| 摘要: | 摘要 在資源永續利用理念的推行下，採用傳統掩埋方式處理廢棄物已變得愈來愈不合時宜。下水污泥灰如何朝向資源、減量、安定及無害化的目標，已是未來污水下水道推廣衍生的新課題。由相關文獻得知，下水污泥具有燒成輕質骨材的潛力，但於操作條件控制將影響到骨材輕質化的效能。本研究的目的，在於控制不同之成型壓力變化對燒成輕質骨材之影響，進一步了解下水污泥灰輕質化之機制。 本研究利用台北民生污水處理廠污泥餅，經實驗室焚化後配合不同的燒製溫度(1,070 C?1,100 C)及時間(20min及30min)，進而探究不同成型壓力(1,000psi ~5,000psi)對試體燒成輕質骨材的影響性。主要使用的儀器包括有：ICP、SEM、XRD、MIP等。 實驗結果發現，試體成型壓力、燒製時間及燒製溫度，對試體輕質化效果，皆有具體而正面的影響效能。且多種成型壓力試體，在燒製溫度達1,080 C時，其密度皆可低於1.6 g/cm3之輕質化標準﹔將燒製溫度提昇至1,100 C，且配合燒製時間為30min時，可產生密度低小於1 g/cm3骨材試體，且體積膨脹率隨試體成型壓力變大而有增加的趨勢，其1,000psi與5,000psi之體積膨脹率分別可達到42.0%與69.2%。經由微結構觀測結果(SEM與MIP)，在燒製溫度控制於1,070、1,080 C時，不同成型壓力試體，已產生少許發泡存在於試體現象而逐漸呈輕質化現象發生，成型壓力和試體輕質化具正面之線性關係﹔當溫度高於1,080 C時，試體輕質化主要受到溫度影響，成型壓力(1,000~5,000psi)的影響則較不顯著。 Abstract To carry out a conception of Sustainable Development, the use of traditional sludge treatments to treat sewage sludge is becoming insufficient and inadequate. It’s a serious assignment in the future for sewage sludge ash(SSA) treatments to achieve the purpose of Resource、Reduction、Stablization and Safety. From literature review it is widely perceived that SSA could be used to produce lightweight aggregate, which can be applied as a construction material. However, many parameters of the abovementioned production will affect the utility of lightweight aggregate. The object of this research is to analyze the effects of compacting pressure on the bloating mechanism of sludge ash and the mechanism properties of the derived aggregates. The sewage sludge ash pellets used in this study were prepared from the sewage sludge cake collected from a secondary sewage treatment plant (Minsheng STP, Taipei). The sludge ash were pulverized and pellitized using various compacting pressures ranging from 1,000~5,000psi, followed by sintering at temperature ranging from 1,070~1,100 C for 20~30 min. to determined for the effects of compacting pressure on their bloating mechanism and mechanic properties. From the experiment a positive relation trends can be seen between the swelling、compacting pressure、the sintering temperature and the sintering time. In general, for various compacting pressure tested, all sludge ash pellets bloated to a density of 1.6 g/cm3 when sintered at the temperature 1,080 C﹔Combination of higher temperature (1,100 C, 30min.) could generate aggregates with density less than 1g/cm3. Furthermore, a positive relation trends can be seen between the swelling and compacting pressure and/or the sintering temperature. For instances, at 1,100 C for 30min. sintering, the pellets with compacting pressure 1,000psi and 5,000psi could result in a swelling of 42.0% and 69.2%, respectively. It can be concluded from the results of this study cited above that the compacting pressure can positively affect the bloating of ash-derived aggregates at temperature ranging from 1,070~1,080 C, whereas at temperature higher than 1,080 C, temperature may governs the densification, resulting no significant difference among pellets formed with different pressures ranging from 1,000psi to 5,000 psi. |
