氯化金屬催化效應對戴奧辛類化合物去氯與加氯之影響

The Catalytic Impact of Chlorinated Metal on PCDD/Fs Dechlorination and/or Chlorination

鍾孟靜(Meng-Ching Chung)

指導教授 ： 林傑

國立屏東科技大學/工學院/環境工程與科學系所/碩士(2009年)

https://doi.org/10.6346/NPUST.2009.00182

摘要

焚化過程中可能衝擊環境層面衍生之飛灰介質含有戴奧辛類化合物(PCDD/Fs)為本研究主要對象，並探討都市廢棄物焚化爐（MSWI）中飛灰於氯化金屬前驅物對PCDD/Fs之催化效應。本研究以都市垃圾焚化爐產生之飛灰，進行金屬氯化物之多重相性反應。並利用填充床反應器設定與實際之空氣污染防制設備中，以模擬氯化汞與結構相似之前驅物質於飛灰介質中，探討戴奧辛與金屬氯化物之間的催化效應與抑制效應，藉以了解物種間之相互轉化特性及多重相性轉換特性。主要研究結果顯示：氯化汞添加五氯酚於飛灰介質中戴奧辛內氣固相分布，結果顯示在氣相中每克飛灰戴奧辛含量為120.8 ng，在固相中戴奧辛的含量則為7631.5 ng，由此試驗可知戴奧辛的生成大多存在於固相中，從PCDD/PCDF比值來看，不論在固相或者在氣相中其比值都大於1，顯示主要優勢物種以PCDD為主。氯化汞添加不同氯酚於飛灰中對戴奧辛生成，結果顯示添加HgCl2及0.2 %TCP和HgCl2及0.2 %PCP濃度各為237.1 ng/g和8052.3 ng/g，其濃度大幅的增加了7815.2 ng/g，增加了約34倍的量。由此可得知由三氯酚增加到五氯酚，其氯數增加不但會使戴奧辛的總濃度提高，且毒性當量值（I-TEQ）相對地也會昇高。氣固相引入氯化汞添加氯酚對戴奧辛生成的影響，結果顯示添加50 ppb HgCl2及HgCl2（0.01 %）濃度各為11919.5 ng/g和8052.3 ng/g，氣相比固相其濃度增加了3867.2 ng/g，增加了約1.5倍的量。由此可知氣相引入氯化汞所生成戴奧辛的濃度大於固相引入氯化汞所生成戴奧辛的濃度，且隨著濃度的增加，氣相引入氯化汞的毒性當量值（I-TEQ）也昇高。飛灰介質中不管有無添加三氯酚或五氯酚，但如果有氯化汞的存在都會促進更多戴奧辛的生成。

關鍵字

金屬氯化物 ； 飛灰 ； 戴奧辛 ； 氯化汞

並列摘要

The combustion treatment process of a municipal solid waste incinerator (MSWI) may cause a significant level of environmental impact. Specifically, the formation of polychlorinated dibenzo-p-dioxin and polychlorinated furans (PCDD/Fs) in the fly ash medium from the incineration system is investigated in this research project. The fly ash produced from the municipal solid waste incinerator was reacted with multiple chlorinated metals. In experiments with PCDD/Fs, mercury(II) chloride and chlorophenols were performed using a bench-scale packed bed reactor at the practical temperature range for air pollution control devices. The experiment explores the catalytic and inhibiting effect between PCDD/Fs and chlorinated metals in order to better understand the relationship between transformation characteristics and multiple transfer characteristics. The results showed that the PCDD/Fs concentration when reacted with mercury(II) chloride mixture matrix pentachlorophenol (PCP) is 128.8 ng in the gas phase and 7631.5 ng in the solid phase. Therefore, PCDD/Fs exist mostly in solid phase. Also, the PCDD:PCDF ratio is consistently greater than 1 in both solid and gas phases, so PCDDs predominate over PCDFs. Furthermore, the research revealed that the PCDD/Fs concentration when reacted with mercury(II) chloride mixture matrix 2,4,6-trichlorophenol (TCP) is 237.1 ng/g in the gas phase and 8052.3 ng/g in the solid phase, an increase of 34 times compared to mixture matrix pentachlorophenol. The increase in chlorine count will enable both the total concentration and I-TEQ to improve. The results revealed that the formation of PCDD/Fs concentration in the 50 ppb mercury(II) chloride mixture matrix pentachlorophenol is 11919.5 ng/g, and the (0.01%) mercury(II) chloride mixture matrix pentachlorophenol is 8052.3 ng/g, an increase of 3867.2 ng/g (which is 1.5 times greater). When mercury(II) chloride is introduced, both the concentration and I-TEQ of the gaseous phase are greater than that of the solid phase. Whether the 2,4,6-trichlorophenol or the pentachlorophenol is added to the fly ash medium, mercury(II) chloride promotes the formation of PCDD/Fs.

並列關鍵字

Chlorinated Metal ； Fly Ash ； PCDD/Fs ； mercury(II) chloride

參考文獻

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dibenzo-p-dioxinsunder simulated municipal solid waste incinerator