鋁質水泥污水管耐硫化氫侵蝕之模擬測試探討

The Simulation Tests Investigation for H2S Attack on the Calcium Aluminate Sewage System

近年來工商業的發展，都市的污水及工業廢水必須使用污水管排放。而污水管經常發現結構體發生劣化及鋼材鏽蝕現象，如今已經了解這種劣化現象是因為由於污水管中所排放的生物分泌物，造成硫化菌新陳代謝產生硫化氫生成物，再轉換為硫酸鹽，而侵蝕管內流體上側之管壁，而與混凝土及鋼材起化學反應造成硫化氫侵蝕之破壞現象。由於鋁質水泥在水化反應之生成物，氫氧化鋁及鋁酸鈣水化物均具有耐酸性能。因此可利用離心法或立模振動法，製造全鋁質或鋁質內襯污水管，根據現場實用經驗顯示，使用50年以上仍可耐硫化氫侵蝕性能。耐久性相當優越、然而必須經過測試才能證實，因此本文探討鋁質水泥污水管受微生菌H2S侵蝕之模擬實驗室測試的情形。這種技術曾先測試鋁質水泥砂漿浸泡在此室中一年。測試結果發現與實際上用此種材料所製作的污水管，在惡劣環境下使用八年的性能比較相當符合。測試變數包括卜特蘭水泥、鋁質水泥、無孔隙之鋁質水泥及摻用與鋁質水泥相同材質之骨材等進行測試比較。並且就卜特蘭水泥與高爐水泥的耐蝕特性作檢討。本文首先對鋼筋混凝土管受硫化侵蝕發生劣化之機理先進行研討，然後闡述H2S腐蝕之研究背景及鋁質水泥砂漿試體，浸泡在細菌腐蝕實驗箱所作之模擬測試結果，與實際工程結構物之耐久性能之檢測結果比較相當一致，此可證實其耐蝕能力。由這些測試結果之文獻回顧，探討鋁質水泥之優越性，預期提供這方面之技術在國內應用。

In response to the needs of outfall sewer system, there are many concrete pipes constructed and usage. The corrosion of concrete structures In sewage environments is a major problem in some piping system. By a biologically influenced process, the metabolism of thiobacilli, hydrogen swift is converted into sulfuric acid, and then it reacts with concrete and causes deterioration, This phenomena are now reasonably well understood. For the purpose of materials testing, the environment is often simulated by laboratory tests with concentrated acid solutions. Such tests, however. do not consider the bacterial aspect of the reality, and therefore can lead to irrelevant conclusions. Therefore, for a reliable result, the interaction between living organisms and their substratum are essential and need to be taken into account. The task is achieved by the use of a simulation chamber for biogenic sulfuric acid corrosion. The biologically influenced corrosion is remodeled under conditions favoring the relevant microorganisms; Thus, an acceleration of the natural process is achieved. In this paper, literature reviews on the investigation conducted on calcium aluminate based mortars in the bacterial corrosion chamber demonstrated for these materials, a good resistance against biogenic sulfuric acid attack. These results are confirmed by the on site observations of sewer pipelines made of calcium aluminate based concrete inspected after up to 35 years service in the harsh environments.