Study of Sludge Dewaterability with Thermal Conditioning

本研究採用的污泥為A淨水廠的PAC 污泥與B 食品廠的有機污泥，研究結果顯 示，毛細汲取時間(CST)為適用性極高之脫 水指標參數，CST 值最低點對應了最佳脫 水效率。對於A 淨水廠PAC 污泥以陽離子 調理劑(PC-325C)調理，其黏滯度與降伏應 力有很高的相關性，兩者均隨加藥量增加 有上升趨勢，以幾丁聚醣調理，在100 mg/l 加藥量所對應的黏度與降伏應力值均出現 最小值，脫水效率最高，以熱調理，黏滯 度隨調理溫度增加而降低，降伏應力在 30~40℃出現低點。對於B 食品廠生物污泥 以陽離子調理劑(PC-325C)調理，黏滯度與 降伏應力在15 mg/l 加藥量會出現最大 值，以幾丁聚醣調理，此二參數在60 mg/l 加藥量出現最小值，以熱調理，在50℃調 理溫度有最佳的脫水效率。調整污泥濃度 發現不同污泥濃度下毛細汲取時間、黏度 值與降伏應力三參數間相關性很高。In the study, samples of sludge include PolyAluminum chloride (PAC) sludge from A water treatment plant, and biological sludge from B food-processing plant. It seems that parameter well adapted for evaluating the dewatering sludge is capillary suction time (CST). The minimum CST is corresponding to the best sludge dewaterability on centrifugation in the study. There is a very close relationship between sludge viscosity and yield stress for PC-325C conditioning of PAC sludge. These two parameters raise as increasing of PC-325C dosage. But, they are both minimum at 100 mg/l of chitosan with the best dewaterability. Sludge viscosity decreases as raising of temperature. Yield stress is minimum at 30 to 40℃ by thermal conditioning. For sludge conditioning of food-processing sludge, both of sludge viscosity and yield stress are maximum at 15mg/l of PC-325C, and they are minimum at 60 mg/l of chitosan. The best dewaterability appears at 50℃. There is a very close relationship among CST, viscosity, and yield stress for the two kinds of sludge by modifying the solids content