| 题名 | 基于Al+Al2O3的六氯苯（HCB）污染物机械化学法降解规律及应用研究 |
| 作者 | 康绍果 |
| 学位类别 | 硕士 |
| 答辩日期 | 2014-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 张付申 |
| 关键词 | 六氯苯 机械化学法 土壤修复 密度泛函理论 Hexachlorobenzene Mechanochemical destruction Soil remediation Density functional theory |
| 其他题名 | Application and Mechanism Study of Mechanochemical Destruction of HCB Contaminants using Al-Al2O3 |
| 学位专业 | 环境工程 |
| 中文摘要 | 本论文以六氯苯（HCB）为模型化合物，研究了机械化学法对持久性有机污染物（POPs）的降解规律，探索了机械化学技术在 HCB废物安全处置及 HCB污染土壤修复领域应用的可行性。主要研究内容及成果包括： （1）机械化学法降解 HCB添加剂的筛选。通过对比试验研究了 15种球磨添加剂对 HCB的降解效果，发现 Al-Al2O3体系具有快速、高效、安全的特点。添加 Al-Al2O3球磨 90 min可以降解 99.9%的 HCB，比传统的 CaO体系节省 60%以上球磨时间。 （2）Al-Al2O3体系降解 HCB废物工艺参数优化。研究了金属添加率、球磨转速、时间、球料比、物料比对 HCB的降解效果的影响，分析了添加剂重复使用的可行性，对相关工艺参数进行了优化。得到的最优条件为：金属添加率 50%，球料比为 30:1，物料比为 20:1，球磨转速 550 r/min，球磨时间 90 min。 （3）探索了机械化学法应用于六氯苯污染土壤修复的可行性。研究了机械化学法对模拟和实际土壤中 HCB污染物的降解效果。发现球磨法在 HCB污染土壤修复领域有较大应用潜力，不同类型的 HCB污染土壤修复效果差异较大；当土壤中 HCB的浓度为 1000 mg/kg时，球磨 180 min，HCB污染物降解率可以达到 95%以上。 （4）通过色质联用仪、离子色谱仪、拉曼光谱仪、X射线衍射仪、傅里叶红外光谱仪以及 X射线荧光光谱仪研究了 HCB机械化学学降解的中间产物分布及最终产物，发现 HCB脱氯形成的主要中间产物为 PeCB、1,2,3,4-TeCB、1,2,3-TrCB以及 1,2-DCB；最终产物为石墨碳、无定形碳、无机氯化合物以及中长链烷烃类物质。 （5）采用 DFT计算化学方法分析了六氯苯球磨降解途径，提出了基于自由基反应的持久性有机污染物机械化学法降解机理。表明机械化学法主要通过电子转移、形成金属-氯苯中间产物以及自由基反应等综合作用来降解 HCB，并实现HCB的开环，最终生成烷烃、石墨碳和无定形碳。 论文研究结果表明，基于 Al-Al2O3体系的机械化学球磨技术可以应用于含POPs废物无害化处置及 HCB污染土壤的工程修复。建议对机械化学法处理 POPs废物和污染土壤技术进行中试实验或者示范项目建设，以期为该方法的实际应用提供进一步的工程实践经验。 |
| 英文摘要 | In this paper, HCB was selected as a model compound. The mechanochemical degradation mechanism and pathway were proposed and the mechanochemical method was applied to remediate the HCB contaminated soils. The main achievements of this dissertation were as follows. (1) Among the 15 tested additives, the mixes of Al and Al2O3 was proved to be an effective and safe additive. After 90 min ball milled, more than 99.9% of HCB could be degraded with the addition of Al and Al2O3. Al-Al2O3 shows much better performance than CaO in mechanochemical destruction of HCB, over 60% of the complete degradation time was saved. (2) Process optimization experiments demonstrated that the best condition for HCB mechanochemical destruction were as follows: Al ratio=0.5, rotation speed= 550 r/min, weight ratio of ball to mixes=30:1 and the charge ratios=20:1, milling time=90 min. (3) Three type of soils were contaminated with HCB, and then mechnochemical destruction method was used to eliminate the HCB in the soils. With three hours of ball milling, over 95% HCB was removed, it meant that mechanochemical method had the potential to remediate the POPs-contaminated soils.. (4) The milled solid residuals were characterized by GC-MS, IC, FTIR spectrum,Raman spectrum, XRD spectrum and XRF in order to determine the degradation and dechlorination intermediates and the final products. Results showed that the final products in solid powder were graphites, amorphous carbon, inorganic chlorine and alkanes. The main dechlorination intermediates were PeCB, 1,2,3,4-TeCB, 1,2,3-TrCB and 1,2-DCB. (5) Density functional theory (DFT) was introduced to explain the mechanochemical destruction pathway of HCB. The mechanism of mechanochemical destruction of POPs based on radical reaction was proposed. It was concluded that the mechanism of mechanochemical destruction of HCB included electron transfer, formed intermediates of metal-chlorobenzenes and radical reaction. Dechlorination,ring cracking, carbonization and polymerization pathways occurred in the degradation reaction. Results of this study illustrated that Al-Al2O3 had the potential to the decontamination and disposal of waste containing POPs and remediation of POPs contaminated soils. Based on this study, pilot experiments or demonstration projects could considered for mechanochemical destruction(MCD) of POPs with the addition of Al-Al2O3. It could provide further experience in engineering practice for the MCD method. |
| 公开日期 | 2015-07-07 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/15637]  |
| 专题 | 生态环境研究中心_固体废弃物处理与资源化实验室 |
| 推荐引用方式 GB/T 7714 | 康绍果. 基于Al+Al2O3的六氯苯（HCB）污染物机械化学法降解规律及应用研究[D]. 北京. 中国科学院研究生院. 2014. |
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