| 摘要: | 本研究藉由統計19座淨水場之水源、原水濁度、加藥量與污泥量等資料，來探討不同淨水場的污泥產量特性。另外，以平鎮淨水場為例，藉由隨機採樣，分析混凝污泥與脫水泥餅之物化特性，以提供後續處置與再利用的參考。 研究結果顯示，19座淨水場之單位污泥產量平均為96 g/m3。其中以河川水為水源的淨水場平均濁度約為290 NTU，高於水庫水的110 NTU，其平均污泥產量也約高出10 g/m3。另外，在原水濁度不同時，濁度與混凝劑對於污泥產量的貢獻度也有所不同，原水低濁度時(< 30 NTU)，濁度與混凝劑兩者對污泥量的貢獻程度相近；一旦原水濁度較高時(30~3000 NTU)，污泥量則大部份由水中濁度顆粒所貢獻。 中低原水濁度時，污泥毯澄清池沉澱污泥的 SS 平均值為3,781 mg/L，傾斜管沉澱池沉澱污泥未定期排泥，因此SS 濃度隨時間變化而增加，其 SS 平均值為23,682 mg/L，。其中傾斜管沉澱池沉澱污泥有較好的沉降性。濃縮池濃縮污泥 SS 平均值為11,371 mg/L，而 SRF 和 CST 值，分別高達1.51×1013 m/kg 與65.3 sec，試驗結果顯示，污泥的脫水性可藉由添加聚丙醯胺(PAM)聚合劑而有所改善。 平鎮淨水場之脫水泥餅之含水率為76.4%，VS 為12.4%，污泥餅化學組成以SiO2 與 Al2O3 為主，含量分別為51.08%與34.62%，顆粒粒徑累積分佈百分比小於75 μm者達96%。 國內淨水場污泥的再利用方式以做為水泥生料、製磚及栽培土為主，再利用趨勢受到廠商分佈、技術與法規影響。初步評估平鎮場之泥餅再利用的方式，以取代水泥與栽培土較為適合，做為骨材或管溝回填料，則受限於泥餅的物理工程性質，並不適宜直接使用。 The objectives of this study were to evaluate the characteristics of sludge production and the reuse potential of sludge cake from various water treatment plants in Taiwan. The statistical analysis of water source, raw water turbidity and coagulant dosage related to sludge quantities from 19 different plants was carried out. In addition, the physical and chemical properties of coagulation sludge and dewatering sludge cake from Ping-Jan Water Treatment Plant were analyzed. According to the statistical data, the average unit sludge production of the 19 water treatment plants was 96 g/m3. It also found that the average unit sludge production from the plants with river as water source was 10 g/m3 higher than those plants took water from reservoir. When the plants had raw water turbidity less than 30 NTU, the sludge quantity generated in these plants was equally contributed by turbidity in raw water and coagulant added. However, when raw water turbidity was high (in the range of 30 to 3000 NTU), the major sludge quantity was contributed by the turbidity in raw water. For coagulation sludge, the average SS concentration of settled sludge from sludge blanket clarifiers in Ping-Jan Water Treatment Plant was 3,781 mg/L. However, due to the settled sludge in tube settling clarifiers was artificial withdraw without on-schedule, the average SS concentration of the settled sludge was 23,682 mg/L and the SS concentration was generally increased with the storage time in tube settling clarifiers. Besides, the coagulation sludge from tube settling clarifiers indicated a better settling and thickening properties. In addition, the samples of thickening sludge took from gravity thickener had an average SS concentration of 11,371 mg/L, SRF of 1.51×1013 m/kg, and CST of 65.3 sec. The properties of dewatering sludge cake showed that the water content and VS were 76.4% and 12.4%, respectively, and the major chemical composition were 51.08% of SiO2 and 34.62% of Al2O3. The cumulative particle size of sludge cake was 96% less than 75 μm. The results of this study also indicated that the sludge cake from various water treatment plants in Taiwan were mostly reused as cement material, brick manufacture and cultivate soil. The potential and distribution of these reuse technology depended on sludge generated quantities, reuse organization location, specification and regulation. Based on the analysis results of sludge properties and composition, reuses of sludge cake from Ping-Jan Water Treatment Plant is better for cement material and cultivate soil. However, due to the limitations of the physical and engineering properties of the sludge cake, direct reuse of the sludge cake as backfill soil or aggregate without any modification is unfavorable. |
