| 摘要: | 隨著各火力電廠之操作，廢水處理設施產生之污泥須依規定進行處理與處置，為配合永續發展廢棄物資源化之需求，如何經由研究，尋找出較符合經濟效益的資源化方式，降低廢棄物的排放，則為現今企業永續發展之重要指標。 本研究採集並調查7家火力發電廠之污泥樣品(含廢水污泥與FGD污泥)，每月污泥產量約1,900噸。為能將污泥資源化，本研究以焚化方式將廢水污泥製成灰渣，進行基本特性分析、水泥材料化、人造骨材以及製磚之研究，目的希望建立污泥灰渣特性並將其應用於營建替代材料。研究結果顯示各污泥之銅、鉛、鎘及鉻等重金屬，皆符合現行有害事業廢棄物認定標準之規定，屬一般事業廢棄物。由化學成份分析結果顯示，不同的廢水污泥來源或操作方式有非常大的不同特性，各污泥灰之主要成份可歸納為SiO2、Al2O3、Fe2O3及CaO等。另外，各污泥之pH值約介於7.15-9.90之間，屬中間偏鹼性。由於不同的污泥來源有極大的差異性，故本研究主要以林口火力發電廠之廢水污泥焚化灰當作後續資源化之研究重點。 研究發現，林口廠之廢水污泥焚化灰可做為水泥材料之局部取代、製成灰渣細骨材及拌製高壓混凝土磚等資源化產品；但因工程需求條件之不同，灰渣取代水泥與壓磚之較適取代量為10∼20%；造粒細骨材取代天然細骨材之較適取代量為50%，除了灰渣中之氯離子與造粒細骨材之高吸水率問題外，各類之取代皆符合產品或工程規範之基本要求。 The operation of thermal power plant has accompanied a lot of sludge in Taiwan per year. The sewage sludge has produced from a wastewater processing station must dispose following the regulations. In order to achieve the objective of sustainable development, we should place emphasis on the economical resource, reduce the emission of waste and make use of discarded or trashed materials. The production of sludge in thermal power plant has reached 1,900 tons per month. Since the landfill site is insufficient, the thermal power plant wastewater sludge must be incinerated and the ash must be recycled and reused. For this reason, this study investigated the feasibility of reusing wastewater sludge ash in construction materials to replace partial materials. Consequently, the properties of ash, mortar, concrete, aggregate and brick were analyzed. In this study, sludge sampled from different thermal power plant was burned into ash in the laboratory. According to the research results, the sludge has low heavy metal including Pb, Cd, Cr and Cu, so it belongs to general enterprise waste. Then the chemical composition of sludge was summed up in SiO2, Al2O3, Fe2O3 and CaO. The wastewater sludge ash is also found a porous material with irregular surface. When the ash was used to replace mortar cement, its water-adsorption capability will result in the reduction of mortar workability and compressive strength. Besides, the pH of sludge is between 7.15-9.90. Because different operating sequence and the source of wastewater will influence the properties of resource, we choose wastewater sludge of Lin-Kou thermal power plant to carry resource out follow-up. The wastewater sludge ash of Lin-Kou thermal power plant can be reused to replace cement and aggregate respectively with sludge ash and artificial aggregate that is composed of ash and cement. On the other hand, the sludge ash is also reused to manufacture compressed concrete paving units. Cements or bricks are being substituted for sludge ash, and 10-20 percent of sludge ash is more appropriate. For fine aggregate, 50 percent of artificial fine aggregate is applicable to concrete. Sludge ash is reused to take the place of construction materials satisfy the requests of standard specification except higher absorbent of artificial fine aggregate and Cl- concentration. |
