台北都會區垃圾焚化飛灰衛生掩埋滲出水中重金屬特性

Characterization of Heavy Metals in Leachate from a Sanitary Landfill Accepting Incineration Fly Ash in Taipei City

賴宥霖(You-Lin Lai)

指導教授 ： 林嘉明

國立臺灣大學/公共衛生學院/環境衛生研究所/碩士(2008年)

https://doi.org/10.6342/NTU.2008.01568

摘要

本研究目的為探討自1994年起都市型衛生掩埋場接受垃圾焚化飛灰固化物掩埋後，重金屬於掩埋場滲出水中的特性。以台北市山豬窟垃圾衛生掩埋場為觀察對象，收集歷史性(2003~2007)監測資料進行分析。
結果發現，北投、內湖、木柵三座焚化廠的飛灰固化物是掩埋場主要的掩埋物，每年的飛灰固化物進場掩埋量大約在15000公噸上下，而來自北投焚化廠的量最多。飛灰固化物中所含的重金屬有鉻、鉛、鎘、汞、銅、鋅、砷。飛灰固化物中金屬總量的80%以上為鋅及鉛，而於滲出水中該兩種金屬則占有67%。此外，各金屬的釋出率大致上是平穩的。雖然汞、砷於滲出水中的量很少，但其釋出率顯示此兩金屬具高釋出特性。
金屬累積釋出率在無底渣掩埋時期低於掩埋量中含底渣70%以上時期。滲出水中的鉛及鎘濃度有逐年增加的傾向，砷的濃度變化趨勢則相反。此外，滲出水中鉻及砷與BOD、COD、TOC、NH3- N之間有顯著正相關。滲出水中鉻、汞濃度則有季節及年份上顯著的變動，但與雨量無關。
總之，已經有妥善固化處理的垃圾焚化飛灰，掩埋於年資很久、生垃圾很少且降解趨於穩定的還原性環境之衛生掩埋場，飛灰固化物中的金屬在滲出水中的出現，就長時間來看，其釋出維持於一個穩定的狀態。

關鍵字

衛生掩埋場 ； 垃圾滲出水 ； 飛灰固化物 ； 重金屬 ； 垃圾焚化

並列摘要

This study aimed to characterize heavy metal in leachate discharged from a municipal sanitary landfill for ash of incinerators in Taipei. Sanzhuku Sanitary Landfill Site was our study subject. Historical data during 2003-2007 were collected and analyzed on monthly and yearly basis.
The results showed that stabilized/solidified fly ash from Bei-Tou, Nei-Hu and Muzha incinerators predominated in the municipal sanitary landfill. Approximately 15000 tons of solidified fly ash were disposed annually to this landfill with a great portion of ash generated from Bei-Tou incinerator. The heavy metals contained in fly ash included Cr, Pb Cd, Hg, Cu, Zn and As. Zn and Pb accounted for more than 80% of total metals in solidified fly ash, and for 67% in leachate. The estimated cumulative leachated percentages of all metals were generally steady. The estimated cumulative leachated percentage indicated that Hg and As had higher leachability than other metals although only trace amount of Hg and As occurred in the leachate.
The cumulative leachated percentage of metals after bottom ash had been eliminated was lower in comparison with that when bottom ash accounted for 70% and greater of total landfill amount. The concentration of Pb and Cd in leachate significantly increased year by year, but the trend for As was opposite. In addition, the concentration of Cr and As positively correlated to BOD, COD, TOC, NH3- N. Seasonal and annual fluctuation of Cr and Hg concentration in leachate, that was irrelevant to rainfall, were also occured.
The results implicate that heavy metals in solidified ash tend to leach out steadily at low rate in a lon-term sanitary landfill at the stage of methanogenic phase.

並列關鍵字

sanitary landfill ； leachate ； stabilized/solidified fly ash ； heavy metal ； waste incineration

參考文獻

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