种典型的二苯甲酮类紫外防晒剂，以发光菌急性毒性测试方法评价光-氯联合处理前后毒性变化，揭示分子结构、反应条件与毒性变化的相关性。在此基础上，选取 2,3,4-三羟基二苯甲酮（B9）为研究对象，进一步研究其在光-氯联合处理过程中的转化机制和毒性变化，借助 UPLC-MS方法检测产物，利用发光菌急性毒性实验测定毒性变化。并与 B9氯化、光化学转化特征进行比对，揭示光、氯对 B9转化的影响。具体研究内容及结果如下： 1、选择 11种二苯甲酮类化合物为对象，运用发光菌急性毒性实验评价其在光-氯联合处理前后急性毒性变化，揭示了分子结构（羟基数量、位置和种类）和反应条件（pH值和氯剂量）对毒性变化的影响。研究发现：苯环上羟基数量少的化合物经光-氯联合处理后毒性容易升高；苯环上羟基数相同的化合物，羟基在苯环 3或4位的比在2位的经处理后毒性容易升高；羟基分布在两个苯环上的化合物比在一个苯环上的经处理后毒性更容易升高；含有甲氧基和磺酸基等其他取代基的化合物处理后毒性容易升高。此外，pH条件和氯投加剂量对光-氯联合处理后的毒性变化也存在影响，酸性体系中毒性最容易升高、其次为碱性体系，中性体系中毒性最不容易升高。随着投加氯剂量的升高，毒性升高程度先增大后减小。在毒性研究的基础上，采用定量 -结构活性相关模型(QSAR)进一步验证分子结构与毒性变化之间的相关性，计算所得结果与发光菌急性毒性实验结果相一致。 2、选择 2,3,4-三羟基二苯甲酮（B9）为研究对象，比较了其在光-氯联合处理过程、氯化过程及光化学过程中的转化特征及毒性变化，讨论了不同氯剂量（0.4倍氯、1倍氯和3倍氯）、不同光源（紫外光、可见光和太阳光）及不同光照强度（45 mW/cm2、135 mW/cm2、250 mW/cm2和350 mW/cm2）对其转化特征的影响。同时以二级处理出水为基质，研究了B9在太阳光照下的转化特征及毒性变化，提示了 B9在自然环境中的归趋与风险。研究结果显示，高强度的紫外光照能够促进B9的光解；在光-氯联合处理过程中氯是促进 B9降解的主要因素，而光主要促进氯化产物的降解。UPLC-MS检测结果显示，B9在光-氯联合处理过程及单独氯化处理中检出 4种主要产物，在紫外光照处理中检出 2种主要产物，在二级处理出水基质中添加B9经太阳光照后检出3种主要产物。毒性测试结果显示，以上处理后毒性均有显著升高的现象。本文研究发现，多种二苯甲酮类紫外防晒剂经过光 -氯联合处理后毒性升高；B9在光-氯联合、单独氯化及单独光照处理过程中均有毒性显著升高现象。特别是二级处理出水基质中的 B9在太阳光下会发生降解，毒性显著升高，表明 B9进入实际水体后存在较高环境风险。因此，在实际生产生活中应减少该类物质的使用，或者在水处理环节中优化处理工艺将其去除，以降低其对生态环境安全的危害。 |
| 英文摘要 | Benzophenones (BPs), as low cost and efficient UV-filters, are widely used nowadays. They can enter the environment via swimming, domestic sewage and industrial wastewater discharges. Many studies demonstrated that BPs exert multiple biological toxicity, such as endocrine disrupting effect and genotoxicity. Chlorination disinfection is one of necessary units in water treatment process, and highly toxic disinfection by-products would be generated in the process. To reduce the formation of toxic disinfection by-products, photo-chlorination combined disinfection treatment has been explored. Widely used BPs UV-filters can access to water treatment process, their transformation characteristics in photo induction - chlorination combined water treatment process should be payed more attention. In this paper, 11 typical BPs UV-filters were selected, the photobacterium acute toxicity assay was used to screen the toxicity variation before and after photo induction -chlorination treatment. The relationship between molecular structures, operational conditions and toxicity variation was revealed. Furthermore, 2,3,4-trihydroxy benzophenone (B9) was selected as target compound. The UPLC-MS method was used to identify the transformation products and photobacterium assay was used to screen the acute toxicity variation. The transformation mechanism and toxicity variation of B9 in photo-chlorination combined process was further investigated, and the transformation characteristics in chlorination and photochemical process were compared. The main results are shown as following: 1. 11 BPs were selected as target compounds to evaluate the toxicity variation of BPs before and after photo induction-chlorination disinfection process. The effects of molecular structures (number and position of hydroxyl groups, other groups) and operational conditions (pH values and chlorine dosages) on toxicity variation were revealed. The results were as following: BPs with less hydroxyl groups easily increased in toxicity after treatment. For those BPs containing the same hydroxyl group numbers, the one with hydroxyl groups locating at 3-, or 4-position easier increased in toxicity after treatment than those at 2-position; the one with hydroxyl groups distributing on two benzene rings easier increased in toxicity. BPs with methoxyl group