工業廢水汙泥資材化技術評估

Assessing the Sludge from Industrial Wastewater Treatment Plants as Construction Material

林凱隆(Kae-Long Lin)

《國立宜蘭大學工程學刊》 3期 (2007/02) Pp. 1-16

https://doi.org/10.6176/BCE.2007.03.11

摘要

依據工業區環保中心統計資料顯示，現階段該中心所管轄之38處工業區綜合污水處理廠污泥產出量約60萬噸/年，依其特性可分成有機性污泥及重金屬污泥等兩大類。本研究秉持「向水中取礦」之原則，依工業區綜合污水處理廠廢水污泥特性，選定北部某工業區重金屬污泥及中部某工業區有機廢水污泥作為試驗材料，經前處理後，利用實驗室規模高溫爐模擬實窯操作現況，分別於950℃（8小時）以及1400℃（6小時），之操作條件下，評估有機及重金屬污泥燒製環保磚及環保水泥之可行性。結果顯示，所有試驗之成品其重金屬均符合TCLP之標準。將工業區有機性污泥取代黏土燒結製作環保磚，其比例在20%以下時，樣本比重為1.8-2.0，抗壓強度達171-401 kgf/cm^2，吸水率低於19%，符合一級及二級建築磚之工程性質。另將工業區廢水處理廠重金屬污泥與淨水污泥、下水污泥及煉鋼爐渣混合取代鋁土、矽砂及鐵砂等天然礦物燒製環保水泥熟料，替代生料比例可達20%。環保水泥熟料均含有C3S、C2S、C4AF及C3A等晶相物種，在不同養護齡期下，漿體之抗壓強度及核磁共振（NMR）等巨微觀分析數據，與傳統波特蘭水泥漿體水化反應趨勢相符。

關鍵字

污泥 ； 燒結 ； 環保水泥 ； 環保磚

並列摘要

There are 600,000 tons of sludge produced annually from 39 industrial wastewater treatment plants in Taiwan. In this study, the heavy metal sludge ash and organic wastewater sludge ash are used as experimental materials. Raw meal was prepared for a pre-determined recipe, then heated to 950℃ for eight hours during sintering to produce eco-brick, and 1400℃ for six hours during the clinkerization process, using a simulated incinerator and a smelter. The results indicate the leaching concentrations of all tested samples met Toxicity Characteristic leaching Procedure (TCLP) requirements. The eco-brick samples containing 20% industrial sludge ash could reach a compressive strength of around 171-401 kgf/cm^2. The specific gravities of bricks were all less than 2 gk/cm^3. Bricks made from mixtures containing 20% PCB sludge ash could reach a 210 kgf/cm^2 compressive strength. The specific gravities of the bricks were all less than 2 kg/cm^3. The 24-hour absorption rates of the bricks were all less than 19%. The specific gravity, water adsorption, and compressive strength suggested that bricks made from mixtures containing 20% industrial sludge ash and bricks made from mixtures containing 15% PCB sludge ash could meet the general requirement for brick. In addition, three new types of hydraulic cements (referred to as eco-cement) were developed. Sludge ash from industrial sludge ash, water purification plants and primary sewage treatment plants, as well as waste from steel-works (ferrate), as partial replacements for clay, silica, alumina, and iron oxide in the raw meal for cement. The results indicate that it is feasible to use sludge ash and steel-making wastes to replace up to 20% of the mineral components in the raw materials for cement (also referred to as raw meal). The major components of the Portland cement composition, C3S(i.e., 3CaO.SiO2), C2S(i.e., 2CaO. SiO2), C3A(i.e., 3CaOAl2O3), and C4AF(i.e., 4CaO.Al2O3.Fe2O3) were all found in the waste-derived clinkers. The compressive strength and the degree of hydration of eco-cement pastes were similar to OPC paste at the appropriate curing age.

並列關鍵字

Sludge ； Sintering ； Eco-cement ； Eco-brick