焚化爐灰燼微奈米特性輕質骨材之再利用研究

Characterization of Micro-nanoscale MSWI Ash and reuse of lightweight aggregate

陳右儒(You-Ru Chen)

指導教授 ： 羅煌木

朝陽科技大學/理工學院/環境工程與管理系/碩士(2011年)

摘要

台灣都市固體廢棄物處理方式以焚化為主，以掩埋、資源回收及堆肥為輔。焚化爐處理燃燒垃圾，可回收熱能與電力，但其產生之底灰與飛灰也相對增多。底灰與飛灰中含有鎘、鉻、鎳、銅、鋅、鉛等重金屬，對人體健康有所危害。因此，灰燼的適當處理與資源再利用，也愈來愈受到重視。
本研究旨在探討焚化爐灰燼微奈米製備與特性分析及輕質骨材再利用的可行性，灰燼微奈米製備以高能球磨機（Retsch PM 100）進行物理研磨，並以高效能雷射粒徑分析儀（HPPS）進行粒徑分析。再以混合比例（1：0、3：1、1：1、1：3、0：1）與三種燒結溫度（800℃、1000℃、1200℃）進行固化，並進行微奈米灰燼與混合燒結灰燼以事業廢棄物毒性特性溶出（Toxicity characterisitic leaching procedure，TCLP）分析六大重金屬之濃度，以及分析微奈米灰燼與混合燒結灰燼之密度、比重、吸水率基本工程特性，並以水硬式水泥墁料抗壓強度試驗法（CNS 1010）進行微奈米灰燼與混合燒結灰燼之單軸抗壓強度試驗，以不同替代率（0％、20％、40％、60％、80％、100％）替代水泥砂漿中之砂作為輕質骨材，最後將水泥砂漿試體浸至pH 7之水中，以螢光菌急毒性試驗法(Microtox)檢測其毒性，目的在探討焚化爐灰燼經固化處理後掩埋至地下，雨水及地下水之酸鹼度是否會造成掩埋之固化灰燼之重金屬溶出及未來微奈米混合灰燼利用建築材料上是否會造成其毒性產生。
本研究結果如下：
1. 原灰燼之毒性溶出底灰之Cr超過法令標準值0.68 mg L-1，飛灰Cd超出法規標準值0.1 mg L-1，微奈米混合燒結灰燼的部分均符合法規標準。
2. 原灰燼之螢光菌急毒性試驗(Microtox)皆未達EC50與EC20，未研磨與研磨後微奈米混合燒結灰燼有微量毒性，其毒性為研磨前＞研磨後。
3. 密度及比重之高低順序為1200℃＞1000℃＞800℃，吸水率為800℃＞1000℃＞1200℃。
4. 單軸抗壓強度高低順序為燒結溫度1200℃＞1000℃＞800℃，燒結混合灰燼以飛灰：底灰3：1為最高，微奈米混合燒結灰燼以飛灰：底灰1：1為最高，替代率又以20％與40％為最佳。

關鍵字

焚化爐灰燼 ； 微奈米 ； Microtox ； 抗壓強度 ； 水泥砂漿

並列摘要

Municipal solid waste (MSW) is mainly treated by incineration while part by recycling, anaerobic digestion and composting in Taiwan. Incinerator may reduce MSW volume and produce energy and electricity while it may also produce air pollution and bottom and fly ash problems. Bottom ash (BA) and fly ash (FA) contain metals such as cadmium, chromium, nickel, copper, zinc and lead that might cause risk to human health. Thus, the proper treatment of ashes and their potential reuse has become an important issue.
This study aimed to investigate the incinerator ash preparation and characterization of micro-nano BA and FA and their potential reuse as lightweight aggregate. BA and FA were ground by ball mill (Retsch PM 100). They were further measured by high-performance laser particle path analyzer (HPPS) for particle size analysis. Five mixing ratios (BA:FA, 1:0, 3:1, 1:1, 1:3, 0:1) and three various sintering temperature (800℃, 1000℃, 1200℃) were adopted to conduct the experiment. The sintered BA and FA tested samples were further analyzed for toxicity (Toxicity characterisitic leaching procedure, TCLP) and Microtox test. Parameter analysis of sintered BA and FA (with various substitution rate of 0%, 20%, 40%, 60%, 80%, 100% of cement mortar by sand) included density, specific gravity, water absorption and compressive strength for potential light aggregate utilization.
Results of this study can be drawn as following:
1. Cr dissolution in original BA and Cd dissolution in original FA exceeds the standard values (0.68 mg/L for Cr in BA and 0.1 mg/L for Cd respectively) while the dissolution of metals levels of sintered BA and FA met the regulatory standards.
2. Acute toxicity test (Microtox) of original ashes are shown below EC50 and EC20, however, micro-nano ground and non micro-nano ground sintered ashes showed minor toxicity and the toxicity was ground before > ground after.
3. Density and specific gravity were in the order of 1200℃ > 1000℃ > 800℃ while water absorption was 800℃ > 1000℃ > 1200℃.
4. Uniaxial compressive strength by sintering temperature showed the order of 1200℃ > 1000℃ > 800℃. Sintered non micro-nano ashes of FA:BA(3:1) showed the highest compressive strength while sintered micro-nano ashes of FA:BA(1:1) showed the highest compressive strength. In addition, replacement ratios of 20% and 40% by ashes showed the highest compressive strength.

並列關鍵字

Compressive strength ； Incinerator ash ； Micro-nano meter ； Microtox ； Cement mortar

參考文獻

92. 林志棟、施堅仁，「焚化底碴應用於公共工程之研究」，行政院公共工程委員會研究報告（2004）。

104. 陳式毅，「推廣再生材料 法規加油」，財團法人臺灣營建研究院，臺北(2004)。

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