and sulfonic acid group easily increased in toxicity after treatment. The toxicity variation was pH-dependent, the toxicity easiest increased at acid condition, and hardest at neutral condition. The toxicity variation Benzophenones (BPs), as low cost and efficient UV-filters, are widely used nowadays. They can enter the environment via swimming, domestic sewage and industrial wastewater discharges. Many studies demonstrated that BPs exert multiple biological toxicity, such as endocrine disrupting effect and genotoxicity. Chlorination disinfection is one of necessary units in water treatment process, and highly toxic disinfection by-products would be generated in the process. To reduce the formation of toxic disinfection by-products, photo-chlorination combined disinfection treatment has been explored. Widely used BPs UV-filters can access to water treatment process, their transformation characteristics in photo induction -chlorination combined water treatment process should be payed more attention. In this paper, 11 typical BPs UV-filters were selected, the photobacterium acute toxicity assay was used to screen the toxicity variation was also chlorine dose-dependent, as the chlorine dosages increased, the increasing toxicity degree increased and then decreased. To further verify the correlation between molecular structures and toxicity variation,the Quantitative Structure-Activity Relationship (QSAR) was used. The computation result was in accordance with the toxicity test result. 2. 2,3,4-Trihydroxy benzophenone (B9) was selected as target compound, the transformation characteristics and toxicity variation in photo-chlorination, chlorination, photochemical process were compared. The effects of chlorine dosages (0.4-equiv, 1-equiv and 3-equiv), photo sources (ultraviolet, visible and sunlight) and irridation intensity (45 mW/cm2, 135 mW/cm2, 250 mW/cm2,and 350 mW/cm2 a) on transformation characteristics were discussed respectively. Additionally, B9 was spiked into a secondary treatment effluent under sunlight, during which process the transformation characteristic and toxicity variation were also investigated. The results indicated that: during photo-chlorination process, chlorine played predominate role in B9 degradation; in photochemical process, ultraviolet with high intensity easily promoted the photolysis of B9. The results of UPLC-MS showed that:4 products were detected in photo-chlorination /chlorination system, 2 products in ultraviolet photochemical process and 3 in sunlight treatment system in secondary treatment effluent. The toxicity test results showed that the acute toxicity significantly increased during the above processes. The paper showed that many benzophenones exhibited toxicity increase in photo-chlorination process; B9 exhibited toxicity increase in photo-chlorination, chlorination and photochemical process. Specifically, during sunlight treatment in secondary treatment effluent, B9 underwent photo-degradation and exhibited toxicity increase significantly. The results implied that B9 has potential environmental risk.To minimize the harm to the environment, the production and application of B9 should be restricted, and the water treatment process should be optimized. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/37040]  |
| 专题 | 生态环境研究中心_环境化学与生态毒理学国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 于奇. 二苯甲酮类紫外防晒剂光-氯联合处理 急性毒性评价及转化特征研究[D]. 北京. 中国科学院研究生院. 2016. |
入库方式： OAI收割
来源：生态环境研究中心
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