The study of using sewerage sludge as a material

• Main Author: 張賢潭
• Other Authors: 張建智
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/25528155801113854701

碩士 === 國立海洋大學 === 河海工程學系碩士在職專班 === 90 === Accompanied by the uprising of sewerage population rate and commission of the several municipal wastewater treatment plants (WWTP) in the Taipei metropolitan area, the amount of sludge produced by WWTP is increased accordingly. How to effectively treat sludge is then worthy to be considered by all seniors in the engineering field as a common topic. This study is different from the traditional concept of sludge treatment. Under the condition of satisfying the requirements of environmental protection and resource recovery and through the research in material science, engineering and economic respects, this study tries to find an incorporated and feasible scenario to apply the treated sludge as a material to refill the piping trench. The strategy of this study uses 0Portland cement, blast furnace slag powder, and alkali activated reagent as agglomeration material, interfacial activated reagent as sludge particle dispersion agent, and ion stabilization reagent or chelate reagent to suppress the leachability of heavy metals and decomposition of organics. The final product of sludge after treatment is expected to fulfill the requirements in workability, setting time and strength as specified for controlled low strength material (as CLSM). The result of this study shows all of the solidified modules with different additive proportion as suggested can comply with the specification of CLSM in fluidity and setting time. With respect to the test for 12-hour compression strength, however, part of the solidified modules made by the sludge of Pali WWTP fails to fulfill the specification of CLSM since the high concentration of heavy metals initiate the retarding effect to the hydration of blast furnace slag powder. According to this study, the condition of low strength can be significantly improved by reducing the ratio of liquid to colloid. The leaching test also presents that the concentrations of heavy metals after solidification are much lower than the test before solidification. After exposure to the atmosphere for certain period, the solidified modules come out with some villus-like material on the surface. It may be caused by the decomposition of the organics inside of modules. Except that, no mark able crack is observed on the surface. When the solidified modules are applied as refilling material for piping trench, it is evaluated that cracks on surface or inside of the modules will neither cause surrounding soil slack nor settlement of asphalt surface