以微波消化處理焚化飛灰鉛重金屬之研究

Reduction of Lead Metal Leaching from Flyash by Microwave Digestion.

吳宗勳(Tsung-Hsun Wu)

指導教授 ： 章裕民

國立臺北科技大學/工程學院/環境規劃與管理研究所/碩士(2006年)

摘要

焚化飛灰中鉛、鎘重金屬濃度常超出法規之毒性溶出管制標準，致使對後續處理及資源化應用產生諸多限制。本研究於12個月的北部焚化廠採集焚化飛灰與分析，經「事業廢棄物毒性溶出程序」試驗(TCLP)之分析結果發現鉛重金屬最易超出法規管制標準(研究期間共計11次)。故欲使飛灰無害化是以鉛為處理對象。
本研究之目的是利用微波輔助酸消化方式處理焚化飛灰，以期降低鉛重金屬含量，減低其TCLP 溶出量，使飛灰無害化再行資源化處理。本研究以微波功率600W、固液比1/10，在最適微波條件下(硝酸濃度9.0M、消化時間8分鐘、消化溫度140℃)，鉛的微波消化溶出率為94.11％。在微波功率600W、固液比1/10，以微波最佳條件(硝酸濃度0.8M、消化溫度120℃、消化時間6分鐘)，經微波消化處理(Microwave Digestion Treatment)後，其鉛TCLP 溶出量由7.10 mg/L降為4.83 mg/L，已能符合法規管制標準值。
在此最佳微波條件下，對於鉛TCLP 削

關鍵字

微波消化 ； 焚化飛灰 ； 鉛重金屬 ； 削減效率

並列摘要

The TCLP result of Flyash often exceeds the regulation control standards, because of lead and cadmium, and it produces many restrictions to follow-up treatment and recycling treatment. Flyash emitted from a large-scale refuse incinerator in the north was sampled and analysed in this research. Due to the TCLP result, it was discovered that the concentration of lead exceeded the standard most frequently (up to 11 times while studying), and therefore lead was targeted mainly in this study.
The TCLP result of Flyash often exceeds the regulation control standards, because of lead and cadmium, and it produces many restrictions to follow-up treatment and recycling treatment. Flyash emitted from a large-scale refuse incinerator in the north was sampled and analysed in this research. Due to the TCLP result, it was discovered that the concentration of lead exceeded the standard most frequently (up to 11 times while studying), and therefore lead was targeted mainly in this study.
The purpose of this research that Flyash is treated with auxiliary acid by microwave digestion, we hope that it can reduce lead metal content and TCLP leachate, and made it follow-up treatment and recycling treatment. The research used microwave power 600W,and S/L is 1/10, with the suitable microwave operation condition (nitric acid concentration 9.0 mole/L, digesting time 8 minute, and digesting temperature 140 ℃), by microwave digestion lead leaching rate is 94.11%, if it used microwave power 600W,and S/L is 1/10, with the best microwave operation condition (nitric acid concentration 0.8 mole/L, digesting time 6 minute, and digesting temperature 120 ℃), by the result of study, after Microwave Digestion Treatment, the TCLP leachate of lead in reaction ash might could be reduce to 4.83 mg/L from 7.10 mg/L, and the TCLP leachate could keep under the regulation control standards.
Under the best microwave condition, prevention efficiency of Pb TCLP can reach 32.0%. This research finding prevention efficiency of Pb TCLP that is dependence about microwave factors, such as nitric acid concentration, digesting time and digesting temperature. The prevention efficiency of Pb TCLP can be expressed as η= 4.15×10-4 (CM)0.30 (T)1.19 (t)0.48, application which it can have as the project in the future.

並列關鍵字

microwave digestion ； Flyash ； lead metal ； prevention efficiency

參考文獻

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