| 燃煤电厂和垃圾焚烧电厂燃烧产物中卤代多环芳烃的赋存特征和毒性风险 |
| 摘要点击 2427 全文点击 808 投稿时间：2020-07-30 修订日期：2020-09-21 |
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| 中文关键词 燃煤电厂(CFPP) 垃圾焚烧电厂(WIPP) 燃烧产物 脱酸工艺 卤代多环芳烃(HPAHs) |
| 英文关键词 coal-fired power plant(CFPP) waste incineration power plant(WIPP) combustion products de-acidification process halogenated polycyclic aromatic hydrocarbons(HPAHs) |
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| 中文摘要 |
| 研究了燃煤电厂和垃圾焚烧电厂燃烧产物中卤代多环芳烃（HPAHs）的赋存特征、生成机制和毒性效应.结果表明，燃煤电厂和垃圾电厂飞灰中氯代PAHs （Cl-PAHs）的含量为1.06~1.67 ng·g-1和2.76 ng·g-1，溴代PAHs （Br-PAHs）的含量为26.4~44.2 ng·g-1和6.31 ng·g-1；垃圾电厂飞灰中Cl-PAHs的含量明显高于燃煤电厂，主要是因为生活垃圾中含有大量的聚氯乙烯为代表的塑料.来自煤粉炉的飞灰中Br-PAHs和Cl-PAHs的含量明显低于循环流化床燃煤飞灰，主要是因为煤粉炉具有更高的燃烧温度和燃烧效率.燃煤电厂飞灰中主要为7-BrBaA和9-ClPhe；垃圾电厂除尘器飞灰中Br-PAHs主要为9-BrPhe和2-ClAnt.7-BrBaA和9，10-Br2Ant在燃煤电厂除尘器飞灰的含量远高于其在底灰和脱硫石膏的含量，但摩尔质量相对较小的2-BrFle在飞灰、底灰和脱硫石膏中的含量相近.垃圾电厂除尘器飞灰经过半干法脱酸后Br-PAHs的含量减少50%以上，但是经过螯合剂稳固化作用之后飞灰中Br-PAHs的含量明显升高.Pearson相关分析结果表明，燃煤电厂不同燃烧产物的HPAHs生成机制相同，而垃圾焚烧电厂不同产物中HPAHs具有不同的生成机制，飞灰螯合化过程导致HPAHs的二次生成.垃圾电厂除尘器飞灰中HPAHs的TEQs值（10.0×10-3 ng·g-1）与燃煤电厂相近（8.87×10-3~15.0×10-3 ng·g-1）.对于垃圾电厂不同燃烧产物，脱酸工艺能够显著去除7-BrBaA从而降低飞灰的TEQ值，而飞灰螯合化后TEQ值达到螯合前的5.4倍.燃煤电厂的飞灰因年产量较大，且总HPAHs的TEQs值相对较高，对其处理和资源化利用应考虑HPAHs带来的生态风险. |
| 英文摘要 |
| Coal-fired power plants (CFPPs) and waste incineration power plants (WIPPs) represent a large portion of polycyclic aromatic hydrocarbons (PAHs) sources in the environment, among which halogenated PAHs (HPAHs) are more toxic to the human body compared with their corresponding parent PAHs. In the current work, we investigated the occurrence, formation mechanism, and toxicity effects of HPAHs in the coal and waste combustion products from three CFPPs and one WIPP. The results indicate that the contents of chlorinated PAHs (Cl-PAHs) in the fly ash from the CFPPs and WIPP were 1.06-1.67 ng·g-1 and 2.76 ng·g-1, respectively, and the contents of brominated PAHs (Br-PAHs) in the fly ash from the CFPPs and WIPP were 26.4-44.2 ng·g-1 and 6.31 ng·g-1, respectively. The HPAH contents in the fly ash from the WIPP were significantly higher than those from the CFPPs primarily due to the abundant plastics in the domestic waste, represented by polyvinyl chloride, resulting in the formation of Cl-PAHs during combustion. The HPAH contents in the fly ash from the pulverized coal-fired (PC) boiler were significantly higher than those from the circulating fluidized bed (CFB) boiler mostly due to the higher combustion temperature operated in the PC boiler. The HPAHs in the fly ash from coal combustion were predominantly 7-BrBaA and 9-ClPhe, and those from domestic combustion were predominantly 9-BrPhe and 2-ClAnt. In addition, the contents of 7-BrBaA and 9,10-Br2 Ant in the coal combustion fly ash were significantly higher than those in domestic waste combustion fly ash, whereas 2-BrFle exhibited a contrasting profile. The content of Br-PAHs in the fly ash treated by semi-dry deacidification was twice that in dust removal fly ash but significantly increased in the chelating agent stabilization fly ash. The Pearson correlation analysis indicated the the formation mechanism of Cl-PAHs and Br-PAHs were the same but a secondary formation of HPAHs during the chelating agent stabilization of the fly ash was deduced. The TEQ values of the HPAHs in the fly ash (8.87×10-3-15.0×10-3 ng·g-1) from the WIPP were similar to those in the fly ash from the CFPPs (10.0×10-3 ng·g-1), which were significantly reduced in the fly ash treated by semi-dry deacidification due to the removal of 7-BrBaA. Moreover, the TEQ values of the HPAHs in the fly ash increased 5.4 times after the chelating agent stabilization. The ecological risk should be considered for the CFPP fly ash due to their massive amount of discharge and high TEQ values. |
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