以逐步萃取程序及溶出試驗評估都市垃圾焚化底渣長期穩定特性之研究

Long-term Stabilization Assessment of MSWI Bottom Ash by Using Sequential Extraction Procedures and Leaching Tests

劉彥均(Yen-Chun Liu)

指導教授 ： 林正芳

國立臺灣大學/工學院/環境工程學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.01041

摘要

本研究探討台灣地區一般都市垃圾焚化後底渣之基本特性與重金屬含量分佈，並藉由不同溶出程序探討底渣在長時間酸雨淋洗下，其重金屬溶出潛勢，目的即在模擬底渣進行長期陸地掩埋時可能對環境造成的影響；再根據底渣淋滲一個月後之溶出結果建立一質量傳輸數學模式來模擬污染物的移動情形，作為底渣再利用風險評估之基本資料；並藉由底渣穩定化測試，探求合適之穩定化處理物質，進而增加焚化底渣資源再利用之妥適性。
研究結果顯示，兩廠底渣之基本特性與重金屬分佈有些微差異，主要視垃圾本身性質、收集分類方式等而不同；重金屬含量皆以銅最高，約為5300－6600 mg/kg。長期管柱溶出試驗結果以銅累積溶出量最多，約190－270 mg/kg，佔總量之8%－14%；穩定化測試結果以添加Na2S效果最佳，在短期批次試驗中其削減率達85%以上，在長期管柱溶出試驗中其削減率高達97%。以逐步萃取試驗分析底渣中重金屬型態比例，銅在可交換態佔1%，碳酸鹽鍵結態約佔10%，鐵錳氧化物鍵結態佔34－44%，有機及硫化物鍵結態佔10－20%，其餘殘留態約佔30%；淋滲時間愈久或添加穩定劑可降低可交換態與碳酸鹽鍵結態之比例，而有提高鐵錳氧化物鍵結態、有機及硫化物鍵結態和殘留態比例之趨勢。
本研究建立之質傳數學模式經實驗結果驗證後得到良好的結果，足以證明模式之正確性。

關鍵字

焚化底渣 ； 溶出試驗 ； 逐步萃取程序 ； 穩定化 ； 質傳模式

並列摘要

This study mainly examines the environmental effect of bottom ash from MSW incinerator by means of some different leaching tests along with simulated acid rain. The objectives also try to estimate the leaching potential of heavy metal in environment during a long period and to establish the fundamental data for risk assessment of the utilization of bottom ash; furthermore, to find a suitable stabilizer in order to promote the reuse of bottom ash. A mass transfer mathematical model is presented to predict quantity and quality of leachate from short-term column leaching test.
Samples used here contain high amounts of Cu, which range from 5300 to 6600 mg per kg bottom ash. As time goes by, the amount of Cu leaches are twice more than that of any other metals in column test, and may reach up to a ratio 15% of its total mass. According to the stabilization test, Na2S reacts best in processing, which may reduce a large quantity of leachate by about 85－97%. Results of sequential extraction procedures show that 1% Cu is exchangeable, fraction bounded to carbonate accounts for 10%, fraction bounded to Fe-Mn oxides accounts for 34－44%, fraction bounded to organic matters/sulfide accounts for 10－20%, and the remaining 30% is residual.
Good agreement was obtained by comparing model simulation with data of laboratory column leaching tests. This model can provide us an insight into factors that influence the physicochemical reaction and transport of leachate from bottom ash.

並列關鍵字

Leaching test ； Bottom ash ； Model ； Sequential extraction procedures ； Stabilization

參考文獻

林正芳，2002，無機污泥材料化技術研究報告，行政院環境保護署。

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