• 关键词：非均相Fenton反应  针铁矿  过氧化氢  PCB28

• 基金项目：国家重点基础研究发展规划项目(No.2007CB936604);国家自然科学基金项目(No.20707029, 40671093)

• 林志荣
• 1. 南京信息工程大学 环境科学与工程学院,南京 210044;
  2. 中国科学院 南京土壤研究所中国科学院土壤环境与污染修复重点实验室,南京 210008

• 赵玲
• 中国科学院 南京土壤研究所中国科学院土壤环境与污染修复重点实验室,南京 210008

• 董元华
• 中国科学院 南京土壤研究所中国科学院土壤环境与污染修复重点实验室,南京 210008

• 徐建强
• 南京信息工程大学 环境科学与工程学院,南京 210044

• 摘要：以针铁矿(α-FeOOH)为催化剂,在针铁矿与H₂O₂组成的非均相Fenton体系内对PCB28的降解进行了研究,讨论了针铁矿、H₂O₂浓度和体系pH对PCB28降解率的影响,并初步揭示了PCB28的降解机理.结果表明,PCB28在非均相Fenton体系中能发生明显的降解作用.PCB28的降解率随H₂O₂和针铁矿初始浓度增加而显著增加.pH对PCB28降解率的影响表现为pH=3>pH=8>pH=5>pH=7>pH=9.在加入自由基猝灭剂甲醇后,PCB28基本不发生降解作用,表明反应的主要活性物质是羟基自由基.在反应过程中只溶出少量的铁离子,进一步表明降解反应是直接发生在FeOOH的表面,而非通过FeOOH溶出的铁离子组成均相Fenton体系降解PCB28.

• Abstract：Using goethite as a catalyst, the degradation of PCB28 was studied in the heterogeneous Fenton system containing goethite and hydrogen peroxide (H₂O₂). The dosage effect of goethite and H₂O₂ and the pH of the system on the degradation efficiency of PCB28 were also discussed. Moreover, the degradation mechanism of PCB28 in the heterogeneous Fenton system was discovered. Results showed that PCB28 was significantly degraded in the heterogeneous Fenton system. The degradation efficiency of PCB28 increased with the increaseing dosage of goethite and H₂O₂. The degradation efficiency of PCB28 was affected by the pH of the system, with the order of pH=3>pH=8>pH=5>pH=7>pH=9. No degradation of PCB28 was observed after methanol as a quenching reagent of the hydroxyl radicals was added into the heterogeneous Fenton system, indicating that the hydroxyl radicals were the reactive species during the degradation of PCB28. Few iron ions (Fe) were detected in the process of the reaction, which further indicated that PCB28 was directly degraded on the surface of goethite rather than by the aqueous Fenton system consisted of the soluble Fe from α-FeOOH.

• Key words：Heterogeneous Fenton reaction  goethite  hydrogen peroxide  PCB28

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